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Sample records for antibacterial peptide fallaxin

  1. Structure-activity study of the antibacterial peptide fallaxin

    DEFF Research Database (Denmark)

    Søndergaard, Sandra Lerche; Frimodt-Møller, Niels; Kragelund, Birthe Brandt

    2007-01-01

    , and Pseudomonas aeruginosa. Here, we report a structure-activity study of fallaxin based on 65 analogs, including a complete alanine scan and a full set of N- and C-terminal truncated analogs. The fallaxin analogs were tested for hemolytic activity and antibacterial activity against methicillin...... and inactive analogs according to mean hydrophobicity H and mean hydrophobic moment µH . Far-UV CD-spectroscopy experiments on fallaxin and several analogs in buffer, in TFE, and in membrane mimetic environments (small unilamellar vesicles) indicated that a coiled-coil conformation could be an important...... structural trait for antibacterial activity. This study provides data that support fallaxin analogs as promising lead structures in the development of new antibacterial agents....

  2. Amphibian antimicrobial peptide fallaxin analogue FL9 affects virulence gene expression and DNA replication in Staphylococcus aureus

    DEFF Research Database (Denmark)

    Gottschalk, Sanne; Gottlieb, Caroline Trebbien; Vestergaard, Martin;

    2015-01-01

    antimicrobials. In the present study, the analogue FL9, based on the amphibian AMP fallaxin, was studied to elucidate its mode of action and antibacterial activity against the human pathogen Staphylococcus aureus. Our data showed that FL9 may have a dual mode of action against S. aureus. At concentrations around...... the MIC, FL9 bound DNA, inhibited DNA synthesis and induced the SOS DNA damage response, whereas at concentrations above the MIC the interaction between S. aureus and FL9 led to membrane disruption. The antibacterial activity of the peptide was maintained over a wide range of NaCl and MgCl2 concentrations......-encoded natural tolerance mechanisms included peptide cleavage and the addition of positive charge to the cell surface, both of which minimized the antimicrobial activity of FL9. Our results add new information about FL9 and its effect on S. aureus, which may aid in the future development of analogues...

  3. Amphibian antimicrobial peptide fallaxin analogue FL9 affects virulence gene expression and DNA replication in Staphylococcus aureus.

    Science.gov (United States)

    Gottschalk, Sanne; Gottlieb, Caroline T; Vestergaard, Martin; Hansen, Paul R; Gram, Lone; Ingmer, Hanne; Thomsen, Line E

    2015-12-01

    The rapid rise in antibiotic-resistant pathogens is causing increased health concerns, and consequently there is an urgent need for novel antimicrobial agents. Antimicrobial peptides (AMPs), which have been isolated from a wide range of organisms, represent a very promising class of novel antimicrobials. In the present study, the analogue FL9, based on the amphibian AMP fallaxin, was studied to elucidate its mode of action and antibacterial activity against the human pathogen Staphylococcus aureus. Our data showed that FL9 may have a dual mode of action against S. aureus. At concentrations around the MIC, FL9 bound DNA, inhibited DNA synthesis and induced the SOS DNA damage response, whereas at concentrations above the MIC the interaction between S. aureus and FL9 led to membrane disruption. The antibacterial activity of the peptide was maintained over a wide range of NaCl and MgCl(2) concentrations and at alkaline pH, while it was compromised by acidic pH and exposure to serum. Furthermore, at subinhibitory concentrations of FL9, S. aureus responded by increasing the expression of two major virulence factor genes, namely the regulatory rnaIII and hla, encoding α-haemolysin. In addition, the S. aureus-encoded natural tolerance mechanisms included peptide cleavage and the addition of positive charge to the cell surface, both of which minimized the antimicrobial activity of FL9. Our results add new information about FL9 and its effect on S. aureus, which may aid in the future development of analogues with improved therapeutic potential.

  4. Amphibian antimicrobial peptide fallaxin analogue FL9 affects virulence gene expression and DNA replication in Staphylococcus aureus

    DEFF Research Database (Denmark)

    Gottschalk, Sanne; Gottlieb, Caroline Trebbien; Vestergaard, Martin;

    2015-01-01

    The rapid rise in antibiotic-resistant pathogens is causing increased health concerns, and consequently there is an urgent need for novel antimicrobial agents. Antimicrobial peptides (AMPs), which have been isolated from a wide range of organisms, represent a very promising class of novel antimic...

  5. Towards Identify Selective Antibacterial Peptides Based on Abstracts Meaning

    Directory of Open Access Journals (Sweden)

    Liliana I. Barbosa-Santillán

    2016-01-01

    Full Text Available We present an Identify Selective Antibacterial Peptides (ISAP approach based on abstracts meaning. Laboratories and researchers have significantly increased the report of their discoveries related to antibacterial peptides in primary publications. It is important to find antibacterial peptides that have been reported in primary publications because they can produce antibiotics of different generations that attack and destroy the bacteria. Unfortunately, researchers used heterogeneous forms of natural language to describe their discoveries (sometimes without the sequence of the peptides. Thus, we propose that learning the words meaning instead of the antibacterial peptides sequence is possible to identify and predict antibacterial peptides reported in the PubMed engine. The ISAP approach consists of two stages: training and discovering. ISAP founds that the 35% of the abstracts sample had antibacterial peptides and we tested in the updated Antimicrobial Peptide Database 2 (APD2. ISAP predicted that 45% of the abstracts had antibacterial peptides. That is, ISAP found that 810 antibacterial peptides were not classified like that, so they are not reported in APD2. As a result, this new search tool would complement the APD2 with a set of peptides that are candidates to be antibacterial. Finally, 20% of the abstracts were not semantic related to APD2.

  6. Towards Identify Selective Antibacterial Peptides Based on Abstracts Meaning

    Science.gov (United States)

    Barbosa-Santillán, Liliana I.; Sánchez-Escobar, Juan J.; Calixto-Romo, M. Angeles; Barbosa-Santillán, Luis F.

    2016-01-01

    We present an Identify Selective Antibacterial Peptides (ISAP) approach based on abstracts meaning. Laboratories and researchers have significantly increased the report of their discoveries related to antibacterial peptides in primary publications. It is important to find antibacterial peptides that have been reported in primary publications because they can produce antibiotics of different generations that attack and destroy the bacteria. Unfortunately, researchers used heterogeneous forms of natural language to describe their discoveries (sometimes without the sequence of the peptides). Thus, we propose that learning the words meaning instead of the antibacterial peptides sequence is possible to identify and predict antibacterial peptides reported in the PubMed engine. The ISAP approach consists of two stages: training and discovering. ISAP founds that the 35% of the abstracts sample had antibacterial peptides and we tested in the updated Antimicrobial Peptide Database 2 (APD2). ISAP predicted that 45% of the abstracts had antibacterial peptides. That is, ISAP found that 810 antibacterial peptides were not classified like that, so they are not reported in APD2. As a result, this new search tool would complement the APD2 with a set of peptides that are candidates to be antibacterial. Finally, 20% of the abstracts were not semantic related to APD2. PMID:27366202

  7. Characterization of a possible uptake mechanism of selective antibacterial peptides.

    Science.gov (United States)

    Polanco, Carlos; Samaniego, José Lino; Castañón-González, Jorge Alberto; Buhse, Thomas; Sordo, Marili Leopold

    2013-01-01

    Selective antibacterial peptides containing less than 30 amino acid residues, cationic, with amphipathic properties, have been the subject of several studies due to their active participation and beneficial effects in strengthening the immune system of all living organisms. This manuscript reports the results of a comparison between the group of selective antibacterial peptides and another group called "cell penetrating peptides". An important number of the selective antibacterial peptides are cell penetrating peptides, suggesting that their toxicity is related to their uptake mechanism. The verification of this observation also includes the adaptation of a method previously published, called Polarity index, which reproduces and confirms the action of this new set of peptides. The efficiency of this method was verified based on four different databases, yielding a high score. The verification was based exclusively on the peptides already reported in the databases which have been experimentally verified.

  8. Characterization of Selective Antibacterial Peptides by Polarity Index

    Directory of Open Access Journals (Sweden)

    C. Polanco

    2012-01-01

    Full Text Available In the recent decades, antibacterial peptides have occupied a strategic position for pharmaceutical drug applications and became subject of intense research activities since they are used to strengthen the immune system of all living organisms by protecting them from pathogenic bacteria. This work proposes a simple and easy statistical/computational method through a peptide polarity index measure by which an antibacterial peptide subgroup can be efficiently identified, that is, characterized by a high toxicity to bacterial membranes but presents a low toxicity to mammal cells. These peptides also have the feature not to adopt to an alpha-helicoidal structure in aqueous solution. The double-blind test carried out to the whole Antimicrobial Peptide Database (November 2011 showed an accuracy of 90% applying the polarity index method for the identification of such antibacterial peptide groups.

  9. Characterization of Selective Antibacterial Peptides by Polarity Index

    Science.gov (United States)

    Polanco, C.; Samaniego, J. L.; Buhse, T.; Mosqueira, F. G.; Negron-Mendoza, A.; Ramos-Bernal, S.; Castanon-Gonzalez, J. A.

    2012-01-01

    In the recent decades, antibacterial peptides have occupied a strategic position for pharmaceutical drug applications and became subject of intense research activities since they are used to strengthen the immune system of all living organisms by protecting them from pathogenic bacteria. This work proposes a simple and easy statistical/computational method through a peptide polarity index measure by which an antibacterial peptide subgroup can be efficiently identified, that is, characterized by a high toxicity to bacterial membranes but presents a low toxicity to mammal cells. These peptides also have the feature not to adopt to an alpha-helicoidal structure in aqueous solution. The double-blind test carried out to the whole Antimicrobial Peptide Database (November 2011) showed an accuracy of 90% applying the polarity index method for the identification of such antibacterial peptide groups. PMID:22611416

  10. Induction, selection and antibacterial activity of the antibacterial peptides from lepldopteran insect cultured cell lines

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    We induced 3 cell lines that were in vitro cultured from Lepidoptera with heat inactivated Escherichia coil DH5α to stimulate the antibacterial peptide followed by antibacterial activity assay,induction dynamic research and Tricine sodium dodecyl sulfate-polyacrylamide gel electrophoresis (Tricine SDS-PAGE) experiment.The antibacterial activity of the induced BTI-Tn-5B1 cell line was the highest,and the antibacterial activity increased gradually to the highest level in 16 hours after stimulation.A new antibacterial peptide with a molecular weight of about 8000 Da was preferentially induced in Trichoplusia ni BTI-Tn-5B1 ceils in 16 hours after stimulation.Antibacterial activity assays indicated that it had inhibition against Staphylococcus aureus,Escherichia coli K12D31 and Salmonella derby.It has especially strong inhibition against Gram-negative bacteria such as Escherichia coli KI2D31 and Salmonella derby.

  11. Prediction of Antibacterial Activity from Physicochemical Properties of Antimicrobial Peptides

    NARCIS (Netherlands)

    de Sousa Pereira Simoes de Melo, Manuel; Ferre, Rafael; Feliu, Lidia; Bardaji, Eduard; Planas, Marta; Castanho, Miguel A. R. B.

    2011-01-01

    Consensus is gathering that antimicrobial peptides that exert their antibacterial action at the membrane level must reach a local concentration threshold to become active. Studies of peptide interaction with model membranes do identify such disruptive thresholds but demonstrations of the possible co

  12. Small Peptides Derived from Penetratin as Antibacterial Agents.

    Science.gov (United States)

    Parravicini, Oscar; Somlai, Csaba; Andujar, Sebastián A; Garro, Adriana D; Lima, Beatriz; Tapia, Alejandro; Feresin, Gabriela; Perczel, Andras; Tóth, Gabor; Cascales, Javier López; Rodríguez, Ana M; Enriz, Ricardo D

    2016-04-01

    The synthesis, in vitro evaluation and conformational study of several small-size peptides acting as antibacterial agents are reported. Among the compounds evaluated, the peptides Arg-Gln-Ile-Lys-Ile-Trp-Arg-Arg-Met-Lys-Trp-Lys-Lys-NH2 , Arg-Gln-Ile-Lys-Ile-Arg-Arg-Met-Lys-Trp-Arg-NH2 , and Arg-Gln-Ile-Trp-Trp-Trp-Trp-Gln-Arg-NH2 exhibited significant antibacterial activity. These were found to be very active antibacterial compounds, considering their small molecular size. In order to better understand the antibacterial activity obtained for these peptides, an exhaustive conformational analysis was performed, using both theoretical calculations and experimental measurements. Molecular dynamics simulations using two different media (water and trifluoroethanol/water) were employed. The results of these theoretical calculations were corroborated by experimental circular dichroism measurements. A brief discussion on the possible mechanism of action of these peptides at molecular level is also presented. Some of the peptides reported here constitute very interesting structures to be used as starting compounds for the design of new small-size peptides possessing antibacterial activity.

  13. Prediction of antibacterial activity from physicochemical properties of antimicrobial peptides.

    Directory of Open Access Journals (Sweden)

    Manuel N Melo

    Full Text Available Consensus is gathering that antimicrobial peptides that exert their antibacterial action at the membrane level must reach a local concentration threshold to become active. Studies of peptide interaction with model membranes do identify such disruptive thresholds but demonstrations of the possible correlation of these with the in vivo onset of activity have only recently been proposed. In addition, such thresholds observed in model membranes occur at local peptide concentrations close to full membrane coverage. In this work we fully develop an interaction model of antimicrobial peptides with biological membranes; by exploring the consequences of the underlying partition formalism we arrive at a relationship that provides antibacterial activity prediction from two biophysical parameters: the affinity of the peptide to the membrane and the critical bound peptide to lipid ratio. A straightforward and robust method to implement this relationship, with potential application to high-throughput screening approaches, is presented and tested. In addition, disruptive thresholds in model membranes and the onset of antibacterial peptide activity are shown to occur over the same range of locally bound peptide concentrations (10 to 100 mM, which conciliates the two types of observations.

  14. Detection of selective antibacterial peptides by the Polarity Profile method.

    Science.gov (United States)

    Polanco, Carlos; Buhse, Thomas; Samaniego, José Lino; Castañón-González, Jorge Alberto

    2013-01-01

    Antimicrobial peptides occupy a prominent place in the production of pharmaceuticals, because of their effective contribution to the protection of the immune system against almost all types of pathogens. These peptides are thoroughly studied by computational methods designed to shed light on their main functions. In this paper, we propose a computational approach, named the Polarity Profile method that represents an improvement to the former Polarity Index method. The Polarity Profile method is very effective in detecting the subgroup of antibacterial peptides called selective cationic amphipathic antibacterial peptides (SCAAP) that show high toxicity towards bacterial membranes and exhibit almost zero toxicity towards mammalian cells. Our study was restricted to the peptides listed in the antimicrobial peptides database (APD2) of December 19, 2012. Performance of the Polarity Profile method is demonstrated through a comparison to the former Polarity Index method by using the same sets of peptides. The efficiency of the Polarity Profile method exceeds 85% taking into account the false positive and/or false negative peptides.

  15. Anisotropic membrane curvature sensing by antibacterial peptides

    CERN Document Server

    Gómez-Llobregat, Jordi; Lindén, Martin

    2014-01-01

    Many proteins and peptides have an intrinsic capacity to sense and induce membrane curvature, and play crucial roles for organizing and remodeling cell membranes. However, the molecular driving forces behind these processes are not well understood. Here, we describe a new approach to study curvature sensing, by simulating the direction-dependent interactions of single molecules with a buckled lipid bilayer. We analyze three antimicrobial peptides, a class of membrane-associated molecules that specifically target and destabilize bacterial membranes, and find qualitatively different sensing characteristics that would be difficult to resolve with other methods. These findings provide new insights into the microscopic mechanisms of antimicrobial peptides, which might aid the development of new antibiotics. Our approach is generally applicable to a wide range of curvature sensing molecules, and our results provide strong motivation to develop new experimental methods to track position and orientation of membrane p...

  16. An FPGA implementation to detect selective cationic antibacterial peptides.

    Science.gov (United States)

    Polanco González, Carlos; Nuño Maganda, Marco Aurelio; Arias-Estrada, Miguel; del Rio, Gabriel

    2011-01-01

    Exhaustive prediction of physicochemical properties of peptide sequences is used in different areas of biological research. One example is the identification of selective cationic antibacterial peptides (SCAPs), which may be used in the treatment of different diseases. Due to the discrete nature of peptide sequences, the physicochemical properties calculation is considered a high-performance computing problem. A competitive solution for this class of problems is to embed algorithms into dedicated hardware. In the present work we present the adaptation, design and implementation of an algorithm for SCAPs prediction into a Field Programmable Gate Array (FPGA) platform. Four physicochemical properties codes useful in the identification of peptide sequences with potential selective antibacterial activity were implemented into an FPGA board. The speed-up gained in a single-copy implementation was up to 108 times compared with a single Intel processor cycle for cycle. The inherent scalability of our design allows for replication of this code into multiple FPGA cards and consequently improvements in speed are possible. Our results show the first embedded SCAPs prediction solution described and constitutes the grounds to efficiently perform the exhaustive analysis of the sequence-physicochemical properties relationship of peptides.

  17. Detection of selective cationic amphipatic antibacterial peptides by Hidden Markov models.

    Science.gov (United States)

    Polanco, Carlos; Samaniego, Jose L

    2009-01-01

    Antibacterial peptides are researched mainly for the potential benefit they have in a variety of socially relevant diseases, used by the host to protect itself from different types of pathogenic bacteria. We used the mathematical-computational method known as Hidden Markov models (HMMs) in targeting a subset of antibacterial peptides named Selective Cationic Amphipatic Antibacterial Peptides (SCAAPs). The main difference in the implementation of HMMs was focused on the detection of SCAAP using principally five physical-chemical properties for each candidate SCAAPs, instead of using the statistical information about the amino acids which form a peptide. By this method a cluster of antibacterial peptides was detected and as a result the following were found: 9 SCAAPs, 6 synthetic antibacterial peptides that belong to a subregion of Cecropin A and Magainin 2, and 19 peptides from the Cecropin A family. A scoring function was developed using HMMs as its core, uniquely employing information accessible from the databases.

  18. High Selective Performance of Designed Antibacterial and Anticancer Peptide Amphiphiles.

    Science.gov (United States)

    Chen, Cuixia; Chen, Yucan; Yang, Cheng; Zeng, Ping; Xu, Hai; Pan, Fang; Lu, Jian Ren

    2015-08-12

    Short designed peptide amphiphiles are attractive at killing bacteria and inhibiting cancer cell growth, and the flexibility in their structural design offers a great potential for improving their potency and biocompatibility to mammalian host cells. Amino acid sequences such as G(IIKK)nI-NH2 (n≥3) have been shown to be membrane lytic, but terminal amino acid modifications could impose a huge influence on their performance. We report in this work how terminal amino acid modifications to G(IIKK)3I-NH2 influence its α-helical structure, membrane penetrating ability, and selective actions against different cell types. Deletion of an N-terminal Gly or a C-terminal Ile did not affect their antibacterial activity much, an observation consistent with their binding behavior to negatively charged membrane lipid monolayers. However, the cytotoxicity against mammalian cells was much worsened by the N-terminal Gly deletion, consistent with an increase in its helical content. Despite little impact on the antibacterial activity of G(IIKK)3I-NH2, deletion of both terminal amino acids greatly reduced its antitumor activity. Cholesterol present in tumor cell membrane-mimic was thought to constrain (IIKK)3-NH2 from penetrating into the cancerous membranes, evident from its lowest surface physical activity at penetrating model lipid membranes. On the other hand, its low toxicity to normal mammalian cells and high antibacterial activity in vitro and in vivo made it an attractive antibacterial agent. Thus, terminal modifications can help rebalance the different interactions involved and are highly effective at manipulating their selective membrane responses.

  19. Antibacterial Peptide Nucleic Acid-Antimicrobial Peptide (PNA-AMP) Conjugates

    DEFF Research Database (Denmark)

    Hansen, Anna Mette; Bonke, Gitte; Larsen, Camilla Josephine;

    2016-01-01

    )-Tat48-60, BF-2A-RXR, and drosocin-RXR are capable of transporting PNA effectively into E. coli (MICs of 1-4 μM). Importantly, presence of the inner-membrane peptide transporter SbmA was not required for antibacterial activity of PNA-AMP conjugates containing Pep-1-K, KLW-9,13-a, or drosocin-RXR (MICs...

  20. Chicken cathelicidin-2-derived peptides with enhanced immunomodulatory and antibacterial activities against biological warfare agents

    NARCIS (Netherlands)

    Molhoek, E.M.; van Dijk, A.; Veldhuizen, E.J.A.; Dijk-Knijnenburg, H.; Mars-Groenendijk, R.H.; Boele, L.C.L.; Kaman, W.E.; Haagsman, H.P.; Bikker, F.J.

    2010-01-01

    Host defence peptides (HDPs) are considered to be excellent candidates for the development of novel therapeutic agents. Recently, it was demonstrated that the peptide C1-15, an N-terminal segment of chicken HDP cathelicidin-2, exhibits potent antibacterial activity while lacking cytotoxicity towards

  1. Effects of antibacterial peptide on cellular immunity in weaned piglets.

    Science.gov (United States)

    Ren, Z H; Yuan, W; Deng, H D; Deng, J L; Dan, Q X; Jin, H T; Tian, C L; Peng, X; Liang, Z; Gao, S; Xu, S H; Li, G; Hu, Y

    2015-01-01

    The aim of this study was to evaluate the effects of antibacterial peptide (ABP) sufficiency on cellular immune functions by determining the spleen cell cycle and apoptosis, peripheral blood T cell subsets, and T cell proliferation function in weaned piglets. A total of 90 piglets (Duroc × Landrace × Yorkshire) of both sexes were randomly allotted to 5 dietary treatments. Each treatment consisted of 3 replicates with 6 piglets per replicate. The dietary treatments consisted of the negative control (NC; basal diet), positive control (PC; basal diet supplemented with 400 mg/kg Astragalus polysaccharide), and ABP (basal diet mixed with 250, 500, and 1,000 mg/kg ABP). The experimental lasted for 28 d. Two piglets from each replicate were selected randomly for blood samples extraction from the jugular vein to obtain peripheral blood T cell subsets, and T cell proliferation function analysis was performed on d 32, 39, 46, and 53. Two piglets from each replicate were selected and euthanized to observe the spleen cell cycle and apoptosis on d 39 and 53. In ABP-sufficient piglets, the G0/G1 phase of the spleen cell cycle was much lower (P ABP sufficiency (P ABP-sufficient piglets. Percentages of CD3 (+) and CD3 (+)CD4 (+) ratios (d 39, 46, and 53) and CD4 (+)CD8 (+) ratios (d 32, 39, 46, and 53) increased remarkably (P ABP sufficiency compared with NC. These results suggest that ABP sufficiency could increase the T cell population and proliferation function of T cells and could induce decreased percentages of apoptotic cells. Overall, the cellular immune function was evidently improved in weaned piglets. We suggest optimal dosages of 500 mg/kg ABP for 4-wk addition and 1,000 mg/kg ABP for 2-wk addition.

  2. Antibacterial activity and dual mechanisms of peptide analog derived from cell-penetrating peptide against Salmonella typhimurium and Streptococcus pyogenes.

    Science.gov (United States)

    Li, Lirong; Shi, Yonghui; Cheserek, Maureen Jepkorir; Su, Guanfang; Le, Guowei

    2013-02-01

    A number of research have proven that antimicrobial peptides are of greatest potential as a new class of antibiotics. Antimicrobial peptides and cell-penetrating peptides share some similar structure characteristics. In our study, a new peptide analog, APP (GLARALTRLLRQLTRQLTRA) from the cell-penetrating peptide ppTG20 (GLFRALLRLLRSLWRLLLRA), was identified simultaneously with the antibacterial mechanism of APP against Salmonella typhimurium and Streptococcus pyogenes. APP displayed potent antibacterial activity against Gram-negative and Gram-positive strains. The minimum inhibitory concentration was in the range of 2 to 4 μM. APP displayed higher cell selectivity (about 42-fold increase) as compared to the parent peptide for it decreased hemolytic activity and increased antimicrobial activity. The calcein leakage from egg yolk L-α-phosphatidylcholine (EYPC)/egg yolk L-α-phosphatidyl-DL-glycerol and EYPC/cholesterol vesicles demonstrated that APP exhibited high selectivity. The antibacterial mechanism analysis indicated that APP induced membrane permeabilization in a kinetic manner for membrane lesions allowing O-nitrophenyl-β-D-galactoside uptake into cells and potassium release from APP-treated cells. Flow cytometry analysis demonstrated that APP induced bacterial live cell membrane damage. Circular dichroism, fluorescence spectra, and gel retardation analysis confirmed that APP interacted with DNA and intercalated into the DNA base pairs after penetrating the cell membrane. Cell cycle assay showed that APP affected DNA synthesis in the cell. Our results suggested that peptides derived from the cell-penetrating peptide have the potential for antimicrobial agent development, and APP exerts its antibacterial activity by damaging bacterial cell membranes and binding to bacterial DNA to inhibit cellular functions, ultimately leading to cell death.

  3. Characterization of an antibacterial peptide from indian cobra (Naja naja venom

    Directory of Open Access Journals (Sweden)

    M. K. Sachidananda

    2007-01-01

    Full Text Available Due to the development of antibiotic resistance in microorganisms, antimicrobial peptides from natural sources have attracted attention in recent times. Several antimicrobial peptides have been isolated from a wide range of animal sources, particularly snake venoms. Naja naja venom showed antibacterial as well as direct and indirect hemolytic activities, and an antibacterial peptide was purified through gel permeation and ion exchange chromatography. Its molecular mass was 2491Da, which was determined using Matrix Assisted Laser Desorption/Ionization-Time-of-Flight (MALDI-TOF mass spectrometry and the amino acids sequence of the N-terminus was DEQSTHGAYVWKL. The purified peptide showed potent antibacterial activity against Gram-negative and Gram-positive bacterial strains like Escherichia coli, Pseudomonas aeruginosa and Vibrio cholerae, and Staphylococcus aureus, Enterococcus faecalis, Streptococcus pneumoniae, Streptococcus pyogenes, Bacillus subtilis, respectively. The most potent activity was towards Gram-negative bacteria. Activity was retained at concentrations as low as 100µg/ml. Minimum inhibitory concentrations (MIC; in mg of Naja Antibacterial Peptide (NAP and known antibiotics against Gram-positive and Gram-negative bacteria were determined using microdilution susceptibility test in sterile 96-well microdilution plates. However, the peptide did not show direct or indirect hemolytic activity.

  4. Antibacterial activity of a newly developed peptide-modified lysin against Acinetobacter baumannii and Pseudomonas aeruginosa

    Directory of Open Access Journals (Sweden)

    Hang eYang

    2015-12-01

    Full Text Available The global emergence of multidrug-resistant (MDR bacteria is a growing threat to public health worldwide. Natural bacteriophage lysins are promising alternatives in the treatment of infections caused by Gram-positive pathogens, but not Gram-negative ones, like Acinetobacter baumannii and Pseudomonas aeruginosa, due to the barriers posed by their outer membranes. Recently, modifying a natural lysin with an antimicrobial peptide was found able to break the barriers, and to kill Gram-negative pathogens. Herein, a new peptide-modified lysin (PlyA was constructed by fusing the cecropin A peptide residues 1–8 (KWKLFKKI with the OBPgp279 lysin and its antibacterial activity was studied. PlyA showed good and broad antibacterial activities against logarithmic phase A. baumannii and P. aeruginosa, but much reduced activities against the cells in stationary phase. Addition of outer membrane permeabilizers (EDTA and citric acid could enhance the antibacterial activity of PlyA against stationary phase cells. Finally, no antibacterial activity of PlyA could be observed in some bio-matrices, such as culture media, milk, and sera. In conclusion, we reported here a novel peptide-modified lysin with significant antibacterial activity against both logarithmic (without OMPs and stationary phase (with OMPs A. baumannii and P. aeruginosa cells in buffer, but further optimization is needed to achieve broad activity in diverse bio-matrices.

  5. Antibacterial Peptide CecropinB2 Production via Various Host and Construct Systems

    Directory of Open Access Journals (Sweden)

    Wei-Shiang Lai

    2016-01-01

    Full Text Available Cecropin is a cationic antibacterial peptide composed of 35–39 residues. This peptide has been identified as possessing strong antibacterial activity and low toxicity against eukaryotic cells, and it has been claimed that some types of the cecropin family of peptides are capable of killing cancer cells. In this study, the host effect of cloning antibacterial peptide cecropinB2 was investigated. Three different host expression systems were chosen, i.e., Escherichia coli, Bacillus subtilis and Pichia pastoris. Two gene constructs, cecropinB2 (cecB2 and intein-cecropinB2 (INT-cecB2, were applied. Signal peptide and propeptide from Armigeres subalbatus were also attached to the gene construct. The results showed that the best host for cloning cecropinB2 was P. pastoris SMD1168 harboring the gene of pGAPzαC-prepro-cecB2 via Western blot confirmation. The cecropinB2 that was purified using immobilized-metal affinity chromatography resin showed strong antibacterial activity against the Gram-negative strains, including the multi-drug-resistant bacteria Acinetobacter baumannii.

  6. Purification and characterisation of antibacterial peptide-containing compound derived from palm kernel cake.

    Science.gov (United States)

    Tan, Yen Nee; Ayob, Mohd Khan; Wan Yaacob, Wan Ahmad

    2013-01-01

    Palm kernel cake (PKC), the most useful by-product resulted from palm kernel oil production. In this study, PKC-derived protein product was found suitable for use as an antimicrobial agent with potent antibacterial activity, particularly against Bacillus species, after enzymatic hydrolysis with alcalase. The hydrolysate was further purified by gel filtration chromatography. The purified fraction was found to have 14.63±0.70% (w/w) protein, a molecular mass of 2.4kDa and low hemolytic activity (antibacterial effect of purified PKC fraction. This study suggests that the antibacterial PKC compound may be not a pure peptide but instead a peptide-containing compound high in lauric acid derivative.

  7. Purification of a Novel Antibacterial Short Peptide in Earthworm Eisenia foetida

    Institute of Scientific and Technical Information of China (English)

    Yan-Qin LIU; Zhen-Jun SUN; Chong WANG; Shi-Jie LI; Yu-Zhi LIU

    2004-01-01

    A novel antimicrobial short peptide was purified from earthworm (Eisenia foetida) by a five-step protocol including ammonium sulfate precipitation, ultrafiltration, DE-52 ion exchange chromatography, Sephadex G-10 column chromatography, and C-18 reversed-phase HPLC techniques.The purified peptide was applied to the MALDI-TOP MS to determine the molecular mass and was also subjected to TOF MS-MS analysis to determine the amino acid sequence. As a result, a novel antibacterial peptide, named OEP3121, was obtained, with the molecular mass of 510.8 Da and the sequence being "ACSAG".

  8. The antibacterial peptide ABP-CM4: the current state of its production and applications.

    Science.gov (United States)

    Li, Jian Feng; Zhang, Jie; Xu, Xing Zhou; Han, Yang Yang; Cui, Xian Wei; Chen, Yu Qing; Zhang, Shuang Quan

    2012-06-01

    The increasing resistance of bacteria and fungi to currently available antibiotics is a major concern worldwide, leading to enormous efforts to develop new antibiotics with new modes of actions. Antibacterial peptide CM4 (ABP-CM4) is a small cationic peptide with broad-spectrum activities against bacteria, fungi, and tumor cells, which may possibly be used as a promising candidate for a new antibiotic. For pharmaceutical applications, a large quantity of antimicrobial peptides needs to be produced economically. In this communication, the progress in the structural characteristics, heterologous production, and biological evaluation of ABP-CM4 are reviewed.

  9. Optimization of antibacterial peptides by genetic algorithms and cheminformatics

    DEFF Research Database (Denmark)

    Fjell, Christopher D.; Jenssen, Håvard; Cheung, Warren A.

    2011-01-01

    47 of the top rated 50 peptides chosen from an in silico library of nearly 100 000 sequences. Here, we report a method of generating candidate peptide sequences using the heuristic evolutionary programming method of genetic algorithms (GA), which provided a large (19-fold) improvement...

  10. Antibacterial peptide nisin: a potential role in the inhibition of oral pathogenic bacteria.

    Science.gov (United States)

    Tong, Zhongchun; Ni, Longxing; Ling, Junqi

    2014-10-01

    Although the antimicrobial peptide nisin has been extensively studied in the food industry for decades, its application in the oral cavity remains to develop and evaluate its feasibility in treating oral common diseases. Nisin is an odorless, colorless, tasteless substance with low toxicity and with antibacterial activities against Gram-positive bacteria. These biologic properties may establish its use in promising products for oral diseases. This article summarizes the antibacterial efficiency of nisin against pathogenic bacteria related to dental caries and root canal infection and discusses the combination of nisin and common oral drugs.

  11. Arginine-rich self-assembling peptides as potent antibacterial gels.

    Science.gov (United States)

    Veiga, Ana Salomé; Sinthuvanich, Chomdao; Gaspar, Diana; Franquelim, Henri G; Castanho, Miguel A R B; Schneider, Joel P

    2012-12-01

    Hydrogel materials that display inherent activity against bacteria can be used to directly treat accessible wounds to prevent or kill existing infection. Hydrogels composed of self-assembling β-hairpin peptides, having a high content of arginine, were found to be extremely effective at killing both gram-positive and gram-negative bacteria, including multi-drug resistant Pseudomonas aeruginosa. No added antibacterial agents are necessary to realize activity. Using self-assembling peptides for material construction allows facile structure-activity relationships to be determined since changes in peptide sequence at the monomer level are directly transposed to the bulk material's antibacterial properties. SAR studies show that arginine content largely influences the hydrogel's antibacterial activity, and influences their bulk rheological properties. These studies culminated in an optimized gel, composed of the peptide PEP6R (VKVRVRVRV(D)PPTRVRVRVKV). PEP6R gels prepared at 1.5 wt % or higher concentration, demonstrate high potency against bacteria, but are cytocompatible toward human erythrocytes as well as mammalian mesenchymal stem cells. Rheological studies indicate that the gel is moderately stiff and displays shear-thin recovery behavior, allowing its delivery via simple syringe.

  12. Antibacterial Peptides from Plants: What They Are and How They Probably Work

    Directory of Open Access Journals (Sweden)

    Patrícia Barbosa Pelegrini

    2011-01-01

    Full Text Available Plant antibacterial peptides have been isolated from a wide variety of species. They consist of several protein groups with different features, such as the overall charge of the molecule, the content of disulphide bonds, and structural stability under environmental stress. Although the three-dimensional structures of several classes of plant peptides are well determined, the mechanism of action of some of these molecules is still not well defined. However, further studies may provide new evidences for their function on bacterial cell wall. Therefore, this paper focuses on plant peptides that show activity against plant-pathogenic and human-pathogenic bacteria. Furthermore, we describe the folding of several peptides and similarities among their three-dimensional structures. Some hypotheses for their mechanisms of action and attack on the bacterial membrane surface are also proposed.

  13. Synthetic mimic of antimicrobial peptide with nonmembrane-disrupting antibacterial properties.

    Science.gov (United States)

    Gabriel, Gregory J; Madkour, Ahmad E; Dabkowski, Jeffrey M; Nelson, Christopher F; Nüsslein, Klaus; Tew, Gregory N

    2008-11-01

    Polyguanidinium oxanorbornene ( PGON) was synthesized from norbornene monomers via ring-opening metathesis polymerization. This polymer was observed to be strongly antibacterial against Gram-negative and Gram-positive bacteria as well as nonhemolytic against human red blood cells. Time-kill studies indicated that this polymer is lethal and not just bacteriostatic. In sharp contrast to previously reported SMAMPs (synthetic mimics of antimicrobial peptides), PGON did not disrupt membranes in vesicle-dye leakage assays and microscopy experiments. The unique biological properties of PGON, in same ways similar to cell-penetrating peptides, strongly encourage the examination of other novel guanidino containing macromolecules as powerful and selective antimicrobial agents.

  14. Antibacterial activity and mechanism of a scorpion venom peptide derivative in vitro and in vivo.

    Directory of Open Access Journals (Sweden)

    Luyang Cao

    Full Text Available BmKn2 is an antimicrobial peptide (AMP characterized from the venom of scorpion Mesobuthus martensii Karsch by our group. In this study, Kn2-7 was derived from BmKn2 to improve the antibacterial activity and decrease hemolytic activity. Kn2-7 showed increased inhibitory activity against both gram-positive bacteria and gram-negative bacteria. Moreover, Kn2-7 exhibited higher antibacterial activity against clinical antibiotic-resistant strains such as methicillin-resistant Staphylococcus aureus (MRSA. In addition, the topical use of Kn2-7 effectively protected the skin of mice from infection in an S. aureus mouse skin infection model. Kn2-7 exerted its antibacterial activity via a bactericidal mechanism. Kn2-7 killed S. aureus and E. coli rapidly by binding to the lipoteichoic acid (LTA in the S. aureus cell wall and the lipopolysaccharides (LPS in the E. coli cell wall, respectively. Finally, the hemolytic activity of Kn2-7 was significantly decreased, compared to the wild-type peptide BmKn2. Taken together, the Kn2-7 peptide can be developed as a topical therapeutic agent for treating bacterial infections.

  15. A preliminary study on the antibacterial mechanism of Tegillarca granosa hemoglobin by derived peptides and peroxidase activity.

    Science.gov (United States)

    Bao, Yongbo; Wang, Juanjuan; Li, Chenghua; Li, Peifen; Wang, Sufang; Lin, Zhihua

    2016-04-01

    The blood clam, Tegillarca granosa, is one of the few bivalve molluscs containing hemoglobin (Hb). In the present study, we purified two types of T. granosa hemoglobin, Tg-HbI and Tg-HbII, using size exclusion chromatography and measured their antibacterial and peroxidase activities. We also tested antibacterial activities of peptides prepared by trypsin digestion of purified Tg-Hb and reversed-phase high-performance liquid chromatography purification. Purified Tg-HbI and Tg-HbII showed antibacterial activity against Escherichia coli, Pseudomonas putida, Bacillus subtilis, and Bacillus firmus, with differences in minimal inhibitory concentrations (MICs), but lacked antibacterial activity against Vibrio alginolyticus, Vibrio parahaemolyticus, Vibrio harveyi and Staphylococcus aureus. In contrast, 7 Tg-Hb derived peptides exhibited varying degrees of antibacterial activity against V. alginolyticus (MICs: 12-200 μg/ml), V. parahaemolyticus (11-100 μg/ml) and V. harveyi (1-200 μg/ml). The antibacterial activity of Hb derived peptides was confirmed by fluorescence microscopy. In addition, peroxidase activity was detected in Tg-HbI and Tg-HbII. The results indicated that in addition to functioning as a respiratory protein T. granosa hemoglobins likely play a role in host antibacterial defense probably via a peroxidase activity of native molecules and some internal peptides released from the proteins.

  16. Antibacterial activities of peptides from the water-soluble extracts of Italian cheese varieties.

    Science.gov (United States)

    Rizzello, C G; Losito, I; Gobbetti, M; Carbonara, T; De Bari, M D; Zambonin, P G

    2005-07-01

    Water-soluble extracts of 9 Italian cheese varieties that differed mainly for type of cheese milk, starter, technology, and time of ripening were fractionated by reversed-phase fast protein liquid chromatography, and the antimicrobial activity of each fraction was first assayed toward Lactobacillus sakei A15 by well-diffusion assay. Active fractions were further analyzed by HPLC coupled to electrospray ionization-ion trap mass spectrometry, and peptide sequences were identified by comparison with a proteomic database. Parmigiano Reggiano, Fossa, and Gorgonzola water-soluble extracts did not show antibacterial peptides. Fractions of Pecorino Romano, Canestrato Pugliese, Crescenza, and Caprino del Piemonte contained a mixture of peptides with a high degree of homology. Pasta filata cheeses (Caciocavallo and Mozzarella) also had antibacterial peptides. Peptides showed high levels of homology with N-terminal, C-terminal, or whole fragments of well known antimicrobial or multifunctional peptides reported in the literature: alphaS1-casokinin (e.g., sheep alphaS1-casein (CN) f22-30 of Pecorino Romano and cow alphaS1-CN f24-33 of Canestrato Pugliese); isracidin (e.g., sheep alphaS1-CN f10-21 of Pecorino Romano); kappacin and casoplatelin (e.g., cow kappa-CN f106-115 of Canestrato Pugliese and Crescenza); and beta-casomorphin-11 (e.g., goat beta-CN f60-68 of Caprino del Piemonte). As shown by the broth microdilution technique, most of the water-soluble fractions had a large spectrum of inhibition (minimal inhibitory concentration of 20 to 200 microg/mL) toward gram-positive and gram-negative bacterial species, including potentially pathogenic bacteria of clinical interest. Cheeses manufactured from different types of cheese milk (cow, sheep, and goat) have the potential to generate similar peptides with antimicrobial activity.

  17. Inducing and isolation of antibacterial peptides from oriental fruit fly, Bactrocera dorsalis Hendel

    Institute of Scientific and Technical Information of China (English)

    XIANG-LI DANG; JIN-HUAN TIAN; HUI-YU YI; WEN-XIAN WANG; MIN ZHENG; YI-FENG LI; YANG CAO; SHUO-YANG WEN

    2006-01-01

    One antibacterial activity fraction from an immunized dipteran insect, Bactrocera dorsalis, was isolated and purified by prepurification, ion-exchange chromatography, gel filtration chromatography and reverse-phase high performance liquid chromatography (HPLC). The final purified fraction was checked on the Smart system HPLC and was judged as a pure fraction. The results of physical and biological analysis revealed that this fraction is heat stable and showed strong activities against Gram-positive bacterial growth. It possesses antibicrobial peptide properties and is worth further investigation.

  18. 贻贝抗菌肽的分离纯化%Isolation and Purification of Antibacterial Peptides from Mussel

    Institute of Scientific and Technical Information of China (English)

    李哲; 张彬; 顾铭; 王长海

    2012-01-01

    [目的]从贻贝中提取具有抗菌作用的多肽.[方法]以紫贻贝为原料,采用0.5%的乙酸直接提取方式提取抗菌肽,再经过Sephacryl S-100聚丙烯酰胺凝胶色谱进行纯化,收集各馏分并用滤纸片扩散法测定其抗菌活性及对各种细菌的最低抑菌浓度,使用SDS-PAGE测定抗菌肽的分子质量,测定其在100℃条件下不同处理时间和不同pH条件下抗菌活性的变化.[结果]使用0.5%的乙酸作为提取液粗提取抗菌肽具有较高的提取效率,使用Sephacryl S-100纯化抗菌肽,可将抗菌肽纯化为单一物质.分离纯化出的贻贝抗菌肽具有较强的抗菌性,分子质量为5 908,且具有耐高温、耐酸碱的性质.[结论]该研究为抗菌肽的大规模生产奠定了基础.%[ Objective] This study aimed to extract antibacterial peptides from mussel. [ Method] Blue mussels were used as raw materials for direct extraction of antibacterial peptides by using 0.5% acetic acid, and the antibacterial peptides were isolated and purified by Sephacryl S-100 polyacrylamide gel chromatography. The fractions were collected for determination of antibacterial activity and minimum inhibitory concentration ( MIC) for a variety of bacterial species by filter paper diffusion assay. Molecular weight of the antibacterial peptides was determined by SDS-PAGE. Variation of antibacterial activity of antibacterial peptides was measured at 100 t under conditions of different processing time and different pH. [ Result] 0.5% acetic acid was used for crude extraction of antimicrobial peptides as extraction solution and led to relatively high extraction efficiency. By using Sephaeryl S-100, the antimicrobial peptides could be purified as a single substance. The isolated and purified antibacterial peptides of mussel had relatively strong antimicrobial properties with molecular weight of 5 908, showing heat-resistance acid-alkaline resistance. [ Conclusion ] This study had laid the theoretical

  19. Antibacterial peptides "bacteriocins": an overview of their diverse characteristics and applications.

    Science.gov (United States)

    Nishie, Mami; Nagao, Jun-Ichi; Sonomoto, Kenji

    2012-03-01

    Bacteriocins are ribosomally synthesized antibacterial peptides produced by bacteria that inhibit the growth of similar or closely related bacterial strains. A number of bacteriocins from a wide variety of bacteria have been discovered, and their diverse structures have been reported. Growing evidence suggests that bacteriocins have diverse structures, modes of action, mechanisms of biosynthesis and self-immunity, and gene regulation. Bacteriocins are considered as an attractive compound in food and pharmaceutical industries to prevent food spoilage and pathogenic bacterial growth. Furthermore, elucidation of their biosynthesis has led to the use of bacteriocin-controlled gene-expression systems and the biosynthetic enzymes of lantibiotics, a class of bacteriocins, as tools to design novel peptides. In this review, we summarize and discuss currently known information on bacteriocins produced by Gram-positive bacteria and their applications.

  20. Production and characterization of a new antibacterial peptide obtained from Aeribacillus pallidus SAT4

    Directory of Open Access Journals (Sweden)

    Syed Aun Muhammad

    2015-12-01

    Full Text Available A novel thermophilic bacterial strain of the genus Aeribacillus was isolated from Thar Dessert Pakistan. This strain showed significant antibacterial activity against Micrococcus luteus, Staphylococcus aureus, and Pseudomonas aeruginosa. The strain coded as ‘SAT4’ resembled with Aeribacillus pallidus in the morphological, biochemical and molecular tests. The production of antibacterial metabolites by SAT4 was optimized. These active metabolites were precipitated by 50% ammonium sulphate and purified through sephadex G-75 gel permeation chromatography and reverse phase HPLC. The molecular weight of 37 kDa was examined by SDS-PAGE. The structural elucidation of the purified product was studied by FTIR, 1H and 13C NMR. The X-ray diffractions study showed that the crystals belonged to the primitive orthorhombic lattice (a = 12.137, b = 13.421, c = 14.097 Å and 3D structure (proposed name: Aeritracin was determined. This new peptide antibacterial molecule can get a position in pharmaceutical and biotechnological industrial research.

  1. Comparison of antibacterial effects between antimicrobial peptide and bacteriocins isolated from Lactobacillus plantarum on three common pathogenic bacteria

    OpenAIRE

    Ming, Liu; Zhang, Qian; Yang, Le; Huang, Jian-An

    2015-01-01

    New strategies for the prevention or treatment of infections are required. The purpose of this study is to evaluate the effects of antimicrobial peptides and bacteriocins isolated from Lactobacillus plantarum on growth and biofilm formation of three common pathogenic microbes. The antibacterial properties of the antimicrobial peptide Tet213 and bacteriocins were tested by the disc diffusion method. Tet213 and bacteriocins showed inhibitory effects on biofilm formation for the three organisms,...

  2. 抗菌肽作用机制的研究进展%Advances on Action Mechanism of Antibacterial Peptides

    Institute of Scientific and Technical Information of China (English)

    刘立伟; 邓磊

    2012-01-01

    As the important defense substance in innate immune system, the antibacterial peptides have the strong bactericidal properties. To review the several mechanisms of antimicrobial peptides.%抗菌肽是宿主防御系统的重要成分,具有强烈的杀菌特性。综述了抗菌肽的几种作用机制。

  3. Genome Sequence of Geobacillus sp. Strain ZGt-1, an Antibacterial Peptide-Producing Bacterium from Hot Springs in Jordan.

    Science.gov (United States)

    Alkhalili, Rawana N; Hatti-Kaul, Rajni; Canbäck, Björn

    2015-07-23

    This paper reports the draft genome sequence of the firmicute Geobacillus sp. strain ZGt-1, an antibacterial peptide producer isolated from the Zara hot spring in Jordan. This study is the first report on genomic data from a thermophilic bacterial strain isolated in Jordan.

  4. Antibacterial Peptides of The Ovine Reproductive Tract%绵羊生殖道抗菌肽

    Institute of Scientific and Technical Information of China (English)

    陈琛; 王新华; 薄新文

    2009-01-01

    The female sheep reproductive tracts were freshly collected from a local meat processing plant and used as experimental materials. Two antibacterial peptides were isolated and characterized from female sheep reproductive tracts by two consecutive chromatographic steps. The peptide isolation procedures included acetic acid extraction, dialyzed, gel filtration chromatography on Sephadex G-50, and reverse phase high-performance liquid chromatography (RP-HPLC). Their molecular mass were 4 820.47 u and 4 012.5 u, respectively, analyzed by MALDI-TOF-MS. The partial N-terminal amino acid sequences of two peptides were determined as AYVLDEPKP and YDSGA, respectively, by Edman degradation. The antimicrobial activity was tested during each purification step by the radial diffusion plate assay and broth microdilution method. These two peptides showed good antimicrobial activities against reference strains of G~+(S. Aureus ATCC2592 and Streptococcu ATCC55121), G~-(E. Coli ATCC25922) and fungi(C. Albicans ATCC2002). The peptides did not show active hemolytic activity against rabbit blood red cells and had no significant effects on human blood coagulation system. The discovery of antibacterial peptides in sheep reproductive system reveals that antibacterial peptides may play a role in innate immunity against microorganisms in a wide range of animal species.%以屠宰场收集的新鲜、健康、雌性绵羊牛殖器官为原材料.采用乙酸浸提、透析、Sephadex G-50凝胶过滤层析和反相高效液相色谱(RP-HPLC)等方法分离纯化绵羊生殖道抗菌肽.以G+、G-和真菌为抗菌活性检测指示菌株,利用薄层琼脂糖孔穴扩散法、微量肉汤稀释法进行抗菌活性检测.对分离纯化所得纯品进行分子质量质谱测定、纯度鉴定、N端测序,并对其性质进行研究.结果表明:分离纯化所得两个绵羊生殖道抗菌肽分子质量分别为4820.47 u和4012.5 u,N端部分氨基酸序列分别

  5. Enabling the Discovery and Virtual Screening of Potent and Safe Antimicrobial Peptides. Simultaneous Prediction of Antibacterial Activity and Cytotoxicity.

    Science.gov (United States)

    Kleandrova, Valeria V; Ruso, Juan M; Speck-Planche, Alejandro; Dias Soeiro Cordeiro, M Natália

    2016-08-08

    Antimicrobial peptides (AMPs) represent promising alternatives to fight against bacterial pathogens. However, cellular toxicity remains one of the main concerns in the early development of peptide-based drugs. This work introduces the first multitasking (mtk) computational model focused on performing simultaneous predictions of antibacterial activities, and cytotoxicities of peptides. The model was created from a data set containing 3592 cases, and it displayed accuracy higher than 96% for classifying/predicting peptides in both training and prediction (test) sets. The technique known as alanine scanning was computationally applied to illustrate the calculation of the quantitative contributions of the amino acids (in their respective positions of the sequence) to the biological effects of a defined peptide. A small library formed by 10 peptides was generated, where peptides were designed by considering the interpretations of the different descriptors in the mtk-computational model. All the peptides were predicted to exhibit high antibacterial activities against multiple bacterial strains, and low cytotoxicity against various cell types. The present mtk-computational model can be considered a very useful tool to support high throughput research for the discovery of potent and safe AMPs.

  6. Antioxidant, ACE-Inhibitory and antibacterial activities of Kluyveromyces marxianus protein hydrolysates and their peptide fractions

    Directory of Open Access Journals (Sweden)

    Mahta Mirzaeia

    2016-07-01

    Full Text Available Background: There has been evidence that proteins are potentially excellent source of antioxidants, antihypertensive and antimicrobial peptides, and that enzymatic hydrolysis is an effective method to release these peptides from protein molecules. The functional properties of protein hydrolysates depends on the protein substrate, the specificity of the enzymes, the conditions used during proteolysis, degree of hydrolysis, and the nature of peptides released including molecular weight, amino acid composition, and hydrophobicity. Context and purpose of this study: The biomass of Kluyveromyces marxianus was considered as a source of ACE inhibitory, antioxidant and antimicrobial peptides. Results: Autolysis and enzymatic hydrolysis were completed respectively, after 96 h and 5 h. Overall, trypsin (18.52% DH and chymotrypsin (21.59% DH treatments were successful in releasing antioxidant and ACE inhibitory peptides. Autolysate sample (39.51% DH demonstrated poor antioxidant and ACE inhibitory activity compared to trypsin and chymotrypsin hydrolysates. The chymotrypsin 3-5 kDa (301.6±22.81 μM TE/mg protein and trypsin < 3 kDa (280.16±39.16 μM TE/mg protein permeate peptide fractions showed the highest DPPH radical scavenging activity. The trypsin <3 kDa permeate peptide fraction showed the highest ABTS radical scavenging (1691.1±48.68 μM TE/mg protein and ACE inhibitory (IC50=0.03±0.001 mg/mL activities. The fraction (MW=5-10 kD obtained after autolysis treatment showed antibacterial activity against St. aureus and Lis. monocytogenes in well diffusion screening. The minimum inhibitory concentration (MIC value was 13.3 mg/mLagainst St. aureus and Lis. monocytogenes calculated by turbidimetric assay and it showed bactericidal activity against St. aureus at 21.3 mg/mL protein concentration. Conclusions: Altogether, the results of this study reveal that K. marxianus proteins contain specific peptides in their sequences which can be released by

  7. Potent Antibacterial Antisense Peptide-Peptide Nucleic Acid Conjugates Against Pseudomonas aeruginosa

    DEFF Research Database (Denmark)

    Ghosal, Anubrata; Nielsen, Peter E

    2012-01-01

    Pseudomonas aeruginosa is an opportunistic pathogen causing severe infections in hospital settings, especially with immune compromised patients, and the increasing prevalence of multidrug resistant strains urges search for new drugs with novel mechanisms of action. In this study we introduce...... essential bacterial gene involved in fatty acid synthesis) of P. aeruginosa (PA01) and characterized these compounds according to their antimicrobial activity and mode of action. Four antisense PNA oligomers conjugated to the H-(R-Ahx-R)(4)-Ahx-ßala or the H-(R-Ahx)(6)-ßala peptide exhibited complete growth...

  8. Ligand and Structure-Based Approaches for the Identification of Peptide Deformylase Inhibitors as Antibacterial Drugs

    Directory of Open Access Journals (Sweden)

    Jian Gao

    2016-07-01

    Full Text Available Peptide deformylase (PDF is a metalloprotease catalyzing the removal of a formyl group from newly synthesized proteins, which makes it an important antibacterial drug target. Given the importance of PDF inhibitors like actinonin in antibacterial drug discovery, several reported potent PDF inhibitors were used to develop pharmacophore models using the Galahad module of Sybyl 7.1 software. Generated pharmacophore models were composed of two donor atom centers, four acceptor atom centers and two hydrophobic groups. Model-1 was screened against the Zinc database and several compounds were retrieved as hits. Compounds with Qfit values of more than 60 were employed to perform a molecular docking study with the receptor Escherichia coli PDF, then compounds with docking score values of more than 6 were used to predict the in silico pharmacokinetic and toxicity risk via OSIRIS property explorer. Two known PDF inhibitors were also used to perform a molecular docking study with E. coli PDF as reference molecules. The results of the molecular docking study were validated by reproducing the crystal structure of actinonin. Molecular docking and in silico pharmacokinetic and toxicity prediction studies suggested that ZINC08740166 has a relatively high docking score of 7.44 and a drug score of 0.78.

  9. Ligand and Structure-Based Approaches for the Identification of Peptide Deformylase Inhibitors as Antibacterial Drugs

    Science.gov (United States)

    Gao, Jian; Liang, Li; Zhu, Yasheng; Qiu, Shengzhi; Wang, Tao; Zhang, Ling

    2016-01-01

    Peptide deformylase (PDF) is a metalloprotease catalyzing the removal of a formyl group from newly synthesized proteins, which makes it an important antibacterial drug target. Given the importance of PDF inhibitors like actinonin in antibacterial drug discovery, several reported potent PDF inhibitors were used to develop pharmacophore models using the Galahad module of Sybyl 7.1 software. Generated pharmacophore models were composed of two donor atom centers, four acceptor atom centers and two hydrophobic groups. Model-1 was screened against the Zinc database and several compounds were retrieved as hits. Compounds with Qfit values of more than 60 were employed to perform a molecular docking study with the receptor Escherichia coli PDF, then compounds with docking score values of more than 6 were used to predict the in silico pharmacokinetic and toxicity risk via OSIRIS property explorer. Two known PDF inhibitors were also used to perform a molecular docking study with E. coli PDF as reference molecules. The results of the molecular docking study were validated by reproducing the crystal structure of actinonin. Molecular docking and in silico pharmacokinetic and toxicity prediction studies suggested that ZINC08740166 has a relatively high docking score of 7.44 and a drug score of 0.78. PMID:27428963

  10. Role of glycosylation in the anticancer activity of antibacterial peptides against breast cancer cells.

    Science.gov (United States)

    Han, Yang-Yang; Liu, Hong-Yan; Han, Dong-Ju; Zong, Xi-Cui; Zhang, Shuang-Quan; Chen, Yu-Qing

    2013-11-01

    Antibacterial peptides (ABPs) with cancer-selective toxicity have received much more attention as alternative chemotherapeutic agents in recent years. However, the basis of their anticancer activity remains unclear. The modification of cell surface glycosylation is a characteristic of cancer cells. The present study investigated the effect of glycosylation, in particular sialic acid, on the anticancer activity of ABPs. We showed that aurein 1.2, buforin IIb and BMAP-28m exhibited selective cytotoxicity toward MX-1 and MCF-7 breast cancer cells. The binding activity, cytotoxicity and apoptotic activity of ABPs were enhanced by the presence of O-, N-glycoproteins, gangliosides and sialic acid on the surface of breast cancer cells. Among N-, O-glycoproteins and ganglioside, O-glycoproteins almost had the strongest effect on the binding and cytotoxicity of the three peptides. Further, up-regulation of hST6Gal1 in CHO-K1 cells enhanced the susceptibility of cells to these peptides. Finally, the growth of MX-1 xenograft tumors in mice was significantly suppressed by buforin IIb treatment, which was associated with induction of apoptosis and inhibition of vascularization. These data demonstrate that the three peptides bind to breast cancer cells via an interaction with surface O-, N-glycoproteins and gangliosides. Sialic acids act as key glycan binding sites for cationic ABP binding to glycoproteins and gangliosides. Therefore, glycosylation in breast cancer cells plays an important role in the anticancer activity of ABPs, which may partly explain their cancer-selective toxicity. Anticancer ABPs with cancer-selective cytotoxicity will be promising candidates for anticancer therapy in the future.

  11. Antifungal mechanism of antibacterial peptide, ABP-CM4, from Bombyx mori against Aspergillus niger.

    Science.gov (United States)

    Zhang, Jie; Wu, Xi; Zhang, Shuang-Quan

    2008-12-01

    Antibacterial peptide, CM4 (ABP-CM4), a 35 amino acid peptide from Chinese silkworm-Bombyx mori, displayed a strong antifungal activity against Aspergillus niger, Trichoderma viride and Gibberella saubinetii. Scanning electron microcopy showed that the morphology of conidia became more irregular and swelled when treated with ABP-CM4 at its minimal inhibitory concentration (MIC) of 8 muM. A cell wall regeneration assay indicated that the plasma membrane was the prime target of ABP-CM4 action. Confocal laser scanning microscopy showed that the cytoskeleton of A. niger was destroyed when treated with ABP-CM4 at 8 muM. Furthermore, transmission electron microscopy showed that the membrane and the cellular organelles of fungus were disrupted and there were many vacuoles in the fungal cellular space after the treatment with ABP-CM4. A gel-retardation assay showed that ABP-CM4 bound the DNA of A. niger. Our results suggest that ABP-CM4 exerts its antifungal activity by disrupting the structure of cell membranes and the cytoskeleton and interacts with the organelles, such as the mitochondrion and with the DNA in the fungal cell, subsequently resulting in cell death.

  12. Modulating the activity of short arginine-tryptophan containing antibacterial peptides with N-terminal metallocenoyl groups

    Directory of Open Access Journals (Sweden)

    H. Bauke Albada

    2012-10-01

    Full Text Available A series of small synthetic arginine and tryptophan containing peptides was prepared and analyzed for their antibacterial activity. The effect of N-terminal substitution with metallocenoyl groups such as ferrocene (FcCO and ruthenocene (RcCO was investigated. Antibacterial activity in different media, growth inhibition, and killing kinetics of the most active peptides were determined. The toxicity of selected derivatives was determined against erythrocytes and three human cancer cell lines. It was shown that the replacement of an N-terminal arginine residue with a metallocenoyl moiety modulates the activity of WRWRW-peptides against Gram-positive and Gram-negative bacteria. MIC values of 2–6 µM for RcCO-W(RW2 and 1–11 µM for (RW3 were determined. Interestingly, W(RW2-peptides derivatized with ferrocene were significantly less active than those derivatized with ruthenocene which have similar structural but different electronic properties, suggesting a major influence of the latter. The high activities observed for the RcCO-W(RW2- and (RW3-peptides led to an investigation of the origin of activity of these peptides using several important activity-related parameters. Firstly, killing kinetics of the RcCO-W(RW2-peptide versus killing kinetics of the (RW3 derivative showed faster reduction of the colony forming units for the RcCO-W(RW2-peptide, although MIC values indicated higher activity for the (RW3-peptide. This was confirmed by growth inhibition studies. Secondly, hemolysis studies revealed that both peptides did not lead to significant destruction of erythrocytes, even up to 500 µg/mL for (RW3 and 250 µg/mL for RcCO-W(RW2. In addition, toxicity against three human cancer cell lines (HepG2, HT29, MCF7 showed that the (RW3-peptide had an IC50 value of ~140 µM and the RcW(RW2 one of ~90 µM, indicating a potentially interesting therapeutic window. Both the killing kinetics and growth inhibition studies presented in this work point to a

  13. Modulating the activity of short arginine-tryptophan containing antibacterial peptides with N-terminal metallocenoyl groups.

    Science.gov (United States)

    Albada, H Bauke; Chiriac, Alina-Iulia; Wenzel, Michaela; Penkova, Maya; Bandow, Julia E; Sahl, Hans-Georg; Metzler-Nolte, Nils

    2012-01-01

    A series of small synthetic arginine and tryptophan containing peptides was prepared and analyzed for their antibacterial activity. The effect of N-terminal substitution with metallocenoyl groups such as ferrocene (FcCO) and ruthenocene (RcCO) was investigated. Antibacterial activity in different media, growth inhibition, and killing kinetics of the most active peptides were determined. The toxicity of selected derivatives was determined against erythrocytes and three human cancer cell lines. It was shown that the replacement of an N-terminal arginine residue with a metallocenoyl moiety modulates the activity of WRWRW-peptides against Gram-positive and Gram-negative bacteria. MIC values of 2-6 µM for RcCO-W(RW)(2) and 1-11 µM for (RW)(3) were determined. Interestingly, W(RW)(2)-peptides derivatized with ferrocene were significantly less active than those derivatized with ruthenocene which have similar structural but different electronic properties, suggesting a major influence of the latter. The high activities observed for the RcCO-W(RW)(2)- and (RW)(3)-peptides led to an investigation of the origin of activity of these peptides using several important activity-related parameters. Firstly, killing kinetics of the RcCO-W(RW)(2)-peptide versus killing kinetics of the (RW)(3) derivative showed faster reduction of the colony forming units for the RcCO-W(RW)(2)-peptide, although MIC values indicated higher activity for the (RW)(3)-peptide. This was confirmed by growth inhibition studies. Secondly, hemolysis studies revealed that both peptides did not lead to significant destruction of erythrocytes, even up to 500 µg/mL for (RW)(3) and 250 µg/mL for RcCO-W(RW)(2). In addition, toxicity against three human cancer cell lines (HepG2, HT29, MCF7) showed that the (RW)(3)-peptide had an IC(50) value of ~140 µM and the RcW(RW)(2) one of ~90 µM, indicating a potentially interesting therapeutic window. Both the killing kinetics and growth inhibition studies presented in

  14. Expression, Purification and Antibacterial Activity of NK-Lysin Mature Peptides from the Channel Catfish (Ictalurus punctatus

    Directory of Open Access Journals (Sweden)

    Shurui Cai

    2016-08-01

    Full Text Available Antimicrobial peptides (AMPs are small peptides and play important roles in host innate immune response against microbial invasion. Aquatic animals secrete different kinds of antimicrobial peptides which have antimicrobial activity towards microorganisms. NK-lysins, mature peptides produced by cytotoxic T lymphocytes and natural killer cells, are comprised of 74–78 amino acid residues, demonstrating broad-spectrum antimicrobial activity against bacteria, fungi, protozoa, and parasites. In this study, three distinct NK-lysin mature peptide (mNKLs, transcripts (76 amino acid residues cloned from the channel catfish (Ictalurus punctatus head kidney were ligated into plasmid vector pET-32a(+ to express the mNKLs fusion protein. The fusion protein was successfully expressed in E. coli Rosetta (DE3 under optimized conditions. After purification by affinity column chromatography, the fusion protein was successfully cleaved by enterokinase and released the peptide mNKLs. Tricine-SDS-PAGE results showed that mNKLs (approximately 8.6 kDa were successfully expressed. The purified peptide mNKLs exhibited antibacterial activity against Staphylococcus aureus and E. coli.

  15. Structure-Activity Relationship and Mode of Action of a Frog Secreted Antibacterial Peptide B1CTcu5 Using Synthetically and Modularly Modified or Deleted (SMMD) Peptides.

    Science.gov (United States)

    Abraham, Parvin; Sundaram, Anand; R, Asha; V, Reshmy; George, Sanil; Kumar, K Santhosh

    2015-01-01

    All life forms are equipped with rapidly acting, evolutionally conserved components of an innate immune defense system that consists of a group of unique and diverse molecules known as host defense peptides (HDPs). A Systematic and Modular Modification and Deletion (SMMD) approach was followed to analyse the structural requirement of B1CTcu5, a brevinin antibacterial peptide amide identified from the skin secretion of frog Clinotarsus curtipes, India, to show antibacterial activity and to explore the active core region. Seventeen SMMD-B1CTcu5 analogs were designed and synthesised by C and N-terminal amino acid substitution or deletion. Enhancement in cationicity by N-terminal Lys/Arg substitution or hydrophobicity by Trp substitution produced no drastic change in bactericidal nature against selected bacterial strains except S. aureus. But the sequential removal of N-terminal amino acids had a negative effect on bactericidal potency. Analog B1CTcu5-LIAG obtained by the removal of four N-terminal amino acids displayed bactericidal effect comparable to, or in excess of, the parent peptide with reduced hemolytic character. Its higher activity was well correlated with the improved inner membrane permeabilisation capacity. This region may act as the active core of B1CTcu5. Presence of C-terminal disulphide bond was not a necessary condition to display antibacterial activity but helped to promote hemolytic nature. Removal of the C-terminal rana box region drastically reduced antibacterial and hemolytic activity of the peptide, showing that this region is important for membrane targeting. The bactericidal potency of the D-peptide (DB1CTcu5) helped to rule out the stereospecific interaction with the bacterial membrane. Our data suggests that both the C and N-terminal regions are necessary for bactericidal activity, even though the active core region is located near the N-terminal of B1CTcu5. A judicious modification at the N-terminal region may produce a short SMMD analog

  16. Antibacterial activity of novel cationic peptides against clinical isolates of multi-drug resistant Staphylococcus pseudintermedius from infected dogs.

    Directory of Open Access Journals (Sweden)

    Mohamed F Mohamed

    Full Text Available Staphylococcus pseudintermedius is a major cause of skin and soft tissue infections in companion animals and has zoonotic potential. Additionally, methicillin-resistant S. pseudintermedius (MRSP has emerged with resistance to virtually all classes of antimicrobials. Thus, novel treatment options with new modes of action are required. Here, we investigated the antimicrobial activity of six synthetic short peptides against clinical isolates of methicillin-susceptible and MRSP isolated from infected dogs. All six peptides demonstrated potent anti-staphylococcal activity regardless of existing resistance phenotype. The most effective peptides were RRIKA (with modified C terminus to increase amphipathicity and hydrophobicity and WR-12 (α-helical peptide consisting exclusively of arginine and tryptophan with minimum inhibitory concentration50 (MIC50 of 1 µM and MIC90 of 2 µM. RR (short anti-inflammatory peptide and IK8 "D isoform" demonstrated good antimicrobial activity with MIC50 of 4 µM and MIC90 of 8 µM. Penetratin and (KFF3K (two cell penetrating peptides were the least effective with MIC50 of 8 µM and MIC90 of 16 µM. Killing kinetics revealed a major advantage of peptides over conventional antibiotics, demonstrating potent bactericidal activity within minutes. Studies with propidium iodide and transmission electron microscopy revealed that peptides damaged the bacterial membrane leading to leakage of cytoplasmic contents and consequently, cell death. A potent synergistic increase in the antibacterial effect of the cell penetrating peptide (KFF3K was noticed when combined with other peptides and with antibiotics. In addition, all peptides displayed synergistic interactions when combined together. Furthermore, peptides demonstrated good therapeutic indices with minimal toxicity toward mammalian cells. Resistance to peptides did not evolve after 10 passages of S. pseudintermedius at sub-inhibitory concentration. However, the MICs of amikacin

  17. Antibacterial activity of novel cationic peptides against clinical isolates of multi-drug resistant Staphylococcus pseudintermedius from infected dogs.

    Science.gov (United States)

    Mohamed, Mohamed F; Hammac, G Kenitra; Guptill, Lynn; Seleem, Mohamed N

    2014-01-01

    Staphylococcus pseudintermedius is a major cause of skin and soft tissue infections in companion animals and has zoonotic potential. Additionally, methicillin-resistant S. pseudintermedius (MRSP) has emerged with resistance to virtually all classes of antimicrobials. Thus, novel treatment options with new modes of action are required. Here, we investigated the antimicrobial activity of six synthetic short peptides against clinical isolates of methicillin-susceptible and MRSP isolated from infected dogs. All six peptides demonstrated potent anti-staphylococcal activity regardless of existing resistance phenotype. The most effective peptides were RRIKA (with modified C terminus to increase amphipathicity and hydrophobicity) and WR-12 (α-helical peptide consisting exclusively of arginine and tryptophan) with minimum inhibitory concentration50 (MIC50) of 1 µM and MIC90 of 2 µM. RR (short anti-inflammatory peptide) and IK8 "D isoform" demonstrated good antimicrobial activity with MIC50 of 4 µM and MIC90 of 8 µM. Penetratin and (KFF)3K (two cell penetrating peptides) were the least effective with MIC50 of 8 µM and MIC90 of 16 µM. Killing kinetics revealed a major advantage of peptides over conventional antibiotics, demonstrating potent bactericidal activity within minutes. Studies with propidium iodide and transmission electron microscopy revealed that peptides damaged the bacterial membrane leading to leakage of cytoplasmic contents and consequently, cell death. A potent synergistic increase in the antibacterial effect of the cell penetrating peptide (KFF)3K was noticed when combined with other peptides and with antibiotics. In addition, all peptides displayed synergistic interactions when combined together. Furthermore, peptides demonstrated good therapeutic indices with minimal toxicity toward mammalian cells. Resistance to peptides did not evolve after 10 passages of S. pseudintermedius at sub-inhibitory concentration. However, the MICs of amikacin and

  18. Cytocompatibility, antibacterial activity and biodegradability of self-assembling beta-hairpin peptide-based hydrogels for tissue regenerative applications

    Science.gov (United States)

    Salick, Daphne Ann

    Every year, millions of people suffer from tissue loss or failure. One approach to repair damaged or diseased tissue is through tissue/organ transplantation. However, one of the major problems which exist with this approach is that there are more people in need of a transplant than there are donors. Over the past several decades, scientists and doctors have come together to find a way to overcome this challenge. This collaboration has led to the development of biomimetic scaffolds, which closely mimic the desired tissue of interest to act as a substitute for the unfunctional tissue, with hopes to improve the quality of life. The Schneider and Pochan labs have developed a biomimetic scaffold using self-assembling beta-hairpin peptides. The self-assembly event can be triggered in response to physiological conditions, which is dictated by the monomer, to form non covalently crosslinked mechanically rigid hydrogels. In vitro studies showed that hydrogels were cytocompatible and may not elicit a pro-inflammatory response from murine macrophages. These material properties show promise for the use of these hydrogels in tissue engineering. When implanting a material into a host, a major concern is the introduction of infection. Infection, if not prevented or halted, results in poor tissue integration and function, ultimately leading to implant removal from the host. Interestingly, the beta-hairpin hydrogels were shown to exhibit antibacterial properties against pathogens commonly found in hospital environments. This inherently antibacterial hydrogel is advantageous because it may help decrease or diminish bacterial contamination when implanted in vivo, which may help to increase the success of implants. Also, a unique and exciting feature of these peptide-based hydrogels is their ability to shear-thin and self-heal. Hydrogels can be directly formed in a syringe and be subsequently delivered to a tissue defect in a minimally invasive manner where they will recover to their

  19. First Multitarget Chemo-Bioinformatic Model To Enable the Discovery of Antibacterial Peptides against Multiple Gram-Positive Pathogens.

    Science.gov (United States)

    Speck-Planche, Alejandro; Kleandrova, Valeria V; Ruso, Juan M; Cordeiro, M N D S

    2016-03-28

    Antimicrobial peptides (AMPs) have emerged as promising therapeutic alternatives to fight against the diverse infections caused by different pathogenic microorganisms. In this context, theoretical approaches in bioinformatics have paved the way toward the creation of several in silico models capable of predicting antimicrobial activities of peptides. All current models have several significant handicaps, which prevent the efficient search for highly active AMPs. Here, we introduce the first multitarget (mt) chemo-bioinformatic model devoted to performing alignment-free prediction of antibacterial activity of peptides against multiple Gram-positive bacterial strains. The model was constructed from a data set containing 2488 cases of AMPs sequences assayed against at least 1 out of 50 Gram-positive bacterial strains. This mt-chemo-bioinformatic model displayed percentages of correct classification higher than 90.00% in both training and prediction (test) sets. For the first time, two computational approaches derived from basic concepts in genetics and molecular biology were applied, allowing the calculations of the relative contributions of any amino acid (in a defined position) to the antibacterial activity of an AMP and depending on the bacterial strain used in the biological assay. The present mt-chemo-bioinformatic model constitutes a powerful tool to enable the discovery of potent and versatile AMPs.

  20. A multifunctional peptide based on the neutrophil immune defense molecule, CAP37, has antibacterial and wound-healing properties.

    Science.gov (United States)

    Kasus-Jacobi, Anne; Noor-Mohammadi, Samaneh; Griffith, Gina L; Hinsley, Heather; Mathias, Lauren; Pereira, H Anne

    2015-02-01

    CAP37, a protein constitutively expressed in human neutrophils and induced in response to infection in corneal epithelial cells, plays a significant role in host defense against infection. Initially identified through its potent bactericidal activity for Gram-negative bacteria, it is now known that CAP37 regulates numerous host cell functions, including corneal epithelial cell chemotaxis. Our long-term goal is to delineate the domains of CAP37 that define these functions and synthesize bioactive peptides for therapeutic use. We report the novel finding of a multifunctional domain between aa 120 and 146. Peptide analogs 120-146 QR, 120-146 QH, 120-146 WR, and 120-146 WH were synthesized and screened for induction of corneal epithelial cell migration by use of the modified Boyden chamber assay, antibacterial activity, and LPS-binding activity. In vivo activity was demonstrated by use of mouse models of sterile and infected corneal wounds. The identity of the amino acid at position 132 (H vs. R) was important for cell migration and in vivo corneal wound healing. All analogs demonstrated antimicrobial activity. However, analogs containing a W at position 131 showed significantly greater antibacterial activity against the Gram-negative pathogen Pseudomonas aeruginosa. All analogs bound P. aeruginosa LPS. Topical administration of analog 120-146 WH, in addition to accelerating corneal wound healing, effectively cleared a corneal infection as a result of P. aeruginosa. In conclusion, we have identified a multifunctional bioactive peptide, based on CAP37, that induces cell migration, possesses antibacterial and LPS-binding activity, and is effective at healing infected and noninfected corneal wounds in vivo.

  1. Antibacterial properties of hLf1-11 peptide onto titanium surfaces: a comparison study between silanization and surface initiated polymerization.

    Science.gov (United States)

    Godoy-Gallardo, Maria; Mas-Moruno, Carlos; Yu, Kai; Manero, José M; Gil, Francisco J; Kizhakkedathu, Jayachandran N; Rodriguez, Daniel

    2015-02-09

    Dental implant failure can be associated with infections that develop into peri-implantitis. In order to reduce biofilm formation, several strategies focusing on the use of antimicrobial peptides (AMPs) have been studied. To covalently immobilize these molecules onto metallic substrates, several techniques have been developed, including silanization and polymer brush prepared by surface-initiated atom transfer radical polymerization (ATRP), with varied peptide binding yield and antibacterial performance. The aim of the present study was to compare the efficiency of these methods to immobilize the lactoferrin-derived hLf1-11 antibacterial peptide onto titanium, and evaluate their antibacterial activity in vitro. Smooth titanium samples were coated with hLf1-11 peptide under three different conditions: silanization with 3-aminopropyltriethoxysilane (APTES), and polymer brush based coatings with two different silanes. Peptide presence was determined by X-ray photoelectron spectroscopy, and the mechanical stability of the coatings was studied under ultrasonication. The LDH assays confirmed that HFFs viability and proliferation were no affected by the treatments. The in vitro antibacterial properties of the modified surfaces were tested with two oral strains (Streptococcus sanguinis and Lactobacillus salivarius) showing an outstanding reduction. A higher decrease in bacterial attachment was noticed when samples were modified by ATRP methods compared to silanization. This effect is likely due to the capacity to immobilize more peptide on the surfaces using polymer brushes and the nonfouling nature of polymer PDMA segment.

  2. ANTIBACTERIAL EFFECT OF COMPOUNDS OF PEPTIDE NATURE CONTAINED IN AQUEOUS EXTRACT OF BRASSICA NAPUS SOLANUM LYCOPERSICUM AND TETRAGONIA TETRAGONIOIDES LEAVES

    Directory of Open Access Journals (Sweden)

    Tereza Neubauerová

    2015-04-01

    Full Text Available Treatment of infections caused by pathogenic bacteria is still harder. Due to increasing number of microbial species resistant against so far invented antibiotics. This presents great problem for public health. One of the potential solutions seems to be antimicrobial peptides. Those peptides are synthetized in all organisms as a part of innate immunity with rapid mode of antimicrobial action. Lot of them have been isolated from bacteria, plants, insects and mammals as well. Our project was aimed on finding such peptides in plant extracts, respectively in leaves of Brassica napus (canola, Solanum lycopersicum (tomato and Tetragonia tetragonioides (New Zealand spinach. We used several separation techniques to obtain fractions containing compounds of peptide nature with hydrophobic character. Antimicrobial activity of these fractions was tested against several gram-positive and gram-negative bacteria. Mass spectrometry analysis of antimicrobial active fractions proved presence of low molecular peptides with molecular masses 1.9 - 4.9 kDa and a partial amino acid sequence in hydrophobic part of Tetragonia extract. In hydrophilic fraction of the Solanum extract with proved antibacterial activity two patogenesis-related proteins with antifungal activity NP24 and TPM-1 were detected.

  3. Isolation and characterisation of a novel antibacterial peptide from a native swine intestinal tract-derived bacterium.

    Science.gov (United States)

    Xin, Haiyun; Ji, Shengyue; Peng, Jiayin; Han, Peng; An, Xiaopeng; Wang, Shan; Cao, Binyun

    2017-02-27

    Antimicrobial peptides (AMPs) are highly associated with antipathogenic activity, without generating drug resistance in targeted bacteria. In this study, the existence of AMPs in the Tibetan swine, a China-native, cold-resistant and seldom-sick breed of pig, was investigated. A peptide secreted by a Tibetan swine intestinal tract-derived Bacillus strain was isolated using reversed-phase chromatography (RPC), ultrafiltration and reversed-phase high-performance liquid chromatography (RP-HPLC). The peptide was identified by mass spectrometry and was characterised for activity against Escherichia coli and Staphylococcus aureus. The 16-amino acid peptide (ASVVNKLTGGVAGLLK), named TP, had a molecular mass of 1568.919 Da and exhibited inhibitory activity against Gram-positive and Gram-negative bacteria [minimum inhibitory concentrations (MICs) of 2.5-5 µM and 10-20 µM for E. coli and S. aureus, respectively] as well as human MKN-45 and NB4 tumour cell lines [50% inhibitory concentration (IC50) = 4.686 µM and 11.479 µM, respectively]. TP also exhibited weak haemolytic activity. Furthermore, TP enhanced cell membrane permeability and K(+) outflow, bound with E. coli genomic DNA in vitro and inhibited E. coli growth. Thus, TP represents a strong candidate as an antibacterial peptide.

  4. Absence of in vitro innate immunomodulation by insect-derived short proline-rich antimicrobial peptides points to direct antibacterial action in vivo.

    Science.gov (United States)

    Fritsche, Stefanie; Knappe, Daniel; Berthold, Nicole; von Buttlar, Heiner; Hoffmann, Ralf; Alber, Gottfried

    2012-10-01

    Some antimicrobial peptides (AMPs) have been described to exert immunomodulatory effects, which may contribute to their in vivo antibacterial activity. Very recently, we could show that novel oncocin and apidaecin derivatives are potently antibacterially active in vivo. Therefore, we studied oncocin and apidaecin derivatives for their effects on murine dendritic cells (DC) and macrophages and compared them with well-known immunomodulatory activities of murine cathelicidin-related antimicrobial peptide (CRAMP). To characterize the immunomodulatory activity of the peptides on key cells of the innate immune system, we stimulated murine DC and macrophages with the oncocin and apidaecin derivatives alone, or in combination with lipopolysaccharide (LPS). We analyzed the secretion of pro-inflammatory cytokines, the expression of surface activation markers, and the chemotactic activity of the AMPs. In contrast to LPS, none of the oncocin and apidaecin derivatives alone has an influence on cytokine or surface marker expression by DC and macrophages. Furthermore, the tested oncocin and apidaecin derivatives do not modulate the immune response after LPS stimulation, whereas CRAMP shows a reduction of the LPS-mediated immune response as expected. All peptides tested are not chemotactic for DC. Together, lack of in vitro immunomodulatory effects by oncocin and apidaecin derivatives on key cells of the innate murine immune system suggests that their potent in vivo antibacterial activity relies on a direct antibacterial effect. This will simplify further pharmaceutical investigation and development of insect peptides as therapeutic compounds against bacterial infections.

  5. [The comparative characteristics of antibacterial properties of the peptides of the active site of GM-CSF, and substances delivered from supernatants of hematopoietic progenitor CD34+45- cells].

    Science.gov (United States)

    Zurochka, A V; Zurochka, V A; Kostolomova, E G; Dobrynina, M A; Sykhoveĭ, Iu G; Gritsenko, V A

    2012-01-01

    The antibacterial activity of synthetic peptides of the active site of GM-CSF and supernatants of CD34+45- hematopoietic progenitor cells has been investigated GM-CSF peptides and cell supernatants were found to possess pronounced antibacterial activity, at that a combination of these substances has a more pronounced activity in comparison with the single substances. Possible mechanisms of the identified effects of synthetic peptides and substances from the supernatants of CD34+5- cells are discussed.

  6. Novel short antibacterial and antifungal peptides with low cytotoxicity: Efficacy and action mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Qi, Xiaobao; Zhou, Chuncai; Li, Peng [School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, 637459 Singapore (Singapore); Xu, Weixin [School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, 637551 Singapore (Singapore); Cao, Ye; Ling, Hua; Ning Chen, Wei; Ming Li, Chang; Xu, Rong [School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, 637459 Singapore (Singapore); Lamrani, Mouad [Menicon Co., Ltd. Immeuble Espace Cordeliers, 2, rue President Carnot, 69002 Lyon (France); Mu, Yuguang, E-mail: ygmu@ntu.edu.sg [School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, 637551 Singapore (Singapore); Leong, Susanna Su Jan [School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, 637459 Singapore (Singapore); Wook Chang, Matthew, E-mail: matthewchang@ntu.edu.sg [School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, 637459 Singapore (Singapore); Chan-Park, Mary B., E-mail: mbechan@ntu.edu.sg [School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, 637459 Singapore (Singapore)

    2010-07-30

    Research highlights: {yields} Short antimicrobial peptides with nine and eleven residues were developed. {yields} These peptides show strong bactericidal activity against clinically important bacterial and fungal pathogens. {yields} These peptides exhibit high stability in the presence of salts, and low cytotoxicity. {yields} These peptides exert their action by disrupting membrane lipids. -- Abstract: Short antimicrobial peptides with nine and eleven residues were developed against several clinically important bacterial and fungal pathogens (specifically Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Candida albicans, and Fusarium solani). Twelve analogues of previously reported peptides BP76 (KKLFKKILKFL) and Pac-525 (KWRRWVRWI) were designed, synthesized, and tested for their antimicrobial activities. Two of our eleven amino acid peptides, P11-5 (GKLFKKILKIL) and P11-6 (KKLIKKILKIL), have very low MICs of 3.1-12.5 {mu}g ml{sup -1} against all five pathogens. The MICs of these two peptides against S. aureus, C. albicans and F. solani are four to ten times lower than the corresponding MICs of the reference peptide BP76. P9-4 (KWRRWIRWL), our newly designed nine-amino acid analogue, also has particularly low MICs of 3.1-6.2 {mu}g ml{sup -1} against four of the tested pathogens; these MICs are two to eight times lower than those reported for Pac-525 (6.2-50 {mu}g ml{sup -1}).These new peptides (P11-5, P11-6 and P9-4) also exhibit improved stability in the presence of salts, and have low cytotoxicity as shown by the hemolysis and MTT assays. From the results of field-emission scanning electron microscopy, membrane depolarization and dye-leakage assays, we propose that these peptides exert their action by disrupting membrane lipids. Molecular dynamics simulation studies confirm that P11-6 peptide maintains relatively stable helical structure and exerts more perturbation action on the order of acyl tail of lipid bilayer.

  7. A new synthetic peptide having two target of antibacterial action in E. coli ML35

    Directory of Open Access Journals (Sweden)

    Hernando Curtidor

    2016-12-01

    Full Text Available The increased resistance of microorganisms to the different antimicrobials available to today has highlighted the need to find new therapeutic agents, including natural and/or synthetic antimicrobial peptides. This study has evaluated the antimicrobial activity of synthetic peptide 35409 (RYRRKKKMKKALQYIKLLKE against S. aureus ATCC 29213, P. aeruginosa ATCC 15442 and E. coli ML 35 (ATCC 43827. The results have shown that peptide 35409 inhibited the growth of these three bacterial strains, having 16 fold greater activity against E. coli and P. aeruginosa, but requiring less concentration regarding E. coli (22 µM. When analyzing this activity against E. coli compared to time taken, it was found that this peptide inhibited bacterial growth during the first 60 min and reduced CFU/mL 1 log after 120 min had elapsed. This antimicrobial peptide permeabilized the E. coli membrane by interaction with membrane phospholipids, mainly phosphatidylethanolamine, inhibited cell division and induced filamentation, suggesting two different targets of action within a bacterial cell. Cytotoxicity studies revealed that peptide 35409 had low hemolytic activity and was not cytotoxic for two human cell lines. We would thus propose, in the light of these findings, that the peptide 35409 sequence should provide a promising template for designing broad-spectrum antimicrobial peptides.

  8. Neutrophil antibacterial peptides, multifunctional effector molecules in the mammalian immune system.

    Science.gov (United States)

    Gudmundsson, G H; Agerberth, B

    1999-12-17

    The bactericidal machinery of mammalian neutrophils is built up of many components with different chemical properties, involving proteins, peptides and oxygen-dependent radicals. All these components work in synergy, leading to destruction and elimination of ingested microbes. During the eighties, it gradually became clear, that cationic peptides are a part of the oxygen-independent bactericidal effectors in phagocytic cells. In mammals, these antimicrobial peptides are represented by two families, the defensins and the cathelicidins. These potent broad spectra peptides are included as immediate effector molecules in innate immunity. The detailed killing mechanism for these effectors is partly known, but nearly all of them have membrane affinity, and permeate bacterial membranes, resulting in lysis of the bacteria. This peptide-membrane interaction includes also eukaryotic membranes, that implicates cytotoxic effects on host cells. Studies in vitro have established that the microenvironment is critical for their activities. In connection to cystic fibrosis, the effects of microenvironment changes are apparent, causing inactivation of peptide defences and leading to repeated serious bacterial infections. Thus, the importance of the microenvironment is also supported in vivo. Additional functions of these peptides such as chemotactic, mitogenic and stimulatory in the wound healing process suggest further important roles for these peptides.

  9. Construction of Antibacterial Peptide CecropinB Eukaryotic Recombinant Vector and Its Expression in Dairy Goat Mammary Gland Epithelial Cells

    Institute of Scientific and Technical Information of China (English)

    GAO Xuejun; TONG Huili; YIN Deyun; ZHANG Li

    2008-01-01

    To investigate the expression of antibacterial peptide CecropinB eDNA in dairy goat mammary gland epithelial cells, the CecropinB gene was eloned and was inserted into a eukaryotic vector pECFP-Cl to construct the recombinant plasmid pECFP-B by genetic engineering technique. Recombinant plasmid pECFP-B was transfected into dairy goat mammary gland epithelial to detect the bactericidal activity of CeeropinB. The expression of CecropinB was also detected. The result of RT-PCR demonstrated CecropinB gene was expressed in transfeeted cells. CecropinB recombinant plasmid DNA was injected into udders and CecropinB was expressed in mammary gland, exhibiting bactericidal activity to Staphylococcus aureus in vivo experiments.

  10. Composite electrospun nanomembranes of fish scale collagen peptides/chito-oligosaccharides: antibacterial properties and potential for wound dressing

    Directory of Open Access Journals (Sweden)

    Li P

    2011-04-01

    Full Text Available Yan Wang1, Chen-lu Zhang2, Qun Zhang1, Ping Li1,31School of Life Sciences and Technology, Tongji University, Shanghai, People’s Republic of China; 2College of Life Sciences, Nanjing Agricultural University, Nanjing, People’s Republic of China; 3Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai, People’s Republic of ChinaPurpose: The objective of the present investigation was to evaluate the antibacterial properties and the biocompatibility of composite electrospun nanofibrous membranes (NFMs with low-molecular-weight fish scale collagen peptides (FSCP and chito-oligosaccharide (COS, to determine their potential for use as wound dressings.Methods: Low-molecular-weight FSCP were combined with COS to prepare nanofibers by electrospinning, and polyvinyl alcohol (PVA was used for enhancing fiber-forming ability. Transmission electron microscope and scanning electron microscope methods were used to observe bacterial adhesion and the bacterial cell membrane. Fibroblast cell viability was determined using the 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assay.Results: The best FSCP/COS mass ratio for electrospinning was 2:1, and the nanofibers had small dimensions ranging from 50 to 100 nm. The NFM showed good antibacterial activities against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli. The antibacterial activity against S. aureus was higher than against E. coli. The pili and adhesive fimbriae of E. coli promoted bacterial adhesion to the NFM surfaces, and S. aureus biofilms aided S. aureus adhesion on the surface of NFMs. Damage to the bacterial cell membrane indicates that the NFMs could lead to the release of intracellular materials, particularly with S. aureus. In addition, FSCP/COS NFM rapidly increased the permeability of the outer membranes of E. coli. The electrospun NFM with FSCP and COS had good biocompatibility in vitro and supported

  11. Synthesis and Mechanism Insight of a Peptide-Grafted Hyperbranched Polymer Nanosheet with Weak Positive Charges but Excellent Intrinsically Antibacterial Efficacy.

    Science.gov (United States)

    Gao, Jingyi; Wang, Mingzhi; Wang, Fangyingkai; Du, Jianzhong

    2016-06-13

    Antimicrobial resistance is an increasingly problematic issue in the world and there is a present and urgent need to develop new antimicrobial therapies without drug resistance. Antibacterial polymers are less susceptible to drug resistance but they are prone to inducing serious side effects due to high positive charge. Herein we report a peptide-grafted hyperbranched polymer which can self-assemble into unusual nanosheets with highly effective intrinsically antibacterial activity but weak positive charges (+ 6.1 mV). The hyperbranched polymer was synthesized by sequential Michael addition-based thiol-ene and free radical mediated thiol-ene reactions, and followed by ring-opening polymerization of N-carboxyanhydrides (NCAs). The nanosheet structure was confirmed by transmission electron microscopy (TEM) and atomic force microscopy (AFM) studies. Furthermore, a novel "wrapping and penetrating" antibacterial mechanism of the nanosheets was revealed by TEM and it is the key to significantly decrease the positive charges but have a very low minimum inhibitory concentration (MIC) of 16 μg mL(-1) against typical Gram-positive and Gram-negative bacteria. Overall, our synthetic strategy demonstrates a new insight for synthesizing antibacterial nanomaterials with weak positive charges. Moreover, the unique antibacterial mechanism of our nanosheets may be extended for designing next-generation antibacterial agents without drug resistance.

  12. Comparative Study on Test Methods for Antibacterial Activities of Antibacterial Peptides from Spleen of Japanese Eel (Anguilla japonica)%日本鳗鲡脾脏抗菌肽抗菌活性检测方法的比较

    Institute of Scientific and Technical Information of China (English)

    梁英; 黄文树; 关瑞章

    2014-01-01

    The study was to establish a simple and sensitive test method for antibacterial activity analysis in the separation and purification of antibacterial peptides from the spleen of Japanese eel ( Anguilla japonica) . Exper-iment by using spleen protein of molecular mass<10 ku from Japanese eel as antibacterial peptide samples, to compare the sensitivity, advantages and disadvantages of three test methods. In these three test methods, two conventional methods were agar plate fovea diffusion method and microporous liquid culture method and anoth-er was trace liquid culture method, for testing antibacterial activities of antibacterial peptides against three com-mon pathogenic bacterial strains of eel, including Edwardsiella tarda, Aeromonas sp. and Aeromonas hy-drophila. The results showed that compared with the agar plate fovea diffusion method and microporous liquid culture method, the trace liquid culture method had the advantages of simple operation and easy to observe re-sult. Furthermore, this method with the best sensitivity and using the least sample quantity could be suitable for testing antibacterial activities in the separation and purification of antibacterial peptides from the spleen of eel, especially for identifying antibacterial activity of the a few and single fraction obtained in late stage of separa-tion and purification. This study suggests that the trace liquid culture method is suitable for testing antibacterial activities of antibacterial peptides from the spleen of Japanese eel.%本试验旨在建立一种在日本鳗鲡脾脏抗菌肽分离纯化过程中简便、灵敏的检测其抗菌活性的方法。试验以日本鳗鲡脾脏分子质量小于10 ku的蛋白质为抗菌肽样品,选择琼脂板孔穴扩散法和微孔液体培养法2种传统方法及微量液体培养法为检测方法,比较这3种方法在抗菌肽对3种鳗鲡常见致病菌株(迟钝爱德华菌、气单胞菌、嗜水气单胞菌)抗菌活性检测中的灵

  13. Interaction between Antibacterial Peptide Apep10 and Escherichia coli Membrane Lipids Evaluated Using Liposome as Pseudo-Stationary Phase

    Science.gov (United States)

    Li, Man

    2017-01-01

    Liposomes constructed from Escherichia coli membrane lipids were used as a pseudo-stationary phase in capillary electrophoresis and immobilised liposome chromatography to evaluate the interaction between antibacterial peptide (ABP) Apep10 and bacterial membrane lipids. The peptide mobility decreased as the concentration of liposomes increased, providing evidence for the existence of this interaction. The binding constant between Apep10 and the Escherichia coli membranes lipid liposome was higher than that of Apep10 with a mixed phospholipids liposome at the same temperature. The capillary electrophoresis results indicate that the binding ability of Apep10 with a liposome was dependent on the liposome’s lipid compositions. Thermodynamic analysis by immobilised liposome chromatography indicated that hydrophobic and electrostatic effects contributed to the partitioning of Apep10 in the membrane lipids. The liposomes constructed from bacterial membrane lipid were more suitable as the model membranes used to study dynamic ABP/membrane interactions than those constructed from specific ratios of particular phospholipids, with its more biomimetic phospholipid composition and contents. This study provides an appropriate model for the evaluation of ABP-membrane interactions. PMID:28052090

  14. 抗菌肽作用机制及应用研究进展%Advance in mechanism and application of antibacterial peptide

    Institute of Scientific and Technical Information of China (English)

    刘世财; 范琳琳; 郑珩; 张秋怡

    2016-01-01

    在这抗生素耐药性病菌不断出现的时代,新型抗菌药物的发现已迫在眉睫。而抗菌肽为大多数生物对入侵病原体的自然防御系统的重要组成部分,具有独特的抗菌作用机制,迅速杀菌且不易引发细菌的耐药性,可单独或与抗生素联合使用杀伤病原体,是一类极具发展潜力的生物药物。本文根据抗菌肽的理化性质,作用机制及抗菌肽的设计等进行综述,并对几种有前景的抗菌肽作一简单介绍。%In the era of outbreaking of antibiotic resistance, the discovery of new antibacterial drugs is emergent.Antimicrobial peptides are important components of the natural defenses of most living organisms against invading pathogens.The unique antibacterial mechanism, direct bactericidal effect, relatively slow of resistance acquirement, and can used alone or combined with antibiotics, make antimicrobial peptides be attractive potential antibacterial drugs.In this paper, we review the physicochemical property of antibacterial peptides, action mechanism and design of antimicrobial peptides, and give a brief introduction of several promising antimicrobial peptides.

  15. PEGylation of the peptide Bac7(1-35) reduces renal clearance while retaining antibacterial activity and bacterial cell penetration capacity.

    Science.gov (United States)

    Benincasa, Monica; Zahariev, Sotir; Pelillo, Chiara; Milan, Annalisa; Gennaro, Renato; Scocchi, Marco

    2015-05-05

    The proline-rich antibacterial peptide Bac7(1-35) protects mice against Salmonella typhimurium infection, despite its rapid clearance. To overcome this problem the peptide was linked to a polyethylene glycol (PEG) molecule either via a cleavable ester bond or via a non-hydrolysable amide bond. Both the PEGylated conjugates retained most of the in vitro activity against S. typhimurium. In addition, the ester bond was cleaved in human serum or plasma, releasing a carboxymethyl derivative of Bac7(1-35) which accounts for a higher activity of this peptide with relative to the other, non-hydrolysable form. Both PEGylated peptides maintained the capacity of the unconjugated form to kill bacteria without permeabilizing the bacterial membranes, by penetrating into cells. They exploited the same transporter as unmodified Bac7(1-35), suggesting it has the capacity to internalize quite sizeable cargo if this is linked to Bac7 fragment. PEGylation allows the peptide to have a wide distribution in mice, and a slow renal clearance, indicating that this strategy would improve the bioavailability of Bac7, and in principle of other antimicrobial peptides. This can be an equally important issue to reducing cytotoxicity for therapeutic use of these antibacterials.

  16. Antibacterial Effects of a Cell-Penetrating Peptide Isolated from Kefir.

    Science.gov (United States)

    Miao, Jianyin; Guo, Haoxian; Chen, Feilong; Zhao, Lichao; He, Liping; Ou, Yangwen; Huang, Manman; Zhang, Yi; Guo, Baoyan; Cao, Yong; Huang, Qingrong

    2016-04-27

    Kefir is a traditional fermented milk beverage used throughout the world for centuries. A cell-penetrating peptide, F3, was isolated from kefir by Sephadex G-50 gel filtration, DEAE-52 ion exchange, and reverse-phase high-performance liquid chromatography. F3 was determined to be a low molecular weight peptide containing one leucine and one tyrosine with two phosphate radicals. This peptide displayed antimicrobial activity across a broad spectrum of organisms including several Gram-positive and Gram-negative bacteria as well as fungi, with minimal inhibitory concentration (MIC) values ranging from 125 to 500 μg/mL. Cellular penetration and accumulation of F3 were determined by confocal laser scanning microscopy. The peptide was able to penetrate the cellular membrane of Escherichia coli and Staphylococcus aureus. Changes in cell morphology were observed by scanning electron microscopy (SEM). The results indicate that peptide F3 may be a good candidate for use as an effective biological preservative in agriculture and the food industry.

  17. Isolation and biological activities of antibacterial peptides from sheep small intestines%羊小肠抗菌肽分离及其生物活性研究

    Institute of Scientific and Technical Information of China (English)

    承伟; 叶兆伟; 姜华

    2011-01-01

    目的:从羊小肠提取抗菌肽并对其抑菌作用进行研究,寻找廉价易得的广谱高效天然抗菌肽.方法:葡聚糖凝胶分离及反相高效液相色谱法提纯羊小肠活性抗菌肽;采用琼脂平板打孔法进行抑菌效果的测定;SDS-PAGE电泳分析相对分子质量.结果:反相高效液相色谱法分离出现3个主峰,其中之一对大肠杆菌和金葡球菌有较高抑菌活性(蛋白浓度分别为38,19,10 mg·mL-1);相对分子质量约为40 Ku.结论:实验得到的抗菌肽材料易得,对G-菌和G+菌均有较强的抑制作用.%Objective: To isolate antibacterial peptides from small intestines of sheep, and investigate their antibacterial activities. Methods: The gel filtration chromatography with Sephadex G-25 was used to separate different components from the small intestine extracts of sheep. The separated components were analyzed by agar diffusion plate method to determine their antibacterial activities. The active component was further separated by reversed-phase high-performance liquid chromatography. The purity and molecular weight of the peptide with antibacterial activity was determined by SDS-PAGE. Results: The antibacterial peptides separated from sheep small intestine showed a highly activity to inhibit growth of Escherichia coli and Staphylococcus aureus at protein concentrations of 38, 19, 10 mg·mL-1. Its molecular weight was about 40 Ku. Conclusion: The new antibacterial peptides are easily obtained, and has significant antimicrobial activity.

  18. Expression of Antimicrobial Peptide Dybowskin-2CAMa in Pichia pastoris and Characterization of its Antibacterial Activity

    Directory of Open Access Journals (Sweden)

    Lili Jin

    2013-08-01

    Full Text Available In this study we used a yeast expression system to express a new antimicrobial peptide dybowskin-2CAMa from the skin cDNA library of Rana amurenisis. The entire coding region of the dybowskin-2CAMa was cloned into the plasmid pPICZ&alpha-A and then transformed into competent P. pastoris X33. The expressed dybowskin-2CAMa was purified from the culture supernatant by Sephadex G-25 and YMC*GEL ODS-A chromatography followed by C18 reverse phased HPLC. The purified peptide exhibited a single band of about 2 kDa when resolved by Tricine-SDS-PAGE. Its exact molecular weight was 2456.46 Da which was consistent with the value predicted from its deduced amino acid sequence. Antimicrobial activity assay showed that the recombinant dybowskin-2CAMa could inhibit the growth of a broad spectrum of bacteria, while displaying very low level of hemolytic activity (&le4% relative to Triton X-100, even at concentration of up to 500 &mug/mL.

  19. The Cyclic Antibacterial Peptide Enterocin AS-48: Isolation, Mode of Action, and Possible Food Applications

    Directory of Open Access Journals (Sweden)

    María José Grande Burgos

    2014-12-01

    Full Text Available Enterocin AS-48 is a circular bacteriocin produced by Enterococcus. It contains a 70 amino acid-residue chain circularized by a head-to-tail peptide bond. The conformation of enterocin AS-48 is arranged into five alpha-helices with a compact globular structure. Enterocin AS-48 has a wide inhibitory spectrum on Gram-positive bacteria. Sensitivity of Gram-negative bacteria increases in combination with outer-membrane permeabilizing treatments. Eukaryotic cells are bacteriocin-resistant. This cationic peptide inserts into bacterial membranes and causes membrane permeabilization, leading ultimately to cell death. Microarray analysis revealed sets of up-regulated and down-regulated genes in Bacillus cereus cells treated with sublethal bacteriocin concentration. Enterocin AS-48 can be purified in two steps or prepared as lyophilized powder from cultures in whey-based substrates. The potential applications of enterocin AS-48 as a food biopreservative have been corroborated against foodborne pathogens and/or toxigenic bacteria (Listeria monocytogenes, Bacillus cereus, Staphylococcus aureus, Escherichia coli, Salmonella enterica and spoilage bacteria (Alicyclobacillus acidoterrestris, Bacillus spp., Paenibacillus spp., Geobacillus stearothermophilus, Brochothrix thermosphacta, Staphylococcus carnosus, Lactobacillus sakei and other spoilage lactic acid bacteria. The efficacy of enterocin AS-48 in food systems increases greatly in combination with chemical preservatives, essential oils, phenolic compounds, and physico-chemical treatments such as sublethal heat, high-intensity pulsed-electric fields or high hydrostatic pressure.

  20. The Cyclic Antibacterial Peptide Enterocin AS-48: Isolation, Mode of Action, and Possible Food Applications

    Science.gov (United States)

    Grande Burgos, María José; Pérez Pulido, Rubén; López Aguayo, María del Carmen; Gálvez, Antonio; Lucas, Rosario

    2014-01-01

    Enterocin AS-48 is a circular bacteriocin produced by Enterococcus. It contains a 70 amino acid-residue chain circularized by a head-to-tail peptide bond. The conformation of enterocin AS-48 is arranged into five alpha-helices with a compact globular structure. Enterocin AS-48 has a wide inhibitory spectrum on Gram-positive bacteria. Sensitivity of Gram-negative bacteria increases in combination with outer-membrane permeabilizing treatments. Eukaryotic cells are bacteriocin-resistant. This cationic peptide inserts into bacterial membranes and causes membrane permeabilization, leading ultimately to cell death. Microarray analysis revealed sets of up-regulated and down-regulated genes in Bacillus cereus cells treated with sublethal bacteriocin concentration. Enterocin AS-48 can be purified in two steps or prepared as lyophilized powder from cultures in whey-based substrates. The potential applications of enterocin AS-48 as a food biopreservative have been corroborated against foodborne pathogens and/or toxigenic bacteria (Listeria monocytogenes, Bacillus cereus, Staphylococcus aureus, Escherichia coli, Salmonella enterica) and spoilage bacteria (Alicyclobacillus acidoterrestris, Bacillus spp., Paenibacillus spp., Geobacillus stearothermophilus, Brochothrix thermosphacta, Staphylococcus carnosus, Lactobacillus sakei and other spoilage lactic acid bacteria). The efficacy of enterocin AS-48 in food systems increases greatly in combination with chemical preservatives, essential oils, phenolic compounds, and physico-chemical treatments such as sublethal heat, high-intensity pulsed-electric fields or high hydrostatic pressure. PMID:25493478

  1. The human cathelicidin LL-37--A pore-forming antibacterial peptide and host-cell modulator.

    Science.gov (United States)

    Xhindoli, Daniela; Pacor, Sabrina; Benincasa, Monica; Scocchi, Marco; Gennaro, Renato; Tossi, Alessandro

    2016-03-01

    The human cathelicidin hCAP18/LL-37 has become a paradigm for the pleiotropic roles of peptides in host defence. It has a remarkably wide functional repertoire that includes direct antimicrobial activities against various types of microorganisms, the role of 'alarmin' that helps to orchestrate the immune response to infection, the capacity to locally modulate inflammation both enhancing it to aid in combating infection and limiting it to prevent damage to infected tissues, the promotion of angiogenesis and wound healing, and possibly also the elimination of abnormal cells. LL-37 manages to carry out all its reported activities with a small and simple, amphipathic, helical structure. In this review we consider how different aspects of its primary and secondary structures, as well as its marked tendency to form oligomers under physiological solution conditions and then bind to molecular surfaces as such, explain some of its cytotoxic and immunomodulatory effects. We consider its modes of interaction with bacterial membranes and capacity to act as a pore-forming toxin directed by our organism against bacterial cells, contrasting this with the mode of action of related peptides from other species. We also consider its different membrane-dependent effects on our own cells, which underlie many of its other activities in host defence. This article is part of a Special Issue entitled: Pore-Forming Toxins edited by Mauro Dalla Serra and Franco Gambale.

  2. Antibacterial Peptide-Based Gel for Prevention of Medical Implanted-Device Infection

    Science.gov (United States)

    Mateescu, Mihaela; Baixe, Sébastien; Garnier, Tony; Jierry, Loic; Ball, Vincent; Haikel, Youssef; Metz-Boutigue, Marie Hélène; Nardin, Michel; Schaaf, Pierre; Etienne, Olivier; Lavalle, Philippe

    2015-01-01

    Implanted medical devices are prone to infection. Designing new strategies to reduce infection and implant rejection are an important challenge for modern medicine. To this end, in the last few years many hydrogels have been designed as matrices for antimicrobial molecules destined to fight frequent infection found in moist environments like the oral cavity. In this study, two types of original hydrogels containing the antimicrobial peptide Cateslytin have been designed. The first hydrogel is based on alginate modified with catechol moieties (AC gel). The choice of these catechol functional groups which derive from mussel’s catechol originates from their strong adhesion properties on various surfaces. The second type of gel we tested is a mixture of alginate catechol and thiol-terminated Pluronic (AC/PlubisSH), a polymer derived from Pluronic, a well-known biocompatible polymer. This PlubisSH polymer has been chosen for its capacity to enhance the cohesion of the composition. These two gels offer new clinical uses, as they can be injected and jellify in a few minutes. Moreover, we show these gels strongly adhere to implant surfaces and gingiva. Once gelled, they demonstrate a high level of rheological properties and stability. In particular, the dissipative energy of the (AC/PlubisSH) gel detachment reaches a high value on gingiva (10 J.m-2) and on titanium alloys (4 J.m-2), conferring a strong mechanical barrier. Moreover, the Cateslytin peptide in hydrogels exhibited potent antimicrobial activities against P. gingivalis, where a strong inhibition of bacterial metabolic activity and viability was observed, indicating reduced virulence. Gel biocompatibility tests indicate no signs of toxicity. In conclusion, these new hydrogels could be ideal candidates in the prevention and/or management of periimplant diseases. PMID:26659616

  3. Antibacterial Peptide-Based Gel for Prevention of Medical Implanted-Device Infection.

    Directory of Open Access Journals (Sweden)

    Mihaela Mateescu

    Full Text Available Implanted medical devices are prone to infection. Designing new strategies to reduce infection and implant rejection are an important challenge for modern medicine. To this end, in the last few years many hydrogels have been designed as matrices for antimicrobial molecules destined to fight frequent infection found in moist environments like the oral cavity. In this study, two types of original hydrogels containing the antimicrobial peptide Cateslytin have been designed. The first hydrogel is based on alginate modified with catechol moieties (AC gel. The choice of these catechol functional groups which derive from mussel's catechol originates from their strong adhesion properties on various surfaces. The second type of gel we tested is a mixture of alginate catechol and thiol-terminated Pluronic (AC/PlubisSH, a polymer derived from Pluronic, a well-known biocompatible polymer. This PlubisSH polymer has been chosen for its capacity to enhance the cohesion of the composition. These two gels offer new clinical uses, as they can be injected and jellify in a few minutes. Moreover, we show these gels strongly adhere to implant surfaces and gingiva. Once gelled, they demonstrate a high level of rheological properties and stability. In particular, the dissipative energy of the (AC/PlubisSH gel detachment reaches a high value on gingiva (10 J.m-2 and on titanium alloys (4 J.m-2, conferring a strong mechanical barrier. Moreover, the Cateslytin peptide in hydrogels exhibited potent antimicrobial activities against P. gingivalis, where a strong inhibition of bacterial metabolic activity and viability was observed, indicating reduced virulence. Gel biocompatibility tests indicate no signs of toxicity. In conclusion, these new hydrogels could be ideal candidates in the prevention and/or management of periimplant diseases.

  4. Hepcidin is an antibacterial, stress-inducible peptide of the biliary system.

    Directory of Open Access Journals (Sweden)

    Pavel Strnad

    Full Text Available BACKGROUND/AIMS: Hepcidin (gene name HAMP, an IL-6-inducible acute phase peptide with antimicrobial properties, is the key negative regulator of iron metabolism. Liver is the primary source of HAMP synthesis, but it is also produced by other tissues such as kidney or heart and is found in body fluids such as urine or cerebrospinal fluid. While the role of hepcidin in biliary system is unknown, a recent study demonstrated that conditional gp130-knockout mice display diminished hepcidin levels and increased rate of biliary infections. METHODS: Expression and localization of HAMP in biliary system was analyzed by real time RT-PCR, in-situ hybridization, immunostaining and -blotting, while prohepcidin levels in human bile were determined by ELISA. RESULTS: Hepcidin was detected in mouse/human gallbladder and bile duct epithelia. Biliary HAMP is stress-inducible, in that it is increased in biliary cell lines upon IL-6 stimulation and in gallbladder mucosa of patients with acute cholecystitis. Hepcidin is also present in the bile and elevated prohepcidin levels were observed in bile of primary sclerosing cholangitis (PSC patients with concurrent bacterial cholangitis compared to PSC subjects without bacterial infection (median values 22.3 vs. 8.9; p = 0.03. In PSC-cholangitis subjects, bile prohepcidin levels positively correlated with C-reactive protein and bilirubin levels (r = 0.48 and r = 0.71, respectively. In vitro, hepcidin enhanced the antimicrobial capacity of human bile (p<0.05. CONCLUSION: Hepcidin is a stress-inducible peptide of the biliary epithelia and a potential marker of biliary stress. In the bile, hepcidin may serve local functions such as protection from bacterial infections.

  5. Expression in Escherichia coli and purification of bioactive antibacterial peptide ABP-CM4 from the Chinese silk worm, Bombyx mori.

    Science.gov (United States)

    Li, Bao-Cun; Zhang, Shuang-Quan; Dan, Wen-Bing; Chen, Yu-Qing; Cao, Peng

    2007-07-01

    The antibacterial peptide CM4 (ABP-CM4), isolated from Chinese Bombys mori, is a 35-residue cationic, amphipathic alpha-helical peptide that exhibits a broad range of antimicrobial activity. To explore a new approach for the expression of ABP-CM4 in E. coli, the gene ABP-CM4, obtained by recursive PCR (rPCR), was cloned into the vector pET32a to construct a fusion expression plasmid. The fusion protein Trx-CM4 was expressed in soluble form, purified by Ni(2+)-chelating chromatography, and cleaved by formic acid to release recombinant CM4. Purification of rCM4 was achieved by affinity chromatography and reverse-phase HPLC. The purified of recombinant peptide showed antimicrobial activities against E. coli K(12)D(31), Penicillium chrysogenum, Aspergillus niger and Gibberella saubinetii. According to the antimicrobial peptide database (http://aps.unmc.edu/AP/main.html), 116 peptides contain a Met residue, but only 5 peptides contain the AspPro site, indicating a broader application of formic acid than CNBr in cleaving fusion protein. The successful application to the expression of the ABP-CM4 indicates that the system is a low-cost, efficient way of producting milligram quantities of ABP-CM4 that is biologically active.

  6. Research Progress on Antibacterial Peptides%抗菌肽的研究进展

    Institute of Scientific and Technical Information of China (English)

    魏中琴; 高雅婷; 马奔科; 甘春丽

    2015-01-01

    Resistance of bacterial is an increasingly serious problem,which results in urgency for new type antibiotics develop-ment.Antimicrobial peptides (ABPs)have great clinical significance due to character of broad—spectrum antimicrobial activity and mechanisms different from traditional antibiotics, Several studies have shown that ABPs have effects on bacterial,virues and cancer cells,and are not easy to produce bacterial resistance. They form the first line of host defense against pathogenic infections,and they are key components of the ancient innate immune system. The review summarized the classification,mechanism,clinical uses,etc.%近年来,由于细菌耐药性问题越发严峻,开发新型抗菌制剂已经越来越受到重视。抗菌肽具有抗菌谱广,有别于抗生素的抗菌机制,能有效地抑杀真菌、病毒、寄生虫等,并能选择性的杀灭肿瘤细胞,不易产生耐药性,而对人畜毒副作用极小,构成宿主防御病原微生物入侵的第一道屏障,是机体免疫系统的重要成分,抗菌肽作为新药开发具有广阔的前景。本文主要就目前抗菌肽的分类、抗菌机制、临床应用等方面做简要介绍。

  7. Chitosan nanoparticles loaded with the antimicrobial peptide temporin B exert a long-term antibacterial activity in vitro against clinical isolates of Staphylococcus epidermidis

    Directory of Open Access Journals (Sweden)

    Anna Maria Piras

    2015-04-01

    Full Text Available Nowadays, the alarming rise in multidrug-resistant microorganisms urgently demands for suitable alternatives to current antibiotics. In this regard, antimicrobial peptides (AMPs have received growing interest due to their broad spectrum of activities, potent antimicrobial properties, unique mechanisms of action and low tendency to induce resistance. However, their pharmaceutical development is hampered by potential toxicity, relatively low stability and manufacturing costs. In the present study, we tested the hypothesis that the encapsulation of the frog-skin derived AMP temporin B (TB into chitosan nanoparticles (CS-NPs could increase peptide’s antibacterial activity, while reducing its toxic potential. TB-loaded CS-NPs with good dimensional features were prepared, based on the ionotropic gelation between CS and sodium tripolyphosphate. The encapsulation efficiency of TB in the formulation was up to 75%. Release kinetic studies highlighted a linear release of the peptide from the nanocarrier, in the adopted experimental conditions. Interestingly, the encapsulation of TB in CS-NPs demonstrated to reduce significantly the peptide’s cytotoxicity against mammalian cells. Additionally, the nanocarrier evidenced a sustained antibacterial action against various strains of Staphylococcus epidermidis for at least 4 days, with up to 4-log reduction in the number of viable bacteria compared to plain CS-NPs at the end of the observational period. Of note, the antimicrobial evaluation tests demonstrated that while the intrinsic antimicrobial activity of CS ensured a burst effect, the gradual release of TB further reduced the viable bacterial count, preventing the regrowth of the residual cells and ensuring a long-lasting antibacterial effect. The developed nanocarrier is eligible for the administration of several AMPs of therapeutic interest with physical-chemical characteristics analogue to those of TB.

  8. 抗菌肽RSRP与常用抗菌药的体外联合药敏试验%Testing the antibacterial activity of antibacterial peptides in rabbit sacculus rotundus combined with eleven kinds of antibiotics in vitro

    Institute of Scientific and Technical Information of China (English)

    陈红伟; 吴俊伟; 刘娟; 张志强; 崔龙萍; 李英伦

    2013-01-01

    为探讨家兔圆小囊抗菌肽(RSRP)的体外抗菌活性以及与抗菌药之间的协同效应关系,采用琼脂糖弥散试验检测RSRP对8株供试细菌的抗菌活性,然后采用棋盘微量稀释法,选取11种常用抗菌药,分别测定其对临床分离的耐药大肠杆菌的最小抑菌浓度,再采用分级抑制浓度指数来定量检测RSRP与抗菌药之间的抗菌作用关系.结果显示,RSRP对8株供试菌均有不同程度的抗菌活性,分级抑制浓度指数从小于0.3到大于5不等.证实该抗菌肽与不同的抗菌药之间协同、相加、无关和拮抗作用关系均存在,其中与β-内酰胺类药物氨苄西林钠、头孢噻呋钠表现明显的协同作用.%To investigate the antibacterial activity of antibacterial peptides from rabbit sacculus rotundus(RSRP) and its synergic interaction with antibiotics,the antibacterial activity of RSRP against 8 bacteria was detected by agarose diffusion assay,and then fractional inhibitory concentration indexes(FICs) of eleven kinds of antibiotics and RSRP were measured by the checkerboard microdilution method. Results demonstrated that there were different degree antibacterial activity of RSRP against the eight bacteria,the FIC values ranged from less than 0. 3 to more than 5 ;and there were synergic,additive,indifference and antagonistic interaction between RSRP and the antibiotics. Among them,there was evidently synergic interaction between RSRP and ampicillin sodium,ceftiofur sodium.

  9. Budesonide suppresses pulmonary antibacterial host defense by down-regulating cathelicidin-related antimicrobial peptide in allergic inflammation mice and in lung epithelial cells

    Directory of Open Access Journals (Sweden)

    Wang Peng

    2013-02-01

    Full Text Available Abstract Background Glucocorticoids are widely regarded as the most effective treatment for asthma. However, the direct impact of glucocorticoids on the innate immune system and antibacterial host defense during asthma remain unclear. Understanding the mechanisms underlying this process is critical to the clinical application of glucocorticoids for asthma therapy. After sensitization and challenge with ovalbumin (OVA, BALB/c mice were treated with inhaled budesonide and infected with Pseudomonas aeruginosa (P. aeruginosa. The number of viable bacteria in enflamed lungs was evaluated, and levels of interleukin-4 (IL-4 and interferon-γ (IFN-γ in serum were measured. A lung epithelial cell line was pretreated with budesonide. Levels of cathelicidin-related antimicrobial peptide (CRAMP were measured by immunohistochemistry and western blot analysis. Intracellular bacteria were observed in lung epithelial cells. Results Inhaled budesonide enhanced lung infection in allergic mice exposed to P. aeruginosa and increased the number of viable bacteria in lung tissue. Higher levels of IL-4 and lower levels of IFN-γ were observed in the serum. Budesonide decreased the expression of CRAMP, increased the number of internalized P. aeruginosa in OVA-challenged mice and in lung epithelial cell lines. These data indicate that inhaled budesonide can suppress pulmonary antibacterial host defense by down-regulating CRAMP in allergic inflammation mice and in cells in vitro. Conclusions Inhaled budesonide suppressed pulmonary antibacterial host defense in an asthmatic mouse model and in lung epithelium cells in vitro. This effect was dependent on the down-regulation of CRAMP.

  10. Application of Antibacterial Peptides in Study of Rice Disease Resistance%抗菌肽在水稻抗病研究中的应用

    Institute of Scientific and Technical Information of China (English)

    董肇楠; 梅家松; 何正权; 刘文真

    2015-01-01

    Antimicrobial peptides ( AMPs) are a series of short peptides with antibacterial activity against foreign pathogens,which are widely distributed in organisms. AMPs,owning advantages such as wide spec-trum antimicrobial properties and little probability to cause pathogens’ drug-resistance,can significantly improve the animal and plant disease resistance. In the present report,we summarize the biological cha-racteristics,classification and action mechanism of antimicrobial peptides,intensively review the research progress of antimicrobial peptides from several different sources in the prevention and control of rice bac-terial blight,blast and sheath blight,and raise the existing problems and future development proposals.%抗菌肽是生物体抵御外来入侵病菌的一系列短肽,在生物界中广泛存在。抗菌肽具有广谱杀菌活性及不易引起病原微生物产生耐药性等优点,可以显著提高动植物的抗病能力。总结了抗菌肽的生物学特性、分类与作用机制,重点介绍了几种不同来源的抗菌肽在水稻白叶枯病、稻瘟病及纹枯病等病害防治方面的应用研究进展,并提出了存在的问题和发展建议。

  11. Isolation and physico-chemical characterization of an antifungal and antibacterial peptide produced by Bacillus licheniformis A12.

    Science.gov (United States)

    Gálvez, A; Maqueda, M; Martínez-Bueno, M; Lebbadi, M; Valdivia, E

    1993-07-01

    An antifungal substance named peptide A12-C has been purified to homogeneity from supernatants of sporulated cultures of Bacillus licheniformis A12. It consists of a 0.77-kDa hydrophilic peptide containing two residues of Glu and one of Arg, Ala, Pro, Tyr and Orn. No fatty acids, phosphorus or carbohydrates have been detected. Peptide A12-C is active on several fungi (Microsporum canis CECT 2797, Mucor mucedo CECT 2653, M. plumbeus (CCM F 443, Sporothrix schenckii CECT 2799 and Trichophyton mentagrophytes CECT 2793) and bacteria (Bacillus megaterium, Corynebacterium glutamicum, Sarcina and Mycobacterium), although the latter are less sensitive.

  12. Research progress in antibacterial mechanisms of antimicrobial peptides%抗菌肽抗菌机制的研究进展

    Institute of Scientific and Technical Information of China (English)

    孙红; 薛越; 黄宁

    2013-01-01

    Antimicrobial peptides(AMPs),a kind of small peptides which widely exist in many organisms,are an important component of the innate immune system.They can not only effectively defense against bacteria,but also fungi,viruses,parasites and even cancer cells.With the properties of rapid microbicidal action,broad-specutrum activity,uneasy to develop drug resistance and others,AMPs have been the research focus of medicine,livestock and aquaculture at present.In this paper,the antibacterial mechanisms of AMPs are reviewed.%抗菌肽是广泛存在于生物体内的一类小分子多肽,是生物固有免疫系统的重要组成部分.抗菌肽不仅能够有效杀灭细菌,而且还对真菌、病毒、寄生虫甚至肿瘤细胞都具有一定的杀伤作用.抗菌肽因其作用迅速、广谱抗菌、不易产生耐药性等诸多特点,已成为医药卫生、畜牧养殖、水产动物等领域研究的热点.本文就当前抗菌肽抗菌机制的研究进展作一综述.

  13. Clinical Research of Synthetic Antibacterial Peptide in Antibacterial Properties of Oral Bacteria%人工合成抗菌肽对口腔细菌抗菌性能的临床研究

    Institute of Scientific and Technical Information of China (English)

    刘晓丹

    2016-01-01

    菌肽对口腔细菌的抗菌性能不同,Temporin-1CEa的最小抑菌浓度较小,且抑菌效果佳。%Objective To investigate synthetic antibacterial peptide in antibacterial properties of oral bacteria.Methods 9 kinds of synthetic antibacterial peptide(Brevinin,chensinin-1,chensinin-1b,L-K5V1,L-K6,L-K6V1, L-K6V2 and temporin lcea,Temporin-1CEb)and 6 kinds of oral bacteria(Candida albicans,Fusobacterium nucleatum, Lactobacilus acidophilus,Streptococcus mutans,Streptococcus salivarius,Streptococcus sanguinis)were used to vitro experiment.Synthetic antibacterial peptide in antibacterial properties of oral bacteria was analyzed.Results Chensinin-1b,L-K5V1,L-K6,L-K6V1,L-K6V2,Temporin-1CEa had high inhibitory rate with Candida albicans.Brevinin, chensinin-1b,L-K5V1,L-K6,L-K6V1,L-K6V2,Temporin-1CEa,Temporin-1CEb had high inhibitory rate with Fusobacterium nucleatum,Streptococcus mutans,Streptococcus salivarius,Streptococcus sanguinis.Brevinin,chensinin-1,chensinin-1b, L-K5V1,L-K6,L-K6V1,L-K6V2,Temporin-1CEa,Temporin-1CEb had high inhibitory rate with Lactobacilus acidophilus. Minimum inhibitory concentrations of Brevinin:Streptococcus sanguinis>Fusobacterium nucleatum>Streptococcus salivarius>Streptococcus mutans>Lactobacilus acidophilus.Minimum inhibitory concentrations of chensinin-1: Lactobacilus acidophilus.Minimum inhibitory concentrations of chensinin-1b:Lactobacilus acidophilus>Streptococcus salivarius>Streptococcus sanguinis>Fusobacterium nucleatum>Candida albicans>Streptococcus mutans. Minimum inhibitory concentrations of L-K5V1:Lactobacilus acidophilus>Fusobacterium nucleatum>Streptococcus mutans>Candida albicans>Streptococcus salivarius>Streptococcus sanguinis.Minimum inhibitory concentrations of L-K6:Streptococcus salivarius>Streptococcus sanguinis>Candida albicans>Streptococcus mutans>Fusobacterium nucleatum>Lactobacilus acidophilus.Minimum inhibitory concentrations of L-K6V1:Lactobacilus acidophilus>Streptococcus sanguinis>Streptococcus salivarius

  14. Nisin-activated hydrophobic and hydrophilic surfaces: assessment of peptide adsorption and antibacterial activity against some food pathogens.

    Science.gov (United States)

    Karam, Layal; Jama, Charafeddine; Mamede, Anne-Sophie; Boukla, Samir; Dhulster, Pascal; Chihib, Nour-Eddine

    2013-12-01

    An effective antimicrobial packaging or food contact surface should be able to kill or inhibit micro-organisms that cause food-borne illnesses. Setting up such systems, by nisin adsorption on hydrophilic and hydrophobic surfaces, is still a matter of debate. For this purpose, nisin was adsorbed on two types of low-density polyethylene: the hydrophobic native film and the hydrophilic acrylic acid-treated surface. The antibacterial activity was compared for those two films and it was highly dependent on the nature of the surface and the nisin-adsorbed amount. The hydrophilic surfaces presented higher antibacterial activity and higher amount of nisin than the hydrophobic surfaces. The effectiveness of the activated surfaces was assessed against Listeria innocua and the food pathogens Listeria monocytogenes, Bacillus cereus, and Staphylococcus aureus. S. aureus was more sensitive than the three other test bacteria toward both nisin-functionalized films. Simulation tests to mimic refrigerated temperature showed that the films were effective at 20 and 4 °C with no significant difference between the two temperatures after 30 min of exposure to culture media.

  15. Selectivity in the potentiation of antibacterial activity of α-peptide/β-peptoid peptidomimetics and antimicrobial peptides by human blood plasma

    DEFF Research Database (Denmark)

    Hein-Kristensen, Line; Knapp, Kolja M.; Franzyk, Henrik;

    2013-01-01

    Antimicrobial peptides (AMPs) are promising leads for novel antibiotics; however, their activity is often compromised under physiological conditions. The purpose of this study was to determine the activity of alpha-peptide/beta-peptoid peptidomimetics and AMPs against Escherichia coli...... and Staphylococcus aureus in the presence of human blood-derived matrices and immune effectors. The minimum inhibitory concentration (MIC) of two peptidomimetics against E. coli decreased by up to one order of magnitude when determined in 50% blood plasma as compared to MHB media. The MIC of a membrane-active AMP......, LL-I/3, also decreased, whereas two intracellularly acting AMPs were not potentiated by plasma. Blood serum had no effect on activity against E. coli and neither matrix had an effect on activity against S. aureus. Unexpectedly, physiological concentrations of human serum albumin did not influence...

  16. Prospect on Antibacterial Peptides Secreted from Amphibian Skins%两栖类动物皮肤分泌抗菌肽的研究进展

    Institute of Scientific and Technical Information of China (English)

    肖冰; 和七一; 张康; 李金波; 余晓东

    2012-01-01

    近年因病原性细菌耐药性日趋严重,迫切需要从各种自然资源中寻找新的抗菌药物;因两栖类抗菌肽具有分子量小、水溶性好、抗原性低、抗菌作用强等优点,成为筛选抗菌药物的重要研究对象.本文就两栖抗菌肽的生物活性、分子结构、家族分类、抗菌分子机制、应用价值及研究前景等方面进行了综述.当前的研究表明,两栖类抗菌肽除具有抗菌作用外还有抗病毒抗肿瘤溶血等作用;它们因结构可分为3类:线性α-螺旋多肽、环性肽和含10~13个氨基酸残基长度的多肽;目前已发现抗菌肽有很多家族如Magainin家族、Aurein家族、Bombinin家族、Bombinin-like 家族Brevinin家族等抗菌肽家族不同其生物活性也不同;它们杀菌主要通过膜裂解或膜不裂解机制完成;已发现两栖类抗菌肽在临床医药、食品保鲜防腐、农业生产等领域具有广阔的应用价值.随着在分子水平上深入的研究,两栖类抗菌肽将突破表达量低、特异性差、产量小、成本高等局限性,为人类制备新型抗菌药提供更多可用的资源.%Due to drug resistance of pathogenic bacteria having been become serious in the recent years, it is rather impending to search for new antimicrobial drugs from various natural sources. Naturally, amphibian antibacterial peptides (ABPs) have been given much attentions and become an important object for our screening antimicrobial drugs from them because of ABP' s special features with small molecular weight, water-solubility and low antigenicity. This paper provides an overview on the biological activities, molecular structures, family classification, antimicrobial mechanism, application values and research prospects of ABPs. It was found that ABPs also have some anti-viral, anti-tumor and hemolytic activities in addition to anti-bacterial activity. According to their different structures there are three types of ABPs: linear ot

  17. 抗菌肽对肿瘤细胞的作用机制及应用前景%The mechanism of action and application prospects of antibacterial peptide on tumor cells

    Institute of Scientific and Technical Information of China (English)

    聂守民; 赵瑞君; 杜斌; 王文建; 原发家

    2015-01-01

    Antibacterial peptide is a kind of polypeptide with antimicrobial activity,widely existing in nature.It is an important element of the host immune defenses with the characteristics of broad anti-bacterial spectrum,relatively small molecular weight,as well as good thermal stability and solubility in water.It is more important that it exhibits selective effects on tumor cells with little toxicity and damage to normal cells.Moreover,it is less easy to develop drug resistance.So,it is expected to become a new generation of anti-cancer drugs with broad application prospects.In this paper,the comprehensive researches on antimicrobial peptide in recent years were summarized with the emphasis on the mechanism of action of antibacterial peptide on tumor cells and its application prospect.%抗菌肽(antibacterial peptide)是具有抗菌活性的一类多肽,广泛存在于生物界.它是宿主免疫防御系统的重要成分,具有广谱杀菌、相对分子量较小、热稳定性及水溶性好等优点,更重要的是它可以选择性作用于肿瘤细胞,对正常细胞损伤小,毒性小,不易产生耐药性,有望开发成为新一代具有广阔应用前景的抗癌药物.该文综合近年来抗菌肽的研究,概述了抗菌肽对肿瘤细胞的作用机制及其应用前景.

  18. Muraymycin nucleoside-peptide antibiotics: uridine-derived natural products as lead structures for the development of novel antibacterial agents

    Directory of Open Access Journals (Sweden)

    Daniel Wiegmann

    2016-04-01

    Full Text Available Muraymycins are a promising class of antimicrobial natural products. These uridine-derived nucleoside-peptide antibiotics inhibit the bacterial membrane protein translocase I (MraY, a key enzyme in the intracellular part of peptidoglycan biosynthesis. This review describes the structures of naturally occurring muraymycins, their mode of action, synthetic access to muraymycins and their analogues, some structure–activity relationship (SAR studies and first insights into muraymycin biosynthesis. It therefore provides an overview on the current state of research, as well as an outlook on possible future developments in this field.

  19. Muraymycin nucleoside-peptide antibiotics: uridine-derived natural products as lead structures for the development of novel antibacterial agents

    Science.gov (United States)

    Wirth, Marius; Niro, Giuliana; Leyerer, Kristin

    2016-01-01

    Summary Muraymycins are a promising class of antimicrobial natural products. These uridine-derived nucleoside-peptide antibiotics inhibit the bacterial membrane protein translocase I (MraY), a key enzyme in the intracellular part of peptidoglycan biosynthesis. This review describes the structures of naturally occurring muraymycins, their mode of action, synthetic access to muraymycins and their analogues, some structure–activity relationship (SAR) studies and first insights into muraymycin biosynthesis. It therefore provides an overview on the current state of research, as well as an outlook on possible future developments in this field. PMID:27340469

  20. The partial characterization of the antibacterial peptide bacteriocin G2 produced by the probiotic bacteria Lactobacillus plantarum G2

    Directory of Open Access Journals (Sweden)

    SVETLANA L. ŠEATOVIĆ

    2011-05-01

    Full Text Available The aim of this study was the partial characterization of the antimicrobial peptide bacteriocin G2 produced by probiotic bacteria Lactobacillus plantarum G2, which was isolated from a clinical sample of a healthy person. Antimicrobial substance was secreted in the supernatant of an L. plantarum G2 culture, and showed a diverse spectrum of antimicrobial activity of all the tested strains of the genera Lactobacillus and the pathogenic bacteria Staphylococcus aureus and Salmonella аbony. Isoelectric focusing revealed that bacteriocin G2 is a cationic peptide (pI about 10 with a molecular mass of 2.2 kDa according to tricine–sodium dodecyl sulphate–polyacrylamide gel electrophoresis, SDS-PAGE. The antimicrobial activity of bacteriocin G2 was diminished by the proteolytic action of trypsin and proteinase K. Bacteriocin G2 preserved its biological activity in the temperature range 40–60 °C (15 min, which was lost at 80 °C. Bacteriocin G2 was stable in the pH range 2–9, while treatment with 1 % Tween 80 and 1 % urea resulted in increased antimicrobial activity. The probiotic strain L. plantarum G2 produces the antimicrobial substance proteinaceous in nature with bacteriocin characteristics. Bacteriocin production is one of the key properties of probiotic bacteria with clinical potential as anti-infective agents, which will increase the likelihood of its in vivo efficacy.

  1. 抗菌肽作用机制及改造策略研究进展%Advances in the study of the mechanisms of action of antibacterial peptides and strategies to transform them

    Institute of Scientific and Technical Information of China (English)

    孙长峰; 仲维霞; 王洪法

    2013-01-01

    Antimicrobial peptides (AMPs) are key components of the innate immune system that constitute a diverse class of naturally occurring antimicrobial molecules.AMPs have been found to exhibit a broad range of activities against microorganisms,including Gram-positive and Gram-negative bacteria,fungi,mycoplasma,and viruses.Some antibacterial peptides also have antitumor activity.This review focuses on the classification of antibacterial peptides,their mechanisms of action,strategies for their transformation,and existing problems with their use.%抗菌肽是生物体先天性免疫系统的重要组成成分,是多种不同具有抗菌活性天然多肽分子的统称.研究发现抗菌肽具有抗包括G+细菌,G细菌,真菌,支原体,病毒在内的多种病原体的广谱作用活性,有些抗菌肽还具有抗肿瘤活性.本文主要综述了抗菌肽的分类、作用机制、改造策略及其应用中存在的问题.

  2. Antimicrobial peptide melimine coating for titanium and its in vivo antibacterial activity in rodent subcutaneous infection models.

    Science.gov (United States)

    Chen, Renxun; Willcox, Mark D P; Ho, Kitty Ka Kit; Smyth, Daniel; Kumar, Naresh

    2016-04-01

    Implant-associated infections represent a significant health problem and financial burden on healthcare systems. Current strategies for the treatment or prevention of such infections are still inadequate and new strategies are needed in this era of antibiotic resistance. Melimine, a synthetic antimicrobial peptide with broad spectrum activity against bacteria, fungi and protozoa, has been shown to be a promising candidate for development as antimicrobial coating for biomedical devices and implants. In this study, the in vitro and in vivo antimicrobial activity of melimine-coated titanium was tested. The titanium surface was amine-functionalised with 3-aminopropyltriethoxysilane (APTES) followed by reaction with a bifunctional linker 4-(N-maleimidomethyl)cyclohexane-1-carboxylic 3-sulfo-n-hydroxysuccinimide ester (Sulfo-SMCC) to yield a maleimide functionalised surface. Melimine was then tethered to the surface via a thioether linkage through a Michael addition reaction of the cysteine at its N-terminus with the maleimide moiety. Melimine coating significantly reduced in vitro adhesion and biofilm formation of Pseudomonas aeruginosa by up to 62% and Staphylococcus aureus by up to 84% on the titanium substrates compared to the blank (p < 0.05). The activity was maintained after ethylene oxide gas sterilisation. The coating was also challenged in both mouse and rat subcutaneous infection models and was able to reduce the bacterial load by up to 2 log10 compared to the uncoated surface (p < 0.05). Melimine coating is a promising candidate for development as a surface antimicrobial that can withstand industrial sterilisation while showing good biocompatibility.

  3. Structure,function and molecular design strategies of antibacterial peptide SMAP-29:a review%抗菌肽SMAP-29结构功能及分子设计策略

    Institute of Scientific and Technical Information of China (English)

    陈琛; 吴三桥; 李新生; 张小莺; 闫茂仓

    2011-01-01

    Antibacterial peptides are a family of host-defense peptides most of which are gene-encoded and produced by living organisms of all types.Antibacterial peptides are small molecular proteins with broad antimicrobial spectrum against bacteria, viruses, fungi and sometimes even as anticancer peptide.SMAP-29, a cathelicidin-like peptide derived from sheep myeloid, line α-helical Structure, exerts a powerful broad antimicrobial activity against different pathogens including Gram-positive and Gram-negative bacteria, fungi, viruses, parasites, spirochaetes, chlamydia and antiendotoxin activity, and particular antibacterial mechanism, rapidly to permeabilize membranes of susceptible organisms.This paper summarizes the lately research progress of SMAP-29 and Variants including the characteristics of structure, structure-activity relationships,mode of action, diverse biological functions, gene recombinant and expression.We put emphasis on the necessity of molecular design, and primary and secondary structure-based modification, to provides a strong foundation for further drug development and design of SMAP-29.%抗菌肽是生物体内产生的一种具有生物活性的小分子多肽,具有广谱抗细茵、抗病毒、抗真菌甚至抗癌作用.SMAP-29是来源于绵羊骨髓细胞,包含29个氨基酸的Cathelicidin类α-螺旋结构抗茵肽.SMAP-29具有多种生物活性,包括抗革兰氏阳/阴性菌、抗真菌、抗病毒、抗寄生虫、抗螺旋体、抗衣原体和中和内毒素活性,并且具有作用机制独特、快速杀灭细菌的特点.以下综述了SMAP-29抗菌肽家族的基因和蛋白结构、结构与活性关系、作用机制、生物功能、基因重组表达,重点阐述了SMAP-29结构,分子设计的必要性和基于SMAP-29一级、二级结构进行分子设计策略,为SMAP-29药物设计和研究开发奠定了基础.

  4. APD: the Antimicrobial Peptide Database

    OpenAIRE

    Wang, Zhe; Wang, Guangshun

    2004-01-01

    An antimicrobial peptide database (APD) has been established based on an extensive literature search. It contains detailed information for 525 peptides (498 antibacterial, 155 antifungal, 28 antiviral and 18 antitumor). APD provides interactive interfaces for peptide query, prediction and design. It also provides statistical data for a select group of or all the peptides in the database. Peptide information can be searched using keywords such as peptide name, ID, length, net charge, hydrophob...

  5. FLa -AA -FLc抗菌肽抑菌活性理化因素研究%Effects of Physical and Chemical Factors on Antibacterial Activity of Antimicrobial Peptide FLa -AA-FLc

    Institute of Scientific and Technical Information of China (English)

    安亚雄; 李海涛; 王坤; 朱言柱; 刘艳环; 冯卓; 苗利光

    2013-01-01

      以金黄色葡萄球菌为指示菌,采用琼脂扩散法,在不同温度、酸碱度、盐浓度、金属离子条件下,对FLa-AA-FLc抗菌肽抑菌活性的变化情况进行了深入研究。结果发现:FLa-AA-FLc抗菌肽对热和pH不敏感,醋酸铵能显著降低其抑菌活性,金属离子除Fe3+外,其他金属离子对其抑菌活性没有影响。本项试验为FLa-AA-FLc抗菌肽的生产工艺和使用方式研究提供依据。%  The aim of this study was to examine the antibacterial activity of FLa -AA-FLc .The staphylococcus aurous was used to examine the antibacterial activity of FLa-AA-FLc using the agar diffusion method .This experiment was carried out under different physical and chemical conditions such as temperature ,pH ,salt concentrations and metal cations .The results showed that antimicrobial peptide FLa -AA-FLc was not sensitive to pH and high temperature ,ammonium acetate could remarkably reduce the antibacterial activity of FLa -AA-FLc ,and Fe3+ affect-ed the antibacterial activity of FLa-AA-FLc .It will provide theoretical basis for the production process and application of FLa -AA-FLc .

  6. 饲喂蝇蛆抗菌肽对白痢鸡血液生化指标的影响%Effect of Antibacterial Peptides from Musca Domestica Larvae on Physiology and Biochemistry Indices in the Blood of Pullorum Chicken

    Institute of Scientific and Technical Information of China (English)

    申红; 王俊刚; 秦文彬; 衡建胜; 乔书培; 周刚; 赵博; 贾斌

    2011-01-01

    为了测定蝇蛆抗菌肽对白痢鸡血液生化指标的影响,选用75只白痢三黄肉仔鸡,随机分为5个组,用蝇蛆抗菌肽替换抗生素治疗白痢鸡,比较分析添加未经处理蝇蛆组、灭活沙门氏菌处理蝇蛆组、蝇蛆中粗提抗菌肽组、抗生素组与对照组(不加抗生素和抗菌肽)中白痢鸡各项生理生化指标的变化情况.结果显示,白痢鸡饲喂抗菌肽后红细胞数(RBC)与对照组相比显著增多(P<0.05),白细胞(WBC)数量显著减少(P<0.05),血液中总蛋白、白蛋白、球蛋白含量均显著高于对照组(P<0.05),并降低了白痢鸡血清总脂的含量(P<0.05),血清中转氨酶含量有所降低,但差异不显著(P>0.05).%The present study aimed to detect physiology and biochemistry indices in the blood of chicken affected by antibacterial peptides from Musca domestica larvae. Seventy-five flesh chickens were choosen and randomly divided into five groups:group Ⅰ (diet added with untreated Musca domestica larvae); group Ⅱ (diet added with Musca domestica larvae treated with inactived Salmonella). Group Ⅲ (diet added with antibacterial peptides from Musca domestica larvae) .group Ⅳ (diet added with antibiotic) and controls (basal diet). Results showed that the number of red blood cells (RBC) .blood total protein,albumin and globulin in group Ⅲ and group Ⅳ were significant than that in controls,which indicated that the same effect occurred between diet added with antibacterial peptides from Musca domestica larvae and antibiotic. In addition,serum total lipid content and the number of WBC in the treatment groups was significantly reduced,compared with the control group (P0. 05).

  7. Antibacterial textiles

    NARCIS (Netherlands)

    Bhaskara, Usha Rashmi

    2015-01-01

    The aim of this thesis was the antibacterial functionalization of textiles and its application in professional laundries. The antibacterial functionalization was meant for the various textile packages lent out by the laundry companies to their customers from hotels, hospital or food industries. The

  8. EFFECT OF MUSCA DOMESTICA ANTIBACTERIAL PEPTIDES ON THE PROLIFERATION, INVASION AND MIGRATION OF HEPG2 CELLS%家蝇幼虫抗菌肽对肝癌HepG2细胞增殖、侵袭及迁移的影响∗

    Institute of Scientific and Technical Information of China (English)

    邢佳欣; 刘娟娟; 聂守民; 郭姗; 赵瑞君; 程璟侠

    2016-01-01

    In order to study the antitumor function of the housefly antibacterial peptide in a more comprehensive way, this article studied the antitumor function of housefly antimicrobial peptides on the tumor cell proliferation, invasion and migration. To induce antibacterial peptides, we use the needle to prick housefly then go through a process of low temperature centrifugal, solid phase extraction and freeze⁃drying to obtain antibacterial peptides crude extract, and then adjust antibacterial peptides to different concentrations to inhibit CCK8, cell migration and invasion experiment. The experiment show that housefly antimicrobial peptide can inhibit HepG2 cells proliferation, and the dose⁃response characteristics is closely effected by its concentration. Low concentration of antibacterial peptides (60μg/mL) can also effectively inhibit the migration and invasion of HepG2 cells. In conclusion, the crude extractings of antibacterial peptides from housefly larvae can inhibit the proliferation, invasion and migration of HepG2 cells.%为了更全面的探究家蝇抗菌肽的抗肿瘤作用,本文从肿瘤细胞增殖、侵袭、迁移的角度研究家蝇幼虫抗菌肽对肿瘤细胞的抑制作用。通过针刺诱导家蝇三龄幼虫、低温离心、固相萃取后冻干获取抗菌肽粗提物,将所获抗菌肽调整至不同浓度进行CCK8细胞增殖实验。并通过细胞划痕实验和细胞侵袭实验判断家蝇抗菌肽对肝癌HepG2细胞迁移和侵袭的影响。实验结果显示家蝇抗菌肽能够明显抑制肝癌HepG2细胞的增殖,且作用效果与浓度呈剂量依赖特点。低浓度的抗菌肽(60μg/mL)能有效抑制肝癌HepG2细胞迁移及侵袭。

  9. Cloning, prokaryotic expression and antifungal assay of Tenecin gene encoding an antibacterial peptide from Tenebrio molitor%黄粉虫抗菌肽Tenecin基因的克隆、原核表达及其抑菌活性

    Institute of Scientific and Technical Information of China (English)

    刘影; 姜玉新; 李朝品

    2011-01-01

    Objective To clone tenecin gene, an antibacterial peptide gene, from Tenebrio molitor for its prokaryotic expression and explore the molecular mechanism for regulating the expression of antibacterial peptide in Tenebrio molitor larvae. Methods The antibacterial peptide was induced from the larvae of Tenebrio molitor by intraperitoneal injection of Escherichia coli DH-5α (1×108/ml). RT-PCR was performed 72 h after the injection to clone Tenecin gene followed by sequencing and bioinformatic analysis. The recombinant expression vector pET-28a(+)-Tenetin was constructed and transformed into E. Coli BL21(DE3) cells and the expression of tenecin protein was observed after IPTG induction. Results Tenecin expression was detected in transformed E.coli using SDS-PAGE after 1 mmol/L IPTG induction. Tenecin gene, which was about 255 bp in length, encoded Tenecin protein with a relative molecular mass of 9 kD. Incubation of E.coli with 80, 60, 40, and 20 μg/ml tenecin for 18 h resulted in a diameter of the inhibition zone of 25.1± 0.03, 20.7±0.06, 17.2±0.11 and 9.3±0.04 mm, respectively. Conclusion Tenecin protein possesses strong antibacterial activity against E. Coli DH-5α, which warrants further study of this protein for its potential as an antibacterial agent in clinical application.%目的 为研究黄粉虫体内抗菌肽表达调控的分子机制,克隆黄粉虫抗菌肽Tenecin基因,并研究其原核表达产物的抑菌活性.方法 用大肠杆菌DH-5α菌液(1×108/ml)腹部注射黄粉虫5龄幼虫,72 h后提取其总RNA,RT-PCR克隆Tenecin 基因,测序并进行生物信息学分析;构建原核表达重组载体pET-28a(+)-Tenecin并转入大肠杆菌BL21菌株,用IPTG诱导观察其表达情况;将4种不同浓度的原核表达产物Tenecin蛋白作用于大肠杆菌DH-5α,测量抑菌圈直径大小,观察其抑菌作用.结果 电泳及测序结果显示:Tenecin基因的大小为255 bp左右;用1 mmol/L IPTG诱导后,经SDS-PAGE电泳检测在9

  10. 家蝇幼虫分泌型抗菌肽对大肠埃希菌抑制作用%Anti-Escherichica coli effect of antibacterial peptides from Musca domestica larvae secretion

    Institute of Scientific and Technical Information of China (English)

    国果; 吴建伟; 付萍

    2012-01-01

    目的 探讨家蝇幼虫分泌型抗菌肽的抗菌机制.方法 利用透射电镜、十二烷基硫酸钠(SDS)-聚丙烯酰胺凝胶电泳(PAGE)及流式细胞仪等技术初步探索了家蝇幼虫分泌型抗菌肽对大肠埃希菌作用机理.结果 经20、40及80 μg/mL抗菌肽作用后,大肠埃希菌液的A570值分别增加了0.170、0.032、-0.030,对照组增加了0.363;菌体外胞内酶含量各组分别增加0.148、0.230、0.324,对照组无变化;电镜观察显示抗菌肽可使菌体皱缩,细胞内容物外泄;SDS-PAGE检测发现,作用后菌体的某些蛋白条带浓度降低或消失,有新的条带出现;流式细胞仪显示抗菌肽作用后处于细胞周期中复制期(R期)的细菌量只占总数的11.89%,而对照组占45.25%,比实验组高33%.结论 家蝇幼虫分泌型抗菌肽可通过改变细菌细胞膜的通透性,抑制细菌某些蛋白的合成等发挥抗菌作用.%Objective To explore anti-Escherichia coli ( E. coli) mechanism of antibacterial peptides from Musca domestica larvae secretion. Methods Electron microscope, sodium dodecyl sulfonate-polyacylate gel electrophoresis (SDS-PAGE) ,and flow cytometry were used to study the anti-E. coli mechanism of antibacterial peptide extracted from housefly (Musca domestica) larvae. Results The bacterial number decreased obviously and the endoenzyme leaked out after the treatment of antibacterial peptide. Transmission electron microscope showed that the bacterial cells shrinked and became smaller and thinner. The cell contents of E. coli leaked out. SDS-PAGE electrophoregram showed that some of the solubility proteins of the bacterium diminished or even vanished and some new protein bands appeared. Cell cycle was affected and the count of bacteria increased in phase I but reduced in phase R( 11. 89% vs 45. 25% ) compared to that of the control. And the E. coli went into declining phase directly instead of normal logarithmic phase. Conclusion The permeability of cellular

  11. 阳离子抗菌肽的杀菌及抗药性机制的研究进展%Research Progress on Cationic Antimicrobial Peptides in Antibacterial and Drug-resistant Mechanism

    Institute of Scientific and Technical Information of China (English)

    洪军; 胡建业

    2012-01-01

    阳离子抗菌肽是生物体抵御外源性病原微生物入侵而产生的一类小分子多肽,广泛分布于生物体内,具有广谱抗菌活性,是生物体先天性免疫防御系统的重要组成部分.除了具有抗细菌功能外,还具有抗真菌、抗原虫、抗病毒及抑制肿瘤细胞等功能,并对正常的真核细胞毒性较低,是新一代抗生素的理想替代品,但是同抗生素一样,部分细菌也能对抗菌肽产生抗药性.作者将从阳离子抗菌肽的杀菌及抗药性机制等方面进行阐述.%Cationic antimicrobial peptides were a class of small peptides with anti-extrogenous pathogen invasion. As an important component of congenital immune defense system against infections, they were widely distributed in vivo. It exhibited potent and broad-spectrum activities against both Gram-positive and Gram-negative bacteria, fungi, viruses, protozoa, and cancer cells,and normal eukaryotic cells with low toxicity. It was an ideal alternative to a new generation of antibiotics. However, the same as antibiotics, some bacteria were resistant to certain antimicrobial peptides. The antibacterial and drug-resistant mechanism of the cationic antimicrobial peptides were summarized in the article to provide certain reference.

  12. pH和色谱柱对日本鳗鲡肝脏抗菌肽分离纯化效果的影响及抗菌活性检测%Effects of pH and chromatographic column on isolation,purification of antibacterial peptide from Japanese eel liver,and determination of antibacterial activity

    Institute of Scientific and Technical Information of China (English)

    张东玲; 关瑞章; 黄文树; 熊静; 徐继松; 宋宝东

    2013-01-01

    In order to quickly isolate and purify antimicrobial peptide, different flow phase pH values (cation change pH 3. 0,4. 0,5. 0, and reverse-phase liquid chromatography pH 2. 0,4. 5,7. 0), and different chromatographic columns ( cation-change and gel chromatography coupled with reverse-phase liquid chromatography respectively) were used to isolate and purify antibacterial peptide from Anguilla japonica liver,and the results were analysed and compared. The merits and drawbacks of agar plate diffusion and microporous liquid culture methods on determination of antibacterial activity were analysed. The results showed that pH 4.0 buffer solution was the best flow phase in three-pH-value buffer solutions, which had 16.43% extraction ratio and isolated two elution peaks;We did not obtain perfect result from reverse-phase liquid chromatography ( RPC ) in three-pH-value buffer solutions;Sephadex G-25 gel coupled with RPC significantly improved the isolation effect, elution peak amounts were greater, peaks were sharper and narrower,baseline was flatter and low than those of cation exchange coupled with RPC. Agar plate diffuse method to determine antibacterial activity was simple to operate, and experimental result was intuitional. It required much protein,so it should be used to determine antibacterial activity during protein crude extraction period;Microporous liquid culture method to determine antibacterial activity was sensitive. It required little protein, so it should be used to determine antibacterial activity during isolation and purification of protein in chromatography period.%为了能够快捷地分离纯化出单一的抗菌肽,实验采用不同pH值(离子交换流动相pH3.0、4.0、5.0;反相液相层析流动相pH 2.0、4.5、7.0)缓冲液,不同色谱柱(离子交换和凝胶过滤层析柱分别与反相液相层析柱)联用对日本鳗鲡肝脏抗菌肽分离纯化效果进行了比较,并分析了琼脂板扩散法和微孔液体培

  13. Peptides: A new class of anticancer drugs

    Directory of Open Access Journals (Sweden)

    Ryszard Smolarczyk

    2009-07-01

    Full Text Available Peptides are a novel class of anticancer agents embracing two distinct categories: natural antibacterial peptides, which are preferentially bound by cancer cells, and chemically synthesized peptides, which bind specifically to precise molecular targets located on the surface of tumor cells. Antibacterial peptides bind to both cell and mitochondrial membranes. Some of these peptides attach to the cell membrane, resulting in its disorganization. Other antibacterial peptides penetrate cancer cells without causing cell membrane damage, but they disrupt mitochondrial membranes. Thanks to phage and aptamer libraries, it has become possible to obtain synthetic peptides blocking or activating some target proteins found in cancer cells as well as in cells forming the tumor environment. These synthetic peptides can feature anti-angiogenic properties, block enzymes indispensable for sustained tumor growth, and reduce tumor ability to metastasize. In this review the properties of peptides belonging to both categories are discussed and attempts of their application for therapeutic purposes are outlined.

  14. Effects of Single Amino Acid Substitution on the Biophysical Properties and Biological Activities of an Amphipathic α-Helical Antibacterial Peptide Against Gram-Negative Bacteria

    Directory of Open Access Journals (Sweden)

    Juanjuan Tan

    2014-07-01

    Full Text Available An antimicrobial peptide, known as V13K, was utilized as the framework to study the effects of charge, hydrophobicity and helicity on the biophysical properties and biological activities of α-helical peptides. Six amino acids (Lys, Glu, Gly, Ser, Ala, and Leu were individually used to substitute the original hydrophobic valine at the selected sixteenth location on the non-polar face of V13K. The results showed that the single amino acid substitutions changed the hydrophobicity of peptide analogs as monitored by RP-HPLC, but did not cause significant changes on peptide secondary structures both in a benign buffer and in a hydrophobic environment. The biological activities of the analogs exhibited a hydrophobicity-dependent behavior. The mechanism of peptide interaction with the outer membrane and cytoplasmic membrane of Gram-negative bacteria was investigated. We demonstrated that this single amino acid substitution method has valuable potential for the rational design of antimicrobial peptides with enhanced activities.

  15. Separation, Purification and Biological Activity Detection of Antibacterial Peptide Produced by Streptococcus lactis%乳酸链球菌抗菌肽的分离纯化及生物活性检测

    Institute of Scientific and Technical Information of China (English)

    盛博文; 杨海君; 关向杰

    2012-01-01

    This study aimed to separate and purify the Streptococcus lactis -antimicrobial peptides which had wide antimicrobial properties by gel filtration chromatography and HPLC. Staphyiococcus aureus (ATCC25923), Escherkkia coli (ATCC25922), Pseudomonas aeruginosa, Bacillus subtilh, Yersinia and Enterococcw fat calls were used to research the bactericidal mechanism and antibacterial spectrum of the Streptococcus lactis -antimicrobial peptide . The results showed that a species of Streptococcus /aeas-antimicrobial peptides which had killing effects on all bacterial cells except Pseudomonas aerugiiwsa was obtained by separation and purification. The microporous structure of Staphyiococcus aureus (ATCC25923) was observed by transmission electron microscopy when Ihe Streptococcus lactis -antimicrobial peptide was added. The transmission electron microscopy results showed that the Streptococcus lactis -antimicrobial peptide caused the Staphyiococcus aureus (ATCC25923) cells broken, swelling and leakage .accompanied cytoplasmic diluted, cell membrane boundaries blurred or even completely dissolved, and made them apoptosis ultimately.%通过凝胶过滤层析及制备型高效液相色谱法,从乳酸链球菌发酵液中筛选分离出了具有广谱抗菌活性的物质,利用金黄色葡萄球菌( ATCC25923)、大肠杆菌(ATCC25922)、绿脓杆菌、枯草芽孢杆菌、耶尔森菌.粪肠球菌对该活性物质的抗菌谱及杀菌机理进行了研究.结果表明:经过分离纯化,得到的较纯的活性物质为乳酸链球抗菌肽,该物质除了对绿脓杆菌没有杀伤作用, 对其他5种细菌均具有杀伤作用.透射电镜观察结果显示,金黄色葡萄球菌(ATCC25923)经抗菌肽处理后,细胞出现破损或肿胀,有部分细胞内容物外泄,并伴有细胞质稀释的现象,细胞膜界限模糊不清,细胞膜甚至完全溶解.由于细胞内容物外渗,最终导致菌体死亡.

  16. 家蝇抗菌物质诱导表达后的电泳分析%Induction of antibacterial peptide from Musca domestica and preliminary isolation by polyacrylamide gel electrophoresis

    Institute of Scientific and Technical Information of China (English)

    许兵红; 曾莉萍; 董卫华

    2011-01-01

    目的 探讨家蝇抗菌肽的诱导及电泳分离方法.方法 家蝇三龄幼虫针刺体壁诱导后,第48h提取其血淋巴,置于100℃、80℃水浴10s、30s、lmin、3min、5min等不同时间后,观察不同温度处理不同时间后的去杂蛋白效果和对溶壁微球菌的抑菌效果,并对各样品进行电泳分离.结果 血淋巴100℃水浴10s、30s、1min仍有抑菌活性,处理3min和5min无抑菌活性;80℃水浴30s-5min均有抑菌活性,电泳显示100℃处理3min和5min的样品与其他相比缺少2条蛋白区带.结论 针刺诱导的家蝇抗菌肽分离时血淋巴预处理采用80℃水浴lmin去杂蛋白效果较好,诱导的血淋巴100℃处理3min和5min即丧失抗菌活性,电泳显示缺少2条区带,此2条差异区带可能为抗菌肽组份.%The objective of this study was to induce and preliminarily isolate antibacterial peptide from Musca domestica by mean of polyacrylamide gel electrophoresis. After being induced by pricking for 48 hours, the hemolymph was collected and tested against Micrococcus lysodeikticus, and then the bacteriostatic effects were observed and the diameters of clear inhibitory ring were recorded respectively. After being bathed at 100℃ and 80℃ for 10sec, 30sec, lmin, 3min and 5min, each hemolymph was centrifuged at 10000r/min for 10min to get rid of unwanted proteins, and the supernatant was tested against M. lysodeikticus and displayed by polyacrylamide gel electrophoresis. The hemolymph didn't possess antibacterial activity against M. lysodeikticus after being bathed at 100℃ for 3min and 5min, but possessed antibacterial activity in others. It was also found that the two samples which were bathed at 100℃ for 3min and 5min were lack of two special bands from the others. It implies that bathing at 80℃ for 1min and then centrifuging could get rid of unwanted proteins in a large extent, which indicated that the two special bands are the components of the antibacterial peptides induced

  17. 纯化蛆虫分泌物抗菌肽对糖尿病大鼠溃疡创面的抗菌作用%Antibacterial effect of purified maggot secretion antimicrobial peptides on ulcer wound of diabetic rats

    Institute of Scientific and Technical Information of China (English)

    高磊; 尹叶锋; 王寿宇; 王江宁

    2012-01-01

    背景:蛆虫的分泌物对感染创面具有良好的抗菌作用,经课题组研究证实分泌物中有抑制细菌和杀灭细菌的成分抗菌肽,并对该抗菌肽进行了有效纯化.目的:观察纯化蛆虫分泌物抗菌肽对糖尿病大鼠溃疡创面的抗菌和促愈合作用.方法:取3.5月龄雄性SD大鼠20只,体质量330~370 g,制备糖尿病大鼠溃疡创面模型.随机均分为2组,实验组创面涂以纯化的蛆虫分泌物抗菌肽,对照组不予处理.结果与结论:实验组创面清洁,新鲜肉芽生长,无脓性分泌物,愈合情况良好,无金色葡萄球菌感染;对照组创面渗出、糜烂严重,创面不断加大加深,愈合情况不良,金色葡萄球菌感染率为70%.术后7,14,21,28 d,实验组溃疡面积明显小于对照组,差异均有显著性意义(P < 0.05).结果表明纯化的蛆虫分泌物抗菌肽有效促进糖尿病大鼠溃疡创面愈合,预防组织细菌感染.%BACKGROUND: Maggot secretions have a good antibacterial effect on infected wounds. The studies have confirmed that there are antimicrobial peptides that can inhibit and kill the bacteria in the maggot secretions, and we have carried out effective purification of the peptide.OBJECTIVE: To investigate the antibacterial effect and wound healing of purified maggot secretion antimicrobial peptides on ulcer wound of diabetic rats.METHODS: Twenty 3.5-month-old male SD rats weighing 330-370 g was used to prepare diabetic ulcer wound model. The rats were randomly divided into two groups (n=10). In the experimental group, the wounds were coated with purified maggot secretion antimicrobial peptide; the control group was not treated.RESULTS AND CONCLUSION: In the experimental group, the wounds were clean and healed well with fresh granulation, no purulent secretions and no staphylococcus aureus infections. In the control group, wound exudates were found with severe erosion, and the wound was enlarged and deepened that healed poor. The staphylococcus

  18. Antibacterial Activity and Stability Study of Antimicrobial Peptides [L6, K11]-IsCT%抗菌肽[L6,K11]-IsCT抑菌性能及其稳定性研究

    Institute of Scientific and Technical Information of China (English)

    郑文官; 张捷; 杨刚齐; 杨敏; 潘韵; 李永新

    2013-01-01

    IsCT was a non-cell-selective antimicrobial peptide isolated from the scorpion. In order to be used in animal feed, it was necessary to study the effects on inhibiting and killing common pathogenic bacteria. Agar gel diffusion and dilution methods were used in this experiment to study the antibacterial activities and stabilities of [L6 ,K11]-IsCT which was the derivative of IsCT. The results indicated that [L6 , K11]-IsCT had better antibacterial activities to Escherichia coli than Staphylococcus aureus. The minimal inhibitory concentration (MIC) of Escherichia coli was 50 μg/mL. When treated with 121 ℃0. 12 MPa for 30 minutes or 0≤pH≤11.0 for 30 minutes and incubated in artificial gastric juice for 2 h,[L6 ,K11]-IsCT remained excellent antibacterial activities. Therefore, [L6 ,K11]-IsCT presented excellent heat stablility and could resist to extreme pH environment as well as artificial gastric juice.%IsCT最初是从蝎子中分离出的一种非细胞选择性线性抗菌肽,为了将其应用于动物饲料,需研究其对常见致病菌的即制和杀灭作用.本试验采用微量稀释法和琼脂扩散法对ISCT衍生物[L6,K11]-IsCT的抗菌活性及其稳定性进行探索.结果显示,相对于金黄色葡萄球菌,[L6,K11]-IsCT对大肠杆菌具有更好的抑制作用,其对大肠杆菌的最小抑菌浓度为50 μg/mL.另外,该衍生物对高温表现出很好的稳定性,同时具有很好的酸碱耐受性和人工胃液耐受性.经121℃、0.12 MPa处理30 min,以及2.0≤pH≤11.0处理30 min或人工胃液2h孵育处理后,依然能保持很好的抑菌活性.

  19. Study on Induced Antibacterial Peptide in Stressed Earthworms as A Biochemistry Biomarker in Environmental Risk Assessment%应激蚯蚓诱导抗菌肽作为环境风险评价生化标记的研究

    Institute of Scientific and Technical Information of China (English)

    孙振钧

    2001-01-01

    Antibacterial peptides exist in earthworms with low concentrations in normal environments. In order to test the quantitative and active variation of peptides with environmental situation surrounding earthworms, a set of antibacterial peptide assay were used on 3 stressed earthworm ways to verify the possibility of induced antibacterial peptides (IAP) as a novel candidate biomarker used for risk assessment in earthworm ecotoxicolo gy. Stress - peptides characterized with strong bacteriostatic activities, high heat stability and less than 10Kd molecular weight was separated from the extract of coelomic fluid by methods of heat treatment, ultrafilter and molecular sieve. The physicochemical and antibacterial properties of antibacterial peptides were verified by us ing the methods of plate growth inhibition assay, bactericidal assay and belt growth inhibition assay with poly acrylamide gel electrophoresis. The result showed that peptide A3-4-2, a Gly rich acid tetradecapeptide, seems to be a suitable candidate biomarker. It has wide antibacterial chart and bacteriostatic activities and a high level of concentration response to stresses. However, there are differences among various bacterial strains in antibacterial efficiency. Three stresses, including biological treatment (bacteria injection), physical treatments (γ- ray and me chanical injury) and chemical treatments (heavy metal and pesticide pollution) were used to test the sensitivity of induced earthworm antibacterial peptides. The result showed that antibacterial peptides can be induced by almost all inducing treatments used, but there were differences in sensitivity to various stress treatments. The higher sensitivities are alive E coli injection, mechanical injury and heavy metal treatment. In the limited scope that earthworm can tolerate, the stronger the stress to worms, the higher the antibacterial activities of the peptide. It seems that certain target antibacterial substances can be induced by given

  20. Solid Phase Synthesis and Anti-microbial Activities of the Antibacterial Peptide IB-367%抗菌肽IB-367的固相合成与抑菌活性

    Institute of Scientific and Technical Information of China (English)

    王小青; 高杨; 尹志峰; 宫闻婧; 赵红玲; 王良友

    2016-01-01

    采用固相合成方法,以Rink Amide树脂为载体,Fmoc保护氨基酸为原料,经苯并三唑-1-四甲基六氟磷酸酯( HBTU)/N,N-二异丙基乙胺( DIEA)缩合,三氟乙酸/苯甲硫醚/乙二硫醇/苯甲醚裂解体系脱除保护基制得IB-367线性肽(4);4经双氧水氧化制得IB-367一环肽(5);5经碘乙醇溶液氧化合成抗菌肽IB-367(6),收率34.1%,纯度>95.0%,其结构经MS(ESI)和氨基酸组成分析确证。抑菌活性研究结果表明:6对大肠杆菌和金黄色葡萄球菌的最小抑菌浓度为5.0μg· mL-1。%The linear peptides of IB-367(4) was synthesized according to its peptide sequence by con-densation with O-( benzotriazol-yl )-N, N, N′, N′-tetramethy-luronium ( HBTU )/N-Ethyldiisopropyl-amine( DIEA) and deprotection with trifluoroacetic acid/thioanisole/1,2-ethanedithiol/anisole, using rink amide resin as the solid supporter , and Fmoc-amino acids as raw materials .The cyclic peptide of IB-367(5) was formed by oxidation of 4 with H2O2.The antibacterial peptide IB-367(6) with yield of 34.1%and purity>95.0% was obtained by oxidation of 5 with I2 .The structure was confirmed by MS(ESI) and amino acid composition analysis .MIC of 6 on Escherichia coli and Staphylococcus aureus was 5.0 μg· mL-1 .

  1. Antibacterial surface design - Contact kill

    Science.gov (United States)

    Kaur, Rajbir; Liu, Song

    2016-08-01

    Designing antibacterial surfaces has become extremely important to minimize Healthcare Associated Infections which are a major cause of mortality worldwide. A previous biocide-releasing approach is based on leaching of encapsulated biocides such as silver and triclosan which exerts negative impacts on the environment and potentially contributes to the development of bacterial resistance. This drawback of leachable compounds led to the shift of interest towards a more sustainable and environmentally friendly approach: contact-killing surfaces. Biocides that can be bound onto surfaces to give the substrates contact-active antibacterial activity include quaternary ammonium compounds (QACs), quaternary phosphoniums (QPs), carbon nanotubes, antibacterial peptides, and N-chloramines. Among the above, QACs and N-chloramines are the most researched contact-active biocides. We review the engineering of contact-active surfaces using QACs or N-chloramines, the modes of actions as well as the test methods. The charge-density threshold of cationic surfaces for desired antibacterial efficacy and attempts to combine various biocides for the generation of new contact-active surfaces are discussed in detail. Surface positive charge density is identified as a key parameter to define antibacterial efficacy. We expect that this research field will continue to attract more research interest in view of the potential impact of self-disinfective surfaces on healthcare-associated infections, food safety and corrosion/fouling resistance required on industrial surfaces such as oil pipes and ship hulls.

  2. 地衣芽孢杆菌抗菌肽的纯化及抗菌特性分析%Purification of Antimicrobial Peptide from Bacillus licheniformis LY12 and Analysis of Its Antibacterial Properties

    Institute of Scientific and Technical Information of China (English)

    樊陈; 高兆建; 张桂英; 鞠民友; 孙会刚; 杜永凯; 王东星

    2013-01-01

    以研究地衣芽孢杆菌(Bacilluslicheniformis)LY12所产抗菌肽特性,从发酵液中分离纯化该抗菌肽。通过超滤、离子交换层析、分子筛凝胶过滤层析、反向高效液相色谱等方法纯化该抗菌肽。结果显示:LC-ESI-MS质谱测得抗菌肽分子量为2750.785 Da,同Tricine SDS-PAGE分析结果基本一致。体外抗菌试验结果显示,抗菌肽LYF12能够抑制丝状真菌、细菌的生长。对枯草芽孢杆菌(Bacillussubtilis)、大肠杆菌(Escherichia coli)、铜绿假单胞菌(Pseudomonas aeruginosa)、金黄色葡萄球菌(Staphylococcus aureus)、藤黄微球菌(Micrococcus aureus)、蜡状芽孢杆菌(Bacillus cereus)、副溶血性弧菌(Vibrio parachaemolyticus)的最低抑菌浓度分别为9.8、19.8、20.7、7.2、9.6、10.2、15.7μg/mL。从地衣芽孢杆菌LY12分离的抗菌肽显示出对革兰氏阴性细菌、革兰氏阳性细菌及真菌具有较好的抗菌效果,故在食品防腐中具有潜在的应用价值。%To explore the characterization of a novel antimicrobial peptide from from Bacillus licheniformis LY12, the antimicrobial peptide was isolated. The novel antimicrobial peptide designated LYF12, was purified, with a procedure involving ultrafiltration, ion exchange chromatography (DEAE-Sepharose FF), gel filtration (Sephadex G-15), and reverse phase HPLCs on C8 column and C18 column. LC-ESI-MS indicated the molecular mass of the purified peptide was 2750.785 Da, which was in good agreement with the result of Tricine SDS-PAGE. .In vitro bioassays showed that LYF12 inhibits the growth of a variety of microbes, including filamentous fungi and bacteria. The minimum inhibitory concentrations (MIC) against Bacillus subtilis, Escherichiacoli, Pseudomonasaeruginosa, Staphylococcusaureus, Micrococcusaureus, Bacillus cereus, Vibrio parachaemolyticus were 9.8, 19.8, 20.7, 7.2, 9.6, 10.2, 15.7 μg/mL, respectively. Because the purified antimicrobial peptide exhibited antibacterial

  3. Scorpion Peptides Antibacterial Gel for Treating Deep Second Degree Burn in 43 Cases%蝎肽抗菌凝胶治疗深Ⅱ度烧伤43例疗效观察

    Institute of Scientific and Technical Information of China (English)

    封郭生; 吴之坤; 余墨声; 吴小蔚

    2015-01-01

    目的:观察蝎肽抗菌凝胶治疗深Ⅱ度烧伤的疗效并评价其安全性。方法将86例深Ⅱ度烧伤患者按随机数字表法均分为对照组和观察组。常规清创、削痂、抗感染等处理后,对照组采用磺胺嘧啶银乳膏局部覆盖,观察组使用蝎肽抗菌凝胶,疗程至创面愈合。结果观察组创面愈合效率及完整愈合时间明显优于对照组( P﹤0.05)。治疗前两组创面细菌感染率间差异不明显( P﹥0.05),治疗后第3天及第7天,对照组创面细菌感染率显著高于观察组( P﹤0.05)。治疗过程中,对照组疼痛视觉模拟评分( VAS )显著高于观察组( P﹤0.05)。对照组总不良反应发生率为30.23%,明显高于观察组的11.63%( P﹤0.05)。结论蝎肽抗菌凝胶治疗深Ⅱ度烧伤疗效显著,且用药相对安全,值得临床推广。%Objective To observe the curative effect and safety evaluation of scorpion peptides antibacterial gel in treating deep second degree burn patients. Methods 86 cases of deep second degree burn were randomly divided into two groups. The control group was treated by sulfadiazine silver gel and the observation group was treated by scorpion peptides antibacterial gel. The wound healing effi-ciency, complete healing time of wounds, and the results of bacterial culture of the two groups were observed, and the VAS score were observed while dressing wounds. Results The wound healing efficiency and complete healing time of the observation group were signifi-cantly better than those of the control group ( P ﹤ 0. 05 ) . Before treatment, the difference of wound infection rate between the two groups was not significant( P ﹥ 0. 05), but on the 3rd day and 7th day after treatment, the wound infection rate of the control group was sig-nificantly higher than that in the observation group, the difference was statistically significant ( P ﹤ 0. 05 ) . The VAS score during the treatment in the control

  4. 两种合成抗菌肽的结构及抗菌作用机理%Solution structure and antibacterial mechanism of two synthetic antimicrobial peptides

    Institute of Scientific and Technical Information of China (English)

    杨林; 范美华; 刘雪珠; 武梅; 石戈; 廖智

    2011-01-01

    Mytilin-derived-peptide-1 (MDP-1) and mytilin-derived-peptide-2 (MDP-2) are two truncated decapeptides with reversed sequence synthesized corresponding to the residues 20-29 of mytilin-1 (GenBank Accession No. FJ973154) from M. Coruscus. The objective of this study is to characterize the structural basis of these two peptides for their antimicrobial activities and functional differences, and to investigate the inhibitory mechanism of MDPs on Escherichia coli and Sarcina lutea. The structures of MDP-1 and MDP-2 in solution were determined by 'H 2D NMR methods; the antibactericidal effects of MDPs on E. Coli and S. Lutea were observed by transmitted electron microscopy (TEM). Both MDP-1 and MDP-2 have a well-defined loop structure stabilized by two additional disulfide bridges, which resemble the-hairpin structure of mytilin-1 model. The surface profile of MDPs' structureswas characterized by protruding charged residues surrounded by hydrophobic residues. TEM analysis showed that MDPs destroyed cytoplasmic membrane and cell wall of bacteria and the interface between the cell wall and membrane was blurred. Furthermore, some holes were observed in treated bacteria, which resulted in cell death. Structural comparison between MDP-1 and MDP-2 shows that the distribution of positively charged amino acids on the loop of MDPs is topologically different significantly, which might be the reason why MDP-2 has higher activity than MDP-1. Furthermore, TEM results suggested that the bactericidal mechanisms of MDPs against E. Coli and S. Lutea were similar. Both MDP-1 and MDP-2 could attach to the negatively charged bacterial wall by positively charged amino acid residues and destroy the bacteria membrane in a pore-forming manner, thus cause the contents of the cells to release and eventually cell death.%为深入了解两种新型人工抗菌肽mytilin-derived-peptide-1 (MDP-1)和mytilin-derived-peptide-2 (MDP-2)的溶液结构和抗菌机理并探讨两种抗菌肽之间活性

  5. Effect of size and N-terminal residue characteristics on bacterial cell penetration and antibacterial activity of the proline-rich peptide Bac7.

    Science.gov (United States)

    Guida, Filomena; Benincasa, Monica; Zahariev, Sotir; Scocchi, Marco; Berti, Federico; Gennaro, Renato; Tossi, Alessandro

    2015-02-12

    Bac7 is a proline-rich antimicrobial peptide, selective for Gram-negative bacteria, which acts intracellularly after membrane translocation. Progressively shortened fragments of Bac7 allowed determining the minimal sequence required for entry and antimicrobial activity as a 16-residue, N-terminal fragment, while further shortening led to a marked decrease in both functions. Furthermore, two N-terminal arginine residues were required for efficient translocation and activity. Analogues in which these residues were omitted, or where the side chain steric or physicochemical characteristics were systematically altered, were tested on different Escherichia coli strains, including a mutant with a destabilized outer membrane and one lacking the relevant SbmA membrane transport protein. H-bonding capacity, stereochemistry, and charge, in that order, played a determining role for efficient transit through both the outer and cytoplasmic membranes. Our studies allowed building a more detailed model for the mode-of-action of Bac7, and confirming its potential as an anti-infective agent, also suggesting it may be a vehicle for internalization of other antibiotic cargo.

  6. Helicobacter pylori effect of antibacterial peptides from Musca domestica larvae%家蝇幼虫抗菌肽对幽门螺杆菌抗菌作用分析

    Institute of Scientific and Technical Information of China (English)

    黄健; 莫非

    2013-01-01

    目的 探讨家蝇抗菌肽(antibacterial peptides)对幽门螺杆菌(Helicobacter pylori,H.pylori)的抗菌机制.方法 通过绘制抑菌曲线、十二烷基硫酸钠聚丙烯酰胺凝胶电泳(sodium dodecyl sulfate polyacrylamide gel electrophoresis,SDS-PAGE)及双向电泳(two dimensional electrophoresis,2-DE)方法和技术,初步探讨家蝇对幽门螺杆菌作用机理.结果 浓度为40 μg/mL家蝇幼虫抗菌肽使H.pylori不能达到正常的生长高峰进入对数期,而1d后直接进入衰亡期;通过SDS-PAGE检测发现实验组在分子量约66.4 kDa的蛋白条带浓度较对照组降低,而在分子量约40 kDa的蛋白条带浓度较对照组增高.双向电泳结果显示家蝇幼虫抗菌肽干扰了H.pylori的抗氧化系统,影响了H.pylori能量代谢和应激作用功能蛋白的表达.结论 家蝇幼虫抗菌肽对H.pylori具有明显的抑制作用,是通过抑制其生长、干扰其抗氧化系统,以及影响其能量代谢等方面,发挥家蝇幼虫抗菌肽的抑菌机制.

  7. 蛇毒抗菌肽OH-CATH在血浆环境中对大肠杆菌的抗菌作用%The Antibacterial Effects of Snake Venom Antimicrobial Peptide OH-CATH on E.coli in the Presence of Plasma

    Institute of Scientific and Technical Information of China (English)

    高振华; 李思熳; 申吉泓

    2012-01-01

    目的 研究蛇毒抗菌肽OH-CATH在血浆环境中是否会失去抑菌活性.方法 向含血浆LB(B组)和不含血浆LB (A组)中加入不同剂量的蛇毒抗菌肽OH-CATH,使抗菌肽的终浓度为0μg/mL、1 μg/mL、2μg/mL、4μg/mL、8μg/mL、16μg/mL和32μg/mL,再加入普通大肠埃希菌(E.coli ATCC 25922)培养后分别测定两组的O.D值.结果 A和B组O.D值对应点间比较无显著性差异(P>0.05),蛇毒抗菌肽OH-CATH的最小抑菌浓度(MIC)在4~8 g/mL之间.结论 蛇毒抗菌肽OH-CATH在血浆环境中不会迅速降解而失活并且对大肠杆菌具有良好的抗菌效果.%Objective To research whether venom antimicrobial peptide OH-CATH will lose anti-bacterial activity in plasma environment. Method We added different doses of snake venom antimicrobial peptide OH-CATH in LB with (Group B) and without plasma (Group A) to get final concentration of antimicrobial peptides including 0 μg/mL, 1 μg/mL, 2 μg/mL, 4 μg/mL, 8 μLg/mL, 16 μg/mL and 32 μg/mL, and added E.coli ATCC25922 in each EP which were then cultured, and the OD values were detected. Results There was no significant differences in OD value of the corresponding point between group A and B (P>0.05 ). The MIC of snake venom OH-CATH antimicrobial peptides was at the range of 4 ~ 8 μg/m L. Conclusion Venom antibacterial peptide OH-CATH will not be rapidly degraded in the plasma environment and be inactivated, and has good antibacterial effect on Ecoli.

  8. Computer-Aided Design of Antimicrobial Peptides

    DEFF Research Database (Denmark)

    Fjell, Christopher D.; Hancock, Robert E.W.; Jenssen, Håvard

    2010-01-01

    chemical parameters with biological activities of the peptide, using statistical methods. In this review we will discuss two different in silico strategies of computer-aided antibacterial peptide design, a linear correlation model build as an extension of traditional principal component analysis (PCA......) and a non-linear artificial neural network model. Studies on structurally diverse peptides, have concluded that the PCA derived model are able to guide the antibacterial peptide design in a meaningful way, however requiring rather a high homology between the peptides in the test-set and the in silico...... library, to ensure a successful prediction. In contrast, the neural network model, though significantly less explored in relation to antimicrobial peptide design, has proven extremely promising, demonstrating impressive prediction success and ranking of random peptide libraries correlating well...

  9. APD: the Antimicrobial Peptide Database.

    Science.gov (United States)

    Wang, Zhe; Wang, Guangshun

    2004-01-01

    An antimicrobial peptide database (APD) has been established based on an extensive literature search. It contains detailed information for 525 peptides (498 antibacterial, 155 antifungal, 28 antiviral and 18 antitumor). APD provides interactive interfaces for peptide query, prediction and design. It also provides statistical data for a select group of or all the peptides in the database. Peptide information can be searched using keywords such as peptide name, ID, length, net charge, hydrophobic percentage, key residue, unique sequence motif, structure and activity. APD is a useful tool for studying the structure-function relationship of antimicrobial peptides. The database can be accessed via a web-based browser at the URL: http://aps.unmc.edu/AP/main.html.

  10. [Application on food preservative of antimicrobial peptides].

    Science.gov (United States)

    Zhao, Hongyan; Mu, Yu; Zhao, Baohua

    2009-07-01

    Antimicrobial peptides are an integral component of the innate immune system, it can counteract outer membrane pathogen such as bacteria, fungi, viruses, protozoan and so on. Owing to the sterilization and innocuity, it has the potential to be crude food preservative. In this paper the uses of antibacterial peptides in the food preservative were analyzed.

  11. 磷酸盐缓冲液的浓度和pH对革胡子鲶肠道抗菌蛋白/肽分级盐析的影响%Effect of Concentration and pH Value of Phosphate Buffer on Gradient Ammonium Sulphate Fractionation of Antibacterial Protein/peptide from Intestine of African Catfish ( Clarias gariepinus)

    Institute of Scientific and Technical Information of China (English)

    王存; 王晓梅; 季延滨; 徐敏; 戴伟; 潘宝平

    2011-01-01

    [目的]探讨磷酸盐缓冲液的pH和浓度在分级盐析时,对革胡子鲶肠道各组分蛋白/肽的影响.[方法]以不同浓度和pH的磷酸盐缓冲液作为组织匀浆缓冲液,在硫酸铵饱和度为20% 、40%、60%、80%和100%的条件下,对革胡子鲶肠道抗菌蛋白/肽进行分级盐析,并对盐析产物进行称重、电泳检测和抑菌活性分析.[结果]磷酸盐缓冲液的pH为6.0或7.4时,其浓度对盐析产物产量、蛋白沉淀和抑菌效果无显著影响.而pH为8.0、浓度为0.05 mol/L时,硫酸铵饱和度为60%和100%的粗蛋白/肽的产量显著高于浓度为0.02 mol/L的磷酸盐缓冲液粗蛋白含量;大分子蛋白能更好地在硫酸铵饱和度为20%和40%时沉淀下来,而在饱和度为60%、80%和100%能获得分子量相对较小的抗菌蛋白/肽.磷酸盐缓冲液的pH和浓度对抑菌效果无显著影响.[结论]pH 8.0,浓度为0.05 mol/L的磷酸盐缓冲液更适于革胡子鲶肠道抗菌蛋白/肽的提取.%[Objective] The effects of the concentration and pH value of phosphate buffer on the proteins/peptides in each fraction of African catfish in testine were studied. [ Method] The antibacterial proteins/peptides from intestine of African catfish were fractionation by a graded ammonium sulfale (AS) precipitation technique and the fractions were oblained at 20%,40%,60%,80% and 100% saturation with ammo nium sulfale. Each fraction was weight and detected by SDS-PAGE and its antibacterial activity was analyzed. [Result] The concentration of phosphate buffer al pH 6.0 and 7.4 didn't show significant effect on these indexes. At the pH 8.0, concentration of phosphate buffer also didn't show significant effect on antibacterial activity of each fraction. However, the yields of the crude extracts oblained at 60% and 100 % saturated AS were higher in phosphate buffer concentration of 0.05 mol/L than that in 0.02 mol/L phosphate buffer. And the relatively high molecular

  12. Actinopyga lecanora Hydrolysates as Natural Antibacterial Agents

    Directory of Open Access Journals (Sweden)

    Raheleh Ghanbari

    2012-12-01

    Full Text Available Actinopyga lecanora, a type of sea cucumber commonly known as stone fish with relatively high protein content, was explored as raw material for bioactive peptides production. Six proteolytic enzymes, namely alcalase, papain, pepsin, trypsin, bromelain and flavourzyme were used to hydrolyze A. lecanora at different times and their respective degrees of hydrolysis (DH were calculated. Subsequently, antibacterial activity of the A. lecanora hydrolysates, against some common pathogenic Gram positive bacteria (Bacillus subtilis and Staphylococcus aureus and Gram negative bacteria (Escherichia coli, Pseudomonas aeruginosa, and Pseudomonas sp. were evaluated. Papain hydrolysis showed the highest DH value (89.44%, followed by alcalase hydrolysis (83.35%. Bromelain hydrolysate after one and seven hours of hydrolysis exhibited the highest antibacterial activities against Pseudomonas sp., P. aeruginosa and E. coli at 51.85%, 30.07% and 30.45%, respectively compared to the other hydrolysates. Protein hydrolysate generated by papain after 8 h hydrolysis showed maximum antibacterial activity against S. aureus at 20.19%. The potent hydrolysates were further fractionated using RP-HPLC and antibacterial activity of the collected fractions from each hydrolysate were evaluated, wherein among them only three fractions from the bromelain hydrolysates exhibited inhibitory activities against Pseudomonas sp., P. aeruginosa and E. coli at 24%, 25.5% and 27.1%, respectively and one fraction of papain hydrolysate showed antibacterial activity of 33.1% against S. aureus. The evaluation of the relationship between DH and antibacterial activities of papain and bromelain hydrolysates revealed a meaningful correlation of four and six order functions.

  13. New cationic amphiphilic compounds as potential antibacterial agents

    NARCIS (Netherlands)

    Visser, Peter Christian de

    2006-01-01

    Het onderwerp van het in dit proefschrift beschreven onderzoek is de ontwikkeling van nieuwe verbindingen met antibacteriële activiteit gericht tegen Gram-negatieve bacteriën. Deze verbindingen zijn afgeleid van kationische antimicrobiële peptides (CAPs), een klasse van antibiotica die volgens ander

  14. Controlled delivery of antibacterial proteins from biodegradable matrices

    NARCIS (Netherlands)

    Kuijpers, AJ; Engbers, GHM; van Wachem, PB; Krijgsveld, J; Zaat, SAJ; Feijen, J

    1998-01-01

    Prosthetic valve endocarditis is an infrequent, but serious complication of cardiac valve replacement. The infection is caused by the adherence of bacteria to the prosthetic valve or to tissue at the site of implantation. Recently it was shown that antibacterial peptides from blood platelets are inv

  15. Peptide-membrane interactions of arginine-tryptophan peptides probed using quartz crystal microbalance with dissipation monitoring.

    KAUST Repository

    Rydberg, Hanna A

    2014-04-18

    Membrane-active peptides include peptides that can cross cellular membranes and deliver macromolecular cargo as well as peptides that inhibit bacterial growth. Some of these peptides can act as both transporters and antibacterial agents. It is desirable to combine the knowledge from these two different fields of membrane-active peptides into design of new peptides with tailored actions, as transporters of cargo or as antibacterial substances, targeting specific membranes. We have previously shown that the position of the amino acid tryptophan in the peptide sequence of three arginine-tryptophan peptides affects their uptake and intracellular localization in live mammalian cells, as well as their ability to inhibit bacterial growth. Here, we use quartz crystal microbalance with dissipation monitoring to assess the induced changes caused by binding of the three peptides to supported model membranes composed of POPC, POPC/POPG, POPC/POPG/cholesterol or POPC/lactosyl PE. Our results indicate that the tryptophan position in the peptide sequence affects the way these peptides interact with the different model membranes and that the presence of cholesterol in particular seems to affect the membrane interaction of the peptide with an even distribution of tryptophans in the peptide sequence. These results give mechanistic insight into the function of these peptides and may aid in the design of membrane-active peptides with specified cellular targets and actions.

  16. Peptide-membrane interactions of arginine-tryptophan peptides probed using quartz crystal microbalance with dissipation monitoring.

    Science.gov (United States)

    Rydberg, Hanna A; Kunze, Angelika; Carlsson, Nils; Altgärde, Noomi; Svedhem, Sofia; Nordén, Bengt

    2014-07-01

    Membrane-active peptides include peptides that can cross cellular membranes and deliver macromolecular cargo as well as peptides that inhibit bacterial growth. Some of these peptides can act as both transporters and antibacterial agents. It is desirable to combine the knowledge from these two different fields of membrane-active peptides into design of new peptides with tailored actions, as transporters of cargo or as antibacterial substances, targeting specific membranes. We have previously shown that the position of the amino acid tryptophan in the peptide sequence of three arginine-tryptophan peptides affects their uptake and intracellular localization in live mammalian cells, as well as their ability to inhibit bacterial growth. Here, we use quartz crystal microbalance with dissipation monitoring to assess the induced changes caused by binding of the three peptides to supported model membranes composed of POPC, POPC/POPG, POPC/POPG/cholesterol or POPC/lactosyl PE. Our results indicate that the tryptophan position in the peptide sequence affects the way these peptides interact with the different model membranes and that the presence of cholesterol in particular seems to affect the membrane interaction of the peptide with an even distribution of tryptophans in the peptide sequence. These results give mechanistic insight into the function of these peptides and may aid in the design of membrane-active peptides with specified cellular targets and actions.

  17. 青鱼、草鱼、鲢鱼和鳙鱼组蛋白 H2A N-端基因克隆及其衍生抗菌肽%Cloning and Derived Antibacterial Peptides of Histone H2A Gene in Black Carp Mylopharyngodon piceus,Grass Carp Ctenopharyngodon idellus,Silver Carp Hy pophthalmichthys molitrix and Bighead Carp Aristichthys nobilis

    Institute of Scientific and Technical Information of China (English)

    武向敏; 赵燕静; 孔祥会; 江红霞; 李莉; 聂国兴; 李学军

    2014-01-01

    采用RT-PCR方法,以青鱼、草鱼、鲢鱼和鳙鱼肌肉提取总 RNA 为模板,运用 GenBank中BLAST 同源性搜索,寻找亲缘关系相近的鱼类基因序列,采用Primer5设计简并引物,进行 H2A N-端序列扩增,通过胶回收和连接,然后转化到载体中进行克隆测序,分别获得青鱼、草鱼、鲢鱼和鳙鱼组蛋白 H2A N-端基因序列,长为364 bp ,分析发现均属于不稳定蛋白质,等电点为10.48~11.02,平均亲水性为0.179~0.264。序列同源性比对结果显示,青鱼、草鱼、鲢鱼和鳙鱼同狭孔金线鲃和斑马鱼基因H2A编码蛋白质同源性极高,达到85%以上,与其他物种同源性较低,其中狭孔金线鲃与青鱼、草鱼、鲢鱼和鳙鱼的亲缘关系比斑马鱼更近,分子系统学分析也支持这一结果。青鱼、草鱼、鲢鱼和鳙鱼H2A衍生抗菌肽与庸鲽 Hipposin抗菌肽同源性极高,不仅存在碱性氨基酸,还存在酸性氨基酸。组蛋白 H2A N-端可衍生 Hipposin类抗菌肽,均为阳离子α螺旋结构抗菌肽。%Antimicrobial peptide derived from Histone H2A ,one of the chromosome structure protein ,is a cationic antimicrobial peptide showing a potential to substitute antibiotics .The characterization of histone H2A and the derivative antibacterial peptides are important for understanding of the mechanism and antibacterial difference among peptides derived from different H 2A genes in different fish .In this study , RT‐PCR was used to amply the H2A cDNA with the total RNA as the template in black carp Mylopharyngodon piceus , grass carp Ctenopharyngodon idellus , silver carp Hypophthalmichthys molitrix and bighead carp A ristichthys nobilis .The homologous H2A gene sequences were selected in the BLAST in GenBank ,and aligned in software Mega5 . The universal primers were designed in software Primer5 to amplify H2A genes collected and linked with a T‐vector ,and transferred into the

  18. [Heterogenous expression of antimicrobial peptides].

    Science.gov (United States)

    Song, Shanshan; Hu, Guobin; Dong, Xianzhi

    2009-12-01

    Antimicrobial peptides (AMPs), a class of short proteins with a broad spectrum of antibacterial activities, are isolated from a wide variety of animals, both vertebrates and invertebrates, and plants as well as from bacteria and fungi. They are a key component of the innate immune response in most multicellular organisms. Owing to their potent, broad-spectrum antibacterial activities and uneasy developing of drug resistance, these peptides are of great clinical significance. However, preparation of AMPs at a large scale is a severe challenge to the development of the commercial products. Undoubtedly, construction of high-level biological expression systems for the production of AMPs is the key in its clinical application process. Herein, we summarize the progress in researches on heterogenous expression of AMPs in prokaryotic expression systems and eukaryotic expression systems.

  19. Antibacterial properties of nanoparticles.

    Science.gov (United States)

    Hajipour, Mohammad J; Fromm, Katharina M; Ashkarran, Ali Akbar; Jimenez de Aberasturi, Dorleta; de Larramendi, Idoia Ruiz; Rojo, Teofilo; Serpooshan, Vahid; Parak, Wolfgang J; Mahmoudi, Morteza

    2012-10-01

    Antibacterial agents are very important in the textile industry, water disinfection, medicine, and food packaging. Organic compounds used for disinfection have some disadvantages, including toxicity to the human body, therefore, the interest in inorganic disinfectants such as metal oxide nanoparticles (NPs) is increasing. This review focuses on the properties and applications of inorganic nanostructured materials and their surface modifications, with good antimicrobial activity. Such improved antibacterial agents locally destroy bacteria, without being toxic to the surrounding tissue. We also provide an overview of opportunities and risks of using NPs as antibacterial agents. In particular, we discuss the role of different NP materials.

  20. Antibacterials in Household Products

    Science.gov (United States)

    ... residue-producing ). Common examples of this group are triclosan, triclocarban, and benzalkonium chloride. Did you know that over 1000 commercial products contain triclosan or other biocide agents? Antibacterials in household products ...

  1. 抗菌肽研究及其在植物病害控制中的应用%Study on Antibacterial Peptides and Its Application in Plant Disease Control

    Institute of Scientific and Technical Information of China (English)

    王贤达; 林雄杰; 胡菡青; 王宗华; 范国成

    2014-01-01

    Antimicrobial peptides are generally called peptide exhibited antimicrobial activity in organism and it is an important part of the innate immune system in plants and animals .Previous studies have showed that antimicrobial peptides have broad application prospects in agriculture ,medicine ,food and other fields .In the present study ,the origin ,classification ,structural characteristics of antimicrobial peptides and possible mechanism to important plant disease control such as citrus Huanglongbing were reviewed .In the end ,the application prospects and problems w ere discussed .%抗菌肽是在生物体中表现出具有抗菌活性的肽类物质的总称,是生物体先天免疫系统的重要组成部分。大量研究表明抗菌肽在农业、医药和食品等领域具有广阔的应用前景。本文简要介绍抗菌肽的来源、分类和结构特征,着重阐述抗菌肽的作用机理及其在柑橘黄龙病等重要植物病害控制中的应用,展望抗菌肽的应用前景及其存在问题。

  2. The leader peptide of mutacin 1140 has distinct structural components compared to related class I lantibiotics.

    Science.gov (United States)

    Escano, Jerome; Stauffer, Byron; Brennan, Jacob; Bullock, Monica; Smith, Leif

    2014-12-01

    Lantibiotics are ribosomally synthesized peptide antibiotics composed of an N-terminal leader peptide that promotes the core peptide's interaction with the post translational modification (PTM) enzymes. Following PTMs, mutacin 1140 is transported out of the cell and the leader peptide is cleaved to yield the antibacterial peptide. Mutacin 1140 leader peptide is structurally unique compared to other class I lantibiotic leader peptides. Herein, we further our understanding of the structural differences of mutacin 1140 leader peptide with regard to other class I leader peptides. We have determined that the length of the leader peptide is important for the biosynthesis of mutacin 1140. We have also determined that mutacin 1140 leader peptide contains a novel four amino acid motif compared to related lantibiotics. PTM enzyme recognition of the leader peptide appears to be evolutionarily distinct from related class I lantibiotics. Our study on mutacin 1140 leader peptide provides a basis for future studies aimed at understanding its interaction with the PTM enzymes.

  3. Antibacterial multifilament nylon sutures.

    Science.gov (United States)

    Singhal, J P; Singh, J; Ray, A R; Singh, H

    1991-01-01

    Multifilament nylon fibers were made antibacterial by dopping with iodine. Nylon fibers were immersed in acetone solution of iodine for 48 hours at room temperature for dopping of iodine. It was observed that iodine uptake by the nylon fibers increased with the increase in concentration of iodine in the solution. Antibacterial activity of these iodine dopped samples was evaluated by measuring the zone of inhibition. The bacterial species used for this study were Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Klebsiella pneumoniae. Iodine dopped fibers exhibited good antibacterial activity against these bacterial species. Release of iodine in distilled water is sustained for about 30 days. Antibacterial activity of the fibers decreases with the release of iodine in water. Ultra-violet and visible spectroscopic studies showed that tri-iodide ions were released from the dopped samples in the aqueous medium. These I3- ions might be responsible for the observed antibacterial activity. Fiber shrinks on iodine dopping leading to increase in the denier of the fiber. However effect of iodine dopping on the breaking load of fibers is not significant.

  4. Antibacterial agents: patent highlights January to June 2004.

    Science.gov (United States)

    Phillips, Oludotun A

    2004-08-01

    This review presents highlights of 32 patents, published between January and June 2004, detailing different classes of antibacterial agents. Disclosures on novel oxazolidinone derivatives with antibacterial activity continue to dominate patent publications in recent years. Novel oxazolidinone derivatives active against linezolid-resistant cocci are reviewed. Patents on beta-lactam antibiotics focused mainly on developing new processes and formulations to improve cost, purity and pharmacokinetic parameters of existing clinical agents. Disclosures on novel potential dual-acting macrolide-quinolone hybrids designed to overcome erythromycin resistance, and new macrolide derivatives with antimycobacterial activity are described. Also presented are novel antibacterial agents, including peptide deformylase and cell-wall inhibitors, and those with undefined mechanisms of action as potential lead compounds, as well as quinolone and quinoline derivatives.

  5. Peptide design for antimicrobial and immunomodulatory applications.

    Science.gov (United States)

    Haney, Evan F; Hancock, Robert E W

    2013-11-01

    The increasing threat of antibiotic resistance in pathogenic bacteria and the dwindling supply of antibiotics available to combat these infections poses a significant threat to human health throughout the world. Antimicrobial peptides (AMPs) have long been touted as the next generation of antibiotics capable of filling the anti-infective void. Unfortunately, peptide-based antibiotics have yet to realize their potential as novel pharmaceuticals, in spite of the immense number of known AMP sequences and our improved understanding of their antibacterial mechanism of action. Recently, the immunomodulatory properties of certain AMPs have become appreciated. The ability of small synthetic peptides to protect against infection in vivo has demonstrated that modulation of the innate immune response is an effective strategy to further develop peptides as novel anti-infectives. This review focuses on the screening methods that have been used to assess novel peptide sequences for their antibacterial and immunomodulatory properties. It will also examine how we have progressed in our ability to identify and optimize peptides with desired biological characteristics and enhanced therapeutic potential. In addition, the current challenges to the development of peptides as anti-infectives are examined and the strategies being used to overcome these issues are discussed.

  6. Isolation and purification of antibacterial peptides with anti- K562 activity from the Tenebrio molitor Linnaeus larvae%黄粉虫幼虫抗肿瘤细胞K562抗菌肽的分离纯化

    Institute of Scientific and Technical Information of China (English)

    刘颜岗; 程璟侠; 赵瑞君; 樊宏英

    2009-01-01

    目的 从黄粉虫幼虫体内分离纯化具有抗肿瘤细胞K562的抗菌肽.方法 通过超声诱导黄粉虫幼虫大量表达抗菌肽.然后经过研磨、离心、固相萃取、反相高效液相色谱分离纯化黄粉虫幼虫抗菌肽,采用四甲基偶氮噻唑蓝(MTY)比色法和光镜观察法筛选对K562有杀伤作用的抗菌肽.结果 离心上清液上样固相萃取柱,经10%、30%、80%的乙腈水溶液洗脱,只有80%的乙腈水溶液分离组分有活性(P<0.01).该活性组分经反相高效液相色谱纯化后分离出5个具有抗肿瘤活性的峰物质,这5个峰活性都较强(P<0.01),其中峰9、峰4能初步确定为抗菌肽,其他3种有待于进一步的实验证明.结论 黄粉虫幼虫体内存在抗肿瘤细胞K562的抗菌肽和抗菌物质,而且不止一种.%Objective To isolate and purify the antimicrobial peptides with anti-tumor cell K562 activity from the Tenebrio molitor Linnaeus larvae. Methods Antimicrobial peptides of Tenebrio molitor L.larvae induced by ultrasonic waves were isolated and purified by trituration, centrifugalization, solid phase extraction (SPE) and reversed-phase high-performance liquid chromatography (RP-HPLC). Then the antimicrobial peptides with anti-K562 activity were sieved by MTT colorimetric method and light microscope observation. Results Supematant eluted with 10%, 30%, 80% acetonitrile (ACN) in aqueous solution by solid phase extraction, of which, only 80% was active (P<0.01). Five anti-tumor peaks appeared after purification by RP-HPLC, which all had strong activity (P<0.01). Only 9 and 4 peaks could initially identified as antimicrobial peptides, the others still need to be proved. Conclusion There are antimicmbial peptides and anti-hacterial substances which have anti-KS62 activity in the Tenebrio molitor L.larvae, and more than one.

  7. APD2: the updated antimicrobial peptide database and its application in peptide design.

    Science.gov (United States)

    Wang, Guangshun; Li, Xia; Wang, Zhe

    2009-01-01

    The antimicrobial peptide database (APD, http://aps.unmc.edu/AP/main.php) has been updated and expanded. It now hosts 1228 entries with 65 anticancer, 76 antiviral (53 anti-HIV), 327 antifungal and 944 antibacterial peptides. The second version of our database (APD2) allows users to search peptide families (e.g. bacteriocins, cyclotides, or defensins), peptide sources (e.g. fish, frogs or chicken), post-translationally modified peptides (e.g. amidation, oxidation, lipidation, glycosylation or d-amino acids), and peptide binding targets (e.g. membranes, proteins, DNA/RNA, LPS or sugars). Statistical analyses reveal that the frequently used amino acid residues (>10%) are Ala and Gly in bacterial peptides, Cys and Gly in plant peptides, Ala, Gly and Lys in insect peptides, and Leu, Ala, Gly and Lys in amphibian peptides. Using frequently occurring residues, we demonstrate database-aided peptide design in different ways. Among the three peptides designed, GLK-19 showed a higher activity against Escherichia coli than human LL-37.

  8. Layer-by-layer assemblies for antibacterial applications.

    Science.gov (United States)

    Zhu, Xiaoying; Jun Loh, Xian

    2015-12-01

    The adhesion and proliferation of bacteria on various artificial surfaces affects the functionality of these specific interfaces. To overcome the problems caused by bacterial growth on these surfaces, various antibacterial coatings were developed. In this review, we summarized most of the antibacterial surfaces prepared by the Layer-by-Layer (LbL) assembly approach and classified these LbL films based on their antibacterial mechanisms. In the first group, the bactericidal LbL assemblies which incorporate various biocides including heavy metals, antibiotics, cationic molecules, antimicrobial peptides and enzymes are able to kill surrounding or contacted bacteria. In the second group, we focused on the physical aspects of film surfaces. Bacterial adhesion resistant LbL films have been fabricated to adjust the substrate surface properties such as surface free energy (or wettability), roughness, and surface charge which may affect the adhesion of bacteria. Furthermore, as an enhancement in the antibacterial efficiency, multifunctional LbL assemblies combining both bactericidal and adhesion resistant functionalities were discussed. The advantages and limitations of these antibacterial LbL assemblies were summarized and subsequently directions for future development were proposed.

  9. Herbal Antibacterials: A Review

    Directory of Open Access Journals (Sweden)

    Chirag Modi

    2012-02-01

    Full Text Available Plants are rich source of antibacterial agents because they produce wide array of bioactive molecules, most of which probably evolved as chemical defense against predation or infection. A major part of the total population in developing countries still uses traditional folk medicine obtained from plant resources With an estimation of WHO that as many as 80% of world population living in rural areas rely on herbal traditional medicines as their primary health care, the study on properties and uses of medicinal plants are getting growing interests. In recent years this interest to evaluate plants possessing antibacterial activity for various diseases is growing. Different solvent extracts (aqueous, alcohol and ethanol of leaves, flower and seed of various plants selected based on an ethnobotanical survey from India were subjected to in vitro antibacterial activity assay against Gram-positive and Gram-negative bacteria employing different diffusion method. Based on local use of common diseases and Ethnobotanical knowledge, an attempt has been made to assess the antibacterial properties of selected medicinal plants viz. Argemone mexicana (Shialkanta, Aster lanceolatus (White panicle, Capparis thonningii and Capparis tomentosa (Woolly caper bush, Cardiospermum halicacabum (Balloonvine, Cassia alata (Herpetic alata, Centaurea sclerolepis, Cinnamomum zeylanicum (Cinnamon, Curcuma longa (Turmeric, Cymbopogon nervatus, Ficus religiosa (Peepal, Indigofera aspalathoides (Ajara, Marrubium vulgare (Horehound, Medicago Spp.(Medick, Burclover, Morus alba (Mulberry, Ocimum sanctum (Tulsi, Origanum marjorana (Marjoram, Oxalis corniculata (Amli, Piper nigrum (Kala mirch, Plectranthus amboinicus (Indian borage, Patharchur, Plumeria acutifolia (Kachuchi, Salvadora persica (Piludi, Salvia repens and Syzygium aromaticum (Clove for potential antibacterial activity against some important bacterial strains, namely Bacillus subtilis, Bacillus cereus, Staphylococcus

  10. 益生素和抗菌肽联合应用对肉鸡生长性能、肉品质和鸡舍氨气浓度的影响%Effect of Probiotics and Antibacterial Peptide on Growth Performance, Quality of Meat and Henhouse Ammonin Gas of Broilers

    Institute of Scientific and Technical Information of China (English)

    杨玉荣; 梁宏德; 尹清强; 常娟; 姜义宝

    2012-01-01

    To evaluate the effect of probiotics and antibacterial peptide on growth performance, quality of meat and henhouse ammonin gas of broilers, one thousand and six hundred AA broilers were randomly assigned to four groups, five repeat in each group, and 80 chickens for each repeat. Four groups were control group(C), antibiotics group(T1), probiotics group(T2), antibiotics and probiotics group(T3). Trial period was 49 days; quality of meat was analyzed at the end of the study. The results indicated that antibiotics and probiotics combined application could in- crease daily weight gain and dressing percentage, decrease feed conversion ratio and the concentration of ammonin gas in henhouse, improve quality of meat.%试验研究了益生素和抗菌肽联合应用对肉鸡生长性能、肉品质和鸡舍氨气浓度的影响。选用AA肉仔鸡1600只,随机分成4个处理,每个处理5个重复,每个重复80只鸡。4个处理分别为对照组(C)、抗生素组(T1)、微生态制剂组(T2)、微生态制剂和抗菌肽组(T3)。试验期49d,试验结束时测量肉品质。试验结果表明,益生素和抗菌肽联合应用可以提高肉鸡的日增重,降低料重比,提高屠宰率并改善肉品质,降低鸡舍中氨气浓度。

  11. Antibacterial Applications of Nanodiamonds.

    Science.gov (United States)

    Szunerits, Sabine; Barras, Alexandre; Boukherroub, Rabah

    2016-04-12

    Bacterial infectious diseases, sharing clinical characteristics such as chronic inflammation and tissue damage, pose a major threat to human health. The steady increase of multidrug-resistant bacteria infections adds up to the current problems modern healthcare is facing. The treatment of bacterial infections with multi-resistant germs is very difficult, as the development of new antimicrobial drugs is hardly catching up with the development of antibiotic resistant pathogens. These and other considerations have generated an increased interest in the development of viable alternatives to antibiotics. A promising strategy is the use of nanomaterials with antibacterial character and of nanostructures displaying anti-adhesive activity against biofilms. Glycan-modified nanodiamonds (NDs) revealed themselves to be of great promise as useful nanostructures for combating microbial infections. This review summarizes the current efforts in the synthesis of glycan-modified ND particles and evaluation of their antibacterial and anti-biofilm activities.

  12. Antibacterial Applications of Nanodiamonds

    Directory of Open Access Journals (Sweden)

    Sabine Szunerits

    2016-04-01

    Full Text Available Bacterial infectious diseases, sharing clinical characteristics such as chronic inflammation and tissue damage, pose a major threat to human health. The steady increase of multidrug-resistant bacteria infections adds up to the current problems modern healthcare is facing. The treatment of bacterial infections with multi-resistant germs is very difficult, as the development of new antimicrobial drugs is hardly catching up with the development of antibiotic resistant pathogens. These and other considerations have generated an increased interest in the development of viable alternatives to antibiotics. A promising strategy is the use of nanomaterials with antibacterial character and of nanostructures displaying anti-adhesive activity against biofilms. Glycan-modified nanodiamonds (NDs revealed themselves to be of great promise as useful nanostructures for combating microbial infections. This review summarizes the current efforts in the synthesis of glycan-modified ND particles and evaluation of their antibacterial and anti-biofilm activities.

  13. Peptide antibiotics: holy or heretic grails of innate immunity?

    Science.gov (United States)

    Boman, H G

    1996-05-01

    In the last 2 years (1994-95), two symposium volumes and three reviews have been published that were fully devoted to peptide antibiotics (antibacterial peptides or antimicrobial peptides). Since the field has been growing rapidly, this review is largely a follow-up of new results published in the last 2 years. Sequencing of the 16S RNA of the small ribosomal subunit indicate that the microbial world is much larger than generally appreciated. The importance of the natural flora is stressed and its effect on the evolution of peptide antibiotics and immunity in general is discussed.

  14. Synergistic interaction of PMAP-36 and PRW4 with aminoglycoside antibiotics and their antibacterial mechanism.

    Science.gov (United States)

    Wang, Zeyun; Zhang, Licong; Wang, Jue; Wei, Dandan; Shi, Baoming; Shan, Anshan

    2014-12-01

    The antimicrobial peptide PMAP-36 is a highly cationic and amphipathic α-helical peptide. PRW4 is a truncated analog that replaces paired lysine residues with tryptophan along the N-terminal and deletes the C-terminal hydrophobic tail of PMAP-36. Studies on the two peptides have already been performed. However, whether there is a synergistic effect with antibiotics has not been investigated, and the study of the antibacterial mechanism of the peptides is inadequate. In this study, antibiotic-peptide combinations were tested against Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 29213, and the confocal laser scanning microscopy (LSCM) and DNA gel retardation were measured. The results indicated synergy between the peptides and gentamicin when tested against E. coli [fractional lethal concentration (FLC) peptides and gentamicin against S. aureus (0.5 peptides against E. coli and S. aureus (1 DNA binding suggest that PMAP-36 was able to translocate across the bacterial membranes and interact with intracellular DNA, but PRW4 presented no DNA-binding ability. These results indicate that the combination of PMAP-36 and PRW4 with aminoglycosides may provide useful information for clinical application, and the antibacterial mechanism of peptides likely does not solely involve cytoplasmic-membrane permeabilization.

  15. Existing antibacterial vaccines.

    Science.gov (United States)

    Mendoza, Natalia; Ravanfar, Parisa; Satyaprakash, Anita; Satyaprakah, Anita; Pillai, Sivaprabha; Creed, Rosella

    2009-01-01

    There are countless bacterial pathogens that cause disease in humans. Many of these bacterial infections not only cause significant morbidity and mortality in the human population but also cause a significant economic impact on society. Vaccines allow for reduction and potential eradication of such diseases. This article will review the currently approved antibacterial vaccines, which are vaccines for pertussis, tetanus, diphtheria, meningococcus, pneumococcus, Haemophilus influenza, cholera, typhoid, and anthrax.

  16. Antibacterial Au nanostructured surfaces

    Science.gov (United States)

    Wu, Songmei; Zuber, Flavia; Brugger, Juergen; Maniura-Weber, Katharina; Ren, Qun

    2016-01-01

    We present here a technological platform for engineering Au nanotopographies by templated electrodeposition on antibacterial surfaces. Three different types of nanostructures were fabricated: nanopillars, nanorings and nanonuggets. The nanopillars are the basic structures and are 50 nm in diameter and 100 nm in height. Particular arrangement of the nanopillars in various geometries formed nanorings and nanonuggets. Flat surfaces, rough substrate surfaces, and various nanostructured surfaces were compared for their abilities to attach and kill bacterial cells. Methicillin-resistant Staphylococcus aureus, a Gram-positive bacterial strain responsible for many infections in health care system, was used as the model bacterial strain. It was found that all the Au nanostructures, regardless their shapes, exhibited similar excellent antibacterial properties. A comparison of live cells attached to nanotopographic surfaces showed that the number of live S. aureus cells was health care system, was used as the model bacterial strain. It was found that all the Au nanostructures, regardless their shapes, exhibited similar excellent antibacterial properties. A comparison of live cells attached to nanotopographic surfaces showed that the number of live S. aureus cells was information (ESI) available. See DOI: 10.1039/c5nr06157a

  17. Influence of the yjiL-mdtM Gene Cluster on the Antibacterial Activity of Proline-Rich Antimicrobial Peptides Overcoming Escherichia coli Resistance Induced by the Missing SbmA Transporter System.

    Science.gov (United States)

    Krizsan, Andor; Knappe, Daniel; Hoffmann, Ralf

    2015-10-01

    In view of increasing health threats from multiresistant pathogens, antimicrobial peptides (AMPs) and, specifically, proline-rich AMPs (PrAMPs) have been investigated in animal models. PrAMPs enter bacteria via the ABC transporter SbmA and inhibit intracellular targets. We used phage transduction (Tn10 insertion) to screen by random mutagenesis for alternative uptake mechanisms for analogs of apidaecin 1b, a honeybee-derived PrAMP. All 24 apidaecin-resistant mutants had the Tn10 insertion in the sbmA gene. These sbmA::Tn10 insertion mutants and the Escherichia coli BW25113 ΔsbmA (JW0368) strain were still susceptible to the bactenecin PrAMP Bac7(1-35) and oncocin PrAMPs Onc18 and Onc112, as well as to Chex1-Arg20, despite significantly reduced internalizations. In a second round of random mutagenesis, the remaining susceptibility was linked to the yjiL-mdtM gene cluster. E. coli BW25113 and its ΔyjiL null mutant (JW5785) were equally susceptible to all PrAMPs tested, whereas the BW25113 ΔmdtM mutant was less susceptible to oncocins. The JW0368 yjiL::Tn10 transposon mutant (BS2) was resistant to all short PrAMPs and susceptible only to full-length Bac7 and A3-APO. Interestingly, PrAMPs appear to enter bacteria via MdtM, a multidrug resistance transporter (drug/H(+) antiporter) of the major facilitator superfamily (MFS) that can efflux antibiotics, biocides, and bile salts. In conclusion, PrAMPs enter bacteria via ABC and MFS transporters that efflux antibiotics and cytotoxic compounds from the cytoplasm to the periplasm.

  18. 抗菌肽buforin Ⅱ衍生物抑制细菌核酸合成的机制研究%Antibacterial peptides buforin Ⅱ analogues on bacteria by inhibition of DNA synthesis

    Institute of Scientific and Technical Information of China (English)

    苏冠芳; 郝刚; 李莉蓉; 施用晖; 乐国伟

    2012-01-01

    Objective To study the intracellular action of analogues buforin II-A (BF2-A) and buforin II-B (BF2-B) of the antimicrobial peptide buforin II on bacteria. Methods In vitro, the bond of genomic DNA with BF2-A/BF2-B and the change of DNA structure after the binding was investigated with atomic force microscope (AFM) and fluorescence spectra respectively, and the competitive intercalation of BF2-A/BF2-B and ethidium bromide (EB) into genomic DNA were analyzed by fluorescence spectra. In vivo, transmission electron microscope (TEM) observed the cell membrane ultrastructure of Staphylococcus aureus treated by BF2-A/BF2-B. Then flow cytometry analyzed the change of bacterial cell cycle after treated by BF2-A/BF2-B. Finally, binding action between peptide and genes related to DNA synthesis that was harvested by PCR were researched by gel retardation assay. Results BF2-A/ BF2-B bond to DNA. Both the peptides could weaken the fluorescence intensity of EB-DNA complex. BF2-A/BF2-B penetrated into cell without destroying the cell membrane. Bacterial cell cycle after interactions of BF2-A/BF2-Bwith bacteria specifically changed and BF2-A/BF2-B binded with key genes. Besides, all the experiments showed that BF2-B was stronger than BF2-A in the DNA-binding, membrane penetration and blocking the cell cycle. Conclusion BF2-A/BF2-B penetrated into bacteria, and block DNA synthesis phase of cell cycle of bacteria by binding to genes related to DNA synthesis specifically. Above effects of BF2-B are better than BF2-A.%目的 探究抗菌肽buforin Ⅱ的衍生物buforin Ⅱ-A(BF2-A)和buforin Ⅱ-B(BF2-B)对细菌的胞内抑菌作用机制.方法 体外用原子力显微镜观察抗菌肽与基因组DNA的结合情况,荧光光谱分析肽与基冈组DNA的结合方式.体内用透射电镜观察抗菌肽作用后金黄色葡萄球菌细胞膜超微结构的变化,流式细胞仪分析肽对金黄色葡萄球菌细胞周期的影响.最后通过凝胶阻滞实验推测肽与金黄

  19. Antibacterial agents in the cinema.

    Science.gov (United States)

    García Sánchez, J E; García Sánchez, E; Merino Marcos, M L

    2006-12-01

    Numerous procedures used as antibacterial therapy are present in many films and include strategies ranging from different antimicrobial drugs to surgery and supporting measures. Films also explore the correct use and misuse of antimicrobial agents. Side effects and other aspects related to antibacterial therapy have also been reflected in some films. This article refers to the presence of antibacterial agents in different popular movies. There are movies in which antibacterial agents form part of the central plot, while in others it is merely an important part of the plot. In still others, its presence is isolated, and in these it plays an ambient or anecdotal role.

  20. De-novo design of antimicrobial peptides for plant protection.

    Directory of Open Access Journals (Sweden)

    Benjamin Zeitler

    Full Text Available This work describes the de-novo design of peptides that inhibit a broad range of plant pathogens. Four structurally different groups of peptides were developed that differ in size and position of their charged and hydrophobic clusters and were assayed for their ability to inhibit bacterial growth and fungal spore germination. Several peptides are highly active at concentrations between 0,1 and 1 µg/ml against plant pathogenic bacteria, such as Pseudomonas syringae, Pectobacterium carotovorum, and Xanthomonas vesicatoria. Importantly, no hemolytic activity could be detected for these peptides at concentrations up to 200 µg/ml. Moreover, the peptides are also active after spraying on the plant surface demonstrating a possible way of application. In sum, our designed peptides represent new antimicrobial agents and with the increasing demand for antimicrobial compounds for production of "healthy" food, these peptides might serve as templates for novel antibacterial and antifungal agents.

  1. 抗菌肽对热应激肉鸡生长性能及免疫器官的影响%Effects of antibacterial peptides on growth performance and immune organs of broiler under heat stress condition

    Institute of Scientific and Technical Information of China (English)

    包汇慧; 高贤彪; 陈建; 田纪景; 常玲玲; 肖鹏; 杜芳; 汪会玲; 耿雪

    2013-01-01

    In order to verify if antimicrobial peptides(AMP) could modulate growth performance and immune function under heat stress condition,thirty 10-day-old Arbor Acre broiler chickens were randomly grouped into three groups with 10 of each,including control group,heat stress group and AMP treated group(2 mg per bird) with heat stress.Temperature was heated up for 10 days.In result,average body weight gain and FCR in AMP treated group under heat stress condition had significant difference compared to heat stress group (P<0.01).Pathology observation and immunohistochemistry showed that injury degree and expression of heat stress protein 70(HSP70) in the thymus,spleen and bursa of fabricius of AMP treated birds were lower compared to the heat stress group.In conclusion,AM may reduce injuries of immune organs caused by heat stress and increase a body weight gain in broilers.%为了解抗菌肽在热应激条件下对肉鸡生长性能及免疫器官的影响,选用30只2周龄健康AA肉鸡,称重后随机分为3组:常温对照组、单纯热应激组、抗菌肽十热应激组,每组10只,热应激10d.结果,抗菌肽+热应激组与单纯热应激组比较,平均日增重及饲料转化率差异极显著(P<0.01);病理观察发现单纯热应激组肉鸡法氏囊充血、出血,淋巴滤泡星空样变,胸腺皮质区淋巴细胞坏死、排空,脾充血、淤血,淋巴细胞坏死,小肠黏膜水肿脱落,上皮层及固有层炎性细胞浸润;抗菌肽+热应激组无明显病变;免疫组化检测表明,抗菌肽+热应激组肉鸡胸腺、脾、法氏囊中热休克蛋白70(HSP70)的表达少于单纯热应激组.结果表明,在热应激条件下口服抗菌肽可以降低热应激对机体免疫器官的损伤,降低高温对内鸡增重的影响.

  2. Milk proteins as precursors of bioactive peptides

    Directory of Open Access Journals (Sweden)

    Marta Dziuba

    2009-03-01

    Full Text Available Milk proteins, a source of bioactive peptides, are the subject of numerous research studies aiming to, among others, evaluate their properties as precursors of biologically active peptides. Physiologically active peptides released from their precursors may interact with selected receptors and affect the overall condition and health of humans. By relying on the BIOPEP database of proteins and bioactive peptides, developed by the Department of Food Biochemistry at the University of Warmia and Mazury in Olsztyn (www.uwm.edu.pl/biochemia, the profiles of potential activity of milk proteins were determined and the function of those proteins as bioactive peptide precursors was evaluated based on a quantitative criterion, i.e. the occurrence frequency of bioactive fragments (A. The study revealed that milk proteins are mainly a source of peptides with the following types of activity: antihypertensive (Amax = 0.225, immunomodulating (0.024, smooth muscle contracting (0.011, antioxidative (0.029, dipeptidyl peptidase IV inhibitors (0.148, opioid (0.073, opioid antagonistic (0.053, bonding and transporting metals and metal ions (0.024, antibacterial and antiviral (0.024, and antithrombotic (0.029. The enzymes capable of releasing bioactive peptides from precursor proteins were determined for every type of activity. The results of the experiment indicate that milk proteins such as lactoferrin, α-lactalbumin, β-casein and κ-casein hydrolysed by trypsin can be a relatively abundant source of biologically active peptides.

  3. Carbon Nanomaterials as Antibacterial Colloids

    Directory of Open Access Journals (Sweden)

    Michael Maas

    2016-07-01

    Full Text Available Carbon nanomaterials like graphene, carbon nanotubes, fullerenes and the various forms of diamond have attracted great attention for their vast potential regarding applications in electrical engineering and as biomaterials. The study of the antibacterial properties of carbon nanomaterials provides fundamental information on the possible toxicity and environmental impact of these materials. Furthermore, as a result of the increasing prevalence of resistant bacteria strains, the development of novel antibacterial materials is of great importance. This article reviews current research efforts on characterizing the antibacterial activity of carbon nanomaterials from the perspective of colloid and interface science. Building on these fundamental findings, recent functionalization strategies for enhancing the antibacterial effect of carbon nanomaterials are described. The review concludes with a comprehensive outlook that summarizes the most important discoveries and trends regarding antibacterial carbon nanomaterials.

  4. Synthetic Peptides Derived from Bovine Lactoferricin Exhibit Antimicrobial Activity against E. coli ATCC 11775, S. maltophilia ATCC 13636 and S. enteritidis ATCC 13076

    Directory of Open Access Journals (Sweden)

    Nataly De Jesús Huertas Méndez

    2017-03-01

    Full Text Available Linear, dimeric, tetrameric, and cyclic peptides derived from lactoferricin B–containing non-natural amino acids and the RWQWR motif were synthesized, purified, and characterized using RP-HPLC, MALDI-TOF mass spectrometry, and circular dichroism. The antibacterial activity of peptides against Escherichia coli ATCC 11775, Stenotrophomonas maltophilia ATCC 13636, and Salmonella enteritidis ATCC 13076 was evaluated. The minimum inhibitory concentration (MIC and minimum bactericidal concentration (MBC were determined. The synthetic bovine lactoferricin exhibited antibacterial activity against E. coli ATCC 11775 and S. enteritidis ATCC 13076. The dimeric peptide (RRWQWR2K-Ahx exhibited the highest antibacterial activity against the tested bacterial strain. The monomeric, cyclic, tetrameric, and palindromic peptides containing the RWQWR motif exhibited high and specific activity against E. coli ATCC 11775. The results suggest that short peptides derived from lactoferricin B could be considered as potential candidates for the development of antibacterial agents against infections caused by E. coli.

  5. Peptide identification

    Science.gov (United States)

    Jarman, Kristin H [Richland, WA; Cannon, William R [Richland, WA; Jarman, Kenneth D [Richland, WA; Heredia-Langner, Alejandro [Richland, WA

    2011-07-12

    Peptides are identified from a list of candidates using collision-induced dissociation tandem mass spectrometry data. A probabilistic model for the occurrence of spectral peaks corresponding to frequently observed partial peptide fragment ions is applied. As part of the identification procedure, a probability score is produced that indicates the likelihood of any given candidate being the correct match. The statistical significance of the score is known without necessarily having reference to the actual identity of the peptide. In one form of the invention, a genetic algorithm is applied to candidate peptides using an objective function that takes into account the number of shifted peaks appearing in the candidate spectrum relative to the test spectrum.

  6. 抗菌肽基因转化大白菜获得抗病转基因植株及稳定遗传%Pathogen-resistant Transgenic Plant of Brassica pekinensis by TransferingAntibacterial Peptide Gene and Its Genetic Stability

    Institute of Scientific and Technical Information of China (English)

    王关林; 方宏筠; 王火旭; 李洪艳; 魏毓堂

    2002-01-01

    软腐病是大白菜( Brassica pekinensis Rupr.)的三大病害之一.抗菌肽对软腐病菌有很强的杀伤作用.建立了根癌土壤杆菌( Agrobacterium tumefaciens ) EHA105(pMOG410)工程菌的高频转化载体系统,将抗菌肽基因导入目前推广种植的大白菜AB-81自交系,获得了转基因植株.PCR及 Southern blotting分子杂交鉴定表明抗菌肽基因已整合到白菜基因组.转基因植株提取液的体外抑菌实验、试管苗及盆栽转基因植株的病原菌接种抗病测试结果表明转基因植株具有明显的抗病特性,并且能稳定遗传,转基因植株R1自交分离比为3∶1,R5的转基因植株保持抗Km和抗病特性,可望以其为亲本选育出大白菜抗软腐病的新品种.%The soft rot infected by pathogenic bacterium Erwinia aroideae Holland is one of the three serious diseases of Chinese cabbage ( Brassica pekinensis Rupr.). By constructing vector system of high frequency transformation mediated by Agrobacterium tumefaciens EHA105, anti-bacterial peptide gene with strong bactericidal action to pathogenic bacteria was introduced into Chinese cabbage AB-81 self-bred line and the transgenic plants were obtained. PCR and Southern blotting detection showed that target gene was integrated into plant genome of Chinese cabbage. The tests of bacteriostasis action of the extract from transgenic plants in vitro, and the assay of disease-resistant of transgenic plantlets in the tube and the pot by perfusing inoculation with pathogenic bacteria showed obvious resistance to soft rot. This resistance can be a stable heredity by genetic analysis of generations of transgenic plants disease of soft rot was still kept in the R5. These results indicated the possibility of breeding new varieties of anti-soft rot Chinese cabbage by transgenic plants as parents.

  7. Analysis of the Inheritance and Expression of Antibacterial Peptide Gene Shiva A in Transgenic Citrus(Citrus sinensis) during Its Asexual Propagation%抗菌肽Shiva A基因在转基因柑橘无性繁殖后代中的遗传与表达分析

    Institute of Scientific and Technical Information of China (English)

    许兰珍; 何永睿; 彭爱红; 雷天刚; 刘小丰; 邹修平; 姚利晓; 陈善春

    2013-01-01

    In order to further clarify the genetic stability and the target traits of the foreign gene in the progeny of transgenic citrus,the asexual reproduction plants of transgenic Newhall navel orange(Citrus sinensis Osbeck)containing bivalent antibacterial peptide gene(Shiva A-cecropin B) were studied.In this study,the genetic stability of Shiva A gene in To,T1,T2 and T3 progenies of transgenic citrus varieties were analyzed by PCR,Southern hybridization,Real-time quantitative PCR and greenhouse disease index statistic to Xathomonas axonopodis pv.Citri(Hasse) Dye.The results showed that the antimicrobial peptides Shiva A gene was existed and expressed in To,T1,T2 and T3 plants.This meant target gene could be stably inherited from one generation to another through asexual propagating.There was difference of Shiva A gene copy number between transgenic To and its asexual propagation.Southern bloting analysis showed that To generation had two hybridizations,but its progenies had only one hybridization consistent with To generation.It could be speculated that the T0 generation plant was a transgenic multicellular mixed cytochimera.In addition,Realtime quantitative PCR results showed that,even if Shiva A gene in the To generation genome was double copy numbers,but its expression level was lower than a single copy of the T1,T2 and T3 generation.Therefore,in this study,exogenous gene expression and transgene copy number was a negative correlation.The results of this study provide some basic date and the material for extending the stable phenotype of transgenic citrus strains in carrying out the safety evaluation of transgenic plants.%为进一步明确外源基因在转基因柑橘无性繁殖后代中的遗传稳定性及目标性状表现,本研究以转双价抗菌肽基因(ShivaA-cecropinB)纽荷尔脐橙(Citrus Sinensis Osbeck)无性繁殖后代植株为材料,通过PCR扩增,Southern杂交和实时定量PCR检测,以及温室抗病性评价分析等,对抗菌肽ShivaA基

  8. Prediction Model of Antibacterial Activities for Inorganic Antibacterial Agents Based on Artificial Neural Networks

    Institute of Scientific and Technical Information of China (English)

    刘雪峰; 张利; 涂铭旌

    2004-01-01

    Quantitatively evaluation of antibacterial activities of inorganic antibacterial agents is an urgent problem to be solved. Using experimental data by an orthogonal design, a prediction model of the relation between conditions of preparing inorganic antibacterial agents and their antibacterial activities has been developed. This is accomplished by introducing BP artificial neural networks in the study of inorganic antibacterial agents..It provides a theoretical support for the development and research on inorganic antibacterial agents.

  9. Phenotype microarray profiling of the antibacterial activity of red cabbage

    Directory of Open Access Journals (Sweden)

    Hafidh RR

    2012-06-01

    Full Text Available Background: Functional food can be a potent source of wide array of biocomonents with antimicrobial activity. We investigated the antibacterial activity of red cabbage (RC extract on Gram negative and positive ATCC strains. Most intersting, we, for the first time, explored and analysed the complete phenotypic profile of RC-treated bacteria using Omnilog Phenotype Microarray. Results: This study revealed that the phenotype microarray (PM screen was a valuable tool in the search for compounds and their antibacterial mechanisms that can inhibit bacterial growth by affecting certain metabolic pathways. It was shown that RC exerted remarkable antibacterial effect on S. aureus and E. coli bacteria, and PM showed a wide range phenotypic profile of the exerted RC antibacterial activity. RC targeted the peptide, carbon, nutriontional assembly, and sulfur metbolic pathways altogether. The peptidoglycan synthesis pathway was inferred to be targeted by RC extract at a metabolic point different from other available cell wall-targeting drugs; these could be hot targets for the discovery of new therapy for many problematic microbes.Conclusions: Taken together, the phenotype microarray for functional food and medicinal plants can be a very useful tool for profiling their antimicrobial activity. Moreover, extracts of functional food can exert antibacterial activity by hitting a wide range of metabolic pathways, at the same time leading to very difficult condition for bacteria to rapidly develop resistance. Therefore, using functional foods or medicinal plants as such, or as extracts, can be superior on mono-targeting antibiotics if the optimal concentrations and conditions of these functional foods were sought.

  10. Antibacterial diterpenoids from Cedrus atlantica.

    Science.gov (United States)

    Dakir, M; El Hanbali, F; Mellouki, F; Akssira, M; Benharref, A; Quilez Del Moral, J F; Barrero, A F

    2005-10-01

    Four diterpene alcohols were isolated from the neutral hexane extract of the cones of Cedrus atlantica, and their structures were confirmed after comparing their spectral data with literature values. These products exhibited significant antibacterial activity against gram (+/-) bacteria.

  11. Antibacterial resistance: an emerging 'zoonosis'?

    Science.gov (United States)

    Labro, Marie-Thérèse; Bryskier, Jean-Marie

    2014-12-01

    Antibacterial resistance is a worldwide threat, and concerns have arisen about the involvement of animal commensal and pathogenic bacteria in the maintenance and spread of resistance genes. However, beyond the facts related to the occurrence of resistant microorganisms in food, food-producing animals and companion animals and their transmission to humans, it is important to consider the vast environmental 'resistome', the selective pathways underlying the emergence of antibacterial resistance and how we can prepare answers for tomorrow.

  12. Substituted Hydroxyapatites with Antibacterial Properties

    OpenAIRE

    Joanna Kolmas; Ewa Groszyk; Dagmara Kwiatkowska-Różycka

    2014-01-01

    Reconstructive surgery is presently struggling with the problem of infections located within implantation biomaterials. Of course, the best antibacterial protection is antibiotic therapy. However, oral antibiotic therapy is sometimes ineffective, while administering an antibiotic at the location of infection is often associated with an unfavourable ratio of dosage efficiency and toxic effect. Thus, the present study aims to find a new factor which may improve antibacterial activity while also...

  13. Design and Application of Antimicrobial Peptide Conjugates

    Directory of Open Access Journals (Sweden)

    Andre Reinhardt

    2016-05-01

    Full Text Available Antimicrobial peptides (AMPs are an interesting class of antibiotics characterized by their unique antibiotic activity and lower propensity for developing resistance compared to common antibiotics. They belong to the class of membrane-active peptides and usually act selectively against bacteria, fungi and protozoans. AMPs, but also peptide conjugates containing AMPs, have come more and more into the focus of research during the last few years. Within this article, recent work on AMP conjugates is reviewed. Different aspects will be highlighted as a combination of AMPs with antibiotics or organometallic compounds aiming to increase antibacterial activity or target selectivity, conjugation with photosensitizers for improving photodynamic therapy (PDT or the attachment to particles, to name only a few. Owing to the enormous resonance of antimicrobial conjugates in the literature so far, this research topic seems to be very attractive to different scientific fields, like medicine, biology, biochemistry or chemistry.

  14. Identification of antimicrobial peptides by using eigenvectors.

    Science.gov (United States)

    Polanco, Carlos

    2016-01-01

    Antibacterial peptides are subject to broad research due to their potential application and the benefit they can provide for a wide range of diseases. In this work, a mathematical-computational method, called the Polarity Vector Method, is introduced that has a high discriminative level (>70%) to identify peptides associated with Gram (-) bacteria, Gram (+) bacteria, cancer cells, fungi, insects, mammalian cells, parasites, and viruses, taken from the Antimicrobial Peptides Database. This supervised method uses only eigenvectors from the incident polar matrix of the group studied. It was verified with a comparative study with another extensively verified method developed previously by our team, the Polarity Index Method. The number of positive hits of both methods was up to 98% in all the tests conducted.

  15. Bactericidal effect of bovine lactoferrin and synthetic peptide lactoferrin chimera in Streptococcus pneumoniae and the decrease in luxS gene expression by lactoferrin

    NARCIS (Netherlands)

    N. León-Sicairos; U.A. Angulo-Zamudio; J.E. Vidal; C.A. López-Torres; J.G.M. Bolscher; K. Nazmi; R. Reyes-Cortes; M. Reyes-López; M. de la Garza; A. Canizalez-Román

    2014-01-01

    Streptococcus pneumoniae (pneumococcus) is responsible for nearly one million child deaths annually. Pneumococcus causes infections such as pneumonia, otitis media, meningitis, and sepsis. The human immune system includes antibacterial peptides and proteins such as lactoferrin (LF), but its activity

  16. Antimicrobial cyclic peptides for plant disease control.

    Science.gov (United States)

    Lee, Dong Wan; Kim, Beom Seok

    2015-03-01

    Antimicrobial cyclic peptides derived from microbes bind stably with target sites, have a tolerance to hydrolysis by proteases, and a favorable degradability under field conditions, which make them an attractive proposition for use as agricultural fungicides. Antimicrobial cyclic peptides are classified according to the types of bonds within the ring structure; homodetic, heterodetic, and complex cyclic peptides, which in turn reflect diverse physicochemical features. Most antimicrobial cyclic peptides affect the integrity of the cell envelope. This is achieved through direct interaction with the cell membrane or disturbance of the cell wall and membrane component biosynthesis such as chitin, glucan, and sphingolipid. These are specific and selective targets providing reliable activity and safety for non-target organisms. Synthetic cyclic peptides produced through combinatorial chemistry offer an alternative approach to develop antimicrobials for agricultural uses. Those synthesized so far have been studied for antibacterial activity, however, the recent advancements in powerful technologies now promise to provide novel antimicrobial cyclic peptides that are yet to be discovered from natural resources.

  17. Antimicrobial Cyclic Peptides for Plant Disease Control

    Directory of Open Access Journals (Sweden)

    Dong Wan Lee

    2015-03-01

    Full Text Available Antimicrobial cyclic peptides derived from microbes bind stably with target sites, have a tolerance to hydrolysis by proteases, and a favorable degradability under field conditions, which make them an attractive proposition for use as agricultural fungicides. Antimicrobial cyclic peptides are classified according to the types of bonds within the ring structure; homodetic, heterodetic, and complex cyclic peptides, which in turn reflect diverse physicochemical features. Most antimicrobial cyclic peptides affect the integrity of the cell envelope. This is achieved through direct interaction with the cell membrane or disturbance of the cell wall and membrane component biosynthesis such as chitin, glucan, and sphingolipid. These are specific and selective targets providing reliable activity and safety for non-target organisms. Synthetic cyclic peptides produced through combinatorial chemistry offer an alternative approach to develop antimicrobials for agricultural uses. Those synthesized so far have been studied for antibacterial activity, however, the recent advancements in powerful technologies now promise to provide novel antimicrobial cyclic peptides that are yet to be discovered from natural resources.

  18. Polar characterization of antifungal peptides from APD2 Database.

    Science.gov (United States)

    Polanco, Carlos; Samaniego-Mendoza, José Lino; Buhse, Thomas; Castañón-González, Jorge Alberto; Leopold-Sordo, Marili

    2014-11-01

    The increase in the number of pathogens due to fungi that are tolerant to therapies does not grow at the same speed than the advance on new antifungal drugs. In this sense, it is imperative to find anti-fungi peptides that are not detrimental to mammalian cells and have an effective toxicity to fungi. In this work, we use a method called polarity index, to identify anti-fungi peptides with an efficiency of 70 %. This method already published, initially identified selective antibacterial peptides from APD2 Database, and was characterized by developing a comprehensive analysis of the polar dynamics of a peptide from its linear sequence. Discriminating tests showed that in addition to being efficient in this identification, it was also good at rejecting other classifications of peptides found in that same database.

  19. Substituted Hydroxyapatites with Antibacterial Properties

    Directory of Open Access Journals (Sweden)

    Joanna Kolmas

    2014-01-01

    Full Text Available Reconstructive surgery is presently struggling with the problem of infections located within implantation biomaterials. Of course, the best antibacterial protection is antibiotic therapy. However, oral antibiotic therapy is sometimes ineffective, while administering an antibiotic at the location of infection is often associated with an unfavourable ratio of dosage efficiency and toxic effect. Thus, the present study aims to find a new factor which may improve antibacterial activity while also presenting low toxicity to the human cells. Such factors are usually implemented along with the implant itself and may be an integral part of it. Many recent studies have focused on inorganic factors, such as metal nanoparticles, salts, and metal oxides. The advantages of inorganic factors include the ease with which they can be combined with ceramic and polymeric biomaterials. The following review focuses on hydroxyapatites substituted with ions with antibacterial properties. It considers materials that have already been applied in regenerative medicine (e.g., hydroxyapatites with silver ions and those that are only at the preliminary stage of research and which could potentially be used in implantology or dentistry. We present methods for the synthesis of modified apatites and the antibacterial mechanisms of various ions as well as their antibacterial efficiency.

  20. Substituted hydroxyapatites with antibacterial properties.

    Science.gov (United States)

    Kolmas, Joanna; Groszyk, Ewa; Kwiatkowska-Różycka, Dagmara

    2014-01-01

    Reconstructive surgery is presently struggling with the problem of infections located within implantation biomaterials. Of course, the best antibacterial protection is antibiotic therapy. However, oral antibiotic therapy is sometimes ineffective, while administering an antibiotic at the location of infection is often associated with an unfavourable ratio of dosage efficiency and toxic effect. Thus, the present study aims to find a new factor which may improve antibacterial activity while also presenting low toxicity to the human cells. Such factors are usually implemented along with the implant itself and may be an integral part of it. Many recent studies have focused on inorganic factors, such as metal nanoparticles, salts, and metal oxides. The advantages of inorganic factors include the ease with which they can be combined with ceramic and polymeric biomaterials. The following review focuses on hydroxyapatites substituted with ions with antibacterial properties. It considers materials that have already been applied in regenerative medicine (e.g., hydroxyapatites with silver ions) and those that are only at the preliminary stage of research and which could potentially be used in implantology or dentistry. We present methods for the synthesis of modified apatites and the antibacterial mechanisms of various ions as well as their antibacterial efficiency.

  1. Synthesis and Antibacterial Activities of Erythromycin Derivatives

    Institute of Scientific and Technical Information of China (English)

    FENG Run-liang; GONG Ping; FANG Lin; HONG Wei

    2005-01-01

    Ten new erythromycin antibacterial agents containing amidino group were designed and synthesized from erythromycin via oximation, reduction and condensation. Their structures were confirmed by MS and 13C NMR; the synthetic condition(reaction medium)was explored; and their in vtiro antibacterial activities were tested. Compound HMA-3 showed antibacterial activity against staphylococcus aureus, which is equivalent to that of erythromycin A. Compounds HMA-8 and HMA-4 also showed an antibacterial activitiy. But no compound showed bactericidal activity.

  2. A novel insect defensin mediates the inducible antibacterial activity in larvae of the dragonfly Aeschna cyanea (Paleoptera, Odonata)

    NARCIS (Netherlands)

    Bulet, P.; Cociancich, S.; Reuland, M.; Sauber, F.; Bischoff, Rainer; Hegy, G.; Van Dorsselaer, A.; Hetru, C.; Hoffmann, J.A.

    1992-01-01

    The injection of low doses of bacteria into the aquatic larvae of dragonflies (Aeschna cyanea, Odonata, Paleoptera) induces the appearance in their hemolymph of a potent antibacterial activity. We have isolated a 38-residue peptide from this hemolymph which is strongly active against Gram-positive b

  3. Antibacterial Properties of an Austenitic Antibacterial Stainless Steel and Its Security for Human Body

    Institute of Scientific and Technical Information of China (English)

    Ke YANG; Manqi L(U)

    2007-01-01

    An austenitic antibacterial stainless steel is reported in this paper. The very fine and dispersive ε-Cu precipitations in the matrix of the antibacterial steel after the antibacterial treatment endow the steel with antibacterial function. The antibacterial function is strong, long-term and broad-spectrum, and can be maintained even after repeated wear and long time dipping in water. The steel is safe for human body and could be used widely in daily application.

  4. Covalent modification of a ten-residue cationic antimicrobial peptide with levofloxacin

    Directory of Open Access Journals (Sweden)

    Carlos Alberto Rodriguez

    2014-09-01

    Full Text Available The rampant spread of antibiotic resistant bacteria has spurred interest in alternative strategies for developing next-generation antibacterial therapies. As such, there has been growing interest in cationic antimicrobial peptides (CAMPs and their therapeutic applications. Modification of CAMPs via conjugation to auxiliary compounds, including small molecule drugs, is a new approach to developing effective, broad-spectrum antibacterial agents with novel physicochemical properties and versatile antibacterial mechanisms. Here, we’ve explored design parameters for engineering CAMPs conjugated to small molecules with favorable physicochemical and antibacterial properties by covalently affixing a fluoroquinolone antibiotic, levofloxacin, to the ten-residue CAMP Pep-4. Relative to the unmodified Pep-4, the conjugate was found to demonstrate substantially increased antibacterial potency under high salt concentrations. Historically, it has been observed that most CAMPs lose antibacterial effectiveness in such high ionic strength environments, a fact that has presented a challenge to their development as therapeutics. Physicochemical studies revealed that P4LC was more hydrophobic than Pep-4, while mechanistic findings indicated that the conjugate was more effective at disrupting bacterial membrane integrity. Although the inherent antibacterial effect of the incorporated levofloxacin molecules did not appear to be substantially realized in this conjugate, these findings nevertheless suggest that covalent attachment of small molecule antibiotics with favorable physicochemical properties to CAMPs could be a promising strategy for enhancing peptide performance and overall therapeutic potential. These results have broader applicability to the development of future CAMP-antibiotic conjugates for potential therapeutic applications.

  5. Antibacterial Resistance Leadership Group: Open for Business

    OpenAIRE

    Chambers, Henry F.; Bartlett, John G.; Bonomo, Robert A.; Chiou, Christine; Cosgrove, Sara E.; CROSS, HEATHER R.; Daum, Robert S.; Downing, Michele; Evans, Scott R.; Knisely, Jane; Kreiswirth, Barry N.; Lautenbach, Ebbing; Mickley, Brenda S.; Patel, Robin; Pettigrew, Melinda M

    2014-01-01

    The Antibacterial Resistance Leadership Group (ARLG) is tasked with prioritizing, designing, implementing, and conducting clinical studies to address antibacterial resistance. This article outlines clinical research resources and opportunities made available by ARLG and encourages submission of proposals that address antibacterial resistance.

  6. Antimicrobial Peptides

    Directory of Open Access Journals (Sweden)

    Ali Adem Bahar

    2013-11-01

    Full Text Available The rapid increase in drug-resistant infections has presented a serious challenge to antimicrobial therapies. The failure of the most potent antibiotics to kill “superbugs” emphasizes the urgent need to develop other control agents. Here we review the history and new development of antimicrobial peptides (AMPs, a growing class of natural and synthetic peptides with a wide spectrum of targets including viruses, bacteria, fungi, and parasites. We summarize the major types of AMPs, their modes of action, and the common mechanisms of AMP resistance. In addition, we discuss the principles for designing effective AMPs and the potential of using AMPs to control biofilms (multicellular structures of bacteria embedded in extracellular matrixes and persister cells (dormant phenotypic variants of bacterial cells that are highly tolerant to antibiotics.

  7. Peptide consensus sequence determination for the enhancement of the antimicrobial activity and selectivity of antimicrobial peptides

    Science.gov (United States)

    Almaaytah, Ammar; Ajingi, Ya’u; Abualhaijaa, Ahmad; Tarazi, Shadi; Alshar’i, Nizar; Al-Balas, Qosay

    2017-01-01

    The rise of multidrug-resistant bacteria is causing a serious threat to the world’s human population. Recent reports have identified bacterial strains displaying pan drug resistance against antibiotics and generating fears among medical health specialists that humanity is on the dawn of entering a post-antibiotics era. Global research is currently focused on expanding the lifetime of current antibiotics and the development of new antimicrobial agents to tackle the problem of antimicrobial resistance. In the present study, we designed a novel consensus peptide named “Pepcon” through peptide consensus sequence determination among members of a highly homologous group of scorpion antimicrobial peptides. Members of this group were found to possess moderate antimicrobial activity with significant toxicity against mammalian cells. The aim of our design method was to generate a novel peptide with an enhanced antimicrobial potency and selectivity against microbial rather than mammalian cells. The results of our study revealed that the consensus peptide displayed potent antibacterial activities against a broad range of Gram-positive and Gram-negative bacteria. Our membrane permeation studies displayed that the peptide efficiently induced membrane damage and consequently led to cell death through the process of cell lysis. The microbial DNA binding assay of the peptide was found to be very weak suggesting that the peptide is not targeting the microbial DNA. Pepcon induced minimal cytotoxicity at the antimicrobial concentrations as the hemolytic activity was found to be zero at the minimal inhibitory concentrations (MICs). The results of our study demonstrate that the consensus peptide design strategy is efficient in generating peptides. PMID:28096686

  8. Antimicrobial peptides in human sepsis

    Directory of Open Access Journals (Sweden)

    Lukas eMartin

    2015-08-01

    Full Text Available Nearly 100 years ago, antimicrobial peptides (AMPs were identified as an important part of innate immunity. They exist in species from bacteria to mammals and can be isolated in body fluids and on surfaces constitutively or induced by inflammation. Defensins have anti-bacterial effects against Gram-positive and Gram-negative bacteria as well as anti-viral and anti-yeast effects. Human neutrophil peptides (HNP 1-3 and human beta-defensins (HBDs 1-3 are some of the most important defensins in humans. Recent studies have demonstrated higher levels of HNP -1-3 and HBD-2 in sepsis. The bactericidal/permeability increasing protein (BPI attenuates local inflammatory response and decreases systemic toxicity of endotoxins. Moreover, BPI might reflect the severity of organ dysfunction in sepsis. Elevated plasma lactoferrin is detected in patients with organ failure. HNP-1-3, lactoferrin, BPI and heparin-binding protein (HBP are increased in sepsis. Human lactoferrin peptide 1-11 (hLF 1-11 possesses antimicrobial activity and modulates inflammation. The recombinant form of lactoferrin (talactoferrin alpha, TLF has been shown to decrease mortality in critically ill patients. A phase II/III study with TLF in sepsis did not confirm this result. The growing number of multiresistant bacteria is an ongoing problem in sepsis therapy. Furthermore, antibiotics are known to promote the liberation of pro-inflammatory cell components and thus augment the severity of sepsis. Compared to antibiotics, AMPs kill bacteria but also neutralize pathogenic factors such as lipopolysaccharide (LPS. The obstacle to applying naturally occurring AMPs is their high nephro- and neurotoxicity. Therefore, the challenge is to develop peptides to treat septic patients effectively without causing harm. This overview focuses on natural and synthetic AMPs in human and experimental sepsis and their potential to provide significant improvements in the treatment of critically ill with severe

  9. Peptide arrays for screening cancer specific peptides.

    Science.gov (United States)

    Ahmed, Sahar; Mathews, Anu Stella; Byeon, Nara; Lavasanifar, Afsaneh; Kaur, Kamaljit

    2010-09-15

    In this paper, we describe a novel method to screen peptides for specific recognition by cancer cells. Seventy peptides were synthesized on a cellulose membrane in an array format, and a direct method to study the peptide-whole cell interaction was developed. The relative binding affinity of the cells for different peptides with respect to a lead 12-mer p160 peptide, identified by phage display, was evaluated using the CyQUANT fluorescence of the bound cells. Screening allowed identification of at least five new peptides that displayed higher affinity (up to 3-fold) for MDA-MB-435 and MCF-7 human cancer cells compared to the p160 peptide. These peptides showed very little binding to the control (noncancerous) human umbilical vein endothelial cells (HUVECs). Three of these peptides were synthesized separately and labeled with fluorescein isothiocyanate (FITC) to study their uptake and interaction with the cancer and control cells using confocal laser scanning microscopy and flow cytometry. The results confirmed the high and specific affinity of an 11-mer peptide 11 (RGDPAYQGRFL) and a 10-mer peptide 18 (WXEAAYQRFL) for the cancer cells versus HUVECs. Peptide 11 binds different receptors on target cancer cells as its sequence contains multiple recognition motifs, whereas peptide 18 binds mainly to the putative p160 receptor. The peptide array-whole cell binding assay reported here is a complementary method to phage display for further screening and optimization of cancer targeting peptides for cancer therapy and diagnosis.

  10. Short cationic lipopeptides as effective antibacterial agents: Design, physicochemical properties and biological evaluation.

    Science.gov (United States)

    Azmi, Fazren; Elliott, Alysha G; Marasini, Nirmal; Ramu, Soumya; Ziora, Zyta; Kavanagh, Angela M; Blaskovich, Mark A T; Cooper, Matthew A; Skwarczynski, Mariusz; Toth, Istvan

    2016-05-15

    The spread of drug-resistant bacteria has imparted a sense of urgency in the search for new antibiotics. In an effort to develop a new generation of antibacterial agents, we have designed de novo charged lipopeptides inspired by natural antimicrobial peptides. These short lipopeptides are composed of cationic lysine and hydrophobic lipoamino acids that replicate the amphiphilic properties of natural antimicrobial peptides. The resultant lipopeptides were found to self-assemble into nanoparticles. Some were effective against a variety of Gram-positive bacteria, including strains resistant to methicillin, daptomycin and/or vancomycin. The lipopeptides were not toxic to human kidney and liver cell lines and were highly resistant to tryptic degradation. Transmission electron microscopy analysis of bacteria cells treated with lipopeptide showed membrane-damage and lysis with extrusion of cytosolic contents. With such properties in mind, these lipopeptides have the potential to be developed as new antibacterial agents against drug-resistant Gram-positive bacteria.

  11. Anti-bacterial Studies of Silver Nanoparticles

    CERN Document Server

    Theivasanthi, T

    2011-01-01

    We discuss about the antibacterial activities of Silver nanoparticles and compare them on both Gram negative and Gram positive bacteria in this investigation. The activities of Silver nanoparticles synthesized by electrolysis method are more in Gram (-) than Gram (+) bacteria. First time, we increase its antibacterial activities by using electrical power while on electrolysis synthesis and it is confirmed from its more antibacterial activities (For Escherichia coli bacteria). We investigate the changes of inner unit cell Lattice constant of Silver nanoparticles prepared in two different methods and its effects on antibacterial activities. We note that slight change of the lattice constant results in the enhancement of its antibacterial activities.

  12. Defensins and cystein rich peptides: two types of antimicrobial peptides in marine molluscs

    Directory of Open Access Journals (Sweden)

    G Arenas Díaz

    2010-06-01

    Full Text Available This review focuses on defensins and cystein rich peptides, which are the most abundant natural antimicrobial peptides (AMPs described in molluscs. These are compact peptides, 3-5 kDa in molecular mass, cationic and amphipatic; the presence of at least six cysteine residues forming three or four disulfide bridges is their prime structural characteristic. A 3-D structural characterization of these molecules has been included in recent investigations, using currently-available techniques. AMPs have been purified from hemocytes, epithelial tissue and plasma as well as cloned and chemically synthesized. Their antibacterial activity against Gram-positive and Gram-negative bacteria and fungi has been shown; only a synthetic mytilin fragment has displayed activity against viruses.

  13. Antibacterial potential of contemporary dental luting cements.

    Science.gov (United States)

    Daugela, Povilas; Oziunas, Rimantas; Zekonis, Gediminas

    2008-01-01

    The aims of this investigation were to evaluate the antibacterial activities of different types of dental luting cements and to compare antibacterial action during and after setting. Agar diffusion testing was used to evaluate the antibacterial properties of seven types of dental luting cements (glass ionomer cements (GICs), resin modified GICs, resin composite, zinc oxide eugenol, zinc oxide non-eugenol, zinc phosphate, zinc polycarboxylate cements) on Streptococcus mutans bacteria. Instantly mixed zinc phosphate cements showed the strongest antibacterial activity in contrast to the non-eugenol, eugenol and resin cements that did not show any antibacterial effects. Non-hardened glass ionomer, resin modified and zinc polycarboxylate cements exhibited moderate antibacterial action. Hardened cements showed weaker antibacterial activities, than those ones applied right after mixing.

  14. Novel histone-derived antimicrobial peptides use different antimicrobial mechanisms.

    Science.gov (United States)

    Pavia, Kathryn E; Spinella, Sara A; Elmore, Donald E

    2012-03-01

    The increase in multidrug resistant bacteria has sparked an interest in the development of novel antibiotics. Antimicrobial peptides that operate by crossing the cell membrane may also have the potential to deliver drugs to intracellular targets. Buforin 2 (BF2) is an antimicrobial peptide that shares sequence identity with a fragment of histone subunit H2A and whose bactericidal mechanism depends on membrane translocation and DNA binding. Previously, novel histone-derived antimicrobial peptides (HDAPs) were designed based on properties of BF2, and DesHDAP1 and DesHDAP3 showed significant antibacterial activity. In this study, their DNA binding, permeabilization, and translocation abilities were assessed independently and compared to antibacterial activity to determine whether they share a mechanism with BF2. To investigate the importance of proline in determining the peptides' mechanisms of action, proline to alanine mutants of the novel peptides were generated. DesHDAP1, which shows significant similarities to BF2 in terms of secondary structure, translocates effectively across lipid vesicle and bacterial membranes, while the DesHDAP1 proline mutant shows reduced translocation abilities and antimicrobial potency. In contrast, both DesHDAP3 and its proline mutant translocate poorly, though the DesHDAP3 proline mutant is more potent. Our findings suggest that a proline hinge can promote membrane translocation in some peptides, but that the extent of its effect on permeabilization depends on the peptide's amphipathic properties. Our results also highlight the different antimicrobial mechanisms exhibited by histone-derived peptides and suggest that histones may serve as a source of novel antimicrobial peptides with varied properties.

  15. Antibacterial constituents from Melodinus suaveolens.

    Science.gov (United States)

    Li, Jiang-Ling; Lunga, Paul-Keilah; Zhao, Yun-Li; Qin, Xu-Jie; Yang, Xing-Wei; Liu, Ya-Ping; Luo, Xiao-Dong

    2015-04-01

    To investigate the non-alkaloidal chemical constituents of the stems and leaves of Melodinus suaveolens and their antibacterial activities. Compounds were isolated and purified by repeated silica gel, Sephadex LH-20, RP18, and preparative HPLC. Their structures were elucidated by comparison with published spectroscopic data, as well as on the basis of extensive spectroscopic analysis. The antibacterial screening assays were performed by the dilution method. Fourteen compounds were isolated, and identified as lycopersene (1), betulinic aldehyde (2), 3β-acetoxy-22,23,24,25,26,27-hexanordammaran-20-one (3), 3a-acetyl-2, 3, 5-trimethyl-7a-hydroxy-5-(4,8,12-trimethyl-tridecanyl)-1,3a,5,6,7,7a-hexahydro-4-oxainden-1-one (4), 3β-hydroxy-28-norlup-20(29)-ene-17β-hydroperoxide (5), 3β-hydroxy-28-norlup-20(29)-ene-17α-hydroperoxide (6), β-sitosterol (7), 28-nor-urs-12-ene-3β, 17β-diol (8), α-amyrin (9), ergosta-4,6,8(14),22-tetraen-3-one (10), 3β-hydroxy-urs-11-en-28,13β-olide (11), betulin (12), obtusalin (13), and ursolic acid (14). Among the isolates, compounds 1, 2, 6, 8, 10, and 14 showed potent antibacterial activities against the four bacteria. This is the first report of the antibacterial activity of the constituents of Melodinus suaveolens.

  16. Facile biofunctionalization of silver nanoparticles for enhanced antibacterial properties, endotoxin removal, and biofilm control.

    Science.gov (United States)

    Lambadi, Paramesh Ramulu; Sharma, Tarun Kumar; Kumar, Piyush; Vasnani, Priyanka; Thalluri, Sitaramanjaneya Mouli; Bisht, Neha; Pathania, Ranjana; Navani, Naveen Kumar

    2015-01-01

    Infectious diseases cause a huge burden on healthcare systems worldwide. Pathogenic bacteria establish infection by developing antibiotic resistance and modulating the host's immune system, whereas opportunistic pathogens like Pseudomonas aeruginosa adapt to adverse conditions owing to their ability to form biofilms. In the present study, silver nanoparticles were biofunctionalized with polymyxin B, an antibacterial peptide using a facile method. The biofunctionalized nanoparticles (polymyxin B-capped silver nanoparticles, PBSNPs) were assessed for antibacterial activity against multiple drug-resistant clinical strain Vibrio fluvialis and nosocomial pathogen P. aeruginosa. The results of antibacterial assay revealed that PBSNPs had an approximately 3-fold higher effect than the citrate-capped nanoparticles (CSNPs). Morphological damage to the cell membrane was followed by scanning electron microscopy, testifying PBSNPs to be more potent in controlling the bacterial growth as compared with CSNPs. The bactericidal effect of PBSNPs was further confirmed by Live/Dead staining assays. Apart from the antibacterial activity, the biofunctionalized nanoparticles were found to resist biofilm formation. Electroplating of PBSNPs onto stainless steel surgical blades retained the antibacterial activity against P. aeruginosa. Further, the affinity of polymyxin for endotoxin was exploited for its removal using PBSNPs. It was found that the prepared nanoparticles removed 97% of the endotoxin from the solution. Such multifarious uses of metal nanoparticles are an attractive means of enhancing the potency of antimicrobial agents to control infections.

  17. Antibacterial activity of epidural infusions.

    Science.gov (United States)

    Coghlan, M W; Davies, M J; Hoyt, C; Joyce, L; Kilner, R; Waters, M J

    2009-01-01

    The incidence of epidural abscess following epidural catheterisation appears to be increasing, being recently reported as one in 1000 among surgical patients. This study was designed to investigate the antibacterial activity of various local anaesthetics and additives, used in epidural infusions, against a range of micro-organisms associated with epidural abscess. The aim was to determine which, if any, epidural infusion solution has the greatest antibacterial activity. Bupivacaine, ropivacaine and levobupivacaine crystals were dissolved and added to Mueller-Hinton Agar in concentrations of 0.06%, 0.125%, 0.2%, 0.25%, 0.5% and 1%. Fentanyl, adrenaline and clonidine were also mixed with agar in isolation and in combination with the local anaesthetics. Using a reference agar dilution method, the minimum inhibitory concentrations were determined for a range of bacteria. Bupivacaine showed antibacterial activity against Staphylococcus aureus, Enterococcus faecalis and Escherichia coli with minimum inhibitory concentrations between 0.125% and 0.25%. It did not inhibit the growth of Pseudomonas aeruginosa at any of the concentrations tested. Levobupivacaine and ropivacaine showed no activity against Staphylococcus aureus, Enterococcus faecalis and Pseudomonas aeruginosa, even at the highest concentrations tested, and minimal activity against Escherichia coli (minimum inhibitory concentrations 0.5% and 1% respectively). The presence of fentanyl, adrenaline and clonidine had no additional effect on the antibacterial activity of any of the local anaesthetic agents. The low concentrations of local anaesthetic usually used in epidural infusions have minimal antibacterial activity. While the clinical implications of this in vitro study are not known, consideration should be given to increasing the concentration of bupivacaine in an epidural infusion or to administering a daily bolus of 0.25% bupivacaine to reduce the risk of epidural bacterial growth.

  18. Isolation and Purification of an Antibacterial Protein from Immune Induced Haemolymph of American Cockroach, Periplaneta americana

    Directory of Open Access Journals (Sweden)

    Hamid Reza Basseri

    2016-10-01

    Full Text Available Background: Antimicrobial peptides play a role as effectors substances in the immunity of vertebrate and inverte­brate hosts. In the current study, antimicrobial peptide was isolated from the haemolymph of the American cock­roach, Periplaneta americana.Methods: Micrococcus luteus as Gram-positive bacteria and Escherichia coli as Gram-negative bacteria were candi­date for injection. Induction was done by injecting both bacteria into the abdominal cavity of two groups of cock­roaches separately. The haemolymphs were collected 24 hours after post injection and initially tested against both bacteria. Subsequently, the immune induced haemolymph was purified by high performance liquid chromatography (HPLC to separate the proteins responsible for the antibacterial activity.Results: The non-induced haemolymph did not show any activity against both bacteria whereas induced haemo­lymph exhibited high activity against M. luteus but did less against E. coli. Two fractions showed antibacterial activ­ity against M. luteus. Finally the molecular weight of the isolated antibacterial proteins were determined as 72 kDa and 62 kDa using SDS-PAGE.Conclusion: Induced haemolymph of American cockroaches has the ability to produce peptides to combat against Gram-positive bacteria when an immune challenge is mounted. Further work has to be done to sequence of the pro­tein, which it would be advantageous.

  19. Molecular dynamics investigation of the influence of anionic and zwitterionic interfaces on antimicrobial peptides' structure: implications for peptide toxicity and activity

    DEFF Research Database (Denmark)

    Khandelia, Himanshu; Kaznessis, Yiannis N

    2006-01-01

    into the DPC micelle. This correlates well with the lesser toxicity of G10 and T7. There is strong evidence which suggests that synergistic binding of hydrophobic residues drives binding of OVIS to the micelle. The helical content of G10 and T7 is reduced in the presence of DPC, and this leads to less...... properties. Based on the simulations, we argue that secondary structure stability often leads to toxic properties. We also propose that G10 and T7 operate by the carpet mechanism of cell lysis. Toxicity of peptides operating by the carpet mechanism can be attenuated by reducing the peptide helical content....... The goal of this study is to dissect the differences in peptide composition which make the mutant peptides (novispirin-G10 and novispirin-T7) less toxic than the parent peptide ovispirin (OVIS), although all three peptides have highly antibacterial properties. Compared to G10 and T7, OVIS inserts deepest...

  20. Proteins as the source of physiologically and functionally active peptides

    Directory of Open Access Journals (Sweden)

    Anna Iwaniak

    2007-09-01

    Full Text Available The market of functional foods and beverages develops dynamically. Biological activities of many food components which occur naturally become an issue of many scientific and industrial interests. The structural and chemical changes occurring during the proteins processing lead to the release of bioactive peptides. Their multifunctional activity is based on their structure and other factors including e.g. hydrophobicity, charge, or microelements binding properties. This article focuses on peptides with other physiological and functional activities such as antithromobotic, antioxidative, antibacterial and antifungal, sensory, and improving those nutritional value of food.

  1. Neurotropic and neuroprotective activities of the earthworm peptide Lumbricusin

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dae Hong; Lee, Ik Hwan; Nam, Seung Taek; Hong, Ji; Zhang, Peng [Department of Life Science, College of Natural Science, Daejin University, Pocheon, Gyeonggido 487-711 (Korea, Republic of); Hwang, Jae Sam [Department of Agricultural Biology, National Academy of Agricultural Science, RDA, Suwon 441-707 (Korea, Republic of); Seok, Heon [Department of Biomedical Engineering, Jungwon University, Goesan, Chungcheongbukdo 367-700 (Korea, Republic of); Choi, Hyemin; Lee, Dong Gun [School of Life Sciences, KNU Creative Bioresearch Group (BK21 Plus Program), College of Natural Sciences, Kyungpook National University, Daehak-ro 80, Buk-gu, Daegu 702-701 (Korea, Republic of); Kim, Jae Il [School of Life Sciences, Gwangju Institute of Science and Technology, Oryong-dong, Buk-gu, Gwangju 500-712 (Korea, Republic of); Kim, Ho, E-mail: hokim@daejin.ac.kr [Department of Life Science, College of Natural Science, Daejin University, Pocheon, Gyeonggido 487-711 (Korea, Republic of)

    2014-06-06

    Highlights: • 11-mer peptide Lumbricusin, a defensin like peptide, is isolated from earthworm. • We here demonstrated that Lumbricusin has neurotropic and neuroprotective effects. • p27 degradation by Lumbricusin mediates effects of Lumbricusin on neuronal cells. - Abstract: We recently isolated a polypeptide from the earthworm Lumbricus terrestris that is structurally similar to defensin, a well-known antibacterial peptide. An 11-mer antibacterial peptide (NH{sub 2}-RNRRWCIDQQA), designated Lumbricusin, was synthesized based on the amino acid sequence of the isolated polypeptide. Since we previously reported that CopA3, a dung beetle peptide, enhanced neuronal cell proliferation, we here examined whether Lumbricusin exerted neurotropic and/or neuroprotective effects. Lumbricusin treatment induced a time-dependent increase (∼51%) in the proliferation of human neuroblastoma SH-SY5Y cells. Lumbricusin also significantly inhibited the apoptosis and decreased viability induced by treatment with 6-hydroxy dopamine, a Parkinson’s disease-mimicking agent. Immunoblot analyses revealed that Lumbricusin treatment increased ubiquitination of p27{sup Kip1} protein, a negative regulator of cell-cycle progression, in SH-SY5Y cells, and markedly promoted its degradation. Notably, adenoviral-mediated over-expression of p27{sup Kip1} significantly blocked the antiapoptotic effect of Lumbricusin in 6-hydroxy dopamine-treated SH-SY5Y cells. These results suggest that promotion of p27{sup Kip1} degradation may be the main mechanism underlying the neuroprotective and neurotropic effects of Lumbricusin.

  2. Antimicrobial activity of histidine-rich peptides is dependent on acidic conditions.

    OpenAIRE

    Kacprzyk, Lukasz; Rydengård, Victoria; Mörgelin, Matthias; Davoudi, Mina; Pasupuleti, Mukesh; Malmsten, Martin; Schmidtchen, Artur

    2007-01-01

    Synthetic peptides composed of multiples of the consensus heparin-binding Cardin and Weintraub sequences AKKARA and ARKKAAKA are antimicrobial. Replacement of lysine and arginine by histidine in these peptides completely abrogates their antimicrobial and heparin-binding activities at neutral pH. However, the antibacterial activity against Gram-negative (Escherichia coli, Pseudomonas aeruginosa) and Gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus) as well as the fungus Cand...

  3. Small cationic antimicrobial peptides delocalize peripheral membrane proteins.

    Science.gov (United States)

    Wenzel, Michaela; Chiriac, Alina Iulia; Otto, Andreas; Zweytick, Dagmar; May, Caroline; Schumacher, Catherine; Gust, Ronald; Albada, H Bauke; Penkova, Maya; Krämer, Ute; Erdmann, Ralf; Metzler-Nolte, Nils; Straus, Suzana K; Bremer, Erhard; Becher, Dörte; Brötz-Oesterhelt, Heike; Sahl, Hans-Georg; Bandow, Julia Elisabeth

    2014-04-08

    Short antimicrobial peptides rich in arginine (R) and tryptophan (W) interact with membranes. To learn how this interaction leads to bacterial death, we characterized the effects of the minimal pharmacophore RWRWRW-NH2. A ruthenium-substituted derivative of this peptide localized to the membrane in vivo, and the peptide also integrated readily into mixed phospholipid bilayers that resemble Gram-positive membranes. Proteome and Western blot analyses showed that integration of the peptide caused delocalization of peripheral membrane proteins essential for respiration and cell-wall biosynthesis, limiting cellular energy and undermining cell-wall integrity. This delocalization phenomenon also was observed with the cyclic peptide gramicidin S, indicating the generality of the mechanism. Exogenous glutamate increases tolerance to the peptide, indicating that osmotic destabilization also contributes to antibacterial efficacy. Bacillus subtilis responds to peptide stress by releasing osmoprotective amino acids, in part via mechanosensitive channels. This response is triggered by membrane-targeting bacteriolytic peptides of different structural classes as well as by hypoosmotic conditions.

  4. Improved methods for classification, prediction, and design of antimicrobial peptides.

    Science.gov (United States)

    Wang, Guangshun

    2015-01-01

    Peptides with diverse amino acid sequences, structures, and functions are essential players in biological systems. The construction of well-annotated databases not only facilitates effective information management, search, and mining but also lays the foundation for developing and testing new peptide algorithms and machines. The antimicrobial peptide database (APD) is an original construction in terms of both database design and peptide entries. The host defense antimicrobial peptides (AMPs) registered in the APD cover the five kingdoms (bacteria, protists, fungi, plants, and animals) or three domains of life (bacteria, archaea, and eukaryota). This comprehensive database ( http://aps.unmc.edu/AP ) provides useful information on peptide discovery timeline, nomenclature, classification, glossary, calculation tools, and statistics. The APD enables effective search, prediction, and design of peptides with antibacterial, antiviral, antifungal, antiparasitic, insecticidal, spermicidal, anticancer activities, chemotactic, immune modulation, or antioxidative properties. A universal classification scheme is proposed herein to unify innate immunity peptides from a variety of biological sources. As an improvement, the upgraded APD makes predictions based on the database-defined parameter space and provides a list of the sequences most similar to natural AMPs. In addition, the powerful pipeline design of the database search engine laid a solid basis for designing novel antimicrobials to combat resistant superbugs, viruses, fungi, or parasites. This comprehensive AMP database is a useful tool for both research and education.

  5. Identification and characterization of novel host defense peptides from the skin secretion of the fungoid frog, Hydrophylax bahuvistara (Anura: Ranidae).

    Science.gov (United States)

    Vineeth Kumar, Thundi Parambil Vasanth Kumar; Asha, Radhamony; Shyla, Gopal; George, Sanil

    2017-01-10

    Two novel peptides (brevinin1 HYba1 and brevinin1 HYba2) were identified from the skin secretion of the frog Hydrophylax bahuvistara, endemic to Western Ghats, India, and their amino acid sequences were confirmed using cDNA cloning and LC/MS/MS. Antibacterial, hemolytic, and cytotoxic activities of brevinin1 peptides and their synthetic analogs (amidated C-terminus) were investigated and compared. All the peptides except the acidic forms showed antibacterial activity against all tested Gram-positive and Gram-negative bacteria. They exhibited low hemolysis on human erythrocytes and showed potent cytotoxic activity against Hep 3B cancer cell line. Upon amidation, the peptides showed increased activity against the tested microbes without altering their hemolytic and cytotoxic properties. The study also emphasizes the need for screening endemic amphibian fauna of Western Ghats, as a potential source of host defense peptides with possible therapeutic applications in the future.

  6. Antibacterial potency screening of Capparis zeylanica Linn

    Institute of Scientific and Technical Information of China (English)

    Rezaul Haque; Wahedul Islam; Selina Parween

    2016-01-01

    Objective: To conduct the antibacterial potency and minimum inhibitory concentration of extracts (n-hexane, acetone, chloroform and methanol) obtained from the root, leaf and stem of Capparis zeylanica. Methods: The powdered leaf, root and stem samples were Soxhlet extracted sequentially in n-hexane, acetone, chloroform and methanol. Antibacterial potency was evaluated by following the agar diffusion method and amoxicillin disc was used as a control. Results: In vitro antibacterial activity against 12 bacteria was performed with crude extracts. Among them, all the bacteria showed the moderate activity but chloroform and methanolic extracts showed promising antibacterial potency against Staphylococcus aureus, Sarcina lutea, Bacillus megaterium, Bacillus subtilis, Salmonella typhi and Shigella dysenteriae (leaf > root > stem). This activity was evaluated using disc diffusion method with a standard antibiotic, 30 µg/disc of amoxicillin. Conclusions: Strong antibacterial potency of chloroform and methanolic extracts provides new antibacterial compounds.

  7. Antibacterial activity of graphene layers

    Science.gov (United States)

    Dybowska-Sarapuk, Ł.; Kotela, A.; Krzemiński, J.; Janczak, D.; Wróblewska, M.; Marchel, H.; Łegorz, P.; Jakubowska, M.

    2016-09-01

    The bacterial biofilm is a direct cause of complications in management of various medical conditions. There is an ongoing search for a feasible method to prevent its growth, as an alternative to antibiotics, which are ineffective. The aim of the study was to prepare and evaluate a detailed algorithm for production of graphene coatings, using economically efficient methods of printed electronics (such as ink-jet printing or spray coating), and assess their antibacterial properties. Based on the preliminary results of our work we suggest that graphene coating may inhibit the formation of microbial biofilms. Further research is needed to verify antibacterial properties of graphene coatings and its future applications in prevention of biofilm-related infections, e.g. by coating surgical instruments, catheters or tracheostomy tubes. In addition, we propose a series of hypotheses to be evaluated in further work.

  8. Antibacterial phenylpropanoid glycosides from Paulownia tomentosa Steud.

    Science.gov (United States)

    Kang, K H; Jang, S K; Kim, B K; Park, M K

    1994-12-01

    The butanol extract of Paulownia tomentosa stem showed antibacterial activity against Staphylococcus aureus (SG511, 285 and 503), Streptococcus pyogenes (A308 and A77) and Streptococcus faecium MD8b etc. The most active compound of the extract was identified to be campneoside I, which had a minimal inhibitory concentration (MIC) of 150 micrograms/ml against Streptococcus and Staphylococcus species. From such antibacterial activity, the methoxy group of campneoside I was postulated to be the essential element for the antibacterial activity.

  9. Modified Silica Nanofibers with Antibacterial Activity

    Directory of Open Access Journals (Sweden)

    Ivana Veverková

    2016-01-01

    Full Text Available This study is focused on development of functionalized inorganic-organic nanofibrous material with antibacterial activity for wound dressing applications. The nanofibers combining poly(vinyl alcohol and silica were produced by electrospinning from the sol and thermally stabilized. The PVA/silica nanofibers surface was functionalized by silver and copper nanoparticles to ensure antibacterial activity. It was proven that quantity of adsorbed silver and copper nanoparticles depends on process time of adsorption. According to antibacterial tests results, this novel nanofibrous material shows a big potential for wound dressing applications due to its significant antibacterial efficiency.

  10. Human peptide transporters

    DEFF Research Database (Denmark)

    Nielsen, Carsten Uhd; Brodin, Birger; Jørgensen, Flemming Steen;

    2002-01-01

    Peptide transporters are epithelial solute carriers. Their functional role has been characterised in the small intestine and proximal tubules, where they are involved in absorption of dietary peptides and peptide reabsorption, respectively. Currently, two peptide transporters, PepT1 and PepT2...

  11. The cyclic cystine ladder in θ-defensins is important for structure and stability, but not antibacterial activity.

    Science.gov (United States)

    Conibear, Anne C; Rosengren, K Johan; Daly, Norelle L; Henriques, Sónia Troeira; Craik, David J

    2013-04-12

    θ-Defensins are ribosomally synthesized cyclic peptides found in the leukocytes of some primate species and have promising applications as antimicrobial agents and scaffolds for peptide drugs. The cyclic cystine ladder motif, comprising a cyclic peptide backbone and three parallel disulfide bonds, is characteristic of θ-defensins. In this study, we explore the role of the cyclic peptide backbone and cystine ladder in the structure, stability, and activity of θ-defensins. θ-Defensin analogues with different numbers and combinations of disulfide bonds were synthesized and characterized in terms of their NMR solution structures, serum and thermal stabilities, and their antibacterial and membrane-binding activities. Whereas the structures and stabilities of the peptides were primarily dependent on the number and position of the disulfide bonds, their antibacterial and membrane-binding properties were dependent on the cyclic backbone. The results provide insights into the mechanism of action of θ-defensins and illustrate the potential of θ-defensin analogues as scaffolds for peptide drug design.

  12. Enhanced Antimicrobial Activity of AamAP1-Lysine, a Novel Synthetic Peptide Analog Derived from the Scorpion Venom Peptide AamAP1

    Directory of Open Access Journals (Sweden)

    Ammar Almaaytah

    2014-04-01

    Full Text Available There is great interest in the development of antimicrobial peptides as a potentially novel class of antimicrobial agents. Several structural determinants are responsible for the antimicrobial and cytolytic activity of antimicrobial peptides. In our study, a new synthetic peptide analog, AamAP1-Lysine from the naturally occurring scorpion venom antimicrobial peptide AamAP1, was designed by modifying the parent peptide in order to increase the positive charge and optimize other physico-chemical parameters involved in antimicrobial activity. AamAP1-Lysine displayed potent antibacterial activity against Gram-positive and Gram-negative bacteria. The minimum inhibitory concentration was in the range of 5 to 15 µM with a 10 fold increase in potency over the parent peptide. The hemolytic and antiproliferative activity of AamAP1-Lysine against eukaryotic mammalian cells was minimal at the concentration range needed to inhibit bacterial growth. The antibacterial mechanism analysis indicated that AamAP1-Lysine is probably inducing bacterial cell death through membrane damage and permeabilization determined by the release of β-galactosidase enzyme from peptide treated E. coli cells. DNA binding studies revealed that AamAP1-Lysine caused complete retardation of DNA migration and could display intracellular activities in addition to the membrane permeabilization mode of action reported earlier. In conclusion, AamAP1-Lysine could prove to be a potential candidate for antimicrobial drug development in future studies.

  13. High Specific Selectivity and Membrane-Active Mechanism of Synthetic Cationic Hybrid Antimicrobial Peptides Based on the Peptide FV7

    Science.gov (United States)

    Tan, Tingting; Wu, Di; Li, Weizhong; Zheng, Xin; Li, Weifen; Shan, Anshan

    2017-01-01

    Hybrid peptides integrating different functional domains of peptides have many advantages, such as remarkable antimicrobial activity, lower hemolysis and ideal cell selectivity, compared with natural antimicrobial peptides. FV7 (FRIRVRV-NH2), a consensus amphiphilic sequence was identified as being analogous to host defense peptides. In this study, we designed a series of hybrid peptides FV7-LL-37 (17–29) (FV-LL), FV7-magainin 2 (9–21) (FV-MA) and FV7-cecropin A (1–8) (FV-CE) by combining the FV7 sequence with the small functional sequences LL-37 (17–29) (LL), magainin 2 (9–21) (MA) and cecropin A (1–8) (CE) which all come from well-described natural peptides. The results demonstrated that the synthetic hybrid peptides, in particular FV-LL, had potent antibacterial activities over a wide range of Gram-negative and Gram-positive bacteria with lower hemolytic activity than other peptides. Furthermore, fluorescent spectroscopy indicated that the hybrid peptide FV-LL exhibited marked membrane destruction by inducing outer and inner bacterial membrane permeabilization, while scanning electron microscopy (SEM) and transmission electron microscopy (TEM) demonstrated that FV-LL damaged membrane integrity by disrupting the bacterial membrane. Inhibiting biofilm formation assays also showed that FV-LL had similar anti-biofilm activity compared with the functional peptide sequence FV7. Synthetic cationic hybrid peptides based on FV7 could provide new models for combining different functional domains and demonstrate effective avenues to screen for novel antimicrobial agents. PMID:28178190

  14. High Specific Selectivity and Membrane-Active Mechanism of Synthetic Cationic Hybrid Antimicrobial Peptides Based on the Peptide FV7.

    Science.gov (United States)

    Tan, Tingting; Wu, Di; Li, Weizhong; Zheng, Xin; Li, Weifen; Shan, Anshan

    2017-02-06

    Hybrid peptides integrating different functional domains of peptides have many advantages, such as remarkable antimicrobial activity, lower hemolysis and ideal cell selectivity, compared with natural antimicrobial peptides. FV7 (FRIRVRV-NH₂), a consensus amphiphilic sequence was identified as being analogous to host defense peptides. In this study, we designed a series of hybrid peptides FV7-LL-37 (17-29) (FV-LL), FV7-magainin 2 (9-21) (FV-MA) and FV7-cecropin A (1-8) (FV-CE) by combining the FV7 sequence with the small functional sequences LL-37 (17-29) (LL), magainin 2 (9-21) (MA) and cecropin A (1-8) (CE) which all come from well-described natural peptides. The results demonstrated that the synthetic hybrid peptides, in particular FV-LL, had potent antibacterial activities over a wide range of Gram-negative and Gram-positive bacteria with lower hemolytic activity than other peptides. Furthermore, fluorescent spectroscopy indicated that the hybrid peptide FV-LL exhibited marked membrane destruction by inducing outer and inner bacterial membrane permeabilization, while scanning electron microscopy (SEM) and transmission electron microscopy (TEM) demonstrated that FV-LL damaged membrane integrity by disrupting the bacterial membrane. Inhibiting biofilm formation assays also showed that FV-LL had similar anti-biofilm activity compared with the functional peptide sequence FV7. Synthetic cationic hybrid peptides based on FV7 could provide new models for combining different functional domains and demonstrate effective avenues to screen for novel antimicrobial agents.

  15. Caspar, a suppressor of antibacterial immunity in Drosophila.

    Science.gov (United States)

    Kim, Myungjin; Lee, Jun Hee; Lee, Soo Young; Kim, Eunhee; Chung, Jongkyeong

    2006-10-31

    Drosophila has a primitive yet highly effective innate immune system. Although the infection-dependent activation mechanisms of the Drosophila immune system are well understood, its inhibitory regulation remains elusive. To find novel suppressors of the immune system, we performed a genetic screening for Drosophila mutants with hyperactivated immune responses and isolated a loss-of-function mutant of caspar whose product is homologous to Fas-associating factor 1 in mammals. Interestingly, caspar mutant flies showed increased antibacterial immune responses including increased resistance to bacterial infection and a constitutive expression of diptericin, a representative antibacterial peptide gene. Conversely, ectopic expression of caspar strongly suppressed the infection-dependent gene expression of diptericin, which allowed bacterial outgrowth. Consistent with these physiological phenotypes, Caspar negatively regulated the immune deficiency (Imd)-mediated immune responses by blocking nuclear translocation of Relish, an NF-kappaB transcription factor. In addition, we further demonstrated that Dredd-dependent cleavage of Relish, a prerequisite event for the nuclear entry of Relish, is the target of the Caspar-mediated suppression of the Imd pathway. Remarkably, Caspar was highly specific for the Imd pathway and did not affect the Toll pathway, which is crucial for antifungal immunity. Collectively, our elucidation of an inhibitory mechanism of the Imd pathway by Caspar will provide a valuable insight into understanding complex regulatory mechanisms of the innate immune systems in both Drosophila and mammals.

  16. A crustin isoform from black tiger shrimp, Penaeus monodon exhibits broad spectrum anti-bacterial activity

    Directory of Open Access Journals (Sweden)

    Debashis Banerjee

    2015-11-01

    Full Text Available Crustaceans have a powerful non-specific immune mechanism that responds to pathogen invasion and together with cellular responses, generates powerful humoral factors such as antimicrobial peptides. Crustins are a diverse class of antimicrobial peptides that are expressed by the circulating haemocytes of crustaceans. Several isoforms of this molecule are reported and in this study, one isoform from the black tiger shrimp, Penaeus monodon was cloned and expressed in Escherichia coli SG 13009. The purified recombinant crustin peptide had a molecular weight of 22 kDa and exhibited potent anti-bacterial activity in vitro against several Gram positive and Gram negative bacteria that included pathogens of aquatic animals and humans. The recombinant crustin showed a minimal inhibitory concentration of 0.5 μg ml−1 against the vibrio pathogens of shrimp, which suggests its promise for application in aquaculture.

  17. Silyl-based alkyne-modifying linker for the preparation of C-terminal acetylene-derivatized protected peptides.

    Science.gov (United States)

    Strack, Martin; Langklotz, Sina; Bandow, Julia E; Metzler-Nolte, Nils; Albada, H Bauke

    2012-11-16

    A novel linker for the synthesis of C-terminal acetylene-functionalized protected peptides is described. This SAM1 linker is applied in the manual Fmoc-based solid-phase peptide synthesis of Leu-enkephalin and in microwave-assisted automated synthesis of Maculatin 2.1, an antibacterial peptide that contains 18 amino acid residues. For the cleavage, treatment with tetramethylammonium fluoride results in protected acetylene-derivatized peptides. Alternatively, a one-pot cleavage-click procedure affords the protected 1,2,3-triazole conjugate in high yields after purification.

  18. What makes a natural clay antibacterial?

    Science.gov (United States)

    Williams, Lynda B.; Metge, David W.; Eberl, Dennis D.; Harvey, Ronald W.; Turner, Amanda G.; Prapaipong, Panjai; Port-Peterson, Amisha T.

    2011-01-01

    Natural clays have been used in ancient and modern medicine, but the mechanism(s) that make certain clays lethal against bacterial pathogens has not been identified. We have compared the depositional environments, mineralogies, and chemistries of clays that exhibit antibacterial effects on a broad spectrum of human pathogens including antibiotic resistant strains. Natural antibacterial clays contain nanoscale (2+ solubility.

  19. Sustained Release of Antibacterial Lipopeptides from Biodegradable Polymers against Oral Pathogens

    Science.gov (United States)

    Eckhard, Lea H.; Houri-Haddad, Yael; Sol, Asaf; Zeharia, Rotem; Shai, Yechiel; Beyth, Shaul; Domb, Abraham J.

    2016-01-01

    The development of antibacterial drugs to overcome various pathogenic species, which inhabit the oral cavity, faces several challenges, such as salivary flow and enzymatic activity that restrict dosage retention. Owing to their amphipathic nature, antimicrobial peptides (AMPs) serve as the first line of defense of the innate immune system. The ability to synthesize different types of AMPs enables exploitation of their advantages as alternatives to antibiotics. Sustained release of AMPs incorporated in biodegradable polymers can be advantageous in maintaining high levels of the peptides. In this study, four potent ultra-short lipopeptides, conjugated to an aliphatic acid chain (16C) were incorporated in two different biodegradable polymers: poly (lactic acid co castor oil) (PLACO) and ricinoleic acid-based poly (ester-anhydride) (P(SA-RA)) for sustained release. The lipopeptide and polymer formulations were tested for antibacterial activity during one week, by turbidometric measurements of bacterial outgrowth, anti-biofilm activity by live/dead staining, biocompatibility by hemolysis and XTT colorimetric assays, mode of action by fluorescence-activated cell sorting (FACS) and release profile by a fluorometric assay. The results show that an antibacterial and anti-biofilm effect, as well as membrane disruption, can be achieved by the use of a formulation of lipopeptide incorporated in biodegradable polymer. PMID:27606830

  20. Antibacterial activity on electrospun poly(lactide-co-glycolide) based membranes via Magainin II grafting

    Energy Technology Data Exchange (ETDEWEB)

    Yüksel, Emre; Karakeçili, Ayşe, E-mail: akarakecili@eng.ankara.edu.tr

    2014-12-01

    An antimicrobial peptide (AMP), Magainin II (Mag II) was covalently immobilized on poly(lactide-co-glycolide) (PLGA) and PLGA/gelatin electrospun fibrous membranes. The surface immobilization was characterized by X-ray Photoelectron Spectroscopy (XPS). Scanning Electron Microscopy (SEM) and Atomic Force Microscopy studies showed that the surface morphology of the fibers at micron scale was not affected by the immobilization process. The antibacterial activity of the bound Mag II was tested against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus. Bacterial adhesion tests, SEM and confocal analyses revealed that the attachment and survival of bacteria were inhibited on Mag II functionalized membranes. AMP immobilization strategy was introduced as a new perspective for the modulation of antibacterial properties on PLGA based materials prepared by electrospinning. - Highlights: • PLGA and PLGA/gelatin fibrous membranes were prepared by electrospinning. • Antimicrobial peptide Mag II was successfully immobilized on PLGA based membranes. • The antibacterial activity was tested against E. coli and S. aureus. • Bacterial adhesion was inhibited on Mag II functionalized membranes.

  1. Evaluation of quinolone antibacterial consumption

    Directory of Open Access Journals (Sweden)

    E. P. Bernaz

    2016-08-01

    Full Text Available Quinolones are broad-spectrum antibiotics that play an important role in the treatment of serious bacterial infections, especially hospital-acquired infections and others in which resistance to older antibacterial classes is suspected and as first-line therapy is recommended. To determine the place, compare and analyze the use of quinolone antibacterial in the most important departments of EMI during 2009 to 2014 and to assess their results for improvement of patients treatment quality was designed this study. In the evaluated period consumption of quinolone antibacterial in EMI recorded a decline from 91 to 46 DDD/1000 or by 49.45%, in IC departaments from 338.6 to 132.07 or by 61%, and vice versa in SSOT departments an increase from 41.28 to 57.59 DDD/1000 or by 31.51%. Medium annual consumption in all institution recorded 63.03 DDD/1000, respectvely 174.90 in IC and 45.10 in SSOT departments. In 2014 IC departments recorded 2439.8 lei per DDD/1000, that was 8.72 times more than cost of 279.9 lei in SSOT departments and 7.51 times than 324.96 lei per DDD/1000 in all EMI. The yearly medium in EMI is around the same with all other international hospitals of 66.13 DDD/1000 and by 27.23% higher than 49.54 DDD/1000 recorded in large acute Australian public hospitals. The obtained results will be an important data for optimization in planning annual hospital necessities and rational antimicrobial prescribing as well as suggest the idea for expansion development and support antimicrobial stewardship initiatives.

  2. Effect of ester to amide or N-methylamide substitution on bacterial membrane depolarization and antibacterial activity of novel cyclic lipopeptides.

    Science.gov (United States)

    Bionda, Nina; Fleeman, Renee M; Shaw, Lindsey N; Cudic, Predrag

    2013-08-01

    Cyclic lipopeptides derived from the fusaricidin/LI-F family of naturally occurring antibiotics represent particularly attractive candidates for the development of new antibacterial agents. In comparison with natural products, these derivatives may offer better stability under physiologically relevant conditions and lower nonspecific toxicity, while preserving their antibacterial activity. In this study we assessed the ability of cyclic lipodepsipeptide 1 and its analogues--amide 2, N-methylamide 3, and linear peptide 4--to interact with the cytoplasmic membranes of selected Gram-positive bacteria. We also investigated their bacteriostatic/bactericidal modes of action and in vivo potency by using a Galleria mellonella model of MRSA infection. Cyclic lipopeptides 1 and 2 depolarize the cytoplasmic membranes of Gram-positive bacteria in a concentration-dependent manner. The degree of membrane depolarization was influenced by the structural and physical properties of 1 and 2, with the more flexible and hydrophobic peptide 1 being most efficient. However, membrane depolarization does not correlate with bacterial cell lethality, suggesting that membrane-targeting activity is not the main mode of action for this class of antibacterial peptides. Conversely, substitution of the depsipeptide bond in 1 with an N-methylamide bond in 3, or its hydrolysis to peptide 4, lead to a complete loss of antibacterial activity and indicate that the conformation of cyclic lipopeptides plays a role in their antibacterial activities. Cyclic lipopeptides 1 and 2 are also capable of improving the survival of G. mellonella larvae infected with MRSA at varying efficiencies, reflecting their in vitro activities. Gaining more insight into the structure-activity relationship and mode of action of these cyclic lipopeptides may enable the development of new antibiotics of this class with improved antibacterial activity.

  3. Purification and characterization of antibacterial compounds of Pseudoalteromonas flavipulchra JG1.

    Science.gov (United States)

    Yu, Min; Wang, Junfeng; Tang, Kaihao; Shi, Xiaochong; Wang, Shushan; Zhu, Wei-Ming; Zhang, Xiao-Hua

    2012-03-01

    Pseudoalteromonas flavipulchra JG1 produces a protein PfaP and a range of small-molecule compounds with inhibitory activities against Vibrio anguillarum. The PfaP protein was purified from the extracellular products of JG1 by electroelution, and antibacterial activity was observed by an in-gel antibacterial assay. The complete amino acid sequence (694 aa) of PfaP was determined by de novo peptide sequencing and subsequent alignment with the proteome sequence of strain JG1. The calculated molecular mass of PfaP was 77.0 kDa. PfaP was 58 % identical to l-lysine oxidase AlpP of Pseudoalteromonas tunicata D2, and 54 % identical to the marinocine antimicrobial protein of Marinomonas mediterranea MMB-1. Five small molecules (compounds 1-5) with antibacterial activity, which were identified as p-hydroxybenzoic acid (1), trans-cinnamic acid (2), 6-bromoindolyl-3-acetic acid (3), N-hydroxybenzoisoxazolone (4) and 2'-deoxyadenosine (5), were purified by sequential column chromatography over silica gel, Sephadex LH-20 and RP-18 from ethyl acetate extract of strain JG1, and their structures were determined by NMR and MS. Brown compound 3, the only brominated compound, showed antibacterial activity against both Gram-positive and Gram-negative bacteria.

  4. Applications of Circular Dichroism for Structural Analysis of Gelatin and Antimicrobial Peptides

    Directory of Open Access Journals (Sweden)

    Yoonkyung Park

    2012-03-01

    Full Text Available Circular dichroism (CD is a useful technique for monitoring changes in the conformation of antimicrobial peptides or gelatin. In this study, interactions between cationic peptides and gelatin were observed without affecting the triple helical content of the gelatin, which was more strongly affected by anionic surfactant. The peptides did not adopt a secondary structure in the presence of aqueous solution or Tween 80, but a peptide secondary structure formed upon the addition of sodium dodecyl sulfate (SDS. The peptides bound to the phosphate group of lipopolysaccharide (LPS and displayed an alpha-helical conformation while (KW4 adopted a folded conformation. Further, the peptides did not specifically interact with the fungal cell wall components of mannan or laminarin. Tryptophan blue shift assay indicated that these peptides interacted with SDS, LPS, and gelatin but not with Tween 80, mannan, or laminarin. The peptides also displayed antibacterial activity against P. aeruginosa without cytotoxicity against HaCaT cells at MIC, except for HPA3NT3-analog peptide. In this study, we used a CD spectroscopic method to demonstrate the feasibility of peptide characterization in numerous environments. The CD method can thus be used as a screening method of gelatin-peptide interactions for use in wound healing applications.

  5. Antibacterial effects of glass ionomers.

    Science.gov (United States)

    DeSchepper, E J; White, R R; von der Lehr, W

    1989-04-01

    Glass ionomer cements have been shown to possess antimicrobial activity. Proposed mechanisms of action include acidity and fluoride. It was the purpose of this study to determine the antimicrobial effect of 11 glass ionomer cements, their individual powder and liquid components and one resin-bonded liner containing high fluoride ionomer glass against Streptococcus mutans #6715. The role of fluoride and pH in the antibacterial activity was also studied. Using agar diffusion assay methodology, the following results were obtained. All of the glass ionomer cements were inhibitory against S. mutans. The antibacterial cements and slurries that were tested for fluoride, released the ion in excess of reported minimum inhibitory values. The antimicrobial activity of the liquid components, that were tested for the effects of pH changes, was totally lost when the pH was adjusted to 5. The resin bonded liner was inactive against S. mutans and did not release inhibitory concentrations of fluoride. These results indicate that freshly-mixed glass ionomer cements are antimicrobial against S. mutans and that the mechanism of action is probably a function of both fluoride and pH although additional factors may be involved.

  6. Antibacterial Activity of Silicate Bioceramics

    Institute of Scientific and Technical Information of China (English)

    HU Sheng; NING Congqin; ZHOU Yue; CHEN Lei; LIN Kaili; CHANG Jiang

    2011-01-01

    Four kinds of pure silicate ceramic particles, CaSiO3, Ca3SiO5, bredigite and akermanite were prepared and their bactericidal effects were systematically investigated. The phase compositions of these silicate ceramics were characterized by XRD. The ionic concentration meas urement revealed that the Calcium (Ca) ion concentration were relatively higher in Ca3SiO5 and bredigite, and much lower in CaSiO3 and akermanite. Accordingly, the pH values of the four silicate ceramics extracts showed a positive correlation with the particle concentrations. Meanwhile, by decreasing the particle size, higher Ca ion concentrations can be achieved, leading to the increase of aqueous pH value as well. In summary, all of the four silicate ceramics tested in our study showed antibacterial effect in a dose-dependent manner. Generally, the order of their antibacterial activity against E.coli from strong to weak is Ca3SiO5, bredigite, CaSiO3 and akermanite.

  7. Structure and membrane interactions of the homodimeric antibiotic peptide homotarsinin

    Science.gov (United States)

    Verly, Rodrigo M.; Resende, Jarbas M.; Junior, Eduardo F. C.; de Magalhães, Mariana T. Q.; Guimarães, Carlos F. C. R.; Munhoz, Victor H. O.; Bemquerer, Marcelo Porto; Almeida, Fábio C. L.; Santoro, Marcelo M.; Piló-Veloso, Dorila; Bechinger, Burkhard

    2017-01-01

    Antimicrobial peptides (AMPs) from amphibian skin are valuable template structures to find new treatments against bacterial infections. This work describes for the first time the structure and membrane interactions of a homodimeric AMP. Homotarsinin, which was found in Phyllomedusa tarsius anurans, consists of two identical cystine-linked polypeptide chains each of 24 amino acid residues. The high-resolution structures of the monomeric and dimeric peptides were determined in aqueous buffers. The dimer exhibits a tightly packed coiled coil three-dimensional structure, keeping the hydrophobic residues screened from the aqueous environment. An overall cationic surface of the dimer assures enhanced interactions with negatively charged membranes. An extensive set of biophysical data allowed us to establish structure-function correlations with antimicrobial assays against Gram-positive and Gram-negative bacteria. Although both peptides present considerable antimicrobial activity, the dimer is significantly more effective in both antibacterial and membrane biophysical assays.

  8. Structure and membrane interactions of the homodimeric antibiotic peptide homotarsinin

    Science.gov (United States)

    Verly, Rodrigo M.; Resende, Jarbas M.; Junior, Eduardo F. C.; de Magalhães, Mariana T. Q.; Guimarães, Carlos F. C. R.; Munhoz, Victor H. O.; Bemquerer, Marcelo Porto; Almeida, Fábio C. L.; Santoro, Marcelo M.; Piló-Veloso, Dorila; Bechinger, Burkhard

    2017-01-01

    Antimicrobial peptides (AMPs) from amphibian skin are valuable template structures to find new treatments against bacterial infections. This work describes for the first time the structure and membrane interactions of a homodimeric AMP. Homotarsinin, which was found in Phyllomedusa tarsius anurans, consists of two identical cystine-linked polypeptide chains each of 24 amino acid residues. The high-resolution structures of the monomeric and dimeric peptides were determined in aqueous buffers. The dimer exhibits a tightly packed coiled coil three-dimensional structure, keeping the hydrophobic residues screened from the aqueous environment. An overall cationic surface of the dimer assures enhanced interactions with negatively charged membranes. An extensive set of biophysical data allowed us to establish structure-function correlations with antimicrobial assays against Gram-positive and Gram-negative bacteria. Although both peptides present considerable antimicrobial activity, the dimer is significantly more effective in both antibacterial and membrane biophysical assays. PMID:28102305

  9. Cloning, expression, and purification of a new antimicrobial peptide gene from Musca domestica larva.

    Science.gov (United States)

    Pei, Zhihua; Sun, Xiaoning; Tang, Yan; Wang, Kai; Gao, Yunhang; Ma, Hongxia

    2014-10-01

    Musca domestica (Diptera: Muscidae), the housefly, exhibits unique immune defences and can produce antimicrobial peptides upon stimulation with bacteria. Based on the cDNA library constructed using the suppression subtractive hybridization (SSH) method, a 198-bp antimicrobial peptide gene, which we named MDAP-2, was amplified by rapid amplification of cDNA ends (RACE) from M. domestica larvae stimulated with Salmonella pullorum (Enterobacteriaceae: Salmonella). In the present study, the full-length MDAP-2 gene was cloned and inserted into a His-tagged Escherichia coli prokaryotic expression system to enable production of the recombinant peptide. The recombinant MDAP-2 peptide was purified using Ni-NTA HisTrap FF crude column chromatography. The bacteriostatic activity of the recombinant purified MDAP-2 protein was assessed. The results indicated that MDAP-2 had in vitro antibacterial activity against all of the tested Gram- bacteria from clinical isolates, including E. coli (Enterobacteriaceae: Escherichia), one strain of S. pullorum (Enterobacteriaceae: Salmonella), and one strain of Pasteurella multocida. DNA sequencing and BLAST analysis showed that the MDAP-2 antimicrobial peptide gene was not homologous to any other antimicrobial peptide genes in GenBank. The antibacterial mechanisms of the newly discovered MDAP-2 peptide warrant further study.

  10. MAIN FACTORS IN PREPARATION OF ANTIBACTERIAL PARTICLES/PVC COMPOSITE

    Institute of Scientific and Technical Information of China (English)

    Xuehua Chen; Chunzhong Li; Ling Zhang; Shoufang Xu; Qiuling Zhou; Yihua Zhu; Xianzhang Qu

    2004-01-01

    Zirconium phosphate containing silver was chosen as antibacterial particles in preparing antibacterial particles/PVC composite. The effect of surface property of the antibacterial particles and of their filler content on the properties of antibacterial particles/PVC composite was studied. The effect of the interfacial compatibility on mechanical properties of the composite was also discussed. Experimental results showed that the antibacterial PVC composite had good antibacterial property, reaching almost 100% bacteriostatic level at an antibacterial powder filler content of 1.5 phr.

  11. Application of electrolysis to inactivation of antibacterials in clinical use.

    Science.gov (United States)

    Nakano, Takashi; Hirose, Jun; Kobayashi, Toyohide; Hiro, Naoki; Kondo, Fumitake; Tamai, Hiroshi; Tanaka, Kazuhiko; Sano, Kouichi

    2013-04-01

    Contamination of surface water by antibacterial pharmaceuticals (antibacterials) from clinical settings may affect aquatic organisms, plants growth, and environmental floral bacteria. One of the methods to decrease the contamination is inactivation of antibacterials before being discharged to the sewage system. Recently, we reported the novel method based on electrolysis for detoxifying wastewater containing antineoplastics. In the present study, to clarify whether the electrolysis method is applicable to the inactivation of antibacterials, we electrolyzed solutions of 10 groups of individual antibacterials including amikacin sulfate (AMK) and a mixture (MIX) of some commercial antibacterials commonly prescribed at hospitals, and measured their antibacterial activities. AMK was inactivated in its antibacterial activities and its concentration decreased by electrolysis in a time-dependent manner. Eighty to ninety-nine percent of almost all antibacterials and MIX were inactivated within 6h of electrolysis. Additionally, cytotoxicity was not detected in any of the electrolyzed solutions of antibacterials and MIX by the Molt-4-based cytotoxicity test.

  12. Production of antibacterial Bombyx mori cecropin A in mealworm-pathogenic Beauveria bassiana ERL1170.

    Science.gov (United States)

    Lee, Se Jin; Yu, Jeong Seon; Parker, Bruce L; Skinner, Margaret; Je, Yeon Ho; Kim, Jae Su

    2015-01-01

    Efforts are underway to produce antimicrobial peptides in yellow mealworms (Tenebrio molitor), which can be developed as more effective and safer animal feed additives. In this work, we expressed Bombyx mori (Bm) cecropin-A in mealworms by the infection of transformed entomopathogenic Beauveria bassiana ERL1170. The active domain of Bm cecropin A gene was tagged with a signal sequence of B. bassiana for extracellular secretion, and the fragment was inserted into ERL1170 by the restriction enzyme-mediated integration method. Transformant D-6 showed antibacterial activity against Bacillus subtilis and Listeria monocytogenes. Against T. molitor larvae, D-6 had similar mortality to wild-type, and D6-infected mealworm suspension showed strong antibacterial activity against the two bacteria, but not in the wild-type-infected mealworms, thereby increasing the value of mealworms as animal feed additives.

  13. PeptideAtlas

    Data.gov (United States)

    U.S. Department of Health & Human Services — PeptideAtlas is a multi-organism, publicly accessible compendium of peptides identified in a large set of tandem mass spectrometry proteomics experiments. Mass...

  14. Roles of the Peptide Transport Systems and Aminopeptidase PepA in Peptide Assimilation by Helicobacter pylori.

    Science.gov (United States)

    Ki, Mi Ran; Lee, Ji Hyun; Yun, Soon Kyu; Choi, Kyung Min; Hwang, Se Young

    2015-10-01

    Peptide assimilation in Helicobacter pylori necessitates a coordinated working of the peptide transport systems (PepTs) and aminopeptidase (PepA). We found that H. pylori hydrolyzes two detector peptides, L-phenylalanyl-L-3-thiaphenylalanine (PSP) and L-phenylalanyl-L-2- sulfanilylglycine (PSG), primarily before intake and excludes their antibacterial effects, whereas Escherichia coli readily transports them with resultant growth inhibition. PSP assimilation by H. pylori was inhibited by aminopeptidase inhibitor bestatin, but not by dialanine or cyanide-m-chlorophenylhydrazone, contrary to that of E. coli. RT- and qRT-PCR analyses showed that H. pylori may express first the PepTs (e.g., DppA and DppB) and then PepA. In addition, western blot analysis of PepA suggested that the bacterium secretes PepA in response to specific inducers.

  15. Cleaved inflammatory lactoferrin peptides in parotid saliva of periodontitis patients.

    Science.gov (United States)

    Komine, Ken-Ichi; Kuroishi, Toshinobu; Ozawa, Akiko; Komine, Yumiko; Minami, Takumi; Shimauchi, Hidetoshi; Sugawara, Shunji

    2007-03-01

    Lactoferrin (Lf) is a member of the transferrin family of iron-binding anti-bacterial proteins, present in most exocrine secretions, such as saliva, and plays an important role in mucosal defense. In this study, we identified small Lf peptides with Con A low-affinity in the parotid saliva of chronic periodontitis patients by Con A two-dimensional immunoelectrophoresis, Con A affinity chromatography and Western blotting using anti-human Lf polyclonal Ab. N-terminal amino acid sequencing of the four Con A low-affinity Lf peptides confirmed them to be fragments of intact Lf. The detection ratio of the proteinase 3 (PR3)-like activity was elevated in the parotid saliva of periodontitis patients and was associated with the severity of clinical symptoms. PR3 protein was also detected in the parotid saliva of periodontitis patients, and PR3, but not human leukocyte elastase and cathepsin G, degraded intact Lf. Con A low-affinity saliva Lf peptides showed no anti-bacterial activity against Escherichia coli, and had a reduced iron-chelating capacity. Con A low-affinity saliva Lf peptides, PR3-treated Lf preparation and two of four synthetic polypeptides induced the production of interleukin IL-6, monocyte chemoattractant protein-1 and IL-8, and the activation of NF-kappaB in human oral epithelial HSC-2 cells. Furthermore, concentrations of the Lf peptides in the parotid saliva of periodontitis patients were increased with a correlation to the severity of clinical symptoms. These results suggest that Lf in the parotid saliva of periodontitis patients was degraded into small peptides by the PR3-like activity with the capability to induce inflammatory mediators.

  16. Antibacterial Activity of Four Human Beta-Defensins: HBD-19, HBD-23, HBD-27, and HBD-29

    Directory of Open Access Journals (Sweden)

    David Camerini

    2012-03-01

    Full Text Available Human β-defensins (HBD are a family of small antimicrobial peptides that play important roles in the innate and adaptive immune defenses against microbial infection. In this study, we predicted the mature sequences and assessed the antibacterial properties of synthetic HBD-19, HBD-23, HBD-27, and HBD-29 against three species of clinically relevant bacteria: Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. We also examined the cytotoxicity of each β-defensin to human cells. HBD-19 exhibited modest antibacterial effects against E. coli and S. aureus but had little effect on the growth of P. aeruginosa. HBD-23 exhibited substantial antibacterial effects against all three bacterial species and was particularly potent against the Gram-negative species, E. coli and P. aeruginosa. HBD-27 exerted modest antibacterial activity only towards S. aureus while HBD-29 had modest antibacterial activity for E. coli and P. aeruginosa. HBD-23 and HBD-27 showed little or no toxicity to human peripheral blood mononuclear cells, while HBD-19 and HBD-29 decreased cell viability by 20% at 30 μg/mL.

  17. Antimicrobial Peptides in 2014

    Directory of Open Access Journals (Sweden)

    Guangshun Wang

    2015-03-01

    Full Text Available This article highlights new members, novel mechanisms of action, new functions, and interesting applications of antimicrobial peptides reported in 2014. As of December 2014, over 100 new peptides were registered into the Antimicrobial Peptide Database, increasing the total number of entries to 2493. Unique antimicrobial peptides have been identified from marine bacteria, fungi, and plants. Environmental conditions clearly influence peptide activity or function. Human α-defensin HD-6 is only antimicrobial under reduced conditions. The pH-dependent oligomerization of human cathelicidin LL-37 is linked to double-stranded RNA delivery to endosomes, where the acidic pH triggers the dissociation of the peptide aggregate to release its cargo. Proline-rich peptides, previously known to bind to heat shock proteins, are shown to inhibit protein synthesis. A model antimicrobial peptide is demonstrated to have multiple hits on bacteria, including surface protein delocalization. While cell surface modification to decrease cationic peptide binding is a recognized resistance mechanism for pathogenic bacteria, it is also used as a survival strategy for commensal bacteria. The year 2014 also witnessed continued efforts in exploiting potential applications of antimicrobial peptides. We highlight 3D structure-based design of peptide antimicrobials and vaccines, surface coating, delivery systems, and microbial detection devices involving antimicrobial peptides. The 2014 results also support that combination therapy is preferred over monotherapy in treating biofilms.

  18. Peptide Nucleic Acids (PNA)

    DEFF Research Database (Denmark)

    2002-01-01

    A novel class of compounds, known as peptide nucleic acids, bind complementary ssDNA and RNA strands more strongly than a corresponding DNA. The peptide nucleic acids generally comprise ligands such as naturally occurring DNA bases attached to a peptide backbone through a suitable linker....

  19. Peptide Nucleic Acids

    DEFF Research Database (Denmark)

    1998-01-01

    A novel class of compounds, known as peptide nucleic acids, bind complementary ssDNA and RNA strands more strongly than a corresponding DNA. The peptide nucleic acids generally comprise ligands such as naturally occurring DNA bases attached to a peptide backbone through a suitable linker....

  20. Peptide Nucleic Acids

    DEFF Research Database (Denmark)

    2003-01-01

    A novel class of compounds, known as peptide nucleic acids, bind complementary ssDNA and RNA strands more strongly than a corresponding DNA. The peptide nucleic acids generally comprise ligands such as naturally occurring DNA bases attached to a peptide backbone through a suitable linker....

  1. Peptide Nucleic Acid Synthons

    DEFF Research Database (Denmark)

    2004-01-01

    A novel class of compounds, known as peptide nucleic acids, bind complementary ssDNA and RNA strands more strongly than a corresponding DNA. The peptide nucleic acids generally comprise ligands such as naturally occurring DNA bases attached to a peptide backbone through a suitable linker....

  2. Peptide-Carrier Conjugation

    DEFF Research Database (Denmark)

    Hansen, Paul Robert

    2015-01-01

    To produce antibodies against synthetic peptides it is necessary to couple them to a protein carrier. This chapter provides a nonspecialist overview of peptide-carrier conjugation. Furthermore, a protocol for coupling cysteine-containing peptides to bovine serum albumin is outlined....

  3. PH dependent adhesive peptides

    Science.gov (United States)

    Tomich, John; Iwamoto, Takeo; Shen, Xinchun; Sun, Xiuzhi Susan

    2010-06-29

    A novel peptide adhesive motif is described that requires no receptor or cross-links to achieve maximal adhesive strength. Several peptides with different degrees of adhesive strength have been designed and synthesized using solid phase chemistries. All peptides contain a common hydrophobic core sequence flanked by positively or negatively charged amino acids sequences.

  4. Antibacterial Effect of the Conducting Polyaniline

    Institute of Scientific and Technical Information of China (English)

    Nanlin SHI; Xuemei GUO; Hemin JING; Jun GONG; Chao SUN; Ke YANG

    2006-01-01

    Excellent antibacterial performance of polyaniline (Pani) against Escherichia coli and Gram-positive Staphylococcus aureus microorganisms has been demonstrated under both dark and visible light conditions. The electrostatic adherence between the Pani molecules and the bacteria may play a very important role for the antibacterial reaction of the Pani. As a result of our investigation, conducting Pani and its composites/blends are believed to be useful as a new type of antibacterial agent, self-clean as well as multifunctional material for improving the human health and living environment.

  5. Development of Silver Ion Doped Antibacterial Clays and Investigation of Their Antibacterial Activity

    OpenAIRE

    Karel, Filiz B.; Ali S. Koparal; Elif Kaynak

    2015-01-01

    Kaolinite, sepiolite, and clinoptilolite were used as carriers to develop antibacterial materials. The materials were enriched in sodium by ion exchange. Silver ion exchange by silver nitrate followed by phosphoric acid treatment enabled the controlled release of silver. The antibacterial function of the materials was investigated by halo test and the amount of silver released was investigated by energy dispersive X-ray spectroscopy. The enhanced antibacterial efficiency was obtained by minim...

  6. Antimicrobial peptides from the skins of North American frogs.

    Science.gov (United States)

    Conlon, J Michael; Kolodziejek, Jolanta; Nowotny, Norbert

    2009-08-01

    North America is home to anuran species belonging to the families Bufonidae, Eleutherodactylidae, Hylidae, Leiopelmatidae, Ranidae, and Scaphiopodidae but antimicrobial peptides have been identified only in skin secretions and/or skin extracts of frogs belonging to the Leiopelmatidae ("tailed frogs") and Ranidae ("true frogs"). Eight structurally-related cationic alpha-helical peptides with broad-spectrum antibacterial activity, termed ascaphins, have been isolated from specimens of Ascaphus truei (Leiopelmatidae) occupying a coastal range. Characterization of orthologous antimicrobial peptides from Ascaphus specimens occupying an inland range supports the proposal that this population should be regarded as a separate species A. montanus. Ascaphin-8 shows potential for development into a therapeutically valuable anti-infective agent. Peptides belonging to the brevinin-1, esculentin-1, esculentin-2, palustrin-1, palustrin-2, ranacyclin, ranatuerin-1, ranatuerin-2, and temporin families have been isolated from North American ranids. It is proposed that "ranalexins" represent brevinin-1 peptides that have undergone a four amino acid residue internal deletion. Current taxonomic recommendations divide North American frogs from the family Ranidae into two genera: Lithobates and Rana. Cladistic analysis based upon the amino acid sequences of the brevinin-1 peptides provides strong support for this assignment.

  7. Chromogranin A-derived peptides are involved in innate immunity.

    Science.gov (United States)

    Aslam, R; Atindehou, M; Lavaux, T; Haïkel, Y; Schneider, F; Metz-Boutigue, M-H

    2012-01-01

    New endogenous antimicrobial peptides (AMPs) derived from chromogranin A (CgA) are secreted by nervous, endocrine and immune cells during stress. They display antimicrobial activities by lytic effects at micromolar range using a pore-forming mechanism against Gram-positive bacteria, filamentous fungi and yeasts. These AMPs can also penetrate quickly into neutrophils (without lytic effects), where, similarly to "cell penetrating peptides", they interact with cytoplasmic calmodulin, and induce calcium influx via Store Operated Channels therefore triggering neutrophils activation. Staphylococcus aureus and Salmonella enteritis are bacteria responsible for severe infections. We investigated here the effects of S. aureus and S. enteritis bacterial proteases on CgA-derived peptides and evaluated their antimicrobial activities. We showed that the Glu-C protease produced by S. aureus V8 induces the loss of the AMPs antibacterial activities and produces new antifungal peptides. In addition, four antimicrobial CGA-derived peptides (chromofungin, procatestatin, human/bovine catestatin) are degraded when treated with bacterial supernatants from S. aureus and S. enteritis, whereas, cateslytin, the short active form of catestatin, resists to this degradation. Finally, we demonstrate that several antimicrobial CgA-derived peptides are able to act synergistically with antibiotics against bacteria and fungi indicating their roles in innate defense.

  8. Three novel antimicrobial peptides from the skin of the Indian bronzed frog Hylarana temporalis (Anura: Ranidae).

    Science.gov (United States)

    Reshmy, V; Preeji, V; Parvin, A; Santhoshkumar, K; George, S

    2011-05-01

    Amphibian skin secretion is considered as a rich source of bioactive peptides. The present work describes the successful identification of three novel peptides named brevinin-1TEa, brevinin-2TEa and brevinin-2TEb present in the skin secretion of Indian bronzed frog Hylarana temporalis. The deduced open reading frame encoding the biosynthetic precursor of brevinin-1TEa consisted of 70 amino acid residues and brevinin-2TEa and brevinin-2TEb consisted of 71 and 72 amino acids, respectively. All the three peptides showed higher antimicrobial activity against Gram-negative than against Gram-positive bacteria. On the basis of the antibacterial and haemolytic activity, brevinin-2TEb is the most potent peptide reported in the present study. Further research on these peptides may provide potential clue towards newer drug development to combat various microbial diseases.

  9. A molecular dynamics and circular dichroism study of a novel synthetic antimicrobial peptide

    Science.gov (United States)

    Rodina, N. P.; Yudenko, A. N.; Terterov, I. N.; Eliseev, I. E.

    2013-08-01

    Antimicrobial peptides are a class of small, usually positively charged amphiphilic peptides that are used by the innate immune system to combat bacterial infection in multicellular eukaryotes. Antimicrobial peptides are known for their broad-spectrum antimicrobial activity and thus can be used as a basis for a development of new antibiotics against multidrug-resistant bacteria. The most challengeous task on the way to a therapeutic use of antimicrobial peptides is a rational design of new peptides with enhanced activity and reduced toxicity. Here we report a molecular dynamics and circular dichroism study of a novel synthetic antimicrobial peptide D51. This peptide was earlier designed by Loose et al. using a linguistic model of natural antimicrobial peptides. Molecular dynamics simulation of the peptide folding in explicit solvent shows fast formation of two antiparallel beta strands connected by a beta-turn that is confirmed by circular dichroism measurements. Obtained from simulation amphipatic conformation of the peptide is analysed and possible mechanism of it's interaction with bacterial membranes together with ways to enhance it's antibacterial activity are suggested.

  10. Antibacterial activity of Parmelia perlata

    Institute of Scientific and Technical Information of China (English)

    Alwar Vidyalakshmi; Kandaswamy Kruthika

    2012-01-01

    Objective: To test efficacy of Parmelia perlata (P. perlata), which is used in traditional medicine for rapid wound healing against test bacteria that cause wound infections. Methods: Different solvents such as methanol, ethyl acetate and acetone were used for extraction of P. perlata. The sensitivity of the test bacteria to solvent extracts of P. perlata was tested by measuring the zone of inhibition on growth media and by determining the minimal inhibitory concentration and minimal bactericidal concentration. Results: Methanol, ethyl acetate and acetone extracts of P.perlata have shown inhibitory activity against Staphylococcus aureus (S.aureus). Conclusions: The results of the present study indicate that P. perlata has potential antibacterial compounds againstS.aureus that causes multitude of skin infections among human beings. Development of drugs from natural compounds can help us to combat antibiotic-resistant bacteria.

  11. PCR-based site-specific mutagenesis of peptide antibiotics FALL-39 and its biologic activities

    Institute of Scientific and Technical Information of China (English)

    Yun-xia YANG; Yun FENG; Bo-yao WANG; Qi WU

    2004-01-01

    AIM: To construct PGEX-1λT-FALL-39 expression vector and its mutant vector, and study the relationship of function and structure. METHODS: A cDNA encoding mature FALL-39 was cloned from SPCA- 1 cell mRNA and the prokaryotic expression vector PGEX- 1λT-FALL-39 was constructed. Two kinds of polymerase chain reaction (PCR) for the site-direction mutagenesis were used to construct FALL-39 mutant expression vector, FALL-39-Lys-32 and FALL-39-Lys-24. Minimal effective concentration, minimal inhibitory concentration, and minimal bactericidal concentration were used to assay the antibacterial activities of these peptides. Effects of different solution on the antibacterial activity of FALL-39 and FALL-39-Lys-32 were observed by CFU determination. The hemolytic effects of these peptides were also examined on human red blood cells. RESULTS: Two site-specific mutants FALL-39-Lys-32 and FALL-39-Lys24 were obtained by PCR-induced mutagenesis. In comparison with two-step PCR which required two pairs of primers, one step PCR which required one pair of primers is a simple and efficient method for the PCR based site-specific mutagenesis. Using the prokaryotic expression system, the E coli-based products of recombinant FALL39 and its mutant peptides were also obtained. The antibacterial assay showed that FALL-39-Lys-32 and FALL-39-Lys24 were more potential in the antibacterial activity against E coli ML35p and Pseltdomonas aeruginosa ATCC27853 than that of FALL-39, and no increase in hemolysis was observed at the antibacterial concentrations. The antibacterial activity of FALL-39-Lys-32 against E coli was more potent than that of FALL-39 in NaCl-containing LB medium, while its activity was almost the same as FALL-39 in SO2-4 containing Medium E. CONCLUSION: PCR-based mutagensis is a useful model system for studying the structure and function relationship of antimicrobial peptides. Keeping α-helical conformation of FALL-39 and increasing net positive charge can increase the

  12. Selective antimicrobial activity and mode of action of adepantins, glycine-rich peptide antibiotics based on anuran antimicrobial peptide sequences.

    Science.gov (United States)

    Ilić, Nada; Novković, Mario; Guida, Filomena; Xhindoli, Daniela; Benincasa, Monica; Tossi, Alessandro; Juretić, Davor

    2013-03-01

    A challenge when designing membrane-active peptide antibiotics with therapeutic potential is how to ensure a useful antibacterial activity whilst avoiding unacceptable cytotoxicity for host cells. Understanding their mode of interaction with membranes and the reasons underlying their ability to distinguish between bacterial and eukaryotic cytoplasmic cells is crucial for any rational attempt to improve this selectivity. We have approached this problem by analysing natural helical antimicrobial peptides of anuran origin, using a structure-activity database to determine an antimicrobial selectivity index (SI) relating the minimal inhibitory concentration against Escherichia coli to the haemolytic activity (SI=HC(50)/MIC). A parameter that correlated strongly with SI, derived from the lengthwise asymmetry of the peptides' hydrophobicity (sequence moment), was then used in the "Designer" algorithm to propose novel, highly selective peptides. Amongst these are the 'adepantins', peptides rich in glycines and lysines that are highly selective for Gram-negative bacteria, have an exceptionally low haemolytic activity, and are less than 50% homologous to any other natural or synthetic antimicrobial peptide. In particular, they showed a very high SI for E. coli (up to 400) whilst maintaining an antimicrobial activity in the 0.5-4μM range. Experiments with monomeric, dimeric and fluorescently labelled versions of the adepantins, using different bacterial strains, host cells and model membrane systems provided insight into their mechanism of action.

  13. Facile biofunctionalization of silver nanoparticles for enhanced antibacterial properties, endotoxin removal, and biofilm control

    Directory of Open Access Journals (Sweden)

    Lambadi PR

    2015-03-01

    Full Text Available Paramesh Ramulu Lambadi,1,* Tarun Kumar Sharma,1,* Piyush Kumar,1 Priyanka Vasnani,2 Sitaramanjaneya Mouli Thalluri,2 Neha Bisht,1 Ranjana Pathania,1,2 Naveen Kumar Navani1,21Department of Biotechnology, 2Centre of Nanotechnology, Indian Institute of Technology, Roorkee, Uttarakhand, India*These authors contributed equally to this workAbstract: Infectious diseases cause a huge burden on healthcare systems worldwide. Pathogenic bacteria establish infection by developing antibiotic resistance and modulating the host’s immune system, whereas opportunistic pathogens like Pseudomonas aeruginosa adapt to adverse conditions owing to their ability to form biofilms. In the present study, silver nanoparticles were biofunctionalized with polymyxin B, an antibacterial peptide using a facile method. The biofunctionalized nanoparticles (polymyxin B-capped silver nanoparticles, PBSNPs were assessed for antibacterial activity against multiple drug-resistant clinical strain Vibrio fluvialis and nosocomial pathogen P. aeruginosa. The results of antibacterial assay revealed that PBSNPs had an approximately 3-fold higher effect than the citrate-capped nanoparticles (CSNPs. Morphological damage to the cell membrane was followed by scanning electron microscopy, testifying PBSNPs to be more potent in controlling the bacterial growth as compared with CSNPs. The bactericidal effect of PBSNPs was further confirmed by Live/Dead staining assays. Apart from the antibacterial activity, the biofunctionalized nanoparticles were found to resist biofilm formation. Electroplating of PBSNPs onto stainless steel surgical blades retained the antibacterial activity against P. aeruginosa. Further, the affinity of polymyxin for endotoxin was exploited for its removal using PBSNPs. It was found that the prepared nanoparticles removed 97% of the endotoxin from the solution. Such multifarious uses of metal nanoparticles are an attractive means of enhancing the potency of antimicrobial

  14. Two New Antibacterial Iridoids from Patrinia rupestris

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Two new iridoids (1 and 2) were isolated from the roots of Patrinia rupestris (Pall.) Juss.Their structures were elucidated by spectroscopic methods. Compounds 1 and 2 exhibited strong antibacterial activities against Eschecichia coli and Staphylococcus aureus, respectively.

  15. Dendritic nanocomposite for delivery of antibacterial agent

    Institute of Scientific and Technical Information of China (English)

    Pureti Madhu Kumar; PSrinivasa Babu; Shaik Rasheed; Ramadoss Karthikeyan

    2013-01-01

    Objective: To develop and explore the use of PEGylated poly (propylene imine) dendritic architecture for the delivery of an anti bacterial bioactive, Trimethoprim. Methods: For this study, PEGylated poly(propylene imine) dendritic architecture was synthesized and loaded with Trimethoprim and targeted to the resistant producing strains of both gram positive and gram negative. The antibacterial activity was carried out by agar well-diffusion method to compare zone of inhibition with standard drug and plain PPI dendrimer. Results: The study showed that the Trimethoprim loaded dendrimer has significant antibacterial activity than the plain PPI dendrimer, but standard drug was not shown zone of inhibition upon both microorganisms butKlebsiella pneumoniae (K. pneumoniae) the pure drug showed activity. Conclusions: In this study antibacterial activity of synthesized system is also relatively safer and holds potential to deliver any other antibacterial agent to the resistant producing strains.

  16. Antibacterial phenolics from the mangrove Lumnitzera racemosa

    Digital Repository Service at National Institute of Oceanography (India)

    DeSouza, L.; Wahidullah, S.; PrabhaDevi

    be concluded that this plant has antibacterial activity. [Keywords: Lumnitzera racemosa, Antibacterial, Flavonoids, Quercetin, Myricetin] Infectious diseases are still a major scourge of human life, and recent emergence of multidrug resistance... products held at Central Drug Research Institute, Lucknow, India. (1992) 17-21. 3 Consentino S, Tuberoso C I G, Pisano B, Satta M, Mascia V, Arzedi E, Palmas F, In vitro antimicrobial activity and chemical composition of Sardinian Thymus essential oils...

  17. Membrane interaction and secondary structure of de novo designed arginine-and tryptophan peptides with dual function

    KAUST Repository

    Rydberg, Hanna A.

    2012-10-01

    Cell-penetrating peptides and antimicrobial peptides are two classes of positively charged membrane active peptides with several properties in common. The challenge is to combine knowledge about the membrane interaction mechanisms and structural properties of the two classes to design peptides with membrane-specific actions, useful either as transporters of cargo or as antibacterial substances. Membrane active peptides are commonly rich in arginine and tryptophan. We have previously designed a series of arg/trp peptides and investigated how the position and number of tryptophans affect cellular uptake. Here we explore the antimicrobial properties and the interaction with lipid model membranes of these peptides, using minimal inhibitory concentrations assay (MIC), circular dichroism (CD) and linear dichroism (LD). The results show that the arg/trp peptides inhibit the growth of the two gram positive strains Staphylococcus aureus and Staphylococcus pyogenes, with some individual variations depending on the position of the tryptophans. No inhibition of the gram negative strains Proteus mirabilis or Pseudomonas aeruginosa was noticed. CD indicated that when bound to lipid vesicles one of the peptides forms an α-helical like structure, whereas the other five exhibited rather random coiled structures. LD indicated that all six peptides were somehow aligned parallel with the membrane surface. Our results do not reveal any obvious connection between membrane interaction and antimicrobial effect for the studied peptides. By contrast cell-penetrating properties can be coupled to both the secondary structure and the degree of order of the peptides. © 2012 Elsevier Inc.

  18. Antiviral activity of ovotransferrin derived peptides.

    Science.gov (United States)

    Giansanti, Francesco; Massucci, M Teresa; Giardi, M Federica; Nozza, Fabrizio; Pulsinelli, Emy; Nicolini, Claudio; Botti, Dario; Antonini, Giovanni

    2005-05-27

    Ovotransferrin and lactoferrin are iron-binding proteins with antiviral and antibacterial activities related to natural immunity, showing marked sequence and structural homologies. The antiviral activity of two hen ovotransferrin fragments DQKDEYELL (hOtrf(219-227)) and KDLLFK (hOtrf(269-301) and hOtrf(633-638)) towards Marek's disease virus infection of chicken embryo fibroblasts is reported here. These fragments have sequence homology with two bovine lactoferrin fragments with antiviral activity towards herpes simplex virus, suggesting that these fragments could have a role for the exploitation of the antiviral activity of the intact proteins towards herpes viruses. NMR analysis showed that these peptides, chemically synthetized, did not possess any favourite conformation in solution, indicating that both the aminoacid sequence and the conformation they display in the intact protein are essential for the antiviral activity.

  19. Nanostructured Antibacterial Silver Deposited on Polypropylene Nonwovens

    Science.gov (United States)

    Hong-Bo, Wang; Jin-Yan, Wang; Qu-Fu, Wei; Jian-Han, Hong; Xiao-Yan, Zhao

    Nanostructured silver films were deposited on polypropylene (PP) nonwovens by RF magnetron sputter coating to obtain the antibacterial properties. Shake flask test was used to evaluate the antibacterial properties of the materials. Atomic force microscope (AFM) was utilized to observe the surface morphology. Energy-dispersive X-ray (EDX) was also employed to analyze the surface elemental compositions. The antibacterial results indicated that the prolonged deposition time led to a significant improvement in antibacterial effect, and sputtering power and argon pressure did not show obvious effect on antibacterial performance. It is believed that the total amount of silver ions released from the silver coating was increased as the deposition time increased. AFM images and quantitative analysis of EDX, respectively revealed that increase in deposition time led to the increased coverage of silver film and the increased silver weight percentage per unit surface, which provided evidences for the increased release rate of silver ions from the coating. Moreover, it was found that the optimum silver coating thickness was about 3 nm, taking antibacterial effect and cost of production into account.

  20. Antibacterial Activity of Geminized Amphiphilic Cationic Homopolymers.

    Science.gov (United States)

    Wang, Hui; Shi, Xuefeng; Yu, Danfeng; Zhang, Jian; Yang, Guang; Cui, Yingxian; Sun, Keji; Wang, Jinben; Yan, Haike

    2015-12-22

    The current study is aimed at investigating the effect of cationic charge density and hydrophobicity on the antibacterial and hemolytic activities. Two kinds of cationic surfmers, containing single or double hydrophobic tails (octyl chains or benzyl groups), and the corresponding homopolymers were synthesized. The antimicrobial activity of these candidate antibacterials was studied by microbial growth inhibition assays against Escherichia coli, and hemolysis activity was carried out using human red blood cells. It was interestingly found that the homopolymers were much more effective in antibacterial property than their corresponding monomers. Furthermore, the geminized homopolymers had significantly higher antibacterial activity than that of their counterparts but with single amphiphilic side chains in each repeated unit. Geminized homopolymers, with high positive charge density and moderate hydrophobicity (such as benzyl groups), combine both advantages of efficient antibacterial property and prominently high selectivity. To further explain the antibacterial performance of the novel polymer series, the molecular interaction mechanism is proposed according to experimental data which shows that these specimens are likely to kill microbes by disrupting bacterial membranes, leading them unlikely to induce resistance.

  1. Interaction of antimicrobial peptide Plantaricin149a and four analogs with lipid bilayers and bacterial membranes

    Directory of Open Access Journals (Sweden)

    José Luiz de Souza Lopes

    2013-12-01

    Full Text Available The amidated analog of Plantaricin149, an antimicrobial peptide from Lactobacillus plantarum NRIC 149, directly interacts with negatively charged liposomes and bacterial membranes, leading to their lysis. In this study, four Pln149-analogs were synthesized with different hydrophobic groups at their N-terminus with the goal of evaluating the effect of the modifications at this region in the peptide's antimicrobial properties. The interaction of these peptides with membrane models, surface activity, their hemolytic effect on red blood cells, and antibacterial activity against microorganisms were evaluated. The analogs presented similar action of Plantaricin149a; three of them with no hemolytic effect (< 5% until 0.5 mM, in addition to the induction of a helical element when binding to negative liposomes. The N-terminus difference between the analogs and Plantaricin149a retained the antibacterial effect on S. aureus and P. aeruginosa for all peptides (MIC50 of 19 µM and 155 µM to Plantaricin149a, respectively but resulted in a different mechanism of action against the microorganisms, that was bactericidal for Plantaricin149a and bacteriostatic for the analogs. This difference was confirmed by a reduction in leakage action for the analogs. The lytic activity of Plantaricin149a is suggested to be a result of the peptide-lipid interactions from the amphipathic helix and the hydrophobic residues at the N-terminus of the antimicrobial peptide.

  2. [Therapeutic properties of proteins and peptides from colostrum and milk].

    Science.gov (United States)

    Zimecki, Michał; Artym, Jolanta

    2005-01-01

    Colostrum and milk are rich in proteins and peptides which play a crucial role in innate immunity when transferred to the offspring and may accelerate maturation of the immune system in neonates. The immunotropic properties of these proteins prompted investigators research their potential application in prevention and therapy. Lactoferrin (LF) exhibits antibacterial, antifungal, antiviral, antiparasitice, and antitumoral activities. It is protective with regard to intestinal epithelium, promotes bone growth, and accelerates the recovery of immune system function in immunocompromised animals. LF was tried in the treatment of hepatitis C infection and the intestinal form of graft-versus-host disease (GvHD). A proline-rich polypeptide (PRP) demonstrated a variety of immunotropic functions, including the promotion of T-cell maturation and inhibition of autoimmune disorders. PRP, in the form of chewable tablets (Colostrinin) was recently found to improve or stabilize the health status of Alzheimer's disease patients. Casein and casein-derived peptides showed protective activities in enamel demineralization and as caries-preventing agents. The protein hydrolyzates were also protective in diabetic animals, reduced tumor growth, had antihypertensive activity and diminished colicky symptoms in infants. Glycomacropeptide (GMP), a peptide derived from kappa-casein, exhibited various antibacterial and antithrombotic activities. Alpha-lactalbumin (LA) demonstrated antiviral, antitumoral and anti-stress properties. LA-enriched diets were anxiolytic, lowered blood pressure in rats, prevented diarrhea, and led to a better weight gain in malnourished children. HAMLET, a complex of LA and oleic acid, was effective in patients with cutaneous papillomas. Lysozyme found application in infant formulas, the treatment of periodentitis, and the prevention of tooth decay. Milk enriched in lysozyme was used in feeding premature infants suffering from concomitant diseases. Interesting

  3. Discovery of an ultra-short linear antibacterial tetrapeptide with anti-MRSA activity from a structure-activity relationship study.

    Science.gov (United States)

    Lau, Qiu Ying; Ng, Fui Mee; Cheong, Jin Wei Darryl; Yap, Yi Yong Alvin; Tan, Yoke Yan Fion; Jureen, Roland; Hill, Jeffrey; Chia, Cheng San Brian

    2015-11-13

    The overuse and misuse of antibiotics has resulted in the emergence of drug-resistant pathogenic bacteria, including meticillin-resistant Staphylococcus aureus (MRSA), the primary pathogen responsible for human skin and soft-tissue infections. Antibacterial peptides are known to kill bacteria by rapidly disrupting their membranes and are deemed plausible alternatives to conventional antibiotics. One advantage of their membrane-targeting mode of action is that bacteria are unlikely to develop resistance as changing their cell membrane structure and morphology would likely involve extensive genetic mutations. However, major concerns in using peptides as antibacterial drugs include their instability towards plasma proteases, toxicity towards human cells due to their membrane-targeting mode of action and high manufacturing cost. These concerns can be mitigated by developing peptides as topical agents, by the judicial selection of amino acids and developing very short peptides respectively. In this preliminary report, we reveal a linear, non-hemolytic tetrapeptide with rapid bactericidal activity against MRSA developed from a structure-activity relationship study based on the antimicrobial hexapeptide WRWRWR-NH2. Our finding opens promising avenues for the development of ultra-short antibacterials to treat multidrug-resistant MRSA skin and soft tissue infections.

  4. Topical peptides as cosmeceuticals

    Directory of Open Access Journals (Sweden)

    Varadraj Vasant Pai

    2017-01-01

    Full Text Available Peptides are known to have diverse biological roles, most prominently as signaling/regulatory molecules in a broad variety of physiological processes including defense, immunity, stress, growth, homeostasis and reproduction. These aspects have been used in the field of dermatology and cosmetology to produce short, stable and synthetic peptides for extracellular matrix synthesis, pigmentation, innate immunity and inflammation. The evolution of peptides over the century, which started with the discovery of penicillin, has now extended to their usage as cosmeceuticals in recent years. Cosmeceutical peptides may act as signal modulators of the extracellular matrix component, as structural peptides, carrier peptides and neurotransmitter function modulators. Transdermal delivery of peptides can be made more effective by penetration enhancers, chemical modification or encapsulation of peptides. The advantages of using peptides as cosmeceuticals include their involvement in many physiological functions of the skin, their selectivity, their lack of immunogenicity and absence of premarket regulatory requirements for their use. However, there are disadvantages: clinical evidence for efficacy is often weak, absorption may be poor due to low lipophilicity, high molecular weight and binding to other ingredients, and prices can be quite high.

  5. Effects of Antibacterial Peptides on Intestinal Mucosal Morphology, Caecal Microflora and Immune Function of Meat Rabbits%抗菌肽对肉免小肠黏膜形态、盲肠菌群和疫功能的影响

    Institute of Scientific and Technical Information of China (English)

    郭志强; 杨奉珠; 雷岷; 宋代军; 谢晓红

    2012-01-01

    本试验旨在研究不同水平抗菌肽对肉兔小肠黏膜形态、盲肠菌群和免疫功能的影响.选取体重相近的35日龄断奶的新西兰肉兔160只,随机分为5组,每组4个重复,每个重复8只(公母各占1/2).对照组饲喂基础饲粮,试验组分别饲喂在基础饲粮中添加30 mg/kg喹乙醇以及150、200和250 mg/kg抗菌肽的试验饲粮.试验期8周.结果表明:各添加水平抗菌肽均显著提高了空肠绒毛高度,十二指肠、空肠和回肠绒毛高度与隐窝深度的比值以及盲肠乳酸杆菌数量(P<0.05),显著降低了空肠隐窝深度以及盲肠总好氧菌和大肠杆菌数量(P<0.05).此外,200 mg/kg抗菌肽还显著提高了回肠绒毛高度以及盲肠总厌氧菌和双歧杆菌数量(P<0.05),显著降低了十二指肠和回肠隐窝深度(P<0.05),显著增加了血清免疫球蛋白M和补体3含量(P<0.05).由此得出,在饲粮中添加抗菌肽可以改善肉兔小肠黏膜形态,刺激盲肠有益菌的增殖并抑制有害菌的增殖,同时还可提高机体的免疫功能.本试验条件下,抗菌肽在肉兔饲粮中的适宜添加量为200 mg/kg.%This experiment was conducted to evaluate the effects of antimicrobial peptides on intestinal mucosal morphology, caecal microflora and immune function of meat rabbits. A total of 160 New Zealand rabbits weaned at 35 days of age with the similar body weight were randomly allotted into 5 groups with 4 replicates per groups and 8 rabbits per replicate (half male and half female). The rabbits in control group were fed with a basal diet, while those in experimental groups were fed the basal diet supplemented with 30 mg/kg olaquindox, and 150, 200 and250 mg/kg antimicrobial peptides, respectively. The experiment lasted for 8 weeks. The results showed as follows: three supplemental levels of antimicrobial peptides all significantly enhanced the villus height of jejunum, villus height to crypt depth ratio of duodenum, jejunum and ileum

  6. Antibacterial activity in adhesive dentistry: a literature review.

    Science.gov (United States)

    Shafiei, Fereshteh; Memarpour, Mahtab

    2012-01-01

    This literature review summarizes the published research regarding the antibacterial agents used in adhesive dentistry. This article provides information about the clinical applications, beneficial effects, and possible disadvantages of antibacterials when used in various bonding situations.

  7. THE ANTIFUNGAL AND ANTIBACTERIAL ACTIVITY OF TWO PLANTS FROM ASTEMCEAE

    OpenAIRE

    2015-01-01

    In this study, we have found that, Chlysanthemum coronarium has shownantifungal and antibacterial activity, but Inula viscosa didn't show any antifungalor antibacterial activity.Key words: Chrysanthemum coronarium; Inula viscosa; antifungal andantibacterial activities.

  8. Antibacterial Effect of Human Amnion Membrane

    Directory of Open Access Journals (Sweden)

    Kashani, L. (MD

    2015-01-01

    Full Text Available Background and Objective: Along with antibiotics, the use of biological methods to combat bacteria is notably considered. A natural barrier such as amniotic membrane is one of the ways of dealing with bacterial infections. The aim of this study was to determine the antibacterial effect of human amniotic membrane. Materials and Methods: This descriptive study was performed in Dezyani teaching Hospital of Gorgan University of Medical Sciences, Iran. To evaluate the antibacterial activity against Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli bacteria, 20 amniotic membranes were obtained from postpartum mothers and examined by repeated dilution, diffusion and extraction techniques. Data were collected by observation method and described by mean and standard deviation. Results: The antibacterial activity was found in 15% of the samples against Staphylococcus Aureus and Pseudomonas aeruginosa, while no antibacterial activity was found against E. coli. Given the 15% positive responses, "Diffusion" and "repeated dilution" techniques were more effective in investigating the antibacterial effect of amniotic membrane. Conclusion: The results show the probability of antimicrobial effect of amniotic membrane tissue and it seems that this property can be affected by many factors.

  9. Antibacterial resistance: Current problems and possible solutions

    Directory of Open Access Journals (Sweden)

    Sharma Rashmi

    2005-03-01

    Full Text Available Antimicrobial resistance is a natural biological phenomenon of response of microbes to the selective pressure of an antimicrobial drug. Resistance may be inherent, which explains the phenomenon of opportunistic infection or acquired. Concern about the resistance increased in the late 1990′s and since then, many governmental and agency reports have been published regarding the agricultural use of antibacterials, advising less use of antibacterials, appropriate choice of antibacterials and regimens, prevention of cross-infection and development of new antibacterials. The emergence of multidrug resistant strains of Gram-negative bacteria (Pseudomonas, Klebsiella, Enterobacter, Acinetobacter, Salmonella species and Gram-positve organisms (Staphylococcus, Enterococcus, Streptococcus species is the more worrisome in the present therapeutic scenario. Multidrug - resistant tuberculosis is another serious public health problems. Resistance to some agents can be overcome by modifying the dosage regimens (e.g., using high-dose therapy or inhibiting the resistance mechanism (e.g., beta-lactamase inhibitors, whereas other mechanisms of resistance can only be overcome by using an agent from a different class. It is urgently required to ban the sale of antibiotics without prescription, to use antibiotics more judiciously in hospitals by intensive teaching of the principles of the use of antibiotics and to establish better control measures for nosocomial infections. Thus, it is highly recommended that practicing physicians should become aware of the magnitude of existing problem of antibacterial resistance and help in fighting this deadly threat by rational prescribing.

  10. Tunable, antibacterial activity of silicone polyether surfactants.

    Science.gov (United States)

    Khan, Madiha F; Zepeda-Velazquez, Laura; Brook, Michael A

    2015-08-01

    Silicone surfactants are used in a variety of applications, however, limited data is available on the relationship between surfactant structure and biological activity. A series of seven nonionic, silicone polyether surfactants with known structures was tested for in vitro antibacterial activity against Escherichia coli BL21. The compounds varied in their hydrophobic head, comprised of branched silicone structures with 3-10 siloxane linkages and, in two cases, phenyl substitution, and hydrophilic tail of 8-44 poly(ethylene glycol) units. The surfactants were tested at three concentrations: below, at, and above their Critical Micelle Concentrations (CMC) against 5 concentrations of E. coli BL21 in a three-step assay comprised of a 14-24h turbidometric screen, a live-dead stain and viable colony counts. The bacterial concentration had little effect on antibacterial activity. For most of the surfactants, antibacterial activity was higher at concentrations above the CMC. Surfactants with smaller silicone head groups had as much as 4 times the bioactivity of surfactants with larger groups, with the smallest hydrophobe exhibiting potency equivalent to sodium dodecyl sulfate (SDS). Smaller PEG chains were similarly associated with higher potency. These data link lower micelle stability and enhanced permeability of smaller silicone head groups to antibacterial activity. The results demonstrate that simple manipulation of nonionic silicone polyether structure leads to significant changes in antibacterial activity.

  11. MgO nanoparticles as antibacterial agent: preparation and activity

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Zhen-Xing, E-mail: tangzhenxing@126.com [Department of Food Science, Anqing, Vocational and Technical College, Anqing, Anhui (China); Lv, Bin-Feng [Date Palm Research Center, King Faisal University, (Saudi Arabia)

    2014-07-15

    Bacterial pollution is a great risk for human health. Nanotechnology offers a way to develop new inorganic antibacterial agents. Nano-inorganic metal oxide has a potential to reduce bacterial contamination. MgO is an important inorganic oxide and has been widely used in many fields. Many studies have shown that MgO nanoparticles have good antibacterial activity. Therefore, in this paper, the main synthesis methods, antibacterial activity and antibacterial mechanisms of MgO nanoparticles are reviewed. (author)

  12. MgO nanoparticles as antibacterial agent: preparation and activity

    OpenAIRE

    Zhen-Xing Tang; Bin-Feng Lv

    2014-01-01

    Bacterial pollution is a great risk for human health. Nanotechnology offers a way to develop new inorganic antibacterial agents. Nano-inorganic metal oxide has a potential to reduce bacterial contamination. MgO is an important inorganic oxide and has been widely used in many fields. Many studies have shown that MgO nanoparticles have good antibacterial activity. Therefore, in this paper, the main synthesis methods, antibacterial activity and antibacterial mechanisms of MgO nanoparticles are r...

  13. Antimicrobial properties of analgesic kyotorphin peptides unraveled through atomic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, Marta M.B.; Franquelim, Henri G.; Torcato, Ines M. [Instituto de Medicina Molecular, Faculdade de Medicina de Lisboa, Av. Professor Egas Moniz, 1649-028 Lisboa (Portugal); Ramu, Vasanthakumar G.; Heras, Montserrat; Bardaji, Eduard R. [Laboratori d' Innovacio en Processos i Productes de Sintesi Organica (LIPPSO), Departament de Quimica, Universitat de Girona, Campus Montilivi, 17071 Girona (Spain); Castanho, Miguel A.R.B., E-mail: macastanho@fm.ul.pt [Instituto de Medicina Molecular, Faculdade de Medicina de Lisboa, Av. Professor Egas Moniz, 1649-028 Lisboa (Portugal)

    2012-04-13

    Highlights: Black-Right-Pointing-Pointer New kyotorphin derivatives have antimicrobial properties against S. aureus. Black-Right-Pointing-Pointer Atomic force microscopy show membrane disturbing effects of KTP-NH{sub 2} and IbKTP-NH{sub 2}. Black-Right-Pointing-Pointer None of the KTP derivatives are hemolytic. Black-Right-Pointing-Pointer The minimal peptidic sequence with antimicrobial activity is Tyr-Arg, if amidated. -- Abstract: Antimicrobial peptides (AMPs) are promising candidates as alternatives to conventional antibiotics for the treatment of resistant pathogens. In the last decades, new AMPs have been found from the cleavage of intact proteins with no antibacterial activity themselves. Bovine hemoglobin hydrolysis, for instance, results in AMPs and the minimal antimicrobial peptide sequence was defined as Tyr-Arg plus a positively charged amino acid residue. The Tyr-Arg dipeptide alone, known as kyotorphin (KTP), is an endogenous analgesic neuropeptide but has no antimicrobial activity itself. In previous studies new KTP derivatives combining C-terminal amidation and Ibuprofen (Ib) - KTP-NH{sub 2}, IbKTP, IbKTP-NH{sub 2} - were designed in order to improve KTP brain targeting. Those modifications succeeded in enhancing peptide-cell membrane affinity towards fluid anionic lipids and higher analgesic activity after systemic injection resulted therefrom. Here, we investigated if this affinity for anionic lipid membranes also translates into antimicrobial activity because bacteria have anionic membranes. Atomic force microscopy revealed that KTP derivatives perturbed Staphylococcus aureus membrane structure by inducing membrane blebbing, disruption and lysis. In addition, these peptides bind to red blood cells but are non-hemolytic. From the KTP derivatives tested, amidated KTP proves to be the most active antibacterial agent. The combination of analgesia and antibacterial activities with absence of toxicity is highly appealing from the clinical point of view

  14. Insulin C-peptide test

    Science.gov (United States)

    C-peptide ... the test depends on the reason for the C-peptide measurement. Ask your health care provider if ... C-peptide is measured to tell the difference between insulin the body produces and insulin someone injects ...

  15. Biofunctionalization of microgroove titanium surfaces with an antimicrobial peptide to enhance their bactericidal activity and cytocompatibility.

    Science.gov (United States)

    Zhou, Lin; Lai, Yingzhen; Huang, Wenxiu; Huang, Sijia; Xu, Zhiqiang; Chen, Jiang; Wu, Dong

    2015-04-01

    A firm peri-implant soft tissue seal is important for the long-term survival of dental implants, which demands the properties of antibacterial and cytocompatibility of the implant surfaces. In this study, GL13K, a cationic antimicrobial peptide, was immobilized onto microgroove surfaces which were 60 μm in width and 10 μm in depth, and the modified surfaces improved both the properties of antibacterial and cytocompatibility. The method of silanization was used to immobilize the antimicrobial peptide GL13K, which was confirmed by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), atomic force microscopy (AFM), water contact angle measurement. Then the mechanical stability of the coatings was confirmed by ultrasonication. In vitro antibacterial tests confirmed bactericidal activity against Porphyromonas gingivalis without inhibiting its adhesion. In vitro cytocompatibility tests also confirmed that adhesion at later phase and proliferation of HGFs were greater (P<0.01) on the GL13K-modified microgroove surfaces than on the non-treated microgroove surfaces, and both of them were greater than on the smooth surfaces. The phenomenon of the contact guidance, which is cell growth aligned along the microgrooves, was maintained. Overall, this study developed a promising bi-functional surface that combined the physical and chemical properties to promote cytocompatibility and antibacterial activity simultaneously.

  16. [Search for new types of raw materials for antibacterial drugs].

    Science.gov (United States)

    Sidorenko, M L; Buzoleva, L S

    2012-01-01

    Antibacterial properties of the mycelium culture of Fomitopsis officinalis (Vill.: Fr.) Bondartsev et Singer were investigated. It was shown to be an additional source for production of antibacterial substances active against gramnegative bacteria. In the future, the use of Fomitopsis officinalis for production of antibacterial substances active against the pseudotuberculosis pathogen or pseudomonads is quite possible.

  17. Descriptors for antimicrobial peptides

    DEFF Research Database (Denmark)

    Jenssen, Håvard

    2011-01-01

    of antimicrobial drugs, and computational methods utilizing molecular descriptors can significantly accelerate the development of new peptide drug candidates. Areas covered: This paper gives a broad overview of peptide and amino-acid scale descriptors available for AMP modeling and highlights which...

  18. PNA Peptide chimerae

    DEFF Research Database (Denmark)

    Koch, T.; Næsby, M.; Wittung, P.;

    1995-01-01

    Radioactive labelling of PNA has been performed try linking a peptide segment to the PNA which is substrate for protein kinase A. The enzymatic phosphorylation proceeds in almost quantitative yields.......Radioactive labelling of PNA has been performed try linking a peptide segment to the PNA which is substrate for protein kinase A. The enzymatic phosphorylation proceeds in almost quantitative yields....

  19. Peptide Nucleic Acids

    DEFF Research Database (Denmark)

    2004-01-01

    A novel class of compounds known as peptide nucleic acids, bind complementary DNA and RNA strands, and generally do so more strongly than the corresponding DNA or RNA strands while exhibiting increased sequence specificity and solubility. The peptide nucleic acids comprise ligands selected from...

  20. Bacteriocin Inducer Peptides

    Science.gov (United States)

    Novel peptides produced by bacteriocin-producing bacteria stimulate the production of bacteriocins in vitro. The producer bacteria are cultured in the presence of a novel inducer bacteria and a peptide having a carboxy terminal sequence of VKGLT in order to achieve an increase in bacteriocin produc...

  1. Avian host defense peptides

    NARCIS (Netherlands)

    Cuperus, Tryntsje; Coorens, M.; van Dijk, A.; Haagsman, H.P.

    2013-01-01

    Host defense peptides (HDPs) are important effector molecules of the innate immune system of vertebrates. These antimicrobial peptides are also present in invertebrates, plants and fungi. HDPs display broad-spectrum antimicrobial activities and fulfill an important role in the first line of defense

  2. Antibacterial Activity of Punica granatum Linn.

    Directory of Open Access Journals (Sweden)

    Kenan Tunç

    2013-08-01

    Full Text Available In this study, it was investigated that the extracts (ethanol, aceton, methanol, ethyl acetat obtained from fruit peels of the plant to whether has antibacterial effect against Streptococcus mitis CNCTC 4/77, Streptococcus salivarius CNCTC 64/59, Streptococcus mutans CNCTC 8/77, Staphylococcus epidermidis ATCC 12228, Staphylococcus aureus ATCC 29213, Escherichia coli ATCC 25922, Salmonella abony NCTC 6017, Salmonella typhimurium ATCC 14028, Enterococcus faecalis ATCC 29212, Bacillus subtilis ATCC 6633 bacteria strains in vitro. The antibacterial activity of extracts was evaluated according to disc diffusion method. It has been determined that pomegranate peel's extract had the highest inhibition zone diameters ( 18-30 mm against S. epidermidis and S. aureus bacteria strains. The antibacterial activity of plant against Streptococcus mitis is determined in this study for the first time.

  3. Antibacterial activity of eight Brazilian annonaceae plants.

    Science.gov (United States)

    Takahashi, Jacqueline A; Pereira, Cássia R; Pimenta, Lúcia P S; Boaventura, Maria Amélia D; Silva, Luiz G F E

    2006-01-01

    Sixteen extracts, obtained from eight Brazilian plants of Annonaceae family, were screened for their antibacterial activity: Xylopia frutescens, X. aromatica, X. amazonica, X. benthamii, Annona ambotay, A. crassiflora, A. muricata and A. cherimolia. Amongst the investigated extracts, six showed antibacterial activity against at least one of the tested organisms at the concentration of 100 microg/mL. The most active extracts were those prepared from X. frutescens, X. amazonica, and A. ambotay. A phytochemical screening showed the presence of anonaceus acetogenins in some active extracts. Eleven diterpenoids were also tested for comparison purposes. Six were natural products, previously isolated from Xylopia sp. (kaurenoic, frutoic, xylopic, 15beta-hydroxy-kaurenoic and trachylobanic acids plus kaurenol) and five were derivatives of such compounds, obtained by esterification or reduction reactions. Trachylobanic acid showed antibacterial activity against B. subtilis and S. aureus.

  4. Antibacterial resistance leadership group: open for business.

    Science.gov (United States)

    Chambers, Henry F; Bartlett, John G; Bonomo, Robert A; Chiou, Christine; Cosgrove, Sara E; Cross, Heather R; Daum, Robert S; Downing, Michele; Evans, Scott R; Knisely, Jane; Kreiswirth, Barry N; Lautenbach, Ebbing; Mickley, Brenda S; Patel, Robin; Pettigrew, Melinda M; Rodvold, Keith A; Spellberg, Brad; Fowler, Vance G

    2014-06-01

    Funded by the National Institute of Allergy and Infectious Diseases, the Antibacterial Resistance Leadership Group (ARLG) is tasked with developing a clinical research agenda and conducting clinical studies to address the growing public health threat of antibacterial resistance. The ARLG has identified 4 high-priority areas of research: infections caused by gram-negative bacteria, infections caused by gram-positive bacteria, antimicrobial stewardship and infection prevention, and diagnostics. The ARLG will be accepting proposals from the scientific community for clinical research that addresses 1 or more of these high-priority areas. These studies should have the potential to transform medical practice and be unlikely to occur without ARLG support. The purpose of this article is to make interested parties aware of clinical research opportunities made available by ARLG and to encourage submission of clinical research proposals that address the problem of antibacterial resistance.

  5. Molecular structure, chemical synthesis, and antibacterial activity of ABP-dHC-cecropin A from drury (Hyphantria cunea).

    Science.gov (United States)

    Zhang, Jiaxin; Movahedi, Ali; Wang, Xiaoli; Wu, Xiaolong; Yin, Tongming; Zhuge, Qiang

    2015-06-01

    The increasing resistance of bacteria and fungi to currently available antibiotics is a major concern worldwide, leading to enormous efforts to develop new antibiotics with new modes of actions. In this paper, cDNA encoding cecropin A was amplified from drury (Hyphantria cunea) (dHC) pupa fatbody total RNA using RT-PCR. The full-length dHC-cecropin A cDNA encoded a protein of 63 amino acids with a predicted 26-amino acid signal peptide and a 37-amino acid functional domain. We synthesized the antibacterial peptide (ABP) from the 37-amino acid functional domain (ABP-dHC-cecropin A), and amidated it via the C-terminus. Time-of-flight mass spectrometry showed its molecular weight to be 4058.94. The ABP-dHC-cecropin A was assessed in terms of its protein structure using bioinformatics and CD spectroscopy. The protein's secondary structure was predicted to be α-helical. In an antibacterial activity analysis, the ABP-dHC-cecropin A exhibited strong antibacterial activity against E. coli K12D31 and Agrobacterium EHA105.

  6. Self-assembled peptide nanomaterials for biomedical applications: promises and pitfalls

    Science.gov (United States)

    Sun, Linlin; Zheng, Chunli; Webster, Thomas J

    2017-01-01

    Over the last several decades, a great number of advances have been made in the area of self-assembled supramolecules for regenerative medicine. Such advances have involved the design, preparation, and characterization of brand new self-assembled peptide nanomaterials for a variety of applications. Among all biomolecules considered for self-assembly applications, peptides have attracted a great deal of attention as building blocks for bottom-up fabrication, due to their versatility, ease of manufacturing, low costs, tunable structures, and versatile properties. Herein, some of the more exciting new designs of self-assembled peptides and their associated unique features are reviewed and several promising applications of how self-assembled peptides are advancing drug delivery, tissue engineering, antibacterial therapy, and biosensor device applications are highlighted. PMID:28053525

  7. Design and surface immobilization of short anti-biofilm peptides.

    Science.gov (United States)

    Mishra, Biswajit; Lushnikova, Tamara; Golla, Radha M; Wang, Xiuqing; Wang, Guangshun

    2017-02-01

    Short antimicrobial peptides are essential to keep us healthy and their lasting potency can inspire the design of new types of antibiotics. This study reports the design of a family of eight-residue tryptophan-rich peptides (TetraF2W) obtained by converting the four phenylalanines in temporin-SHf to tryptophans. The temporin-SHf template was identified from the antimicrobial peptide database (http://aps.unmc.edu/AP). Remarkably, the double arginine variant (TetraF2W-RR) was more effective in killing methicillin-resistant Staphylococcus aureus (MRSA) USA300, but less cytotoxic to human skin HaCat and kidney HEK293 cells, than the lysine-containing dibasic combinations (KR, RK and KK). Killing kinetics and fluorescence spectroscopy suggest membrane targeting of TetraF2W-RR, making it more difficult for bacteria to develop resistance. Because established biofilms on medical devices are difficult to remove, we chose to covalently immobilize TetraF2W-RR onto the polyethylene terephthalate (PET) surface to prevent biofilm formation. The successful surface coating of the peptide is supported by FT-IR and XPS spectroscopies, chemical quantification, and antibacterial assays. This peptide-coated surface indeed prevented S. aureus biofilm formation with no cytotoxicity to human cells. In conclusion, TetraF2W-RR is a short Trp-rich peptide with demonstrated antimicrobial and anti-biofilm potency against MRSA in both the free and immobilized forms. Because these short peptides can be synthesized cost effectively, they may be developed into new antimicrobial agents or used as surface coating compounds.

  8. Nisin adsorption on hydrophilic and hydrophobic surfaces: evidence of its interactions and antibacterial activity.

    Science.gov (United States)

    Karam, Layal; Jama, Charafeddine; Nuns, Nicolas; Mamede, Anne-Sophie; Dhulster, Pascal; Chihib, Nour-Eddine

    2013-06-01

    Study of peptides adsorption on surfaces remains a current challenge in literature. A complementary approach, combining X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) was used to investigate the antimicrobial peptide nisin adsorption on hydrophilic and hydrophobic surfaces. The native low density polyethylene was used as hydrophobic support and it was grafted with acrylic acid to render it hydrophilic. XPS permitted to confirm nisin adsorption and to determine its amount on the surfaces. ToF-SIMS permitted to identify the adsorbed bacteriocin type and to observe its distribution and orientation behavior on both types of surfaces. Nisin was more oriented by its hydrophobic side to the hydrophobic substrate and by its hydrophilic side to the outer layers of the adsorbed peptide, in contrast to what was observed on the hydrophilic substrate. A correlation was found between XPS and ToF-SIMS results, the types of interactions on both surfaces and the observed antibacterial activity. Such interfacial studies are crucial for better understanding the peptides interactions and adsorption on surfaces and must be considered when setting up antimicrobial surfaces.

  9. Antibacterial Activity of Extracellular Protease Isolated From an Algicolous Fungus Xylaria psidii KT30 Against Gram-Positive Bacteria

    Directory of Open Access Journals (Sweden)

    Taufik Indarmawan

    2016-04-01

    Full Text Available Infectious diseases became more serious problem for public health in recent years. Although existing antibacterial drugs have been relatively effective, they do not rule out the emergence of resistance to the drug. Therefore, the intensive exploration of new bioactive compounds from natural, especially peptide compounds began in recent decades in order-handling infection. This study aimed to isolate, purify and test the potential application of Xylaria psidii KT30 extracellular protease as antibacterial agent against Gram-positive bacteria. X. psidii KT30, a marine fungus isolated from red seaweed Kappaphycus alvarezii showed antibacterial activity against Bacillus subtilis and Staphylococcus aureus. Antibacterial compounds of this fungus were predicted as a group of proteases. Extracellular protease exhibited an optimum activity when potato dextrose broth was used as cultivation medium. Furthermore, the highest activity of these proteases was found on fungal extract after day 15 of cultivation with value of 2.33 ± 0.19 U/mL. The partial purification of proteases using G-75 column chromatography resulted in 2 groups of fractions and showed protease activity based on zymogram assay. The extracellular proteases obtained from those fractions have 3 patterns of molecular mass based on sodium dodecyl sulfate–polyacrylamide gel electrophoresis which are 56.62, 89.12, 162.18 kDa.

  10. Antibiofilm and Antimicrobial Efficacy of DispersinB (registered trademark)-KSL-W Peptide-Based Wound Gel Against Chronic Wound Infection Associated Bacteria

    Science.gov (United States)

    2014-01-21

    16, 21–23]. The DispersinB-KSL-W wound gel exhibited a sus- tained antibacterial activity over a period of 72 h against all the chronic wound...Antibiofilm and Antimicrobial Efficacy of DispersinB-KSL-W Peptide-Based Wound Gel Against Chronic Wound Infection Associated Bacteria Purushottam V...and Acinetobacter baumannii. In addition, the wound gel formulation comprising DispersinB, KSL-W peptide, and a gelling agent Pluronic F-127 showed a

  11. Progress in antibacterial and antifungal chemotherapy.

    Science.gov (United States)

    Fromtling, R A

    2000-08-01

    The European Society of Clinical Microbiology and Infectious Diseases sponsored the 10th European Congress on Clinical Microbiology and Infectious Diseases in Stockholm, Sweden, May 28-31, 2000. At the ECMID, well-attended sessions were held which focused on the pathogenesis and therapy of viral, bacterial and fungal diseases. This report focuses on new information on resistance to antibacterial agents, including data from recent surveillance studies, and the in vitro and investigational clinical activity of new antibacterial (moxifloxacin, telithromycin) and antifungal (fluconazole, itraconazole, voriconazole, amphotericin B, liposomal formulations of amphotericin B, terbinafine and the candins) drugs.

  12. Injectable bioadhesive hydrogels with innate antibacterial properties

    Science.gov (United States)

    Giano, Michael C.; Ibrahim, Zuhaib; Medina, Scott H.; Sarhane, Karim A.; Christensen, Joani M.; Yamada, Yuji; Brandacher, Gerald; Schneider, Joel P.

    2014-06-01

    Surgical site infections cause significant postoperative morbidity and increased healthcare costs. Bioadhesives used to fill surgical voids and support wound healing are typically devoid of antibacterial activity. Here we report novel syringe-injectable bioadhesive hydrogels with inherent antibacterial properties prepared from mixing polydextran aldehyde and branched polyethylenimine. These adhesives kill both Gram-negative and Gram-positive bacteria, while sparing human erythrocytes. An optimal composition of 2.5 wt% oxidized dextran and 6.9 wt% polyethylenimine sets within seconds forming a mechanically rigid (~\

  13. Electrospun antibacterial chitosan-based fibers.

    Science.gov (United States)

    Ignatova, Milena; Manolova, Nevena; Rashkov, Iliya

    2013-07-01

    Chitosan is non-toxic, biocompatible, and biodegradable polysaccharide from renewable resources, known to have inherent antibacterial activity, which is mainly due to its polycationic nature. The combining of all assets of chitosan and its derivatives with the unique properties of electrospun nanofibrous materials is a powerful strategy to prepare new materials that can find variety of biomedical applications. In this article the most recent studies on different approaches for preparation of antibacterial fibrous materials from chitosan and its derivatives such as electrospinning, coating, and electrospinning-electrospraying, loading of drugs or bioactive nanoparticles are summarized.

  14. Role of SbmA in the uptake of peptide nucleic acid (PNA)-peptide conjugates in E. coli.

    Science.gov (United States)

    Ghosal, Anubrata; Vitali, Ally; Stach, James E M; Nielsen, Peter E

    2013-02-15

    Antisense PNA oligomers targeting essential genes (acpP or ftsZ) and conjugated to the delivery peptide L((KFF)(3)K) show complete growth inhibition of wild type E. coli strain (MG1655) with submicromolar MIC. In this study we show that resistant mutants generated against such PNA-peptide conjugates had disruptions in the region of sbmA, a gene encoding an inner membrane peptide transporter. The wild type sensitivity to the PNA conjugates was re-established in the resistance mutants by complementation with sbmA. Furthermore, deletion of sbmA in E. coli AS19, a strain that is sensitive to unmodified PNA, resulted in resistance to PNA. Finally, PNA conjugated with the corresponding non-biological H-D((KFF)(3)K) peptide retained antibacterial activity in sbmA deletion strains, whereas the same conjugate with a protease-sensitive linker did not. These results clearly identify SbmA as a carrier of naked PNA over the inner bacterial membrane and thereby infer that the peptide is transporting the PNA conjugates over the outer membrane. Strains lacking SbmA were used to screen novel peptide-PNA carriers that were SbmA-independent. Four such PNA-peptide conjugates, H-D((KFF)(3)K), H-(RFR)(4)-Ahx-βAla, H-(R-Ahx-R)(4)-Ahx-βAla, and H-(R-Ahx)(6)-βAla, were identified that utilize an alternative uptake mechanism but retain their antimicrobial potency. In addition SbmA is the first protein identified to recognize PNA.

  15. Inhibition of the ferric uptake regulator by peptides derived from anti-FUR peptide aptamers: coupled theoretical and experimental approaches.

    Science.gov (United States)

    Cissé, Cheickna; Mathieu, Sophie V; Abeih, Mohamed B Ould; Flanagan, Lindsey; Vitale, Sylvia; Catty, Patrice; Boturyn, Didier; Michaud-Soret, Isabelle; Crouzy, Serge

    2014-12-19

    The FUR protein (ferric uptake regulator) is an iron-dependent global transcriptional regulator. Specific to bacteria, FUR is an attractive antibacterial target since virulence is correlated to iron bioavailability. Recently, four anti-FUR peptide aptamers, composed of 13 amino acid variable loops inserted into a thioredoxinA scaffold, were identified, which were able to interact with Escherichia coli FUR (EcFUR), inhibit its binding to DNA and to decrease the virulence of pathogenic E. coli in a fly infection model. The first characterization of anti-FUR linear peptides (pF1 6 to 13 amino acids) derived from the variable part of the F1 anti-FUR peptide aptamer is described herein. Theoretical and experimental approaches, in original combination, were used to study interactions of these peptides with FUR in order to understand their mechanism of inhibition. After modeling EcFUR by homology, docking with Autodock was combined with molecular dynamics simulations in implicit solvent to take into account the flexibility of the partners. All calculations were cross-checked either with other programs or with experimental data. As a result, reliable structures of EcFUR and its complex with pF1 are given and an inhibition pocket formed by the groove between the two FUR subunits is proposed. The location of the pocket was validated through experimental mutation of key EcFUR residues at the site of proposed peptide interaction. Cyclisation of pF1, mimicking the peptide constraint in F1, improved inhibition. The details of the interactions between peptide and protein were analyzed and a mechanism of inhibition of these anti-FUR molecules is proposed.

  16. Gene cloning and functional characterization of four novel antimicrobial-like peptides from scorpions of the family Vaejovidae.

    Science.gov (United States)

    Ramírez-Carreto, Santos; Quintero-Hernández, Verónica; Jiménez-Vargas, Juana María; Corzo, Gerardo; Possani, Lourival D; Becerril, Baltazar; Ortiz, Ernesto

    2012-04-01

    From the cDNA libraries made from the venom glands of two scorpions belonging to the Vaejovidae family, four different putative non disulfide-bridged antimicrobial peptides were identified: VmCT1 and VmCT2 from Vaejovis mexicanus smithi plus VsCT1 and VsCT2 from Vaejovis subcristatus. These short peptides (with only 13 amino acid residues each) share important amino acid sequence similarities among themselves and with other reported antimicrobial peptides, but their biological activities vary dramatically. This communication reports the cloning, chemical synthesis and characterization of these peptides. Two peptides, VmCT1 and VmCT2 showed broad-spectrum antibacterial activity with minimum inhibitory concentrations MICs in the range of 5-25 μM and 10-20 μM respectively, whereas their hemolytic activity at these concentrations was low. Structure-function relationships that might determine the differences in activities are discussed.

  17. Investigation of antibacterial mechanism and identification of bacterial protein targets mediated by antibacterial medicinal plant extracts.

    Science.gov (United States)

    Yong, Ann-Li; Ooh, Keng-Fei; Ong, Hean-Chooi; Chai, Tsun-Thai; Wong, Fai-Chu

    2015-11-01

    In this paper, we investigated the antibacterial mechanism and potential therapeutic targets of three antibacterial medicinal plants. Upon treatment with the plant extracts, bacterial proteins were extracted and resolved using denaturing gel electrophoresis. Differentially-expressed bacterial proteins were excised from the gels and subjected to sequence analysis by MALDI TOF-TOF mass spectrometry. From our study, seven differentially expressed bacterial proteins (triacylglycerol lipase, N-acetylmuramoyl-L-alanine amidase, flagellin, outer membrane protein A, stringent starvation protein A, 30S ribosomal protein s1 and 60 kDa chaperonin) were identified. Additionally, scanning electron microscope study indicated morphological damages induced on bacterial cell surfaces. To the best of our knowledge, this represents the first time these bacterial proteins are being reported, following treatments with the antibacterial plant extracts. Further studies in this direction could lead to the detailed understanding of their inhibition mechanism and discovery of target-specific antibacterial agents.

  18. Antibacterial activity in vitro of Thymus capitatus from Jordan.

    Science.gov (United States)

    Qaralleh, Haitham N; Abboud, Muayad M; Khleifat, Khaled M; Tarawneh, Khaled A; Althunibat, Osama Y

    2009-07-01

    This study was carried out to evaluate the antibacterial activity of aqueous and organic extracts of Thymus capitatus L. (Lamiaceae) leaves and stems. Dried ground powder leaves and stems were extracted with water (aqueous extracts), ethanol, dichloromethane and hexane (Soxhlet extracts). The antibacterial activity of these extracts was evaluated against bacteria using disc diffusion method. The result obtained showed that the leaves had stronger antibacterial activity than the stems extracts. The ethanolic extract had the highest yield products and the high antibacterial activity than all other solvents. The results suggest that essential oil as non-polar organic compounds could be the main active compounds in this plant. Therefore the antibacterial activity of leaves ethanol extracts (LEE) was compared with essential oils leaves extracts (LEO) of T. capitatus. The LEO showed greater antibacterial activity than LEE. The LEO showed a broad spectrum of antibacterial activity and the Pseudomonas aeruginosa was the most sensitive bacteria.

  19. Antibacterial activity of silver nanoparticles with different morphologies as well as their possible antibacterial mechanism

    Science.gov (United States)

    Hu, Guansong; Jin, Wenxiu; Chen, Qingyuan; Cai, Yuchun; Zhu, Qiuhua; Zhang, Wanzhong

    2016-10-01

    Silver nanoparticles (AgNPs) have good antibacterial activity and their morphologies have important influence on their activity. The relationship between their bactericidal property and morphology has not been studied thoroughly. Silver triangular nanoplates have basic {111} surface, nanospheres and nanocubes mainly have {100} planes, and nanorods have {100} side surfaces and {111} end facets. It was said that {111} crystal plane of AgNPs may play a prime role in antibacterial progress. Moreover, the antibacterial activity of nanocubes is not very clear when compared to nanoparticles with other morphologies. In this paper, we studied the antibacterial activity of nanocubes and attempted to confirm whether nanoparticles with {111} crystal facet truly had stronger antibacterial activity than other nanoparticles. We prepared four kinds of AgNPs and found silver triangle nanoplates had the best antibacterial activity, while nanospheres, nanocubes and short nanorods showed similar efficacy. It may provide a reference for safe application of AgNPs with different morphologies in the medical field.

  20. Evaluation of antibacterial activity of N-phosphonium chitosan as a novel polymeric antibacterial agent.

    Science.gov (United States)

    Guo, Aijie; Wang, Feihu; Lin, Wentao; Xu, Xiaofen; Tang, Tingting; Shen, Yuanyuan; Guo, Shengrong

    2014-06-01

    N-phosphonium chitosans (NPCSs) with different degrees of substitution (3%, 13% and 21%) were synthesized and evaluated as novel polymeric antibacterial agents. Their antibacterial activities compared with hydroxypropyltrimethyl ammonium chloride chitosan (HACC), parent chitosan and (5-carboxypentyl) triphenylphosphonium bromide (CTPB) were tested against Escherichia coli and two strains of drug-resistance Staphylococcus aureus by minimal inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and biofilm prevention assays. The results show that the NPCS with 3% or 13% substitution has lower MIC and MBC values and stronger ability to inhibit biofilm formation of all the three bacteria than HACC, chitosan and CTPB. In addition, the antibacterial activity of NPCSs increases with their substitution decreasing from 21% to 3%. Overall, the antibacterial activity of NPCS with 3% or 13% substitution is better than that of NPCS with 21% substitution, HACC with 22% substitution, chitosan and CTPB. It can be considered that NPCS with appropriate degree of substitution has favorable antibacterial activity and is a potential polymeric antibacterial agent.

  1. Antibacterial paperboard packaging using microfibrillated cellulose.

    Science.gov (United States)

    Lavoine, Nathalie; Desloges, Isabelle; Manship, Brigitte; Bras, Julien

    2015-09-01

    The industry and consumers are focusing more and more on the development of biodegradable and lightweight food-packaging materials, which could better preserve the quality of the food and improve its shelf-life. In an attempt to meet these requirements, this study presents a novel bio-substrate able to contain active bio-molecules for future food-packaging applications. Based on a paperboard substrate, the development of an antibacterial bio-packaging material is, therein, achieved using a chlorhexidine digluconate (CHX) solution as a model of an antibacterial molecule, mixed with microfibrillated cellulose (MFC) and used as coating onto paperboard samples. AFM and FE-SEM analyses were performed to underline the nanoporous MFC network able to trap and to progressively release the CHX molecules. The release study of CHX was conducted in an aqueous medium and showed a lower proportion (20 %) of CHX released when using MFC. This led to the constant release of low amounts of CHX over 40 h. Antibacterial tests were carried out to assess the preservation of the antibacterial activity of the samples after the release studies. Samples remained active against Bacillus subtilis, with better results being obtained when MFC was used. The preservation of the quality of a model food was finally evaluated paving the way for future promising applications in the food packaging industry.

  2. Antibacterial activity of Pulicaria dysenterica extracts.

    Science.gov (United States)

    Nickavar, Bahman; Mojab, Faraz

    2003-06-01

    Aqueous, methanolic and chloroformic extracts of Pulicaria dysenterica aerial parts were tested for their antibacterial activity using the disc-diffusion assay technique. The methanolic extract was found to be the most effective extract against three out of six tested bacteria. All of the extracts were active against Vibrio cholera.

  3. Antibacterial activity of selected Egyptian ethnomedicinal plants

    Directory of Open Access Journals (Sweden)

    Mashait, M.

    2013-01-01

    Full Text Available Aims: Medicinal plants have recently received the attention of the antimicrobial activity of plants and their metabolites due to the challenge of growing incidences of drug-resistant pathogens. The aims of this study were to determine the antibacterial activities of plant extracts used as ethnomedicinal in Egypt. Methodology and Results: Investigations were carried out to assess the antibacterial efficiency of 11 plant extracts used as ethnopharmacological among Egyptian native people against infectious diseases. Crude methanol, ethanol,chloroform, hexane, acetone and aqueous extract of plants were tested for antibacterial activity in vitro against ten bacterial isolates using the disc diffusion method test. Discs were impregnated with 2 mg/mL of different solvent extracts. Among all the crude extracts, the methanol extract showed the highest activity than other extracts. P. harmala and S. officinalis exhibited highest antibacterial activity against gram positive and negative bacteria while the remainingplants extracts showed less activity. All the plant extracts showed no significant effect against the Bordetella bronchisepta ATCC 4617 except the extracts of M. fragrans and L. sativum. E. coli is the most sensitive microorganism tested, with the lowest MIC value (0.5 mg/mL in the presence of the plant extract of P. harmala and S. officinalis.Conclusion, significance and impact of study: Results obtained herein, may suggest that the ethnomedicinal Egyptian plants possess antimicrobial activity and therefore, they can be used in biotechnological fields as natural preservative ingredients in food and/or pharmaceutical industry.

  4. DRUG-INTERACTIONS WITH QUINOLONE ANTIBACTERIALS

    NARCIS (Netherlands)

    BROUWERS, JRBJ

    1992-01-01

    The quinolone antibacterials are prone to many interactions with other drugs. Quinolone absorption is markedly reduced with antacids containing aluminium, magnesium and/or calcium and therapeutic failure may result. Other metallic ion-containing drugs, such as sucralfate, iron salts, and zinc salts,

  5. Anti-antimicrobial Peptides

    Science.gov (United States)

    Ryan, Lloyd; Lamarre, Baptiste; Diu, Ting; Ravi, Jascindra; Judge, Peter J.; Temple, Adam; Carr, Matthew; Cerasoli, Eleonora; Su, Bo; Jenkinson, Howard F.; Martyna, Glenn; Crain, Jason; Watts, Anthony; Ryadnov, Maxim G.

    2013-01-01

    Antimicrobial or host defense peptides are innate immune regulators found in all multicellular organisms. Many of them fold into membrane-bound α-helices and function by causing cell wall disruption in microorganisms. Herein we probe the possibility and functional implications of antimicrobial antagonism mediated by complementary coiled-coil interactions between antimicrobial peptides and de novo designed antagonists: anti-antimicrobial peptides. Using sequences from native helical families such as cathelicidins, cecropins, and magainins we demonstrate that designed antagonists can co-fold with antimicrobial peptides into functionally inert helical oligomers. The properties and function of the resulting assemblies were studied in solution, membrane environments, and in bacterial culture by a combination of chiroptical and solid-state NMR spectroscopies, microscopy, bioassays, and molecular dynamics simulations. The findings offer a molecular rationale for anti-antimicrobial responses with potential implications for antimicrobial resistance. PMID:23737519

  6. Tumor penetrating peptides

    Directory of Open Access Journals (Sweden)

    Tambet eTeesalu

    2013-08-01

    Full Text Available Tumor-homing peptides can be used to deliver drugs into tumors. Phage library screening in live mice has recently identified homing peptides that specifically recognize the endothelium of tumor vessels, extravasate, and penetrate deep into the extravascular tumor tissue. The prototypic peptide of this class, iRGD (CRGDKGPDC, contains the integrin-binding RGD motif. RGD mediates tumor homing through binding to αv integrins, which are selectively expressed on various cells in tumors, including tumor endothelial cells. The tumor-penetrating properties of iRGD are mediated by a second sequence motif, R/KXXR/K. This C-end Rule (or CendR motif is active only when the second basic residue is exposed at the C-terminus of the peptide. Proteolytic processing of iRGD in tumors activates the cryptic CendR motif, which then binds to neuropilin-1 activating an endocytic bulk transport pathway through tumor tissue. Phage screening has also yielded tumor-penetrating peptides that function like iRGD in activating the CendR pathway, but bind to a different primary receptor. Moreover, novel tumor-homing peptides can be constructed from tumor-homing motifs, CendR elements and protease cleavage sites. Pathologies other than tumors can be targeted with tissue-penetrating peptides, and the primary receptor can also be a vascular zip code of a normal tissue. The CendR technology provides a solution to a major problem in tumor therapy, poor penetration of drugs into tumors. The tumor-penetrating peptides are capable of taking a payload deep into tumor tissue in mice, and they also penetrate into human tumors ex vivo. Targeting with these peptides specifically increases the accumulation in tumors of a variety of drugs and contrast agents, such as doxorubicin, antibodies and nanoparticle-based compounds. Remarkably the drug to be targeted does not have to be coupled to the peptide; the bulk transport system activated by the peptide sweeps along any compound that is

  7. Immunotherapy with Allergen Peptides

    OpenAIRE

    Larché Mark

    2007-01-01

    Specific allergen immunotherapy (SIT) is disease-modifying and efficacious. However, the use of whole allergen preparations is associated with frequent allergic adverse events during treatment. Many novel approaches are being designed to reduce the allergenicity of immunotherapy preparations whilst maintaining immunogenicity. One approach is the use of short synthetic peptides which representing dominant T cell epitopes of the allergen. Short peptides exhibit markedly reduced capacity to cro...

  8. Antimicrobial Peptides in Echinoderms

    OpenAIRE

    Li, C; Haug, T; K Stensvåg

    2010-01-01

    Antimicrobial peptides (AMPs) are important immune effector molecules for invertebrates, including echinoderms, which lack a vertebrate-type adaptive immune system. Here we summarize the knowledge of such peptides in echinoderms. Strongylocins are a novel family of cysteine-rich AMPs, recently identified in the sea urchins, Strongylocentrotus droebachiensis and S. purpuratus. Although these molecules present diverse amino acid sequences, they share an identical cysteine arrangement pattern, d...

  9. N-acylated peptides derived from human lactoferricin perturb organization of cardiolipin and phosphatidylethanolamine in cell membranes and induce defects in Escherichia coli cell division.

    Directory of Open Access Journals (Sweden)

    Dagmar Zweytick

    Full Text Available Two types of recently described antibacterial peptides derived from human lactoferricin, either nonacylated or N-acylated, were studied for their different interaction with membranes of Escherichia coli in vivo and in model systems. Electron microscopy revealed striking effects on the bacterial membrane as both peptide types induced formation of large membrane blebs. Electron and fluorescence microscopy, however demonstrated that only the N-acylated peptides partially induced the generation of oversized cells, which might reflect defects in cell-division. Further a different distribution of cardiolipin domains on the E. coli membrane was shown only in the presence of the N-acylated peptides. The lipid was distributed over the whole bacterial cell surface, whereas cardiolipin in untreated and nonacylated peptide-treated cells was mainly located at the septum and poles. Studies with bacterial membrane mimics, such as cardiolipin or phosphatidylethanolamine revealed that both types of peptides interacted with the negatively charged lipid cardiolipin. The nonacylated peptides however induced segregation of cardiolipin into peptide-enriched and peptide-poor lipid domains, while the N-acylated peptides promoted formation of many small heterogeneous domains. Only N-acylated peptides caused additional severe effects on the main phase transition of liposomes composed of pure phosphatidylethanolamine, while both peptide types inhibited the lamellar to hexagonal phase transition. Lipid mixtures of phosphatidylethanolamine and cardiolipin revealed anionic clustering by all peptide types. However additional strong perturbation of the neutral lipids was only seen with the N-acylated peptides. Nuclear magnetic resonance demonstrated different conformational arrangement of the N-acylated peptide in anionic and zwitterionic micelles revealing possible mechanistic differences in their action on different membrane lipids. We hypothesized that both peptides kill

  10. N-acylated peptides derived from human lactoferricin perturb organization of cardiolipin and phosphatidylethanolamine in cell membranes and induce defects in Escherichia coli cell division.

    Science.gov (United States)

    Zweytick, Dagmar; Japelj, Bostjan; Mileykovskaya, Eugenia; Zorko, Mateja; Dowhan, William; Blondelle, Sylvie E; Riedl, Sabrina; Jerala, Roman; Lohner, Karl

    2014-01-01

    Two types of recently described antibacterial peptides derived from human lactoferricin, either nonacylated or N-acylated, were studied for their different interaction with membranes of Escherichia coli in vivo and in model systems. Electron microscopy revealed striking effects on the bacterial membrane as both peptide types induced formation of large membrane blebs. Electron and fluorescence microscopy, however demonstrated that only the N-acylated peptides partially induced the generation of oversized cells, which might reflect defects in cell-division. Further a different distribution of cardiolipin domains on the E. coli membrane was shown only in the presence of the N-acylated peptides. The lipid was distributed over the whole bacterial cell surface, whereas cardiolipin in untreated and nonacylated peptide-treated cells was mainly located at the septum and poles. Studies with bacterial membrane mimics, such as cardiolipin or phosphatidylethanolamine revealed that both types of peptides interacted with the negatively charged lipid cardiolipin. The nonacylated peptides however induced segregation of cardiolipin into peptide-enriched and peptide-poor lipid domains, while the N-acylated peptides promoted formation of many small heterogeneous domains. Only N-acylated peptides caused additional severe effects on the main phase transition of liposomes composed of pure phosphatidylethanolamine, while both peptide types inhibited the lamellar to hexagonal phase transition. Lipid mixtures of phosphatidylethanolamine and cardiolipin revealed anionic clustering by all peptide types. However additional strong perturbation of the neutral lipids was only seen with the N-acylated peptides. Nuclear magnetic resonance demonstrated different conformational arrangement of the N-acylated peptide in anionic and zwitterionic micelles revealing possible mechanistic differences in their action on different membrane lipids. We hypothesized that both peptides kill bacteria by

  11. 抗菌肽活性及天然抗菌肽的改造%Activities of antimicrobial peptides and the reconstruction of the natural antimicrobial peptides

    Institute of Scientific and Technical Information of China (English)

    张海波; 金莉莉; 王秋雨

    2011-01-01

    抗菌肽具有抗菌谱广、热稳定性强、分子量小及免疫原性小等特点,其杀菌机制独特,病原菌不易产生耐药性,有望开发成新一代肽类抗生素.本文主要综述了影响抗菌肽生物活性的生化性质,即螺旋度、疏水性、两亲性、正电荷数等,并从结构的角度论述了其对抗菌肽抑菌活性的影响.部分抗菌肽具有空间结构不稳定、溶血活性等缺点,限制了其临床应用.因此,对天然抗菌肽的改造也成为目前抗菌肽的研究热点,本文还综述了天然抗菌肽的改造方法.%Natural antimicrobial peptides with the features of broad antibacterial spectrum, high thermal stability, small immunogenicity and molecular weight, are expected to develop into a new generation of peptide antibiotics because of their unique bactericidal mechanism and difficulty to produce drug resistance. The effects of biochemistry character, including helicity, hydrophobicity, amphipathic property and positive charge, of antimicrobial peptides on their biological activity were reviewed in this paper and the relationship between the antibacterial activities and the structure was also discussed. Some natural antimicrobial peptides have defects such as space structure instability and hemolytic activity, which limits their clinical application. Therefore, structural modification of natural peptides has become a hot topic, and some methods for the remodeling of natural antimicrobial peptides were introduced in this paper.

  12. A toy model of prebiotic peptide evolution: the possible role of relative amino acid abundances.

    Science.gov (United States)

    Polanco, Carlos; Buhse, Thomas; Samaniego, José Lino; Castañón González, Jorge Alberto

    2013-01-01

    This paper presents a mathematical-computational toy model based on the assumed dynamic principles of prebiotic peptide evolution. Starting from a pool of amino acid monomers, the model describes in a generalized manner the generation of peptides and their sequential information. The model integrates the intrinsic and dynamic key elements of the initiation of biopolymerization, such as the relative amino acid abundances and polarities, as well as the oligomer reversibility, i.e. fragmentation and recombination, and peptide self-replication. Our modeling results suggest that the relative amino acid abundances, as indicated by Miller-Urey type electric discharge experiments, played a principal role in the early sequential information of peptide profiles. Moreover, the computed profiles display an astonishing similarity to peptide profiles observed in so-called biological common ancestors found in the following three microorganisms; E. coli, M. jannaschii, and S. cereviasiae. The prebiotic peptide fingerprint was obtained by the so-called polarity index method that was earlier reported as a tool for the identification of cationic amphipathic antibacterial short peptides.

  13. Natriuretic Peptides, Diagnostic and Prognostic Biomarkers

    NARCIS (Netherlands)

    J.H.W. Rutten (Joost)

    2010-01-01

    textabstractIn humans, the natriuretic peptide family consists of three different types of peptides: atrial natriuretic peptide (synonym: atrial natriuretic factor), B-type natriuretic peptide (synonym: brain natriuretic peptide) and C-natriuretic peptide.1 Atrial natriuretic peptide (ANP) was the f

  14. Dual Toxic-Peptide-Coding Staphylococcus aureus RNA under Antisense Regulation Targets Host Cells and Bacterial Rivals Unequally

    Directory of Open Access Journals (Sweden)

    Marie-Laure Pinel-Marie

    2014-04-01

    Full Text Available Produced from the pathogenicity islands of Staphylococcus aureus clinical isolates, stable SprG1 RNA encodes two peptides from a single internal reading frame. These two peptides accumulate at the membrane, and inducing their expression triggers S. aureus death. Replacement of the two initiation codons by termination signals reverses this toxicity. During growth, cis-antisense RNA SprF1 is expressed, preventing mortality by reducing SprG1 RNA and peptide levels. The peptides are secreted extracellularly, where they lyse human host erythrocytes, a process performed more efficiently by the longer peptide. The two peptides also inactivate Gram-negative and -positive bacteria, with the shorter peptide more effective against S. aureus rivals. Two peptides are secreted from an individual RNA containing two functional initiation codons. Thus, we present an unconventional type I toxin-antitoxin system expressed from a human pathogen producing two hemolytic and antibacterial peptides from a dual-coding RNA, negatively regulated by a dual-acting antisense RNA.

  15. Two novel non-cationic defensin-like antimicrobial peptides from haemolymph of the female tick, Amblyomma hebraeum.

    Science.gov (United States)

    Lai, Ren; Lomas, Lee O; Jonczy, Jan; Turner, Philip C; Rees, Huw H

    2004-01-01

    Two non-cationic defensin-like antimicrobial peptides, named Amblyomma defensin peptide 1 and Amblyomma defensin peptide 2, were identified from the hard tick, Amblyomma hebraeum, by a combination of suppression subtractive hybridization for differentially expressed genes and proteomics. cDNA clones encoding each of these two defensin-like antimicrobial peptides were isolated from the differentially expressed cDNA library of the tick synganglia (central nervous system). The preproproteins deduced from the cDNA sequences each have 92 amino acid residues. Amblyomma defensin peptide 2 was purified from the haemolymph of fed female ticks. The purified peptide displayed antibacterial activity against Gram-negative and Gram-positive bacteria. Amblyomma defensin peptide 1 was further identified by protein chip capture combined with SELDI-TOF (surface-enhanced laser desorption/ionization-time-of-flight) MS. By screening for differentially expressed proteins, it was found that the expression of Amblyomma defensin peptide 1 was upregulated during 4 days post-feeding. Our findings firstly provide two defensin-like antimicrobial peptides that are particularly novel in being anionic, together with corresponding cDNA sequences, in hard ticks, and prove that the combination of suppression subtractive hybridization and protein profiling is a powerful method to study differentially expressed proteins, especially for organisms without available genome sequence information. PMID:14705963

  16. Natriuretic Peptides, Diagnostic and Prognostic Biomarkers

    OpenAIRE

    Rutten, Joost

    2010-01-01

    textabstractIn humans, the natriuretic peptide family consists of three different types of peptides: atrial natriuretic peptide (synonym: atrial natriuretic factor), B-type natriuretic peptide (synonym: brain natriuretic peptide) and C-natriuretic peptide.1 Atrial natriuretic peptide (ANP) was the fi rst natriuretic peptide to be discovered and in humans ANP is predominantly formed in the cardiomyocytes of the atria.2 B-type natriuretic peptide (BNP) was fi rst discovered in porcine brain hen...

  17. Diversity-Oriented Peptide Stapling

    DEFF Research Database (Denmark)

    Tran, Thu Phuong; Larsen, Christian Ørnbøl; Røndbjerg, Tobias

    2017-01-01

    The introduction of macrocyclic constraints in peptides (peptide stapling) is an important tool within peptide medicinal chemistry for stabilising and pre-organising peptides in a desired conformation. In recent years, the copper-catalysed azide-alkyne cycloaddition (CuAAC) has emerged...... as a powerful method for peptide stapling. However, to date CuAAC stapling has not provided a simple method for obtaining peptides that are easily diversified further. In the present study, we report a new diversity-oriented peptide stapling (DOPS) methodology based on CuAAC chemistry. Stapling of peptides...... incorporating two azide-modified amino acids with 1,3,5-triethynylbenzene efficiently provides (i, i+7)- and (i, i+9)-stapled peptides with a single free alkyne positioned on the staple, that can be further conjugated or dimerised. A unique feature of the present method is that it provides easy access...

  18. Antibacterial effect of Gracilaria verrucosa bioactive on fish pathogenic bacteria

    Directory of Open Access Journals (Sweden)

    Maftuch

    2016-12-01

    Full Text Available Gracilaria verrucosa seaweed is a type of seaweed commonly found in water. This study was conducted to investigate the effect of G. verrucosa on fish pathogenic bacteria to support fish farming. The method used in this research was the separation of G. verrucosa fractions using column chromatography. The active antibacterial fraction of G. verrucosa which is obtained from column chromatography indicated fractions containing antibacterial compounds. It was fraction number 3 by using an eluent 16 (ethanol: 4 (ethyl acetate. Furthermore, based on phytochemical screening, ultraviolet spectrophotometer and LC–MS analysis, antibacterial compounds contained in those fraction number 3 are Alkaloid, Flavonoid, Tannin, Phenolic compound. Based on LC–MS and UV–Vis analysis, flavonoid group, Quercetin-7-methyl-ether is a dominant group of the antibacterial compound on fraction no. 3. This fraction had moderate antibacterial activity against Aeromonas hydrophila, Pseudomonas aeruginosa, Pseudomonas putida and had weak antibacterial activity against Vibrio harveyi and Vibrio algynoliticus bacteria.

  19. Database-Guided Discovery of Potent Peptides to Combat HIV-1 or Superbugs

    Directory of Open Access Journals (Sweden)

    Guangshun Wang

    2013-05-01

    Full Text Available Antimicrobial peptides (AMPs, small host defense proteins, are indispensable for the protection of multicellular organisms such as plants and animals from infection. The number of AMPs discovered per year increased steadily since the 1980s. Over 2,000 natural AMPs from bacteria, protozoa, fungi, plants, and animals have been registered into the antimicrobial peptide database (APD. The majority of these AMPs (>86% possess 11–50 amino acids with a net charge from 0 to +7 and hydrophobic percentages between 31–70%. This article summarizes peptide discovery on the basis of the APD. The major methods are the linguistic model, database screening, de novo design, and template-based design. Using these methods, we identified various potent peptides against human immunodeficiency virus type 1 (HIV-1 or methicillin-resistant Staphylococcus aureus (MRSA. While the stepwise designed anti-HIV peptide is disulfide-linked and rich in arginines, the ab initio designed anti-MRSA peptide is linear and rich in leucines. Thus, there are different requirements for antiviral and antibacterial peptides, which could kill pathogens via different molecular targets. The biased amino acid composition in the database-designed peptides, or natural peptides such as θ-defensins, requires the use of the improved two-dimensional NMR method for structural determination to avoid the publication of misleading structure and dynamics. In the case of human cathelicidin LL-37, structural determination requires 3D NMR techniques. The high-quality structure of LL-37 provides a solid basis for understanding its interactions with membranes of bacteria and other pathogens. In conclusion, the APD database is a comprehensive platform for storing, classifying, searching, predicting, and designing potent peptides against pathogenic bacteria, viruses, fungi, parasites, and cancer cells.

  20. Electron transfer in peptides.

    Science.gov (United States)

    Shah, Afzal; Adhikari, Bimalendu; Martic, Sanela; Munir, Azeema; Shahzad, Suniya; Ahmad, Khurshid; Kraatz, Heinz-Bernhard

    2015-02-21

    In this review, we discuss the factors that influence electron transfer in peptides. We summarize experimental results from solution and surface studies and highlight the ongoing debate on the mechanistic aspects of this fundamental reaction. Here, we provide a balanced approach that remains unbiased and does not favor one mechanistic view over another. Support for a putative hopping mechanism in which an electron transfers in a stepwise manner is contrasted with experimental results that support electron tunneling or even some form of ballistic transfer or a pathway transfer for an electron between donor and acceptor sites. In some cases, experimental evidence suggests that a change in the electron transfer mechanism occurs as a result of donor-acceptor separation. However, this common understanding of the switch between tunneling and hopping as a function of chain length is not sufficient for explaining electron transfer in peptides. Apart from chain length, several other factors such as the extent of the secondary structure, backbone conformation, dipole orientation, the presence of special amino acids, hydrogen bonding, and the dynamic properties of a peptide also influence the rate and mode of electron transfer in peptides. Electron transfer plays a key role in physical, chemical and biological systems, so its control is a fundamental task in bioelectrochemical systems, the design of peptide based sensors and molecular junctions. Therefore, this topic is at the heart of a number of biological and technological processes and thus remains of vital interest.

  1. ANTIBACTERIAL ACTIVITY OF Tridax procumbens Linn

    Directory of Open Access Journals (Sweden)

    V.Bharathi

    2012-04-01

    Full Text Available Tridax procumbens Linn belongs to the family Compositae. The extracts of Tridax procumbens have been reported to have various pharmacological effects like mosquito repellant activity, leishmanicidal, hepatoprotective effect on liver antioxidant system, immunomodulatory effect, wound healing activity and antiprotozoal effects.The methanolic and ethyl acetate extracts of Tridax procumbens were used for this study. The antibacterial activity of methanolic and ethyl acetate leaf extracts of Tridax procumbens Linn (L. were examined against Escherichia coli,,Klebsiella pneumoniae,Salmonella typhi, Bacillus cereus and Staphylococcus aureus. Antibacterial activity was investigated by disc and agarwell diffusion method. The ethyl acetate extracts of the Tridax procumbens showed effective inhibition against the Staphylococcus aureus thancompared to other organism. Therefore the leaves of Tridax procumbens can be considered to be the promising source of antimicrobial compounds.

  2. Cytocompatibility and Antibacterial Properties of Capping Materials

    Science.gov (United States)

    Arciola, Carla Renata; Monaco, Annachiara; Lombardini, Marco

    2014-01-01

    The aim of this study was to evaluate and compare the antimicrobial activity and cytocompatibility of six different pulp-capping materials: Dycal (Dentsply), Calcicur (Voco), Calcimol LC (Voco), TheraCal LC (Bisco), MTA Angelus (Angelus), and Biodentine (Septodont). To evaluate antimicrobial activity, materials were challenged in vitro with Streptococcus mutans, Streptococcus salivarius, and Streptococcus sanguis in the agar disc diffusion test. Cytocompatibility of the assayed materials towards rat MDPC-23 cells was evaluated at different times by both MTT and apoptosis assays. Results significantly differed among the different materials tested. Both bacterial growth inhibition halos and cytocompatibility performances were significantly different among materials with different composition. MTA-based products showed lower cytotoxicity and valuable antibacterial activity, different from calcium hydroxide-based materials, which exhibited not only higher antibacterial activity but also higher cytotoxicity. PMID:24959601

  3. Fast Screening of Antibacterial Compounds from Fusaria

    Directory of Open Access Journals (Sweden)

    Teis Esben Sondergaard

    2016-11-01

    Full Text Available Bio-guided screening is an important method to identify bioactive compounds from fungi. In this study we applied a fast digital time-lapse microscopic method for assessment of the antibacterial properties of secondary metabolites from the fungal genus Fusarium. Here antibacterial effects could be detected for antibiotic Y, aurofusarin, beauvericin, enniatins and fusaric acid after six hours of cultivation. The system was then used in a bio-guided screen of extracts from 14 different Fusarium species, which had been fractionated by HPLC. In this screen, fractions containing the red pigments aurofusarin and bikaverin showed effects against strains of Lactobacillus and Bifidobacterium. The IC50 for aurofusarin against Lactobacillus acidophilus was 8 µM, and against Bifidobacterium breve it was 64 µM. Aurofusarin only showed an effect on probiotic bacteria, leading to the speculation that only health-promoting bacteria with a positive effect in the gut system are affected.

  4. [Antibacterial activity of natural compounds - essential oils].

    Science.gov (United States)

    Hassan, Sherif T S; Majerová, Michaela; Šudomová, Miroslava; Berchová, Kateřina

    2015-12-01

    Since the problem of bacterial resistance has become a serious problem worldwide, it was necessary to search for new active substances that can overcome the problem and enhance the treatment efficacy of bacterial infections. Numerous plant-derived essential oils exhibited significant antibacterial activities. This review aimed to summarize the most promising essential oils that exhibited remarkable antibacterial activities against various bacterial infections, including staphylococcal infections, Helicobacter pylori infections, skin infections, tuberculosis infection and dental bacterial infection. The synergy effect of essential oils in combination with antibiotics, as well as their role in the treatment of bacterial infections have been discussed. Essential oils can be used as models for further studies in vivo and clinical trials.

  5. Cytocompatibility and Antibacterial Properties of Capping Materials

    Directory of Open Access Journals (Sweden)

    Claudio Poggio

    2014-01-01

    Full Text Available The aim of this study was to evaluate and compare the antimicrobial activity and cytocompatibility of six different pulp-capping materials: Dycal (Dentsply, Calcicur (Voco, Calcimol LC (Voco, TheraCal LC (Bisco, MTA Angelus (Angelus, and Biodentine (Septodont. To evaluate antimicrobial activity, materials were challenged in vitro with Streptococcus mutans, Streptococcus salivarius, and Streptococcus sanguis in the agar disc diffusion test. Cytocompatibility of the assayed materials towards rat MDPC-23 cells was evaluated at different times by both MTT and apoptosis assays. Results significantly differed among the different materials tested. Both bacterial growth inhibition halos and cytocompatibility performances were significantly different among materials with different composition. MTA-based products showed lower cytotoxicity and valuable antibacterial activity, different from calcium hydroxide-based materials, which exhibited not only higher antibacterial activity but also higher cytotoxicity.

  6. Antibacterial sesquiterpene aryl esters from Armillaria mellea.

    Science.gov (United States)

    Donnelly, D M; Abe, F; Coveney, D; Fukuda, N; O'Reilly, J; Polonsky, J; Prangé, T

    1985-01-01

    Investigation of the mycelial extract of Armillaria mellea led to the isolation of the known melleolide (2a) and two new sesquiterpene aryl eters, 4-O-methylmelleolide (2b) and judeol (1c). Their structures were deduced from spectral data and that of (2b) confirmed by X-ray analysis. The new esters (1c) and (2b) showed strong antibacterial activity against gram-positive bacteria.

  7. Investigation of the antibacterial activity of pioglitazone

    Directory of Open Access Journals (Sweden)

    Alzoubi KH

    2011-09-01

    Full Text Available Majed M Masadeh1, Nizar M Mhaidat2, Sayer I Al-Azzam2, Karem H Alzoubi21Department of Pharmaceutical Technology; 2Department of Clinical Pharmacy, Faculty of Pharmacy, Jordan University of Science and Technology, Irbid, JordanPurpose: To evaluate the antibacterial potential of pioglitazone, a member of the thiazolidinediones class of drugs, against Gram-positive (Streptococcus pneumoniae and Gram-negative (Escherichia coli and Klebsiella pneumoniae bacteria.Methods: Susceptibility testing was done using the antibiotic disk diffusion method and the minimal inhibitory concentration (MIC of pioglitazone was measured according to the broth micro incubation standard method.Results: Pioglitazone induced a dose-dependent antibacterial activity in which the optimal concentration was 80 µM. Furthermore, results indicated that while E. coli was sensitive (MIC = 31.25 ± 3.87 mg/L to pioglitazone-induced cytotoxicity, S. pneumoniae and K. pneumoniae were resistant (MIC = 62.5 ± 3.77 mg/L and MIC = 62.5 ± 4.14 mg/L, respectively. Moreover, pretreatment of bacteria with a suboptimal concentration of pioglitazone (40 µM before adding amoxicillin, cephalexin, co-trimoxazole, or ciprofloxacin enhanced the antibacterial activity of all agents except co-trimoxazole. This enhancing effect was particularly seen against K. pneumoniae.Conclusion: These results indicate the possibility of a new and potentially important pioglitazone effect and the authors’ ongoing studies aim to illustrate the mechanism(s by which this antibacterial effect is induced.Keywords: pioglitazone, susceptibility testing, antibiotics, diabetes 

  8. [Current status and further prospects of dental resin-based materials with antibacterial properties].

    Science.gov (United States)

    Shi, X; Lu, H B; Mao, J; Gong, S Q

    2016-09-01

    The mode of dental antibacterial resin-based materials can be divided into two types, namely, single and combined antibacterial mode. With regard to single antibacterial mode, only one kind of antibacterial agent is added into the resin, which can be released or act as contacting antibacterial agent. The single mode resin has limitation in sterilization methods and effect. As for combined antibacterial mode, it is a combination of different types of biocides and thus maximizes the sterilizing effect, including the releasing antibacterial agent incorporated with the contacting antibacterial agent or antibacterial agents combined with calcium compound possessing biological mineralization function. In this paper, current status and further prospects of dental resin-based materials with antibacterial properties are reviewed from the perspectives of single and combined antibacterial modes to provide guidance for dental antibacterial resin material research.

  9. In Vitro Antibacterial Activity of Essential Oils against Streptococcus pyogenes

    OpenAIRE

    Julien Sfeir; Corinne Lefrançois; Dominique Baudoux; Séverine Derbré; Patricia Licznar

    2013-01-01

    Streptococcus pyogenes plays an important role in the pathogenesis of tonsillitis. The present study was conducted to evaluate the in vitro antibacterial activities of 18 essential oils chemotypes from aromatic medicinal plants against S. pyogenes. Antibacterial activity of essential oils was investigated using disc diffusion method. Minimum Inhibitory Concentration of essential oils showing an important antibacterial activity was measured using broth dilution method. Out of 18 essential oils...

  10. Substrate independent silver nanoparticle based antibacterial coatings.

    Science.gov (United States)

    Taheri, Shima; Cavallaro, Alex; Christo, Susan N; Smith, Louise E; Majewski, Peter; Barton, Mary; Hayball, John D; Vasilev, Krasimir

    2014-05-01

    Infections arising from bacterial adhesion and colonization on medical device surfaces are a significant healthcare problem. Silver based antibacterial coatings have attracted a great deal of attention as a potential solution. This paper reports on the development of a silver nanoparticles based antibacterial surface that can be applied to any type of material surface. The silver nanoparticles were surface engineered with a monolayer of 2-mercaptosuccinic acid, which facilitates the immobilization of the nanoparticles to the solid surface, and also reduces the rate of oxidation of the nanoparticles, extending the lifetime of the coatings. The coatings had excellent antibacterial efficacy against three clinically significant pathogenic bacteria i.e. Staphylococcus epidermidis, Staphylococcus aureus and Pseudomonas aeruginosa. Studies with primary human fibroblast cells showed that the coatings had no cytotoxicity in vitro. Innate immune studies in cultures of primary macrophages demonstrated that the coatings do not significantly alter the level of expression of pro-inflammatory cytokines or the adhesion and viability of these cells. Collectively, these coatings have an optimal combination of properties that make them attractive for deposition on medical device surfaces such as wound dressings, catheters and implants.

  11. Antibacterial Effects of Silver Loaded Hydroxyapatite

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    The antibacterial capability of silver loaded hydroxyapatite(HA-Ag) in both poor nutrient phosphate buffer saline solution(PBS,pH=7.4)and nutrient rich medium,which represented two kinds of typical conditions in real life,was evaluated respectively using Escherichia coli as a model.At 0.4 mg/mL in PBS solution containing an initial cell concentration of 106/mL,HA-Ag killed all the E.coli cells in the PBS solution within 4.5 h.In a nutrient rich medium containing a cell concentration of 107/mL,HA-Ag exhibited a remarkable inhibitory effect of E.coli cells.The maximum specific growth rate in the medium containing 3 mg/mL HA-Ag was only 0.292, 26% of that in a control sample which was 1.116,and the viable cell concentration in the former HA-Ag medium was just 40% of that in the control.As a safe antibacterial agent,HA-Ag powder demonstrated antibacterial efforts both in poor nutrient and in nutrient rich environment.It seems that the HA-Ag compound hold a lot of promises for practical applications.

  12. Injectable bioadhesive hydrogels with innate antibacterial properties.

    Science.gov (United States)

    Giano, Michael C; Ibrahim, Zuhaib; Medina, Scott H; Sarhane, Karim A; Christensen, Joani M; Yamada, Yuji; Brandacher, Gerald; Schneider, Joel P

    2014-06-24

    Surgical site infections cause significant postoperative morbidity and increased healthcare costs. Bioadhesives used to fill surgical voids and support wound healing are typically devoid of antibacterial activity. Here we report novel syringe-injectable bioadhesive hydrogels with inherent antibacterial properties prepared from mixing polydextran aldehyde and branched polyethylenimine. These adhesives kill both Gram-negative and Gram-positive bacteria, while sparing human erythrocytes. An optimal composition of 2.5 wt% oxidized dextran and 6.9 wt% polyethylenimine sets within seconds forming a mechanically rigid (~1,700 Pa) gel offering a maximum adhesive stress of ~2.8 kPa. A murine infection model showed that the adhesive is capable of killing Streptococcus pyogenes introduced subcutaneously at the bioadhesive's surface, with minimal inflammatory response. The adhesive was also effective in a cecal ligation and puncture model, preventing sepsis and significantly improving survival. These bioadhesives represent novel, inherently antibacterial materials for wound-filling applications.

  13. Natural antibacterial remedy for respiratory tract infections

    Institute of Scientific and Technical Information of China (English)

    Reham F.El-Kased

    2016-01-01

    Objective: To evaluate the antibacterial activity of Egyptian honey against bacteria causing respiratory tract infections.Methods: Sputum and throat swab specimens were used, from which five bacterial species were isolated, namely, Klebsiella pneumonia, Staphylococcus aureus, Streptococcus pyogenes, Pseudomonas aeruginosa and Streptococcus pneumonia were isolated,identified and grown on suitable media for further identification or confirmation. Different concentrations(100%, 75% and 25%) of honey and simulated honey solution were used for activity assay and estimation of minimum inhibitory concentration and minimum bactericidal concentration.Results: All the tested bacterial isolates were completely susceptible to the 75%concentrations of honey and to the 100% concentration of the simulated honey solution. This may be due to the high osmotic pressure exerted by the high sugar content in both honey samples. Moderate susceptibility of the isolated bacteria to honey at 100%v/v concentration, and resistance to honey at 25% concentration and the 75% and 25%concentrations of simulated honey solution, indicated the presence of other antimicrobial components responsible for the activity other than the osmotic pressure.Therefore, it was suggested that honey showed distinguished antibacterial activities against the most common bacteria causing respiratory infections with varied sensitivity.Conclusions: Honey, a non-toxic, nutritious, safe for human consumption and cheap natural antibacterial agent, should be globalized.

  14. EVALUATION OF ANTIBACTERIAL ACTIVITY OF CAFFEINE

    Directory of Open Access Journals (Sweden)

    Pawar Pruthviraj

    2011-04-01

    Full Text Available The present study was carried out with water soluble portion and pure solvent of the acetone, ethanol, methanol, acetonitrile, water extracts of leaves and leaf buds of Camellia sinensis (green tea, and beans of Coffea arabica (coffee. Caffeine (3,7-dihydro-1, 3,7-trimethyl-1H-purine-2,6-dione was isolated from both plants using a liquid-liquid extraction method, detected on thin layer chromatography (TLC plates in comparison with standard caffeine, which served as a positive control. After performing the gross behavioral study, the Antibacterial activity was evaluated against Gram-negative bacteria included; Escherichia coli, Proteus mirabilis, Klebsiella pneumonia and Pseudomonas aeruginosa Both compounds at a concentration of 2 mg/ml showed similar antibacterial activities against all tested bacteria, except for P. mirabilis, and the highest inhibitory effect was observed against P. aeruginosa using a modified agar diffusion method. The minimal inhibitory concentration (MIC of caffeine was determined using a broth microdilution method in 96 multi-well microtitre plates. MIC values ranged from 65.5 to 250.0 µg/ml for the caffeine isolated from coffee and 65.5 to 500.0 µg/ml for green tea caffeine. Combination results showed additive effects against most pathogenic bacteria especially for P. aeruginosa, using both antibacterial assays.

  15. Regenerable Antibacterial Cotton Fabric by Plasma Treatment with Dimethylhydantoin: Antibacterial Activity against S. aureus

    Directory of Open Access Journals (Sweden)

    Chang-E. Zhou

    2017-01-01

    Full Text Available This study examined the influence of variables in a finishing process for making cotton fabric with regenerable antibacterial properties against Staphylococcus aureus (S. aureus. 5,5-dimethylhydantoin (DMH was coated onto cotton fabric by a pad-dry-plasma-cure method. Sodium hypochlorite was used for chlorinating the DMH coated fabric in order to introduce antibacterial properties. An orthogonal array testing strategy (OATS was used in the finishing process for finding the optimum treatment conditions. After finishing, UV-Visible spectroscopy, Scanning Electron Microscopy (SEM, and Fourier Transform Infrared Spectroscopy (FTIR were employed to characterise the properties of the treated cotton fabric, including the concentration of chlorine, morphological properties, and functional groups. The results show that cotton fabric coated with DMH followed by plasma treatment and chlorination can inhibit S. aureus and that the antibacterial property is regenerable.

  16. Antibacterial Resistance in African Catfish Aquaculture: a Review

    Directory of Open Access Journals (Sweden)

    Madubuike U. ANYANWU

    2016-03-01

    Full Text Available Antibacterial resistance (AR is currently one of the greatest threats to mankind as it constitutes health crisis. Extensive use of antibacterial agents in human and veterinary medicine, and farm crops have resulted in emergence of antibacterial-resistant organisms in different environmental settings including aquaculture. Antibacterial resistance in aquaculture is a serious global concern because antibacterial resistance genes (ARGs can be transferred easily from aquaculture setting to other ecosystems and the food chain. African catfish (ACF aquaculture has increased at a phenomenal rate through a continuous process of intensification, expansion and diversification. Risk of bacterial diseases has also increased and consequently there is increased use of antibacterial agents for treatment. Antibacterial resistance in ACF aquaculture has huge impact on the food chain and thus represents risk to public and animal health. In “one health” approach of curbing AR, knowledge of the sources, mechanisms and magnitude of AR in ACF aquaculture and its potential impact on the food chain is important in designing and prioritizing monitoring programs that may generate data that would be relevant for performing quantitative risk assessments, implementation of antibacterial stewardship plans, and developing effective treatment strategies for the control of ACF disease and reducing risk to public health. This review provides insight on the sources, mechanisms, prevalence and impact of antibacterial resistance in ACF aquaculture environment, a setting where the impact of AR is neglected or underestimated.

  17. Research and clinical value of antibacterial-application Software

    Institute of Scientific and Technical Information of China (English)

    LIANG Yong-jie; ZHAI Xiao-bo; HE Li-xian; GUO Zhong-liang; REN Tao; HE Zhi-gao; ZHANG Lu; ZHENG Yong-hua

    2008-01-01

    @@ The resistance to antibacterials therapy has been increasing in recent years.1'2 The rational use of anti-bacterials should include: (1) choosing the right drugs according to the scope of their antibacterials function and making sure they are suitable for treatment of the microorganisms that have induced the infection;3 (2) administering anti-bacterials by a rational method according to their pharmacodynamics;4 (3) paying attention to the systemic condition of the patients according to pharmacokinetics of the drugs.5,6

  18. Limenin, a defensin-like peptide with multiple exploitable activities from shelf beans.

    Science.gov (United States)

    Wong, Jack H; Ng, T B

    2006-05-01

    From the seeds of the shelf bean, an antifungal peptide with a molecular mass of 6.5 kDa was isolated. The isolation procedure comprised affinity chromatography on Affi-gel blue gel, ion exchange chromatography on Mono S, and gel filtration on Superdex 75. The peptide was adsorbed on Affi-gel blue gel and Mono S. It potently suppressed mycelial growth in Botrytis cinerea, Fusarium oxysporum, and Mycosphaerella arachidicola with an IC(50) of 2.9, 2.1, and 0.34 microM, respectively. It exerted antibacterial activity toward several bacterial species with an IC(50) approximating 100 microM. [Methyl-(3)H]-thymidine incorporation into isolated mouse splenocytes was stimulated. [Methyl-(3)H]-thymidine incorporation into M1 (myeloma) and L1210 (leukemia) cells was inhibited. The peptide reduced the activity of HIV-1 reverse transcriptase and also inhibited translation in a cell-free rabbit reticulocyte lysate system.

  19. Flagellin stimulates protective lung mucosal immunity: role of cathelicidin-related antimicrobial peptide.

    Science.gov (United States)

    Yu, Fu-shin; Cornicelli, Matthew D; Kovach, Melissa A; Newstead, Michael W; Zeng, Xianying; Kumar, Ashok; Gao, Nan; Yoon, Sang Gi; Gallo, Richard L; Standiford, Theodore J

    2010-07-15

    TLRs are required for generation of protective lung mucosal immune responses against microbial pathogens. In this study, we evaluated the effect of the TLR5 ligand flagellin on stimulation of antibacterial mucosal immunity in a lethal murine Pseudomonas aeruginosa pneumonia model. The intranasal pretreatment of mice with purified P. aeruginosa flagellin induced strong protection against intratracheal P. aeruginosa-induced lethality, which was attributable to markedly improved bacterial clearance, reduced dissemination, and decreased alveolar permeability. The protective effects of flagellin on survival required TLR5 and were observed even in the absence of neutrophils. Flagellin induced strong induction of innate genes, most notably the antimicrobial peptide cathelicidin-related antimicrobial peptide. Finally, flagellin-induced protection was partially abrogated in cathelicidin-related antimicrobial peptide-deficient mice. Our findings illustrate the profound stimulatory effect of flagellin on lung mucosal innate immunity, a response that might be exploited therapeutically to prevent the development of gram-negative bacterial infection of the respiratory tract.

  20. Synthesis, Structural Characterization, and Bioactivity of the Stable Peptide RCB-1 from Ricinus communis.

    Science.gov (United States)

    Boldbaatar, Delgerbat; Gunasekera, Sunithi; El-Seedi, Hesham R; Göransson, Ulf

    2015-11-25

    The Ricinus communis biomarker peptides RCB-1 to -3 comprise homologous sequences of 19 (RCB-1) or 18 (RCB-2 and -3) amino acid residues. They all include four cysteine moieties, which form two disulfide bonds. However, neither the 3D structure nor the biological activity of any of these peptides is known. The synthesis of RCB-1, using microwave-assisted, Fmoc-based solid-phase peptide synthesis, and a method for its oxidative folding are reported. The tertiary structure of RCB-1, subsequently established using solution-state NMR, reveals a twisted loop fold with antiparallel β-sheets reinforced by the two disulfide bonds. Moreover, RCB-1 was tested for antibacterial, antifungal, and cytotoxic activity, as well as in a serum stability assay, in which it proved to be remarkably stable.

  1. Immunotherapy with Allergen Peptides

    Directory of Open Access Journals (Sweden)

    Larché Mark

    2007-06-01

    Full Text Available Specific allergen immunotherapy (SIT is disease-modifying and efficacious. However, the use of whole allergen preparations is associated with frequent allergic adverse events during treatment. Many novel approaches are being designed to reduce the allergenicity of immunotherapy preparations whilst maintaining immunogenicity. One approach is the use of short synthetic peptides which representing dominant T cell epitopes of the allergen. Short peptides exhibit markedly reduced capacity to cross link IgE and activate mast cells and basophils, due to lack of tertiary structure. Murine pre-clinical studies have established the feasibility of this approach and clinical studies are currently in progress in both allergic and autoimmune diseases.

  2. Therapeutic HIV Peptide Vaccine

    DEFF Research Database (Denmark)

    Fomsgaard, Anders

    2015-01-01

    Therapeutic vaccines aim to control chronic HIV infection and eliminate the need for lifelong antiretroviral therapy (ART). Therapeutic HIV vaccine is being pursued as part of a functional cure for HIV/AIDS. We have outlined a basic protocol for inducing new T cell immunity during chronic HIV-1...... infection directed to subdominant conserved HIV-1 epitopes restricted to frequent HLA supertypes. The rationale for selecting HIV peptides and adjuvants are provided. Peptide subunit vaccines are regarded as safe due to the simplicity, quality, purity, and low toxicity. The caveat is reduced immunogenicity...

  3. β-PEPTIDES CYCLOBUTANIQUES

    OpenAIRE

    Fernandez, Carlos

    2008-01-01

    The synthesis of β-amino acids, structural analogues of?-Amino acids, is an issue essential in the development of oligopeptides. A lot of work has been conducted on the behavior of β-peptide (sequence of β-amino acids) as well as peptides mixed (mixed β-and β- amino acids). As a result, the conformational preference of β-amino acids will induce the appearance of a three-dimensional structure of the oligopeptide ordered. Thus, several types of helices, sheets and elbows were observed in β-olig...

  4. Invertebrate FMRFamide related peptides.

    Science.gov (United States)

    Krajniak, Kevin G

    2013-06-01

    In 1977 the neuropeptide FMRFamide was isolated from the clam, Macrocallista nimbosa. Since then several hundred FMRFamide-related peptides (FaRPs) have been isolated from invertebrate animals. Precursors to the FaRPs likely arose in the cnidarians. With the transition to a bilateral body plan FaRPs became a fixture in the invertebrate phyla. They have come to play a critical role as neurotransmitters, neuromodulators, and neurohormones. FaRPs regulate a variety of body functions including, feeding, digestion, circulation, reproduction, movement. The evolution of the molecular form and function of these omnipresent peptides will be considered.

  5. Dicyclopropylmethyl peptide backbone protectant.

    Science.gov (United States)

    Carpino, Louis A; Nasr, Khaled; Abdel-Maksoud, Adel Ali; El-Faham, Ayman; Ionescu, Dumitru; Henklein, Peter; Wenschuh, Holger; Beyermann, Michael; Krause, Eberhard; Bienert, Michael

    2009-08-20

    The N-dicyclopropylmethyl (Dcpm) residue, introduced into amino acids via reaction of dicyclopropylmethanimine hydrochloride with an amino acid ester followed by sodium cyanoborohydride or triacetoxyborohydride reduction, can be used as an amide bond protectant for peptide synthesis. Examples which demonstrate the amelioration of aggregation effects include syntheses of the alanine decapeptide and the prion peptide (106-126). Avoidance of cyclization to the aminosuccinimide followed substitution of Fmoc-(Dcpm)Gly-OH for Fmoc-Gly-OH in the assembly of sequences containing the sensitive Asp-Gly unit.

  6. The Effect of Selective D- or Nα-Methyl Arginine Substitution on the Activity of the Proline-Rich Antimicrobial Peptide, Chex1-Arg20

    Science.gov (United States)

    Li, Wenyi; Sun, Zhe; O'Brien-Simpson, Neil M.; Otvos, Laszlo; Reynolds, Eric C.; Hossain, Mohammed A.; Separovic, Frances; Wade, John D.

    2017-01-01

    In vivo pharmacokinetics studies have shown that the proline-rich antimicrobial peptide, A3-APO, which is a discontinuous dimer of the peptide, Chex1-Arg20, undergoes degradation to small fragments at positions Pro6-Arg7 and Val19-Arg20. With the aim of minimizing or abolishing this degradation, a series of Chex1-Arg20 analogs were prepared via Fmoc/tBu solid phase peptide synthesis with D-arginine or, in some cases, peptide backbone Nα-methylated arginine, substitution at these sites. All the peptides were tested for antibacterial activity against the Gram-negative bacterium Klebsiella pneumoniae. The resulting activity of position-7 substitution of Chex1-Arg20 analogs showed that arginine-7 is a crucial residue for maintaining activity against K. pneumoniae. However, arginine-20 substitution had a much less deleterious effect on the antibacterial activity of the peptide. Moreover, none of these peptides displayed any cytotoxicity to HEK and H-4-II-E mammalian cells. These results will aid the development of more effective and stable PrAMPs via judicious amino acid substitutions. PMID:28154813

  7. Consequences of increased antibacterial consumption and change in pattern of antibacterial use in Danish hospitals

    DEFF Research Database (Denmark)

    Jensen, Ulrich S; Skjøt-Rasmussen, Line; Olsen, Stefan S;

    2009-01-01

    in all isolates recorded from either blood samples (Escherichia coli and Klebsiella pneumoniae) or urine samples (E. coli) submitted for susceptibility testing to the participating Departments of Clinical Microbiology during 2001-07. RESULTS: The consumption of combinations of penicillins including beta......, multiresistant K. pneumoniae emerged. CONCLUSIONS: The consumption of 'broad-spectrum' antibacterial agents has continued to increase in Danish hospitals. At the same time, an increasing resistance in clinical isolates towards the same antibacterial agents has been observed. However, more detailed information...

  8. Milk-derived proteins and peptides of potential therapeutic and nutritive value.

    Science.gov (United States)

    Zimecki, Michal; Kruzel, Marian L

    2007-01-01

    Milk and colostrum are rich in proteins and peptides which play a crucial role in development of the immune system in mammalian offspring. Immunotropic properties of these compounds prompted investigators to search for their utility in prevention and therapy of various disorders in humans. The following constituents of milk are of particular interest: 1) Lactoferrin (LF)--exhibits antibacterial, antifungal, antiviral, antiparasite and antitumor activities. It is protective with regard to intestinal epithelium, promotes bone growth and accelerates recovery of the immune system function in immunocompromised animal; 2) A Proline-Rich Polypeptide (PRP) shows a variety of immunotropic functions, including promotion of T-cell maturation and inhibition'of autoimmune disorders. PRP was recently found to improve or stabilize the Instrumental Activity of Daily Living status in Alzheimer's disease patients. 3) Casein--has been protective in experimental bacteremia by eliciting myelopoiesis. Casein hydrolyzates were also protective in diabetic animals, reduced the tumor growth and diminished colicky symptoms in infants. Casein-derived peptides have been found to have antihypertensive effects. Glycomacropeptide (GMP)--a peptide derived from kappa casein, exhibits antibacterial and antithrombotic activities. 4) Alpha lactalbumin (LA)--demonstrates antiviral, antitumor and anti-stress properties. LA-enriched diets were anxiolytic, lowered blood pressure in rats, prevented diarrhea and led to a better weight gain in malnourished children. 5) Lysozyme--is effective in treatment of periodentitis and prevention of tooth decay. Milk enriched in lysozyme was used in feeding premature infants suffering from concomitant diseases. 6) Lactoperoxidase--shows antibacterial properties. In conclusion, milk-derived proteins and peptides are bio-accessible and safe for the prevention and treatment of numerous disorders in humans.

  9. Histatins: salivary peptides with copper(II)- and zinc(II)-binding motifs: perspectives for biomedical applications.

    Science.gov (United States)

    Melino, Sonia; Santone, Celeste; Di Nardo, Paolo; Sarkar, Bibudhendra

    2014-02-01

    Natural antimicrobial peptides represent a primordial mechanism of immunity in both vertebrate and nonvertebrate organisms. Among them, histatins belong to a family of human salivary metal-binding peptides displaying potent antibacterial, antifungal and wound-healing activities. These properties, along with the ability of histatins to inhibit collagenases and cysteine proteases, have attracted much attention for their potential use in the treatment of several oral diseases. This review critically assesses the studies carried out to date in order to provide a comprehensive and systematic vision of the information accumulated so far. In particular, the relationship between metal-binding and peptide activity is extensively analysed. The review provides important clues for developing possible therapeutic applications of histatins and their synthetic peptide analogues by creating a set of necessary resource materials to support investigators and industries interested in exploiting their unique properties.

  10. Dual host-defence functions of SPLUNC2/PSP and synthetic peptides derived from the protein.

    Science.gov (United States)

    Gorr, Sven-Ulrik; Abdolhosseini, Mahsa; Shelar, Anuradha; Sotsky, Julie

    2011-08-01

    PSP (parotid secretory protein)/SPLUNC2 (short palate, lung and nasal epithelium clone 2) is expressed in human salivary glands and saliva. The protein exists as an N-glycosylated and non-glycosylated form and both appear to induce agglutination of bacteria, a major antibacterial function for salivary proteins. Both forms of PSP/SPLUNC2 bind LPS (lipopolysaccharide), suggesting that the protein may also play an anti-inflammatory role. Based on the predicted structure of PSP/SPLUNC2 and the location of known antibacterial and anti-inflammatory peptides in BPI (bactericidal/permeability-increasing protein) and LBP (LPS-binding protein), we designed GL13NH2 and GL13K, synthetic peptides that capture these proposed functions of PSP/SPLUNC2. GL13NH3 agglutinates bacteria, leading to increased clearance by macrophages and reduced spread of infection in a plant model. GL13K kills bacteria with a minimal inhibitory concentration of 5-10 μg/ml, kills bacteria in biofilm and retains activity in 150 mM NaCl and 50% saliva. Both peptides block endotoxin action, but only GL13K appears to bind endotoxin. The peptides do not cause haemolysis, haemagglutination in serum, inhibit mammalian cell proliferation or induce an inflammatory response in macrophages. These results suggest that the GL13NH2 and the modified peptide GL13K capture the biological activity of PSP/SPLUNC2 and can serve as lead compounds for the development of novel antimicrobial and anti-inflammatory peptides.

  11. Improved bioactivity of antimicrobial peptides by addition of amino-terminal copper and nickel (ATCUN) binding motifs.

    Science.gov (United States)

    Libardo, M Daben; Cervantes, Jorge L; Salazar, Juan C; Angeles-Boza, Alfredo M

    2014-08-01

    Antimicrobial peptides (AMPs) are promising candidates to help circumvent antibiotic resistance, which is an increasing clinical problem. Amino-terminal copper and nickel (ATCUN) binding motifs are known to actively form reactive oxygen species (ROS) upon metal binding. The combination of these two peptidic constructs could lead to a novel class of dual-acting antimicrobial agents. To test this hypothesis, a set of ATCUN binding motifs were screened for their ability to induce ROS formation, and the most potent were then used to modify AMPs with different modes of action. ATCUN binding motif-containing derivatives of anoplin (GLLKRIKTLL-NH2), pro-apoptotic peptide (PAP; KLAKLAKKLAKLAK-NH2), and sh-buforin (RAGLQFPVGRVHRLLRK-NH2) were synthesized and found to be more active than the parent AMPs against a panel of clinically relevant bacteria. The lower minimum inhibitory concentration (MIC) values for the ATCUN-anoplin peptides are attributed to the higher pore-forming activity along with their ability to cause ROS-induced membrane damage. The addition of the ATCUN motifs to PAP also increases its ability to disrupt membranes. DNA damage is the major contributor to the activity of the ATCUN-sh-buforin peptides. Our findings indicate that the addition of ATCUN motifs to AMPs is a simple strategy that leads to AMPs with higher antibacterial activity and possibly to more potent, usable antibacterial agents.

  12. Antimicrobial potential of lycosin-I, a cationic and amphiphilic peptide from the venom of the spider Lycosa singorensis.

    Science.gov (United States)

    Tan, H; Ding, X; Meng, S; Liu, C; Wang, H; Xia, L; Liu, Z; Liang, S

    2013-07-01

    Antimicrobial peptides (AMPs) are significant components of the innate immune system and play indispensable roles in the resistance to bacterial infection. Here, we investigated the antimicrobial activity of lycosin-I, a 24-residue cationic anticancer peptide derived from Lycosa singorensis with high structural similarity to several cationic and amphiphilic antimicrobial peptides. The antimicrobial activity of lycosin-I against 27 strains of microbes including bacteria and fungi was examined and compared with that of the Xenopus-derived AMP magainin 2 using a microdilution assay. Lycosin-I inhibited the growth of most microorganisms at low micromolar concentrations, and was a more potent inhibitor than magainin 2. Lycosin-I showed rapid, selective and broad-spectrum bactericidal activity and a synergistic effect with traditional antibiotics. In vivo, it showed potent bactericidal activity in a mouse thigh infection model. High Mg2+ concentrations reduced the antibacterial effect of lycosin-I, implying that the peptide might directly interact with the bacterial cell membrane. Uptake of the fluorogenic dye SYTOX and changes in the surface of lycosin-Itreated bacterial cells observed by scanning electron microscopy confirmed that lycosin-I permeabilized the cell membrane, resulting in the rapid bactericidal effect. Taken together, our findings indicate that lycosin-I is a promising peptide with the potential for the development of novel antibacterial agents.

  13. Antibacterial Derivatives of Marine Algae: An Overview of Pharmacological Mechanisms and Applications.

    Science.gov (United States)

    Shannon, Emer; Abu-Ghannam, Nissreen

    2016-04-22

    The marine environment is home to a taxonomically diverse ecosystem. Organisms such as algae, molluscs, sponges, corals, and tunicates have evolved to survive the high concentrations of infectious and surface-fouling bacteria that are indigenous to ocean waters. Both macroalgae (seaweeds) and microalgae (diatoms) contain pharmacologically active compounds such as phlorotannins, fatty acids, polysaccharides, peptides, and terpenes which combat bacterial invasion. The resistance of pathogenic bacteria to existing antibiotics has become a global epidemic. Marine algae derivatives have shown promise as candidates in novel, antibacterial drug discovery. The efficacy of these compounds, their mechanism of action, applications as antibiotics, disinfectants, and inhibitors of foodborne pathogenic and spoilage bacteria are reviewed in this article.

  14. Antibacterial Derivatives of Marine Algae: An Overview of Pharmacological Mechanisms and Applications

    Directory of Open Access Journals (Sweden)

    Emer Shannon

    2016-04-01

    Full Text Available The marine environment is home to a taxonomically diverse ecosystem. Organisms such as algae, molluscs, sponges, corals, and tunicates have evolved to survive the high concentrations of infectious and surface-fouling bacteria that are indigenous to ocean waters. Both macroalgae (seaweeds and microalgae (diatoms contain pharmacologically active compounds such as phlorotannins, fatty acids, polysaccharides, peptides, and terpenes which combat bacterial invasion. The resistance of pathogenic bacteria to existing antibiotics has become a global epidemic. Marine algae derivatives have shown promise as candidates in novel, antibacterial drug discovery. The efficacy of these compounds, their mechanism of action, applications as antibiotics, disinfectants, and inhibitors of foodborne pathogenic and spoilage bacteria are reviewed in this article.

  15. Synergistic Antibacterial Effect of the Combination of ε-Polylysine and Nisin against Enterococcus faecalis.

    Science.gov (United States)

    Liu, Fang; Liu, Mei; Du, Lihui; Wang, Daoying; Geng, Zhiming; Zhang, Muhan; Sun, Chong; Xu, Xiaoxi; Zhu, Yongzhi; Xu, Weimin

    2015-12-01

    This study evaluated the antibacterial effect of the combination of ε-polylysine (ε-PL) and nisin against Enterococcus faecalis strains. The combination of ε-PL and nisin showed synergistic antibacterial activity against three Enterococcus strains. Scanning electron microscopy and a membrane permeability assay revealed that the combined treatment with ε-PL and nisin synergistically damaged the cell morphology of E. faecalis strain R612Z1 cells. Both ε-PL and nisin can dissipate the transmembrane electric potential of E. faecalis R612Z1 cells, but these peptides did not affect the transmembrane pH gradient. The combination of ε-PL and nisin can produce a high reactive oxygen species level in E. faecalis R612Z1 cells. The results indicated that the uptake of ε-PL into cells was promoted through nisin and that the combination of ε-PL and nisin could produce a high reactive oxygen species level in E. faecalis R612Z1 cells, leading to cell growth inhibition.

  16. Avian Antimicrobial Host Defense Peptides: From Biology to Therapeutic Applications

    Directory of Open Access Journals (Sweden)

    Guolong Zhang

    2014-02-01

    Full Text Available Host defense peptides (HDPs are an important first line of defense with antimicrobial and immunomoduatory properties. Because they act on the microbial membranes or host immune cells, HDPs pose a low risk of triggering microbial resistance and therefore, are being actively investigated as a novel class of antimicrobials and vaccine adjuvants. Cathelicidins and β-defensins are two major families of HDPs in avian species. More than a dozen HDPs exist in birds, with the genes in each HDP family clustered in a single chromosomal segment, apparently as a result of gene duplication and diversification. In contrast to their mammalian counterparts that adopt various spatial conformations, mature avian cathelicidins are mostly α-helical. Avian β-defensins, on the other hand, adopt triple-stranded β-sheet structures similar to their mammalian relatives. Besides classical β-defensins, a group of avian-specific β-defensin-related peptides, namely ovodefensins, exist with a different six-cysteine motif. Like their mammalian counterparts, avian cathelicidins and defensins are derived from either myeloid or epithelial origin expressed in a majority of tissues with broad-spectrum antibacterial and immune regulatory activities. Structure-function relationship studies with several avian HDPs have led to identification of the peptide analogs with potential for use as antimicrobials and vaccine adjuvants. Dietary modulation of endogenous HDP synthesis has also emerged as a promising alternative approach to disease control and prevention in chickens.

  17. Biosynthesis of cardiac natriuretic peptides

    DEFF Research Database (Denmark)

    Goetze, Jens Peter

    2010-01-01

    . An inefficient post-translational prohormone maturation will also affect the biology of the cardiac natriuretic peptide system. This review aims at summarizing the myocardial synthesis of natriuretic peptides focusing on B-type natriuretic peptide, where new data has disclosed cardiac myocytes as highly...

  18. An in vitro study on the effects of nisin on the antibacterial activities of 18 antibiotics against Enterococcus faecalis.

    Science.gov (United States)

    Tong, Zhongchun; Zhang, Yuejiao; Ling, Junqi; Ma, Jinglei; Huang, Lijia; Zhang, Luodan

    2014-01-01

    Enterococcus faecalis rank among the leading causes of nosocomial infections worldwide and possesses both intrinsic and acquired resistance to a variety of antibiotics. Development of new antibiotics is limited, and pathogens continually generate new antibiotic resistance. Many researchers aim to identify strategies to effectively kill this drug-resistant pathogen. Here, we evaluated the effect of the antimicrobial peptide nisin on the antibacterial activities of 18 antibiotics against E. faecalis. The MIC and MBC results showed that the antibacterial activities of 18 antibiotics against E. faecalis OG1RF, ATCC 29212, and strain E were significantly improved in the presence of 200 U/ml nisin. Statistically significant differences were observed between the results with and without 200 U/ml nisin at the same concentrations of penicillin or chloramphenicol (pnisin and penicillin or chloramphenicol had a synergetic effect against the three tested E. faecalis strains. The transmission electron microscope images showed that E. faecalis was not obviously destroyed by penicillin or chloramphenicol alone but was severely disrupted by either antibiotic in combination with nisin. Furthermore, assessing biofilms by a confocal laser scanning microscope showed that penicillin, ciprofloxacin, and chloramphenicol all showed stronger antibiofilm actions in combination with nisin than when these antibiotics were administered alone. Therefore, nisin can significantly improve the antibacterial and antibiofilm activities of many antibiotics, and certain antibiotics in combination with nisin have considerable potential for use as inhibitors of this drug-resistant pathogen.

  19. In vitro production and antifungal activity of peptide ABP-dHC-cecropin A.

    Science.gov (United States)

    Zhang, Jiaxin; Movahedi, Ali; Xu, Junjie; Wang, Mengyang; Wu, Xiaolong; Xu, Chen; Yin, Tongming; Zhuge, Qiang

    2015-04-10

    The antimicrobial peptide ABP-dHC-cecropin A is a small cationic peptide with potent activity against a wide range of bacterial species. Evidence of antifungal activity has also been suggested; however, testing of this peptide has been limited due to the low expression of cecropin proteins in Escherichia coli. To improve expression of this peptide in E. coli, ABP-dHC-cecropin A was cloned into a pSUMO vector and transformed into E. coli, resulting in the production of a pSUMO-ABP-dHC-cecropin A fusion protein. The soluble form of this protein was then purified by Ni-IDA chromatography, yielding a total of 496-mg protein per liter of fermentation culture. The SUMO-ABP-dHC-cecropin A fusion protein was then cleaved using a SUMO protease and re-purified by Ni-IDA chromatography, yielding a total of 158-mg recombinant ABP-dHC-cecropin A per liter of fermentation culture at a purity of ≥94%, the highest yield reported to date. Antifungal activity assays performed using this purified recombinant peptide revealed strong antifungal activity against both Candida albicans and Neurospora crassa, as well as Rhizopus, Fusarium, Alternaria, and Mucor species. Combined with previous analyses demonstrating strong antibacterial activity against a number of important bacterial pathogens, these results confirm the use of ABP-dHC-cecropin A as a broad-spectrum antimicrobial peptide, with significant therapeutic potential.

  20. Peptide vectors for gene delivery: from single peptides to multifunctional peptide nanocarriers.

    Science.gov (United States)

    Raad, Markus de; Teunissen, Erik A; Mastrobattista, Enrico

    2014-07-01

    The therapeutic use of nucleic acids relies on the availability of sophisticated delivery systems for targeted and intracellular delivery of these molecules. Such a gene delivery should possess essential characteristics to overcome several extracellular and intracellular barriers. Peptides offer an attractive platform for nonviral gene delivery, as several functional peptide classes exist capable of overcoming these barriers. However, none of these functional peptide classes contain all the essential characteristics required to overcome all of the barriers associated with successful gene delivery. Combining functional peptides into multifunctional peptide vectors will be pivotal for improving peptide-based gene delivery systems. By using combinatorial strategies and high-throughput screening, the identification of multifunctional peptide vectors will accelerate the optimization of peptide-based gene delivery systems.

  1. Antimicrobial activities of chicken β -defensin (4 and 10 peptides against pathogenic bacteria and fungi

    Directory of Open Access Journals (Sweden)

    Haitham Ahmed Yacoub

    2015-04-01

    Full Text Available Host Defense Peptides (HDPs are small cationic peptides found in several organisms. They play a vital role in innate immunity response and immunomodulatory stimulation. This investigation was designed to study the antimicrobial activities of β-defensin peptide-4 (sAvBD-4 and 10 (sAvBD-4 derived from chickens against pathogenic organisms including bacteria and fungi. Ten bacterial strains and three fungal species were used in investigation. The results showed that the sAvBD-10 displayed a higher bactericidal potency against all the tested bacterial strains than that of sAvBD-4. The exhibited bactericidal activity was significant against almost the different bacterial strains at different peptide concentrations except for that of P. aeruginosa and Str. bovis strains where a moderate effect was noted. Both peptides were effective in the inactivation of fungal species tested yielding a killing rate of up to 95%. The results revealed that the synthetic peptides were resistant to salt at a concentration of 50mM NaCl. However, they lost antimicrobial potency when applied in the presence of high salt concentrations. Based on blood hemolysis studies, a little hemolytic effect was showed in the case of both peptides even when applied at high concentrations. The data obtained from this study indicated that synthetic avian peptides exhibit strong antibacterial and antifungal activity. In conclusion, future work and research should be tailored to a better understanding of the mechanisms of action of those peptides and their potential use in the pharmaceutical industry to help reduce the incidence and impact of infectious agent and be marketed as a naturally occurring antibiotic.

  2. Antimicrobial Peptide Structure and Mechanism of Action: A Focus on the Role of Membrane Structure.

    Science.gov (United States)

    Lee, Tzong-Hsien; Hall, Kristopher N; Aguilar, Marie-Isabel

    2016-01-01

    Antimicrobial peptides (AMPs) are showing increasing promise as potential candidate antibacterial drugs in the face of the rapidly emerging bacterial resistance to conventional antibiotics in recent years. The target of these peptides is the microbial membrane and there are numerous models to explain their mechanism of action ranging from pore formation to general membrane disruption. The interaction between the AMP and the target membrane is critical to the specificity and activity of these peptides. However, a precise understanding of the relationship between antimicrobial peptide structure and their cytolytic function in a range of organisms is still lacking. This is a result of the complex nature of the interactions of AMPs with the cell membrane, the mechanism of which can vary considerably between different classes of antimicrobia peptides. A wide range of biophysical techniques have been used to study the influence of a number of peptide and membrane properties on the cytolytic activity of these peptides in model membrane systems. Central to characterisation of this interaction is a quantitative analysis of the binding of peptide to the membrane and the coherent dynamic changes in membrane structure. Recently, dual polarization interferometry has been used to perform an in depth analysis of antimicrobial peptide induced membrane perturbation and with new mass-structure co-fitting kinetic analysis have allowed a real-time label free analysis of binding affinity and kinetics. We review these studies which describe multi-step mechanisms which are adopted by various AMPs in nature and may advance our approach to the development of a new generation of effective antimicrobial therapeutics.

  3. Antimicrobial activities of chicken β-defensin (4 and 10) peptides against pathogenic bacteria and fungi.

    Science.gov (United States)

    Yacoub, Haitham A; Elazzazy, Ahmed M; Abuzinadah, Osama A H; Al-Hejin, Ahmed M; Mahmoud, Maged M; Harakeh, Steve M

    2015-01-01

    Host Defense Peptides (HDPs) are small cationic peptides found in several organisms. They play a vital role in innate immunity response and immunomodulatory stimulation. This investigation was designed to study the antimicrobial activities of β-defensin peptide-4 (sAvBD-4) and 10 (sAvBD-4) derived from chickens against pathogenic organisms including bacteria and fungi. Ten bacterial strains and three fungal species were used in investigation. The results showed that the sAvBD-10 displayed a higher bactericidal potency against all the tested bacterial strains than that of sAvBD-4. The exhibited bactericidal activity was significant against almost the different bacterial strains at different peptide concentrations except for that of Pseudomonas aeruginosa (P. aeruginosa) and Streptococcus bovis (Str. bovis) strains where a moderate effect was noted. Both peptides were effective in the inactivation of fungal species tested yielding a killing rate of up to 95%. The results revealed that the synthetic peptides were resistant to salt at a concentration of 50 mM NaCl. However, they lost antimicrobial potency when applied in the presence of high salt concentrations. Based on blood hemolysis studies, a little hemolytic effect was showed in the case of both peptides even when applied at high concentrations. The data obtained from this study indicated that synthetic avian peptides exhibit strong antibacterial and antifungal activity. In conclusion, future work and research should be tailored to a better understanding of the mechanisms of action of those peptides and their potential use in the pharmaceutical industry to help reduce the incidence and impact of infectious agent and be marketed as a naturally occurring antibiotic.

  4. Biochemical functionalization of peptide nanotubes with phage displayed peptides

    Science.gov (United States)

    Swaminathan, Swathi; Cui, Yue

    2016-09-01

    The development of a general approach for the biochemical functionalization of peptide nanotubes (PNTs) could open up existing opportunities in both fundamental studies as well as a variety of applications. PNTs are spontaneously assembled organic nanostructures made from peptides. Phage display has emerged as a powerful approach for identifying selective peptide binding motifs. Here, we demonstrate for the first time the biochemical functionalization of PNTs via peptides identified from a phage display peptide library. The phage-displayed peptides are shown to recognize PNTs. These advances further allow for the development of bifunctional peptides for the capture of bacteria and the self-assembly of silver particles onto PNTs. We anticipate that these results could provide significant opportunities for using PNTs in both fundamental studies and practical applications, including sensors and biosensors nanoelectronics, energy storage devices, drug delivery, and tissue engineering.

  5. [Antibacterial actions of denture base resin on oral bacteria].

    Science.gov (United States)

    Yamauchi, M; Nigauri, A; Yamamoto, K; Nakazato, G; Kawano, J; Kimura, K

    1989-06-01

    Antibacterial action of various denture base resins on thirteen species of bacteria were studied in vitro. Antibacterial effect of 5% tannin-fluoride preparation, 5% tannic acid and 5% chlorhexidine added to resins on these thirteen bacterial species were also investigated using heat-curing denture base resins. Fresh microwave-curing resin and pour-type resin each showed an antibacterial action on one bacterial strain. Fresh self-curing resins had antibacterial actions on several bacterial strains. However, after storage in water at 37 degrees C for one week, antibacterial action of microwave-curing and pour-type resin were diminished and self-curing resins partially lost their antibacterial actions. Denture base resin containing tannin-fluoride preparation or tannic acid showed an antibacterial effect on one bacterial strain. On the other hand, denture base resin containing chlorhexidine had an antibacterial action on eleven bacterial strains. However, color and mechanical properties of the drug-containing resins were not satisfactory.

  6. Two Novel Antibacterial Flavonoids from Myrsine Africana L.

    Institute of Scientific and Technical Information of China (English)

    KANG,Lu; ZHOU,Jian-Xia; SHEN,Zheng-Wu

    2007-01-01

    Two novel flavonoids, myrsininone A (1), an isoflavone and myrsininone B (2), a flavanone, with very strong antibacterial activities, were isolated from the stems of Myrsine africana L. Their structures were elucidated by extensive spectroscopic analyses. The antibacterial activities were determined by modified Resazuric MIC methods.

  7. Antibacterial activities of PHU - AgNO{sub 3} nanocomposite

    Energy Technology Data Exchange (ETDEWEB)

    Panzaru, Carmen; Danciu, M; Mihailovici, Maria-Sultana [' Gr.T.Popa' University of Medicine and Pharmacy, Iasi (Romania)], E-mail: carmenpanzaru@yahoo.com; Ciobanu, C [' Petru Poni' Institute of Macromolecular Chemistry, Iasi (Romania)

    2009-05-01

    Objective was to characterize the antibacterial action for six combination of PHU-AgNO{sub 3} synthesized in 'Petru Poni' Institute of Macromolecular Chemistry, Iasi, Romania. The advantages of Ag nanoparticles are durability, heat resistant, low toxicity. Silver is known for its antibacterial qualities for a long time and has been used in medicine in topical treatment.

  8. Soluble Eggshell Mebrane Protein:Antibacterial Property and Biodegradability

    Institute of Scientific and Technical Information of China (English)

    YI Feng; YU Jian; LI Qiang; GUO Zhaoxia

    2007-01-01

    The antibacterial property and biodegradability of soluble eggshell membrane protein (SEP)are reported. Unlike the natural eggshell membrane (ESM), SEP does not possess antibacterial property against E.coli. The biodegradation tests with trypsin show that both ESM and SEP are biodegradable.

  9. Methyl carnosate, an antibacterial diterpene isolated from Salvia officinalis leaves.

    Science.gov (United States)

    Climati, Elisa; Mastrogiovanni, Fabio; Valeri, Maria; Salvini, Laura; Bonechi, Claudia; Mamadalieva, Nilufar Zokirzhonovna; Egamberdieva, Dilfuza; Taddei, Anna Rita; Tiezzi, Antonio

    2013-04-01

    Ethanolic extracts of Salvia officinalis leaves demonstrated antibacterial activity against Bacillus cereus. Fractionation of the extracts led to the isolation of the most active antibacterial compound, which, from spectroscopic and LC-MS evidence, was proved to be the diterpene, methyl carnosate.

  10. Syntheses and Antibacterial Activities of Novel Erythromycin O-Alkylamidoximes

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhan-tao; WU Cai-ling; ZHAO Yan-fang; CHENG Mao-sheng; GONG Ping

    2005-01-01

    Nine novel erythromycin O-alkylamidoxime derivatives were prepared in excellent yields via the condensation of different O-alkylhydroxylamines with erythromycin imino ether. The structures of all the compounds prepared were confirmed by 1H NMR, 13C NMR, IR and MS, and their in vtiro antibacterial activities were tested. Among the compounds, two of them showed good antibacterial activities.

  11. MINERAL PROFILE EVOLUTION OF SOME MEDICINAL PLANTS WITH ANTIBACTERIAL EFFECTS

    OpenAIRE

    2016-01-01

    Individual minerals and antibacterial activity were investigated in 5 medicinal plants (pot marigold - Calendula officinalis, burdock - Arctium lappa, celandine - Chelidonium majus, basil- Ocimum basilicum, thyme - Thymus vulgaris) using Atomic Absorption Spectroscopy (AAS) technique and antibiogram  method. The antibacterial susceptibility has been evaluated over 12 strains isolated from milk microflora, belonging to Staphylococcus, Vibrio, Serratia and Bacillus genera. The obtained results ...

  12. Environmentally friendly antibacterial cotton textiles finished with siloxane sulfopropylbetaine.

    Science.gov (United States)

    Chen, Shiguo; Chen, Shaojun; Jiang, Song; Xiong, Meiling; Luo, Junxuan; Tang, Jiaoning; Ge, Zaochuan

    2011-04-01

    This paper reports a novel environmentally friendly antibacterial cotton textile finished with reactive siloxane sulfopropylbetaine(SSPB). The results show that SSPB can be covalently bound onto the cotton textile surface, imparting perdurable antibacterial activity. The textiles finished with SSPB have been investigated systematically from the mechanical properties, thermal stability, hydrophilic properties and antibacterial properties. It is found that the hydrophilicity and breaking strength are improved greatly after the cotton textiles are finished with SSPB. Additionally, the cotton textiles finished with SSPB exhibit good antibacterial activities against gram-positive bacteria Staphylococcus aureus (S.aureus, ATCC 6538), gram-negative bacteria Escherichia coli (E.coli, 8099) and fungi Candida albicans (C.albicans, ATCC 10231). Moreover, SSPB is nonleachable from the textiles, and it does not induce skin stimulation and is nontoxic to animals. Thus, SSPB is ideal candidate for environmentally friendly antibacterial textile applications.

  13. In Vitro Antibacterial Activity of Essential Oils against Streptococcus pyogenes

    Directory of Open Access Journals (Sweden)

    Julien Sfeir

    2013-01-01

    Full Text Available Streptococcus pyogenes plays an important role in the pathogenesis of tonsillitis. The present study was conducted to evaluate the in vitro antibacterial activities of 18 essential oils chemotypes from aromatic medicinal plants against S. pyogenes. Antibacterial activity of essential oils was investigated using disc diffusion method. Minimum Inhibitory Concentration of essential oils showing an important antibacterial activity was measured using broth dilution method. Out of 18 essential oils tested, 14 showed antibacterial activity against S. pyogenes. Among them Cinnamomum verum, Cymbopogon citratus, Thymus vulgaris CT thymol, Origanum compactum, and Satureja montana essential oils exhibited significant antibacterial activity. The in vitro results reported here suggest that, for patients suffering from bacterial throat infections, if aromatherapy is used, these essential oils, considered as potential antimicrobial agents, should be preferred.

  14. Synthesis and Antibacterial Activity of Thiophenes

    Directory of Open Access Journals (Sweden)

    Wedad M. Al-Adiwish

    2012-01-01

    Full Text Available 2-[Bis(methylthiomethylene]propanedinitrile 1a reacted in one-pot successively with piperidine, sodium sulfide, chloroacetonitrile, and potassium carbonate to afford 3-amino-5-(1-piperidinyl-2,4-thiophenedicarbonitrile 2a. Similar reaction using the last three reagents with ethyl 2-cyano-3,3-bis(methylthioacrylate 1b produced ethyl 4-amino-5-cyano-2-(methylthiothiophene-3-carboxylate 2b. The synthesized compounds were characterized by using FT-IR, 1H-NMR, 13C-NMR, and mass spectral data. Antibacterial activities of the synthesized compounds are also reported.

  15. Radiolabelled peptides for oncological diagnosis

    Energy Technology Data Exchange (ETDEWEB)

    Laverman, Peter; Boerman, Otto C.; Oyen, Wim J.G. [Radboud University Nijmegen Medical Centre, Department of Nuclear Medicine, Nijmegen (Netherlands); Sosabowski, Jane K. [Queen Mary University of London, Centre for Molecular Oncology, Barts Cancer Institute, London (United Kingdom)

    2012-02-15

    Radiolabelled receptor-binding peptides targeting receptors (over)expressed on tumour cells are widely under investigation for tumour diagnosis and therapy. The concept of using radiolabelled receptor-binding peptides to target receptor-expressing tissues in vivo has stimulated a large body of research in nuclear medicine. The {sup 111}In-labelled somatostatin analogue octreotide (OctreoScan trademark) is the most successful radiopeptide for tumour imaging, and was the first to be approved for diagnostic use. Based on the success of these studies, other receptor-targeting peptides such as cholecystokinin/gastrin analogues, glucagon-like peptide-1, bombesin (BN), chemokine receptor CXCR4 targeting peptides, and RGD peptides are currently under development or undergoing clinical trials. In this review, we discuss some of these peptides and their analogues, with regard to their potential for radionuclide imaging of tumours. (orig.)

  16. Research Development of Polypeptides Antibacterial Agents%多肽类抗菌剂研究进展

    Institute of Scientific and Technical Information of China (English)

    李艳萍; 李卓荣

    2009-01-01

    The emergence of drug-resistance bacteria has brought a great challenge to the development of new antibiotics. Structure modification of the existing antibiotics and discovering of novel antibacterial agents are the two primary strategies for the development of the new drugs with a great potency against those drug-resistant superbugs. Many peptide compounds possesses antibacterial activity, and this natural ascendency makes them a potential resource for the development of new antibiotics. This review, based on the question that if ribosome is involved in the biosynthetic pathway of polypeptides or not, discussed two groups of polypeptide antibacterial agents, nonribosomal polypeptide antibiotics and ribosome-mediated antimicrobial peptides. Moreover, it also summarized the representative drugs of each group, their mechanisms of action and current developmental status.%耐药菌的出现为抗生素的研发提出了严峻挑战,改造已知物以及发掘新型抗菌剂成为抗菌剂研发的两个主要途径.很多多肽类化合物都具有抗菌的活性,并且在针对耐药菌的新型抗菌剂的研发途径中有天然的优势.本文从生物合成的途径中核糖体的参与与否出发将多肽类抗菌剂分为非核糖体肽-多肽类抗生素和核糖体机制介导的抗菌肽两大类型,并对它们各自的代表药物,抗菌作用特点和研发现状作了综述.

  17. Alteration of the mode of antibacterial action of a defensin by the amino-terminal loop substitution

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Bin [Group of Animal Innate Immunity, State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, 1 Beichen West Road, Chaoyang District, 100101 Beijing (China); Zhu, Shunyi, E-mail: Zhusy@ioz.ac.cn [Group of Animal Innate Immunity, State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, 1 Beichen West Road, Chaoyang District, 100101 Beijing (China)

    2012-10-05

    Highlights: Black-Right-Pointing-Pointer Al-M is an engineered fungal defensin with the n-loop of an insect defensin. Black-Right-Pointing-Pointer Al-M adopts a native defensin-like structure with high antibacterial potency. Black-Right-Pointing-Pointer Al-M kills bacteria through a membrane disruptive mechanism. Black-Right-Pointing-Pointer This work sheds light on the functional evolution of CS{alpha}{beta}-type defensins. -- Abstract: Ancient invertebrate-type and classical insect-type defensins (AITDs and CITDs) are two groups of evolutionarily related antimicrobial peptides (AMPs) that adopt a conserved cysteine-stabilized {alpha}-helical and {beta}-sheet (CS{alpha}{beta}) fold with a different amino-terminal loop (n-loop) size and diverse modes of antibacterial action. Although they both are identified as inhibitors of cell wall biosynthesis, only CITDs evolved membrane disruptive ability by peptide oligomerization to form pores. To understand how this occurred, we modified micasin, a fungus-derived AITDs with a non-membrane disruptive mechanism, by substituting its n-loop with that of an insect-derived CITDs. After air oxidization, the synthetic hybrid defensin (termed Al-M) was structurally identified by circular dichroism (CD) and functionally evaluated by antibacterial and membrane permeability assays and electronic microscopic observation. Results showed that Al-M folded into a native-like defensin structure, as determined by its CD spectrum that is similar to that of micasin. Al-M was highly efficacious against the Gram-positive bacterium Bacillus megaterium with a lethal concentration of 1.76 {mu}M. As expected, in contrast to micasin, Al-M killed the bacteria through a membrane disruptive mechanism of action. The alteration in modes of action supports a key role of the n-loop extension in assembling functional surface of CITDs for membrane disruption. Our work provides mechanical evidence for evolutionary relationship between AITDs and CITDs.

  18. Antimicrobial Peptides (AMPs

    Directory of Open Access Journals (Sweden)

    Mehrzad Sadredinamin

    2016-04-01

    Full Text Available Antimicrobial peptides (AMPs are extensive group of molecules that produced by variety tissues of invertebrate, plants, and animal species which play an important role in their immunity response. AMPs have different classifications such as; biosynthetic machines, biological sources, biological functions, molecular properties, covalent bonding patterns, three dimensional structures, and molecular targets.These molecules have multidimensional properties including antimicrobial activity, antiviral activity, antifungal activity, anti-parasite activity, biofilm control, antitumor activity, mitogens activity and linking innate to adaptive immunity that making them promising agents for therapeutic drugs. In spite of this advantage of AMPs, their clinical developments have some limitation for commercial development. But some of AMPs are under clinical trials for the therapeutic purpose such as diabetic foot ulcers, different bacterial infections and tissue damage. In this review, we emphasized on the source, structure, multidimensional properties, limitation and therapeutic applications of various antimicrobial peptides.

  19. Antimicrobial peptides in Echinoderms

    Directory of Open Access Journals (Sweden)

    C Li

    2010-05-01

    Full Text Available Antimicrobial peptides (AMPs are important immune effector molecules for invertebrates, including echinoderms, which lack a vertebrate-type adaptive immune system. Here we summarize the knowledge of such peptides in echinoderms. Strongylocins are a novel family of cysteine-rich AMPs, recently identified in the sea urchins, Strongylocentrotus droebachiensis and S. purpuratus. Although these molecules present diverse amino acid sequences, they share an identical cysteine arrangement pattern, dissimilar to other known AMPs. A family of heterodimeric AMPs, named centrocins, are also present in S. droebachiensis. Lysozymes and fragments of larger proteins, such as beta-thymocins, actin, histone 2A and filamin A have also been shown to display antimicrobial activities in echinoderms. Future studies on AMPs should be aimed in revealing how echinoderms use these AMPs in the immune response against microbial pathogens.

  20. Avian host defense peptides.

    Science.gov (United States)

    Cuperus, Tryntsje; Coorens, Maarten; van Dijk, Albert; Haagsman, Henk P

    2013-11-01

    Host defense peptides (HDPs) are important effector molecules of the innate immune system of vertebrates. These antimicrobial peptides are also present in invertebrates, plants and fungi. HDPs display broad-spectrum antimicrobial activities and fulfill an important role in the first line of defense of many organisms. It is becoming increasingly clear that in the animal kingdom the functions of HDPs are not confined to direct antimicrobial actions. Research in mammals has indicated that HDPs have many immunomodulatory functions and are also involved in other physiological processes ranging from development to wound healing. During the past five years our knowledge about avian HDPs has increased considerably. This review addresses our current knowledge on the evolution, regulation and biological functions of HDPs of birds.

  1. Non-Membrane Permeabilizing Modes of Action of Antimicrobial Peptides on Bacteria.

    Science.gov (United States)

    Scocchi, Marco; Mardirossian, Mario; Runti, Giulia; Benincasa, Monica

    2016-01-01

    Antimicrobial peptides (AMPs) are a large class of innate immunity effectors with a remarkable capacity to inactivate microorganisms. Their ability to kill bacteria by membranolytic effects has been well established. However, a lot of evidence points to alternative, non-lytic modes of action for a number of AMPs, which operate through interactions with specific molecular targets. It has been reported that non-membrane-permeabilizing AMPs can bind to and inhibit DNA, RNA or protein synthesis processes, inactivate essential intracellular enzymes, or affect membrane septum formation and cell wall synthesis. This minireview summarizes recent findings on these alternative, non-lytic modes of antimicrobial action with an emphasis to the experimental approaches used to clarify each step of their intracellular action, i.e. the cell penetration mechanism, intracellular localization and molecular mechanisms of antibacterial action. Despite the fact that such data exists for a large number of peptides, our analysis indicates that only for a small number of AMPs sufficient data have been collected to support a mode of action with an authentic and substantial contribution by intracellular targeting. In most cases, peptides with non-lytic features have not been thoroughly analyzed, or only a single aspect of their mode of action has been taken into consideration and therefore their mechanism of action can only be hypothesized. A more detailed knowledge of this class of AMPs would be important in the design of novel antibacterial agents against unexploited targets, endowed with the capacity to penetrate into pathogen cells and kill them from within.

  2. Peptides and Food Intake

    OpenAIRE

    Carmen Sobrino Crespo; Aranzazu Perianes Cachero; Lilian Puebla Jiménez; Vicente eBarrios; Eduardo eArilla

    2014-01-01

    The mechanisms for controlling food intake involve mainly an interplay between gut, brain, and adipose tissue (AT), among the major organs. Parasympathetic, sympathetic, and other systems are required for communication between the brain satiety center, gut, and AT. These neuronal circuits include a variety of peptides and hormones, being ghrelin the only orexigenic molecule known, whereas the plethora of other factors are inhibitors of appetite, suggesting its physiological relevance in the r...

  3. Comparative study of antibacterial activity of wood-decay fungi and antibiotics

    OpenAIRE

    A. F. Md. Hassan Iftekhar; Zubaida Khatoon Choudhry; Md. Ismail Khan; Ahmed Abu Saleh

    2011-01-01

    The antibacterial effects of three mushrooms extract Ganoderma lucidum, Auricularia auricula, Pleurotus florida were studied against Staphylococcus aureus and Escherichia coli. A. auricula showed significant antibacterial activity against S. aureus. P. florida showed some antibacterial activity while G. lucidum showed no antibacterial activity. None of the extracts showed any activity against E. coli.

  4. Photodynamic antibacterial effect of graphene quantum dots.

    Science.gov (United States)

    Ristic, Biljana Z; Milenkovic, Marina M; Dakic, Ivana R; Todorovic-Markovic, Biljana M; Milosavljevic, Momir S; Budimir, Milica D; Paunovic, Verica G; Dramicanin, Miroslav D; Markovic, Zoran M; Trajkovic, Vladimir S

    2014-05-01

    Synthesis of new antibacterial agents is becoming increasingly important in light of the emerging antibiotic resistance. In the present study we report that electrochemically produced graphene quantum dots (GQD), a new class of carbon nanoparticles, generate reactive oxygen species when photoexcited (470 nm, 1 W), and kill two strains of pathogenic bacteria, methicillin-resistant Staphylococcus aureus and Escherichia coli. Bacterial killing was demonstrated by the reduction in number of bacterial colonies in a standard plate count method, the increase in propidium iodide uptake confirming the cell membrane damage, as well as by morphological defects visualized by atomic force microscopy. The induction of oxidative stress in bacteria exposed to photoexcited GQD was confirmed by staining with a redox-sensitive fluorochrome dihydrorhodamine 123. Neither GQD nor light exposure alone were able to cause oxidative stress and reduce the viability of bacteria. Importantly, mouse spleen cells were markedly less sensitive in the same experimental conditions, thus indicating a fairly selective antibacterial photodynamic action of GQD.

  5. Silver Nanoparticles as Potential Antibacterial Agents

    Directory of Open Access Journals (Sweden)

    Gianluigi Franci

    2015-05-01

    Full Text Available Multi-drug resistance is a growing problem in the treatment of infectious diseases and the widespread use of broad-spectrum antibiotics has produced antibiotic resistance for many human bacterial pathogens. Advances in nanotechnology have opened new horizons in nanomedicine, allowing the synthesis of nanoparticles that can be assembled into complex architectures. Novel studies and technologies are devoted to understanding the mechanisms of disease for the design of new drugs, but unfortunately infectious diseases continue to be a major health burden worldwide. Since ancient times, silver was known for its anti-bacterial effects and for centuries it has been used for prevention and control of disparate infections. Currently nanotechnology and nanomaterials are fully integrated in common applications and objects that we use every day. In addition, the silver nanoparticles are attracting much interest because of their potent antibacterial activity. Many studies have also shown an important activity of silver nanoparticles against bacterial biofilms. This review aims to summarize the emerging efforts to address current challenges and solutions in the treatment of infectious diseases, particularly the use of nanosilver antimicrobials.

  6. A Novel Antibacterial Compound from Siegesbeckia glabrescens

    Directory of Open Access Journals (Sweden)

    Deokhoon Park

    2012-10-01

    Full Text Available The crude methanol extract of the dried aerial parts of Siegesbeckia glabrescens (Compositae showed antibacterial activity against the foodborne pathogen Staphylococcus aureus. Bioactivity-guided separation led to the isolation of 3-(dodecanoyloxy-2-(isobutyryloxy-4-methylpentanoic acid from nature for the first time. The structure was determined by spectroscopic data analysis (UV, MS, and NMR. The minimal inhibitory concentration (MIC of 3-(dodecanoyloxy-2-(isobutyryloxy-4-methylpentanoic acid against S. aureus was found to be 3.12 μg/mL. In addition, in a further antimicrobial activity assay against Gram-positive (B. subtilis, E. faecalis, P. acnes, S. epidermidis, S. schleiferi subsp. coagulans, S. agalactiae and S. pyrogens, and Gram-negative bacteria (E. coli and P. aeruginosa, and yeast strains (C. alibicans and F. neoformans, the antimicrobial activity of the compound was found to be specific for Gram-positive bacteria. The MIC values of the compound for Gram-positive bacteria ranged from 3.12 to 25 mg/mL. Furthermore, it was found that the 2-(isobutyryloxy-4-methylpentanoic acid substituent may operate as a key factor in the antibacterial activity of the compound, together with the laurate group.

  7. EVALUATION OF ANTIBACTERIAL ACTIVITY OF HERBS

    Directory of Open Access Journals (Sweden)

    Pesaramelli Karteek

    2012-08-01

    Full Text Available Medicinal plants have been used for centuries as remedies for human diseases because they contain components of therapeutic value. The acceptance of traditional medicine as an alternative form of health care and the development of microbial resistance to the available antibiotics has led researchers to investigate the antimicrobial activity of medicinal plants. Wild plants have been reported to have antimicrobial and antioxidant properties for centuries, and indigenous plants have been used in herbal medicine for curing various diseases. The development of bacterial resistance to currently available antibiotics has necessitated the search for new antibacterial agents. In lieu of the above justification, present study aimed at evaluating the In vitro antibacterial studies on the extracts of three herbs namely Punica Granatum, Ricinus communis and Zingiber officinalis carried out on five medically important bacterial strains (Escherichia coli, Bacillus subtilis, Staphylococcus aureus, Pseudomonas aeruginosa and Proteus vulgaris. Based on the present investigation results, extracts has great potential against different microorganisms tested and has inhibitory effect. It can be concluded that these plants can be used as therapeutic natural agents that may serve as lead for the development of new pharmaceuticals addressing the major therapeutic needs.

  8. Retraction: Two novel duck antibacterial peptides, avian β-defensins 9 and 10, with antimicrobial activity.

    Science.gov (United States)

    2013-01-01

    The article by Ma et al. that published in the Journal of Microbiology and Biotechnology (2009, 19: 1447-1455) was used the same data in two journal articles (Acta Veterinaria et Zootechnica Sinica, 2009, 40(9): 1320-1326, Scientia Agricultura Sinica, 2009, 42(4): 1406-1412). Therefore, the article is retracted from JMB as a misconduct of the authors. JMB as the publisher regrets for any inconvenience may have caused by the retraction to readers.

  9. Mechanisms and consequences of bacterial resistance to antimicrobial peptides.

    Science.gov (United States)

    Andersson, D I; Hughes, D; Kubicek-Sutherland, J Z

    2016-05-01

    Cationic antimicrobial peptides (AMPs) are an intrinsic part of the human innate immune system. Over 100 different human AMPs are known to exhibit broad-spectrum antibacterial activity. Because of the increased frequency of resistance to conventional antibiotics there is an interest in developing AMPs as an alternative antibacterial therapy. Several cationic peptides that are derivatives of AMPs from the human innate immune system are currently in clinical development. There are also ongoing clinical studies aimed at modulating the expression of AMPs to boost the human innate immune response. In this review we discuss the potential problems associated with these therapeutic approaches. There is considerable experimental data describing mechanisms by which bacteria can develop resistance to AMPs. As for any type of drug resistance, the rate by which AMP resistance would emerge and spread in a population of bacteria in a natural setting will be determined by a complex interplay of several different factors, including the mutation supply rate, the fitness of the resistant mutant at different AMP concentrations, and the strength of the selective pressure. Several studies have already shown that AMP-resistant bacterial mutants display broad cross-resistance to a variety of AMPs with different structures and modes of action. Therefore, routine clinical administration of AMPs to treat bacterial infections may select for resistant bacterial pathogens capable of better evading the innate immune system. The ramifications of therapeutic levels of exposure on the development of AMP resistance and bacterial pathogenesis are not yet understood. This is something that needs to be carefully studied and monitored if AMPs are used in clinical settings.

  10. [C-peptide physiological effects].

    Science.gov (United States)

    Shpakov, A O; Granstrem, O K

    2013-02-01

    In the recent years there were numerous evidences that C-peptide, which was previously considered as a product of insulin biosynthesis, is one of the key regulators of physiological processes. C-peptide via heterotrimeric G(i/o) protein-coupled receptors activates a wide range of intracellular effector proteins and transcription factors and, thus, controls the inflammatory and neurotrophic processes, pain sensitivity, cognitive function, macro- and microcirculation, glomerular filtration. These effects of C-peptide are mainly expressed in its absolute or relative deficiency occurred in type 1 diabetes mellitus and they are less pronounced when the level of C-peptide is close to normal. Replacement therapy with C-peptide prevents many complications of type 1 diabetes, such as atherosclerosis, diabetic peripheral neuropathy, and nephropathy. C-peptide interacts with the insulin hexamer complexes and induces their dissociation and, as a result, regulates the functional activity of the insulin signaling system. At the same time, C-peptide at the concentrations above physiological may demonstrate pro-inflammatory effects on the endothelial cells and cause atherosclerotic changes in the vessels, which should be considered in the study of pathogenic mechanisms of complications of type 2 diabetes mellitus, where the level of C peptide is increased, as well as in the development of approaches for C-peptide application in clinic. This review is devoted contemporary achievements and unsolved problems in the study of C-peptide, as an important regulator of physiological and biochemical processes.

  11. Five Ochna species have high antibacterial activity and more than ten antibacterial compounds

    Directory of Open Access Journals (Sweden)

    Jacobus N. Eloff

    2012-01-01

    Full Text Available New measures to control infections in humans and other animals are continuously being sought because of the increasing resistance of bacteria to antibiotics. In a wide tree screening survey of the antimicrobial activity of extracts of tree leaves (www.up.ac.za/phyto, Ochna pulchra, a small tree found widely in southern Africa, had good antibacterial activity. We therefore investigated the antibacterial activity of acetone leaf extracts of some other available Ochna spp. Antibacterial activity and the number of antibacterial compounds in acetone leaf extracts of Ochna natalitia, Ochna pretoriensis, O. pulchra, Ochna gamostigmata and Ochna serullata were determined with a tetrazolium violet serial microplate dilution assay and bioautography against Staphylococcus aureus, Escherichia coli, Enterococcus faecalis and Pseudomonas aeruginosa, bacteria commonly associated with nosocomial infections. The percentage yields of the extracts varied from 2.5% to 8%. The minimum inhibitory concentrations of the five species ranged from 40 µg/mL to 1250 µg/mL. E. coli was sensitive to all the extracts. The O. pretoriensis extract was the most active with minimum inhibitory concentrations of 0.065 mg/mL and 0.039 mg/mL against E. coli and E. faecalis, respectively. The O. pretoriensis extract also had the highest total activities of 923 mL/g and 1538 mL/g, indicating that the acetone extract from 1 g of dried plant material could be diluted to 923 mL or 1538 mL and would still kill these bacteria. Based on the bioautography results, the two most active species, O. pretoriensis and O. pulchra, contained at least 10 antibacterial compounds with similar Rf values. Some of these antibacterial compounds were polar and others were non-polar. Variation in the chemical composition of the species

  12. Shedding light on antibacterial activities of cathelicidins

    NARCIS (Netherlands)

    Schneider, V.A.F.

    2016-01-01

    Antibiotic resistance is continuously increasing and has a tremendous impact on human and animal well-being. Attractive alternatives to conventional antibiotics are host defense peptides (HDP), such as chicken cathelicidin-2 (CATH-2) and porcine proline-rich PR-39. HDPs are small cationic molecules

  13. Comparative study of titania nanoparticles and nanotubes as antibacterial agents

    Science.gov (United States)

    Jing, Zhihong; Guo, Daojun; Wang, Weihua; Zhang, Shufang; Qi, Wei; Ling, Baoping

    2011-09-01

    Anatase titania nanoparticles with a high surface area (about 587.7 m 2/g) were synthesized by sol-gel method using isobutyl alcohol as solvent, and then anatase titania nanotubes with needlelike shape, which had diameters of about 5 nm and wall thickness of about 1 nm, could be obtained by microwave process using the above titania nanoparticles as precursors. Both titania nanoparticles and nanotubes were characterized through X-ray diffraction, transmission electron microscopy, high-resolution transmission electron microscopy, Fourier transform infrared spectroscopy, ultraviolet-visible spectroscopy, photoluminescence spectroscopy and nitrogen adsorption-desorption isotherm technique. The antibacterial activities of both titania nanoparticles and nanotubes against Escherichia coli ( E. coli) were developed by quantification and qualitative ways, e.g. microcalorimetric method and disk diffusion method. At the same time, their antibacterial activities against E. coli were also investigated in dark and under UV irradiation. As a result, both the titania nanoparticles and nanotubes had good antibacterial activities against E. coli due to their low inhibitory concentration and large diameter of antibacterial circle. In addition, the titania nanoparticles displayed higher antibacterial activities than those of the titania nanotubes under UV irradiation, though they presented similar antibacterial activities in dark. The differences in antibacterial activities between titania nanoparticles and nanotubes might be attributed to the changes of their microstructure in our works.

  14. Antibacterial kaolinite/urea/chlorhexidine nanocomposites: Experiment and molecular modelling

    Energy Technology Data Exchange (ETDEWEB)

    Holešová, Sylva, E-mail: sylva.holesova@vsb.cz [Nanotechnology Centre, VŠB – Technical University of Ostrava, 17.listopadu 15/2172, CZ-708 33 Ostrava, Poruba (Czech Republic); IT4Innovations Centre of Excellence, VŠB – Technical University of Ostrava, 17.listopadu 15/2172, CZ-708 33 Ostrava, Poruba (Czech Republic); Valášková, Marta; Hlaváč, Dominik [Nanotechnology Centre, VŠB – Technical University of Ostrava, 17.listopadu 15/2172, CZ-708 33 Ostrava, Poruba (Czech Republic); IT4Innovations Centre of Excellence, VŠB – Technical University of Ostrava, 17.listopadu 15/2172, CZ-708 33 Ostrava, Poruba (Czech Republic); Madejová, Jana [Institute of Inorganic Chemistry, SAS, Dúbravská cesta 9, SK-845 36 Bratislava (Slovakia); Samlíková, Magda; Tokarský, Jonáš [Nanotechnology Centre, VŠB – Technical University of Ostrava, 17.listopadu 15/2172, CZ-708 33 Ostrava, Poruba (Czech Republic); IT4Innovations Centre of Excellence, VŠB – Technical University of Ostrava, 17.listopadu 15/2172, CZ-708 33 Ostrava, Poruba (Czech Republic); Pazdziora, Erich [Institute of Public Health Ostrava, Centre of Clinical Laboratories, Partyzánské náměstí 7, CZ-702 00 Ostrava (Czech Republic)

    2014-06-01

    Clay minerals are commonly used materials in pharmaceutical production both as inorganic carriers or active agents. The purpose of this study is the preparation and characterization of clay/antibacterial drug hybrids which can be further included in drug delivery systems for treatment oral infections. Novel nanocomposites with antibacterial properties were successfully prepared by ion exchange reaction from two types of kaolinite/urea intercalates and chlorhexidine diacetate. Intercalation compounds of kaolinite were prepared by reaction with solid urea in the absence of solvents (dry method) as well as with urea aqueous solution (wet method). The antibacterial activity of two prepared samples against Enterococcus faecalis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa was evaluated by finding the minimum inhibitory concentration (MIC). Antibacterial studies of both samples showed the lowest MIC values (0.01%, w/v) after 1 day against E. faecalis, E. coli and S. aureus. A slightly worse antibacterial activity was observed against P. aeruginosa (MIC 0.12%, w/v) after 1 day. Since samples showed very good antibacterial activity, especially after 1 day of action, this means that these samples can be used as long-acting antibacterial materials. Prepared samples were characterized by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The experimental data are supported by results of molecular modelling.

  15. Antibacterial Activity of Dental Cements Containing Quaternary Ammonium Polyethylenimine Nanoparticles

    Directory of Open Access Journals (Sweden)

    Nurit Beyth

    2012-01-01

    Full Text Available Glass ionomer cements (GICs are commonly used for cementing full cast crown restorations. Regrettably, although the dental cements fill the gap between the tooth and the crown, bacterial microleakage may occur, resulting in secondary caries. As microleakage cannot be completely prevented, GICs possessing antibacterial properties are in demand. In the present study the antibacterial activity of insoluble, cross-linked quaternary ammonium polyethylenimine (QPEI nanoparticles incorporated at 1% w/w in two clinically available GICs were studied. The antibacterial activity was tested against Streptococcus mutans and Lactobacillus casei using the direct contact test (DCT and the agar diffusion test (ADT. Using the direct contact test, antibacterial activity (<0.05 was found in both tested GICs with incorporated QPEI nanoparticles, the effect lasting for at least one month. However, the ADT showed no inhibition halo in the test bacteria, indicating that the antimicrobial nanoparticles do not diffuse into the agar. The results show that the incorporation of QPEI nanoparticles in glass ionomer cements has a long-lasting antibacterial effect against Streptococcus mutans and Lactobacillus casei. Changing the antibacterial properties of glass ionomer cements by incorporating QPEI antibacterial nanoparticles may prolong the clinical performance of dental crowns.

  16. Preparation of Antibacterial Nanofibre/Nanoparticle Covered Composite Yarns

    Directory of Open Access Journals (Sweden)

    Fatma Yalcinkaya

    2016-01-01

    Full Text Available The antibacterial efficiency of nanofibre composite yarns with an immobilized antibacterial agent was tested. This novel type of nanofibrous composite material combines the good mechanical properties of the core yarn with the high specific surface of the nanofibre shell to gain specific targeted qualities. The main advantages of nanofibre covered composite yarns over the standard planar nanofibre membranes include high tensile strength, a high production rate, and their ability to be processed by standard textile techniques. The presented paper describes a study of the immobilization of an antibacterial agent and its interaction with two types of bacterial colonies. The aim of the study is to assess the applicability of the new composite nanomaterial in antibacterial filtration. During the experimental tests copper(II oxide particles were immobilized in the polyurethane and polyvinyl butyral nanofibre components of a composite yarn. The antibacterial efficiency was evaluated by using both Gram-negative Escherichia coli and Gram-positive Staphylococcus gallinarum bacteria. The results showed that the composite yarn with polyvinyl butyral nanofibres incorporating copper(II oxide nanoparticles exhibited better antibacterial efficiency compared to the yarn containing the polyurethane nanofibres. The nanofibre/nanoparticle covered composite yarns displayed good antibacterial activity against a number of bacteria.

  17. Antibacterial effects of Solanum tuberosum peel ethanol extract in vitro

    Directory of Open Access Journals (Sweden)

    Amanpour Raana

    2015-04-01

    Full Text Available Introduction: Today, medicinal plants are being widely used due to being natural, available, and cheaper than synthetic drugs and having minimum side effects. Since there were reports about the antibacterial properties of Solanum tuberosum (SE, the aim of this study was to investigate the antibacterial effects of SE ethanol extract in vitro condition on Streptococcus pyogenes, Staphylococcus aureus, Pseudomonas aeruginosa and Klebsiella pneumoniae. Methods: Ethanol extract of SE peel was prepared by maceration method. Initially, antibacterial activity of ethanol extract of SE was qualitatively determined by disk diffusion test; then, the minimum inhibitory concentration and minimum bactericidal concentration were qualitatively determined by micro-dilution method. Results: SE peel extract had antibacterial properties and its effect was more pronounced on gram-positive bacteria, especially S. aureus (0.62±0.00 mg/ml. The extract had antibacterial activity on gram-negative bacteria, P. aeruginosa, too (8.33±2.88 mg/ml. Conclusion: SE peel extract has antibacterial activity and its effect on gram-positive bacteria was more pronounced than the investigated gram-negative bacteria. Therefore, it is suggested that SE peel constituent compounds be determined and to determine the exact mechanism of its antibacterial properties, and more comprehensive research be done to apply it, clinically.

  18. Antibacterial treatment of LDPE with halogen derivatives via cold plasma

    Directory of Open Access Journals (Sweden)

    A. Popelka

    2015-05-01

    Full Text Available The factor limiting the application of low-density polyethylene (LDPE in healthcare is its high susceptibility to bacterial growth. For this reason, we here investigated antibacterial treatments of LDPE foils using appropriate antibacterial agents. Benzalkonium chloride and bronopol were selected because of their satisfactory antibacterial effect, which has been confirmed by their application in the medical and cosmetic industries. The aforementioned substances were immobilized by a multistep approach via the grafting of polyacrylic acid (PAA brushes onto LDPE surfaces pre-treated with low-temperature plasma. Measurements of the surface energy, peel strength of the adhesive joints, X-ray photoelectron spectroscopy (XPS, Fourier-transform infrared spectroscopy with attenuated total reflectance (FTIR-ATR, and atomic force micro scopy (AFM were used to investigate the surface and adhesive properties of the antibacterial-treated LDPE. Moreover, the antibacterial effect was determined via measurements of the inhibition zone of the Staphylococcus aureus (S. aureus bacterial strain. The antibacterial activity of benzalkonium chloride was observed to be more pronounced than that of bronopol. Inhibition-zone measurements of Escherichia coli (E. coli were also conducted, but an antibacterial effect was not observed.

  19. Antibacterial Spectrum and Antibacterial Mechanism of Bacteriophage AB3 Endolysin%噬菌体A B3裂解酶的抗菌谱及其抗菌机制

    Institute of Scientific and Technical Information of China (English)

    张稢; 李秀娟; 陈永

    2014-01-01

    Objective To investigate the antibacterial spectrum and antibacterial mechanism of LysAB3.Method The gel dif-fusion assay is utilized to determine the antibacterial spectrum of LysAB3.The recombinant plasmid is constructed by inser-ting 354 bp in front of LysAB3 gene into the vector pET28a(+).After expression in E.coli BL21(DE3)and purification with Ni2+-NTA sepharose,LysAB3-D is acquired with lack of amphiphilic peptides structure,with the antibacterial activity determined.Results The gel diffusion assay showed that LysAB3 had bactericidal effects against 40 strains of Acinetobacter Baumannii.After the amphiphilic peptides structure was deleted,the antibacterial activity of LysAB3-D dropped from 95 . 8% to 33.3%.Conclusion These results indicate that the antibacterial spectrum of LysAB3 is abroad relatively and the am-phiphilic peptides structure of LysAB3 increase permeability of bacterial outermembrane,which helps the enzymatic catalytic domain degrade the peptidoglycan.%目的:明确噬菌体AB3裂解酶LysAB3的抗菌谱及其抗菌机制。方法利用扩散法检测裂解酶LysAB3的抗菌谱;扩增裂解酶LysAB3基因序列前端的354 bp,以pET28a(+)为载体构建重组质粒,在大肠杆菌BL21(DE3)中表达,Ni2+-NTA亲和层析柱纯化重组蛋白,得到删除了两性多肽结构的裂解酶LysAB3-D,并测定其抗菌率。结果裂解酶LysAB3可以裂解全部40株鲍曼不动杆菌菌株;删除了两性多肽结构后,裂解酶 LysAB3-D 的抗菌率由95.8%下降至33.3%。结论裂解酶LysAB3的抗菌谱较宽;其杀菌机制可能是通过其两性多肽结构增加细菌外膜通透性,辅助酶解催化域进入其中降解肽聚糖。

  20. The Search for Herbal Antibiotics: An In-Silico Investigation of Antibacterial Phytochemicals

    Science.gov (United States)

    Snow Setzer, Mary; Sharifi-Rad, Javad; Setzer, William N.

    2016-01-01

    Recently, the emergence and spread of pathogenic bacterial resistance to many antibiotics (multidrug-resistant strains) have been increasing throughout the world. This phenomenon is of great concern and there is a need to find alternative chemotherapeutic agents to combat these antibiotic-resistant microorganisms. Higher plants may serve as a resource for new antimicrobials to replace or augment current therapeutic options. In this work, we have carried out a molecular docking study of a total of 561 antibacterial phytochemicals listed in the Dictionary of Natural Products, including 77 alkaloids (17 indole alkaloids, 27 isoquinoline alkaloids, 4 steroidal alkaloids, and 28 miscellaneous alkaloids), 99 terpenoids (5 monoterpenoids, 31 sesquiterpenoids, 52 diterpenoids, and 11 triterpenoids), 309 polyphenolics (87 flavonoids, 25 chalcones, 41 isoflavonoids, 5 neoflavonoids, 12 pterocarpans, 10 chromones, 7 condensed tannins, 11 coumarins, 30 stilbenoids, 2 lignans, 5 phenylpropanoids, 13 xanthones, 5 hydrolyzable tannins, and 56 miscellaneous phenolics), 30 quinones, and 46 miscellaneous phytochemicals, with six bacterial protein targets (peptide deformylase, DNA gyrase/topoisomerase IV, UDP-galactose mutase, protein tyrosine phosphatase, cytochrome P450 CYP121, and NAD+-dependent DNA ligase). In addition, 35 known inhibitors were docked with their respective targets for comparison purposes. Prenylated polyphenolics showed the best docking profiles, while terpenoids had the poorest. The most susceptible protein targets were peptide deformylases and NAD+-dependent DNA ligases. PMID:27626453

  1. The Search for Herbal Antibiotics: An In-Silico Investigation of Antibacterial Phytochemicals

    Directory of Open Access Journals (Sweden)

    Mary Snow Setzer

    2016-09-01

    Full Text Available Recently, the emergence and spread of pathogenic bacterial resistance to many antibiotics (multidrug-resistant strains have been increasing throughout the world. This phenomenon is of great concern and there is a need to find alternative chemotherapeutic agents to combat these antibiotic-resistant microorganisms. Higher plants may serve as a resource for new antimicrobials to replace or augment current therapeutic options. In this work, we have carried out a molecular docking study of a total of 561 antibacterial phytochemicals listed in the Dictionary of Natural Products, including 77 alkaloids (17 indole alkaloids, 27 isoquinoline alkaloids, 4 steroidal alkaloids, and 28 miscellaneous alkaloids, 99 terpenoids (5 monoterpenoids, 31 sesquiterpenoids, 52 diterpenoids, and 11 triterpenoids, 309 polyphenolics (87 flavonoids, 25 chalcones, 41 isoflavonoids, 5 neoflavonoids, 12 pterocarpans, 10 chromones, 7 condensed tannins, 11 coumarins, 30 stilbenoids, 2 lignans, 5 phenylpropanoids, 13 xanthones, 5 hydrolyzable tannins, and 56 miscellaneous phenolics, 30 quinones, and 46 miscellaneous phytochemicals, with six bacterial protein targets (peptide deformylase, DNA gyrase/topoisomerase IV, UDP-galactose mutase, protein tyrosine phosphatase, cytochrome P450 CYP121, and NAD+-dependent DNA ligase. In addition, 35 known inhibitors were docked with their respective targets for comparison purposes. Prenylated polyphenolics showed the best docking profiles, while terpenoids had the poorest. The most susceptible protein targets were peptide deformylases and NAD+-dependent DNA ligases.

  2. AKTIVITAS ANTIBAKTERI DAN ANTIOKSIDAN HIDROLISAT HASIL HIDROLISIS PROTEIN SUSU KAMBING DENGAN EKSTRAK KASAR BROMELIN [Antibacterial and Antioxidant Activity of Hydrolysate from Goat Milk Protein Hydrolized by Crude Bromelain Extract

    Directory of Open Access Journals (Sweden)

    Eni Kusumaningtyas

    2015-12-01

    Full Text Available Goat milk is highly nutritious foodstuffs that beneficial for improving health. The milk contains bioactive peptides which produced by hydrolysis process. The aim of this study was to evaluate antibacterial and antioxidant activities of hydrolisate produced from hydrolysis of goat milk protein by crude bromelain extract. Hydrolysis of goat milk protein was conducted using crude bromelain (0.1 U/mL at pH 6, 50°C for 60 min. Hydrolysate was fractionated by using membrane molecular weight cut off 10 kDa. hydrolysate before and after fractionation were assayed for antibacterial and antioxidant activities. Toxicity of the Hydrolysate was determined by hemolysis assay. The result showed that the hydrolysate before and after fractionation inhibited growth of E. coli, S. Typhimurium and L. monocytogenes. Hydrolysate after fractionation has higher antibacterial activity indicated that fractionation was able to improve antibacterial activities of the hydrolysate fraction. The hydrolysate showed scavenging activity to ABTS and DPPH radicals. Fraction 10 kDa not only showed absence of hemolysis but also they were able to reduce autolysis of red blood cells. The result showed that hydrolysate from goat milk hydrolyzed by bromelain were able to be antibacterial and antioxidant.

  3. Structural Characterization of Peptide Antibodies

    DEFF Research Database (Denmark)

    Chailyan, Anna; Marcatili, Paolo

    2015-01-01

    The role of proteins as very effective immunogens for the generation of antibodies is indisputable. Nevertheless, cases in which protein usage for antibody production is not feasible or convenient compelled the creation of a powerful alternative consisting of synthetic peptides. Synthetic peptides...... can be modified to obtain desired properties or conformation, tagged for purification, isotopically labeled for protein quantitation or conjugated to immunogens for antibody production. The antibodies that bind to these peptides represent an invaluable tool for biological research and discovery...

  4. Synthesis and antibacterial properties of copper nanoparticles for Salmonella typhi

    Science.gov (United States)

    Jaiswal, Anamika; Gaherwal, S.; Lodhi, Pavitra Devi; Singh, Jaiveer; Kaurav, Netram; Shrivastava, M. M. P.

    2016-05-01

    In this study, the antibacterial properties of Cu nanoparitcles (Cu-NPs) were investigated against Salmonella typhi. The Cu-NPs were prepared by the reduction of cupper acetate with the help of ethylene glycol (EG), then sample was characterized by XRD for its average particle size identification. The antibacterial activity assessed by well diffusion and disc diffusion method on different concentration of nanoparticles. It was found that these Cu-NPs showed antibacterial activity in form of zone inhibition, wherein, zone of inhibition increased with increase in concentration of Cu-NPs.

  5. Comparison of antibacterial ability of copper and stainless steel

    Institute of Scientific and Technical Information of China (English)

    GENG Ping; ZHANG Wen; TANG Hui; ZHANG Xinai; JIN Litong; FENG Zhen; WU Zirong

    2007-01-01

    In this paper,the electro-analysis and spectrophotometric analysis methods were used to study the antibacterial ability of copper and stainless steel materials.When Escherichia coli (E.coli) and photo-bacteria were used as samples,the antibacterial effect of stainless steel was very weak,while the percentage of bacteria dying from exposure to metallic copper for 30 min was over 90%.The antibacterial ability of copper has a potential application in the field of disinfection,food packaging and piping of drinking water.

  6. Antibacterial activity and physicochemical evaluation of roots of Butea monosperma

    Institute of Scientific and Technical Information of China (English)

    Prashant Tiwari; Ritesh Jain; Kuldeep Kumar; Rahul Mishra; Anish Chandy

    2012-01-01

    Objective: To evaluate the antibacterial activity of the petroleum ether extract of root of Buteamonosperma B. monosperma was studied against Staphylococcus faecalis (S. faecalis), Sterptococcus faecalis (S. faecalis), Aeromonas hydrophilia (A. hydrophilia), Salmonela typhae (S. typhae), Stphylococcus cohni (S. cohni), Escherichia coli (E. coli) and Serratia ficaria (S. ficaria) by using well diffusion method. Results: Petroleum ether extract of root of B. monosperma exhibited a prominent inhibitory effect against bacterial strains. Conclusion: From the result it can be concluded that the B. monosperma extract has potent in vitro antibacterial activity. (B. monosperma). Method: In vitro antibacterial activity of petroleum ether i.e.

  7. ANTIBACTERIAL ACTIVITY TEST OF EXTRACT NYAMPLUNG (Calophyllum inophyllum Linn. LEAVES

    Directory of Open Access Journals (Sweden)

    Mutiara Novianti

    2015-09-01

    Full Text Available Phytochemical screening and antibacterial activity from ethanol extract of nyamplung (Callophylum inophyllum Linn. leaves from Indonesia against Escherichia coli has been done. The extraction was done by soklet extraction using ethanol. Antibacterial activity test using the Optical Density method at λmax 600 nm. The result of phytochemical screening from ethanol extract showed that there were flavonoid compounds, saponins, tannins, phenols and triterpenoids. The result of antibacterial activity test showed that the optimum activity occurs at incubation time of 3 hours with percentase inhibition persentase i.e. 59.03 %.

  8. Synthesis of methacrylate monomers with antibacterial effects against S. mutans.

    Science.gov (United States)

    He, Jingwei; Söderling, Eva; Österblad, Monica; Vallittu, Pekka K; Lassila, Lippo V J

    2011-11-23

    A series of polymerizable quaternary ammonium compounds were synthesized with the aim of using them as immobilized antibacterial agents in methacrylate dental composites, and their structures were characterized by FT-IR, (1)H-NMR, and (13)C-NMR analysis. Their antibacterial activities against the oral bacterium Streptococcus mutans were evaluated in vitro by a Minimum Inhibitory Concentration test, and the results showed that 2-dimethyl-2-hexadecyl-1-methacryloxyethyl ammonium iodide (C16) had the highest antibacterial activity against S. mutans, and 2-dimethyl-2-pentyl-1-methacryloxyethyl ammonium iodide (C5) and 2-dimethyl-2-octyl-1-methacryloxyethyl ammonium iodide (C8) did not show any inhibition.

  9. Exopolysacharides from White Rot Fungi and Their Antibacterial Studies

    Directory of Open Access Journals (Sweden)

    V. Pranitha

    2016-06-01

    Full Text Available In current investigation exopolysacharides are produced from the Trametes sp. and antibacterial activity of exopolysaccharides (EPS was studied. The antibacterial effect of EPS was observed that they were most effective against gram-positive bacteria, especially B. subtilis and S.aureaus with a zone of inhibition 24 mm and 28 mm, respectively, at a concentration of 80 mg/ml. Moreover, with the increasing concentration, the EPS showed significant increase in antibacterial activity. The activity was lowest in the inhibition of gram-negative bacterium, E. coli and P aerogenosa at a low concentration whose inhibition zones are between 5 to 15mm.

  10. ISOLATION AND PARTIAL PURIFICATION OF ANTIMICROBIAL PEPTIDES/PROTEINS FROM DUNG BEETLE, ONTHOPHAGUS TAURUS IMMUNE HEMOLYMPH

    Directory of Open Access Journals (Sweden)

    Vasanth Patil H.B

    2013-06-01

    Full Text Available Antimicrobial peptides are important in the first line of the host defense system of all insect species. In the present study antimicrobial peptide(s were isolated from the hemolymph of the dung beetle Onthophagus taurus. Both non induced and immune induced hemolymphs were tested for their antimicrobial activity against different bacterial strains and C. albicans. Induction was done by injecting E. coli into the abdominal cavity of the O. taurus. The non induced hemolymph did not show activity against any of the tested fungal and bacterial strains where as induced hemolymph showed activity against all tested bacterial strains but no activity against C. albicans. The induced hemolymph was subjected to non reducing SDS-PAGE and UV wavelength scan was performed to detect the presence of peptides. The immune induced hemolymph was purified by gel filtration chromatography to separate the proteins responsible for the antibacterial activity. The fractions within the peak were tested against those bacteria which previously showed sensitivity to the crude immune induced hemolymph. All fractions were found to be active against all tested bacteria with difference in zone of inhibition. The peptides are active against prokaryotes & not against eukaryotes. These properties reveal its unique characteristics and therapeutic application.

  11. APD3: the antimicrobial peptide database as a tool for research and education.

    Science.gov (United States)

    Wang, Guangshun; Li, Xia; Wang, Zhe

    2016-01-04

    The antimicrobial peptide database (APD, http://aps.unmc.edu/AP/) is an original database initially online in 2003. The APD2 (2009 version) has been regularly updated and further expanded into the APD3. This database currently focuses on natural antimicrobial peptides (AMPs) with defined sequence and activity. It includes a total of 2619 AMPs with 261 bacteriocins from bacteria, 4 AMPs from archaea, 7 from protists, 13 from fungi, 321 from plants and 1972 animal host defense peptides. The APD3 contains 2169 antibacterial, 172 antiviral, 105 anti-HIV, 959 antifungal, 80 antiparasitic and 185 anticancer peptides. Newly annotated are AMPs with antibiofilm, antimalarial, anti-protist, insecticidal, spermicidal, chemotactic, wound healing, antioxidant and protease inhibiting properties. We also describe other searchable annotations, including target pathogens, molecule-binding partners, post-translational modifications and animal models. Amino acid profiles or signatures of natural AMPs are important for peptide classification, prediction and design. Finally, we summarize various database applications in research and education.

  12. 抗菌肽的研究及进展%Research Progress in Antimicrobial Peptides

    Institute of Scientific and Technical Information of China (English)

    姚佳; 周玉玲; 张贞; 王宁

    2012-01-01

    Antimicrobial peptides,a kind of small peptides with biological activity, widely existing in various organisms. Antimicrobial peptides are an important component of the innate immune system of organisms. Many findings suggest that antimicrobial peptides not only have the capabilities of antibacterial and inhibition, but also anti-virus and anti-tumor. Here is to summarize the activity, mechanism of action and method of artificial preparation of antimicrobial peptides, and briefly introduce its application and development in each field.%抗菌肽是一种广泛存在于各类生物体内具有生物活性的小分子多肽,它是构成机体天然免疫系统的重要组成部分.各种研究结果表示,抗菌肽不但有抗菌抑菌功能,同时还有抗病毒、抗肿瘤的功效.现对抗菌肽在抑菌活性、作用机制以及人工制备方法等进行总结,并简要介绍目前抗菌肽在各个领域的应用情况及发展进程.

  13. Design of New Antibacterial Enhancers Based on AcrB’s Structure and the Evaluation of Their Antibacterial Enhancement Activity

    Directory of Open Access Journals (Sweden)

    Yi Song

    2016-11-01

    Full Text Available Previously, artesunate (AS and dihydroartemisinine 7 (DHA7 were found to have antibacterial enhancement activity against Escherichia coli via inhibition of the efflux pump AcrB. However, they were only effective against E. coli standard strains. This study aimed to develop effective antibacterial enhancers based on the previous work. Our results demonstrate that 86 new antibacterial enhancers were designed via 3D-SAR and molecular docking. Among them, DHA27 had the best antibacterial enhancement activity. It could potentiate the antibacterial effects of ampicillin against not only E. coli standard strain but also clinical strains, and of β-lactam antibiotics, not non-β-lactamantibiotics. DHA27 could increase the accumulation of daunomycin and nile red within E. coli ATCC 35218, but did not increase the bacterial membrane permeability. DHA27 reduced acrB’s mRNA expression of E. coli ATCC 35218 in a dose-dependent manner, and its antibacterial enhancement activity is related to the degree of acrB mRNA expression in E. coli clinical strains. The polypeptides from AcrB were obtained via molecular docking assay; the pre-incubated polypeptides could inhibit the activity of DHA27. Importantly, DHA27 had no cytotoxicity on cell proliferation. In conclusion, among newly designed antibacterial enhancers, DHA27 had favorable physical and pharmacological properties with no significant cytotoxicity at effective concentrations, and might serve as a potential efflux pump inhibitor in the future.

  14. Improving Peptide Applications Using Nanotechnology.

    Science.gov (United States)

    Narayanaswamy, Radhika; Wang, Tao; Torchilin, Vladimir P

    2016-01-01

    Peptides are being successfully used in various fields including therapy and drug delivery. With advancement in nanotechnology and targeted delivery carrier systems, suitable modification of peptides has enabled achievement of many desirable goals over-riding some of the major disadvantages associated with the delivery of peptides in vivo. Conjugation or physical encapsulation of peptides to various nanocarriers, such as liposomes, micelles and solid-lipid nanoparticles, has improved their in vivo performance multi-fold. The amenability of peptides to modification in chemistry and functionalization with suitable nanocarriers are very relevant aspects in their use and have led to the use of 'smart' nanoparticles with suitable linker chemistries that favor peptide targeting or release at the desired sites, minimizing off-target effects. This review focuses on how nanotechnology has been used to improve the number of peptide applications. The paper also focuses on the chemistry behind peptide conjugation to nanocarriers, the commonly employed linker chemistries and the several improvements that have already been achieved in the areas of peptide use with the help of nanotechnology.

  15. Antitumor Peptides from Marine Organisms

    Directory of Open Access Journals (Sweden)

    Mi Sun

    2011-10-01

    Full Text Available The biodiversity of the marine environment and the associated chemical diversity constitute a practically unlimited resource of new antitumor agents in the field of the development of marine bioactive substances. In this review, the progress on studies of antitumor peptides from marine sources is provided. The biological properties and mechanisms of action of different marine peptides are described; information about their molecular diversity is also presented. Novel peptides that induce apoptosis signal pathway, affect the tubulin-microtubule equilibrium and inhibit angiogenesis are presented in association with their pharmacological properties. It is intended to provide useful information for further research in the fields of marine antitumor peptides.

  16. The Pig PeptideAtlas

    DEFF Research Database (Denmark)

    Hesselager, Marianne Overgaard; Codrea, Marius; Sun, Zhi;

    2016-01-01

    underrepresented in existing repositories. We here present a significantly improved build of the Pig PeptideAtlas, which includes pig proteome data from 25 tissues and three body fluid types mapped to 7139 canonical proteins. The content of the Pig PeptideAtlas reflects actively ongoing research within...... the veterinary proteomics domain, and this article demonstrates how the expression of isoform-unique peptides can be observed across distinct tissues and body fluids. The Pig PeptideAtlas is a unique resource for use in animal proteome research, particularly biomarker discovery and for preliminary design of SRM...

  17. Solid-phase peptide synthesis

    DEFF Research Database (Denmark)

    Jensen, Knud Jørgen

    2013-01-01

    This chapter provides an introduction to and overview of peptide chemistry with a focus on solid-phase peptide synthesis. The background, the most common reagents, and some mechanisms are presented. This chapter also points to the different chapters and puts them into perspective.......This chapter provides an introduction to and overview of peptide chemistry with a focus on solid-phase peptide synthesis. The background, the most common reagents, and some mechanisms are presented. This chapter also points to the different chapters and puts them into perspective....

  18. Design, Synthesis, Molecular Docking, and Antibacterial Evaluation of Some Novel Flouroquinolone Derivatives as Potent Antibacterial Agent

    Directory of Open Access Journals (Sweden)

    Mehul M. Patel

    2014-01-01

    Full Text Available Objective. Quinolone moiety is an important class of nitrogen containing heterocycles widely used as key building blocks for medicinal agents. It exhibits a wide spectrum of pharmacophores and has bactericidal, antiviral, antimalarial, and anticancer activities. In view of the reported antimicrobial activity of various fluoroquinolones, the importance of the C-7 substituents is that they exhibit potent antimicrobial activities. Our objective was to synthesize newer quinolone analogues with increasing bulk at C-7 position of the main 6-fluoroquinolone scaffold to produce the target compounds which have potent antimicrobial activity. Methods. A novel series of 1-ethyl-6-fluoro-4-oxo-7-{4-[2-(4-substituted phenyl-2-(substituted-ethyl]-1-piperazinyl}-1,4-dihydroquinoline-3-carboxylic acid derivatives were synthesized. To understand the interaction of binding sites with bacterial protein receptor, the docking study was performed using topoisomerase II DNA gyrase enzymes (PDB ID: 2XCT by Schrodinger’s Maestro program. In vitro antibacterial activity of the synthesized compounds was studied and the MIC value was calculated by the broth dilution method. Results. Among all the synthesized compounds, some compounds showed potent antimicrobial activity. The compound 8g exhibited good antibacterial activity. Conclusion. This investigation identified the potent antibacterial agents against certain infections.

  19. Anticancer peptides from bacteria

    Directory of Open Access Journals (Sweden)

    Tomasz M. Karpiński

    2013-08-01

    Full Text Available Cancer is a leading cause of death in the world. The rapid development of medicine and pharmacology allows to create new and effective anticancer drugs. Among modern anticancer drugs are bacterial proteins. Until now has been shown anticancer activity among others azurin and exotoxin A from Pseudomonas aeruginosa, Pep27anal2 from Streptococcus pneumoniae, diphtheria toxin from Corynebacterium diphtheriae, and recently discovered Entap from Enterococcus sp. The study presents the current data regarding the properties, action and anticancer activity of listed peptides.

  20. Peptides and Food Intake

    Science.gov (United States)

    Sobrino Crespo, Carmen; Perianes Cachero, Aránzazu; Puebla Jiménez, Lilian; Barrios, Vicente; Arilla Ferreiro, Eduardo

    2014-01-01

    The mechanisms for controlling food intake involve mainly an interplay between gut, brain, and adipose tissue (AT), among the major organs. Parasympathetic, sympathetic, and other systems are required for communication between the brain satiety center, gut, and AT. These neuronal circuits include a variety of peptides and hormones, being ghrelin the only orexigenic molecule known, whereas the plethora of other factors are inhibitors of appetite, suggesting its physiological relevance in the regulation of food intake and energy homeostasis. Nutrients generated by food digestion have been proposed to activate G-protein-coupled receptors on the luminal side of enteroendocrine cells, e.g., the L-cells. This stimulates the release of gut hormones into the circulation such as glucagon-like peptide-1 (GLP-1), oxyntomodulin, pancreatic polypeptides, peptide tyrosine tyrosine, and cholecystokinin, which inhibit appetite. Ghrelin is a peptide secreted from the stomach and, in contrast to other gut hormones, plasma levels decrease after a meal and potently stimulate food intake. Other circulating factors such as insulin and leptin relay information regarding long-term energy stores. Both hormones circulate at proportional levels to body fat content, enter the CNS proportionally to their plasma levels, and reduce food intake. Circulating hormones can influence the activity of the arcuate nucleus (ARC) neurons of the hypothalamus, after passing across the median eminence. Circulating factors such as gut hormones may also influence the nucleus of the tractus solitarius (NTS) through the adjacent circumventricular organ. On the other hand, gastrointestinal vagal afferents converge in the NTS of the brainstem. Neural projections from the NTS, in turn, carry signals to the hypothalamus. The ARC acts as an integrative center, with two major subpopulations of neurons influencing appetite, one of them coexpressing neuropeptide Y and agouti-related protein (AgRP) that increases food

  1. Antibacterial sesquiterpenoid derivatives from Ferula ferulaeoides.

    Science.gov (United States)

    Liu, Tao; Osman, Khadijo; Kaatz, Glenn W; Gibbons, Simon; Mu, Qing

    2013-05-01

    Three new sesquiterpenoid derivatives 1, 2, and 3 were isolated from Ferula ferulaeoides. To confirm the structure, compound 2 was also synthesized via a condensation reaction between compound 1 and 2,2-dimethoxypropane. The structures of these three compounds were elucidated by means of spectroscopic and chemical methods. Their antibacterial activity against drug-resistant Staphylococcus aureus strains were evaluated with MIC values in the range of 0.5-128 µg/mL. Compounds 1 and 3 were capable of inhibiting efflux of ethidium bromide using an in vitro assay. The cytotoxicity of the compounds was evaluated on cultured HEK293 cells, and none of them showed toxicity to HEK293 cells at a concentration of 125 µg/mL.

  2. Antibacterial effect of five Zingiberaceae essential oils.

    Science.gov (United States)

    Norajit, Krittika; Laohakunjit, Natta; Kerdchoechuen, Orapin

    2007-08-23

    Essential oil obtained by hydrodistillation and two different solvent extractions (petroleum ether and ethanol) from five Zingiberaceae species: ginger (Zingiber officinale Roscoe.), galanga (Alpinia galanga Sw.), turmeric (Curcuma longa L.), kaempferia (Boesenbergia pandurata Holtt.) and bastard cardamom (Amomum xanthioides Wall.) was characterized. Volatile components of all extracts were analyzed by gas chromatography-mass spectrometry (GC-MS). The major components of ginger, turmeric, galangal, bastard cardamom and kaempferia were zingiberene, turmerone, methyl chavicol, and gamma-terpinene, respectively. Their antibacterial effects towards Escherichia coli, Staphylococcus aureus, Bacillus cereus and Listeria monocytogenes were tested by a disc diffusion assay. Essential oil of kaempferia and bastard cardamom obtained by hydrodistillation extraction could inhibit growth of all tested bacteria. Essential oil of ginger extracted by hydrodistillation had the highest efficiency against three positive strains of bacteria (S. aureus, B. cereus and L. monocytogenes), with a minimum concentration to inhibit B. cereus and L. monocytogenes of 6.25 mg/mL.

  3. Antibacterial antagonism between fusidic acid and ciprofloxacin.

    Science.gov (United States)

    Uri, J V

    1993-01-01

    A routine laboratory disk susceptibility testing of a resistant Staphylococcus aureus strain showed that around the ciprofloxacin disk, placed by chance in proximity to a fusidic acid disk, the inhibition zone was truncated. Follow-up of this observation by a planned disk approximation method showed that there is a real antagonism between these two antibacterial agents. The antagonism was observed while testing S. aureus isolates including the standard ATCC 25923 strain, with Bacillus subtilis ATCC 6633 spores and also with a mutant Escherichia coli made fusidic acid susceptible. The antagonistic property was found structure-specific, only associated with those fluoroquinolones containing the cyclopropyl substituent at the N1-position: ciprofloxacin, enrofloxacin, sparfloxacin and WIN 57273. Fluoroquinolones without this substituent such as enoxacin, norfloxacin, pefloxacin and ofloxacin were not antagonized by fusidic acid, the steroidal Gram-positive active antibiotic.

  4. Exploring Protein-Peptide Binding Specificity through Computational Peptide Screening.

    Directory of Open Access Journals (Sweden)

    Arnab Bhattacherjee

    2013-10-01

    Full Text Available The binding of short disordered peptide stretches to globular protein domains is important for a wide range of cellular processes, including signal transduction, protein transport, and immune response. The often promiscuous nature of these interactions and the conformational flexibility of the peptide chain, sometimes even when bound, make the binding specificity of this type of protein interaction a challenge to understand. Here we develop and test a Monte Carlo-based procedure for calculating protein-peptide binding thermodynamics for many sequences in a single run. The method explores both peptide sequence and conformational space simultaneously by simulating a joint probability distribution which, in particular, makes searching through peptide sequence space computationally efficient. To test our method, we apply it to 3 different peptide-binding protein domains and test its ability to capture the experimentally determined specificity profiles. Insight into the molecular underpinnings of the observed specificities is obtained by analyzing the peptide conformational ensembles of a large number of binding-competent sequences. We also explore the possibility of using our method to discover new peptide-binding pockets on protein structures.

  5. Antibacterial coating on polymer for space application

    Energy Technology Data Exchange (ETDEWEB)

    Balagna, Cristina, E-mail: cristina.balagna@polito.it [Institute of Materials Physics and Engineering, Department of Applied Science and Technology, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino (Italy); Perero, Sergio; Ferraris, Sara; Miola, Marta [Institute of Materials Physics and Engineering, Department of Applied Science and Technology, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino (Italy); Fucale, Giacomo [Chemical, Clinical and Microbiological Analyses Department C.T.O., Via G. Zuretti 29, 10126 Torino (Italy); Manfredotti, Chiara; Battiato, Alfio [Physics Department, Centre of Excellence ' Nanostructured Interfaces and Surfaces' and CNISM, University of Torino, Via P. Giuria 1, 10125 Torino (Italy); Santella, Daniela [Thales Alenia Space - Italia, Space Infrastructures and Transportation, Engineering - Advanced Projects Unit, Strada Antica di Collegno 253, 10146 Torino (Italy); Verne, Enrica [Institute of Materials Physics and Engineering, Department of Applied Science and Technology, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino (Italy); Vittone, Ettore [Physics Department, Centre of Excellence ' Nanostructured Interfaces and Surfaces' and CNISM, University of Torino, Via P. Giuria 1, 10125 Torino (Italy); Ferraris, Monica [Institute of Materials Physics and Engineering, Department of Applied Science and Technology, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino (Italy)

    2012-08-15

    The microbiological contamination on board of spacecraft and orbital stations is a relevant problem in prolonged space exploration. For this purpose, an antibacterial silver nanocluster silica composite coating was deposited on a commercial polymer Combitherm{sup Registered-Sign }, suitable for aerospace application, using the radio frequency (RF) co-sputtering technique. The presence of metallic silver nanoclusters and silica was confirmed by energy dispersion spectrometry (EDS), x-ray photoelectron spectroscopy (XPS) and localized surface plasmon resonance (LSPR) detected through UV-visible absorption spectrophotometry (UV-Vis). The atomic force microscope (AFM) evidenced the coating morphology. The slight hydrophobicity of both coated and uncoated samples was revealed through the contact angle measurement. The antimicrobial behavior was verified through evaluation of the inhibition halo against several bacterial and fungal species. The coating enhanced the Combitherm{sup Registered-Sign} nano-hardness and its resistance to tensile and perforation tests; the coating wear resistance was measured by abrasion test against Kevlar. A folding procedure on the coated Combitherm{sup Registered-Sign} and storage in air for three months was also carried out without deterioration of the measured properties. The coating deposition did not influence the air permeability of Combitherm{sup Registered-Sign }. -- Highlights: Black-Right-Pointing-Pointer A silver nanocluster silica composite coating was deposited on a polymeric film. Black-Right-Pointing-Pointer A co-sputtering technique was used for the coating deposition. Black-Right-Pointing-Pointer The coating induced an antibacterial effect on the polymer film. Black-Right-Pointing-Pointer The coating improved the nano-hardness and the resistance to tensile and perforation.

  6. Antibacterial action of polyphosphate on Porphyromonas gingivalis.

    Science.gov (United States)

    Moon, Ji-Hoi; Park, Jae-Hong; Lee, Jin-Yong

    2011-02-01

    Polyphosphate [poly(P)] has antibacterial activity against various Gram-positive bacteria. In contrast, Gram-negative bacteria are generally resistant to poly(P). Here, we describe the antibacterial characterization of poly(P) against a Gram-negative periodontopathogen, Porphyromonas gingivalis. The MICs of pyrophosphate (Na(4)P(2)O(7)) and all poly(P) (Na(n + 2)P(n)O(3n + 1); n = 3 to 75) tested for the bacterium by the agar dilution method were 0.24% and 0.06%, respectively. Orthophosphate (Na(2)HPO(4)) failed to inhibit bacterial growth. Poly-P75 was chosen for further study. In liquid medium, 0.03% poly-P75 was bactericidal against P. gingivalis irrespective of the growth phase and inoculum size, ranging from 10(5) to 10(9) cells/ml. UV-visible spectra of the pigments from P. gingivalis grown on blood agar with or without poly-P75 showed that poly-P75 reduced the formation of μ-oxo bisheme by the bacterium. Poly-P75 increased hemin accumulation on the P. gingivalis surface and decreased energy-driven uptake of hemin by the bacterium. The expression of the genes encoding hemagglutinins, gingipains, hemin uptake loci, chromosome replication, and energy production was downregulated, while that of the genes related to iron storage and oxidative stress was upregulated by poly-P75. The transmission electron microscope showed morphologically atypical cells with electron-dense granules and condensed nucleoid in the cytoplasm. Collectively, poly(P) is bactericidal against P. gingivalis, in which hemin/heme utilization is disturbed and oxidative stress is increased by poly(P).

  7. Utilization of Anting-Anting (Acalypha indica) Leaves as Antibacterial

    Science.gov (United States)

    Batubara, Irmanida; Wahyuni, Wulan Tri; Firdaus, Imam

    2016-01-01

    Anting-anting (Acalypha indica) plants is a species of plant having catkin type of inflorescence. This research aims to utilize anting-anting as antibacterial toward Streptococcus mutans and degradation of biofilm on teeth. Anting-anting leaves were extracted by maceration technique using methanol, chloroform, and n-hexane. Antibacterial and biofilm degradation assays were performed using microdilution technique with 96 well. n-Hexane extracts of anting-anting leaves gave the best antibacterial potency with minimum inhibitory concentration and minimum bactericidal concentration value of 500 μg/mL and exhibited good biofilm degradation activity. Fraction of F3 obtained from fractionation of n-hexane's extract with column chromatography was a potential for degradation of biofilm with IC50 value of 56.82 μg/mL. Alkaloid was suggested as antibacterial and degradation of biofilm in the active fraction.

  8. Preparation of Antibacterial Color-Coated Steel Sheets

    Directory of Open Access Journals (Sweden)

    Guoliang Li

    2012-01-01

    Full Text Available A simple method to fabricate antibacterial color-coated steel sheet was presented. The Ag-loaded TiO2 was well dispersed in steel coil coating coupled with some special additives, such as plasticizer, wetting dispersant, and flow agent, and finally became the part of coil coating without any negative influence on the properties of final products. The best process parameters were obtained by substantive trial experiments. Ag-loaded TiO2 with the addition of 2% (w/w in steel coil coating not only improved antibacterial efficiency of the antibacterial color-coated sheet by reaching 99.99%, but also greatly increased the degradation percentage of methyl orange to 88% without decreasing physical properties. The antibacterial color-coated sheets are expected to be used as antimicrobial products in the construction industry considering its low cost and high effectiveness in inhibiting the growth of bacteria.

  9. Study on Microstructure and Nanomechanics Properties of Antibacterial Bone China

    Institute of Scientific and Technical Information of China (English)

    Zhang Zhenyu; Li Hongqi; Zhang Jin; Zhou Hongxiu; Wang Lijuan; Zhang Taihua

    2004-01-01

    Fracture appearance, surface and nanomechanics properties of antibacterial ceramics contairing rare earth phosphate composite antibacterial materials were characterized and measured by SEM, AFM and Nanoindenter, respectively. Results show that grain of fracture surface of antibacterial ceramics grows uniform refinement topography of bubble break-up appears at the surface, which is flat and has liquid character, by adding the phosphate composite containing rare earth, nevertheless needle-like crystal and granular outgrowth form at fracture surface and surface of common ceramics, respectively. Young's modulus of antibacterial ceramic film is 74. 397 GPa and hardness is 8. 134 GPa, which increses by 4.4% and 1.6% comparing with common ceramics, respectively. Loading curves of two kind of ceramics have obvious nonlinear character under 700 nm and linear character between 700 ~ 1000 nm, and unloading curve have obvious linear character.

  10. Antibacterial Constituents of Hainan Morinda citrifolia (Noni) Leaves.

    Science.gov (United States)

    Zhang, Wei-Min; Wang, Wei; Zhang, Jing-Jing; Wang, Zhi-Rong; Wang, Yu; Hao, Wang-Jun; Huang, Wu-Yang

    2016-05-01

    Noni (Morinda citrifolia L.) is an edible and medicinal plant distributed in Hainan, China. The antibacterial activities of the extracts of water (WE), petroleum ether (PEE), ethyl acetate (EAE), chloroform (CE), and n-butanol (BE) were assayed by the disk diffusion method. The results showed that the extracts from Noni leaves possessed antibacterial effects against Bacillus subtilis, Escherichia coli, Proteus vulgaris, and Staphylococcus aureus. Among 5 different extracts, the BE produced the best antibacterial activity. The samples were first extracted by ethanol, and the primary compounds in the BE fraction of ethanol extract was further isolated and identified. Six phenolic compounds, including 5, 15-dimethylmorindol, ferulic acid, p-hydroxycinamic acid, methyl 4-hydroxybenzoate, methyl ferulate, and methyl 4-hydroxycinnamate, were identifiedby NMR. The results indicated that the phenolic compounds might significantly contribute to antibacterial activities of Noni leaves.

  11. Bacterial Histidine Kinases as Novel Antibacterial Drug Targets

    NARCIS (Netherlands)

    Bem, A.E.; Velikova, N.R.; Pellicer, M.T.; Baarlen, van P.; Marina, A.; Wells, J.M.

    2015-01-01

    Bacterial histidine kinases (HKs) are promising targets for novel antibacterials. Bacterial HKs are part of bacterial two-component systems (TCSs), the main signal transduction pathways in bacteria, regulating various processes including virulence, secretion systems and antibiotic resistance. In thi

  12. Antibacterial Coating for Elimination of Pseudomonas aeruginosa and Escherichia coli

    Directory of Open Access Journals (Sweden)

    Zainal Abidin Ali

    2014-01-01

    Full Text Available A polymer antibacterial surface has been successfully developed. The coating system used silane as binder and Ag particles as antibacterial agent. The silver was synthesized using precipitation method. X-ray diffraction (XRD, field emission scanning electron microscopy (FESEM, Brunauer-Emmett-Teller (BET tests, energy-dispersive X-ray spectroscopy (EDX, and X-ray photoelectron spectroscopy (XPS were carried out to evaluate the silver particles. Antibacterial properties of the coating system were tested against gram-negative bacteria, namely, Pseudomonas aeruginosa and Escherichia coli. Different amounts of Ag were used in the coating to optimize its usage. The Japanese International Standard, JISZ2801, was used for bacteria test and the surface developed complies with the standard being antibacterial.

  13. Antibacterial potential of three seagrasses against human pathogens

    Institute of Scientific and Technical Information of China (English)

    Rajasekaran Arumugam; Perumal Anantharaman

    2010-01-01

    Objective:To evaluate the antibacterial activity ofHalophila stipulacea (H. stipulacea), Cymodocea serrulata (C. serrulata) andHalodule pinifolia (H. pinifolia) against seven human bacterial pathogens.Methods:The antibacterial activities of the extracts on the various test organisms using disc diffusion method and Minimum Inhibitory Concentraction(MIC).Results:Methanol and chloroform extracts of all the three seagrasses were active against all the tested pathogens, whereas the hexane extract of seagrasses was not active againstStaphylococcus aureus (S. aureus). Antibacterial activity of three seagrass screened, was in the order ofH. pinifolia >H. stipulacea>C. serrulata.Conclusions: This antibacterial studies can further investigated on seagrasses for purification of bioactive substance and its possible utility in disease control.

  14. Phytochemical constituents and antibacterial activity of some green leafy vegetables

    Institute of Scientific and Technical Information of China (English)

    Ramesa Shafi Bhat; Sooad Al-Daihan

    2014-01-01

    Objective: To investigate the antibacterial activity and photochemicals of five green leafy vegetables against a panel of five bacteria strains. Methods: Disc diffusion method was used to determine the antibacterial activity, while kanamycin was used as a reference antibiotic. The phytochemical screening of the extracts was performed using standard methods. Results:All methanol extracts were found active against all the test bacterial strains. Overall maximum extracts shows antibacterial activity which range from 6 to 15 mm. Proteins and carbohydrates was found in all the green leaves, whereas alkaloid, steroids, saponins, flavonoids, tannins were found in most of the test samples. Conclusions:The obtain result suggests that green leafy vegetables have moderate antibacterial activity and contain various pharmacologically active compounds and thus provide the scientific basis for the traditional uses of the studied vegetables in the treatment of bacterial infections.

  15. Antibacterial effect of Gracilaria verrucosa bioactive on fish pathogenic bacteria

    OpenAIRE

    Maftuch,; Isma Kurniawati; Awaludin Adam; I’ah Zamzami

    2016-01-01

    Gracilaria verrucosa seaweed is a type of seaweed commonly found in water. This study was conducted to investigate the effect of G. verrucosa on fish pathogenic bacteria to support fish farming. The method used in this research was the separation of G. verrucosa fractions using column chromatography. The active antibacterial fraction of G. verrucosa which is obtained from column chromatography indicated fractions containing antibacterial compounds. It was fraction number 3 by using an eluent ...

  16. Emerging trends in the discovery of natural product antibacterials

    DEFF Research Database (Denmark)

    Bologa, Cristian G; Ursu, Oleg; Oprea, Tudor;

    2013-01-01

    mechanisms. Special emphasis is given to the strengths, weaknesses, and opportunities in the natural product antibacterial drug discovery arena, and to emerging applications driven by advances in bioinformatics, chemical biology, and synthetic biology in concert with exploiting bacterial phenotypes....... These efforts have identified a critical mass of natural product antibacterial lead compounds and discovery technologies with high probability of successful implementation against emerging bacterial pathogens....

  17. Evaluation of Antibacterial Effectiveness of Desensitizers against Oral Bacteria

    OpenAIRE

    Duran, Ismet; Sengun, Abdulkadir; Hadimli, Hasan Huseyin; Ulker, Mustafa

    2008-01-01

    Objectives Desensitizers contribute to better clinical results by reducing the rate of cervical dentin sensitivity. However, information on their antibacterial effect is limited. This study examined the antibacterial activities of a triclosan containing (Seal & Protect), a benzalconium containing desensitizer (Micro Prime), a fluoride containing prophilaxy paste (Sultan Desensitizer), two fluoride containing varnishes (Cavity Shealth and Ultra EZ), and a dentin bonding primer (All Bond). Meth...

  18. Antibacterial Activity of Copaiba Oil Gel on Dental Biofilm

    OpenAIRE

    Simões, Cláudia A.C.G.; Conde, Nikeila C. de Oliveira; Venâncio, Gisely N.; Milério, Patrícia S.L.L.; Bandeira, Maria F.C.L.; da Veiga Júnior, Valdir F.

    2016-01-01

    Amazonian biodiversity products that have been used for years in folk medicine, have emerged as feasible and promising alternatives for the inhibition of microorganisms in dental biofilm. Copaiba oil, a phytotherapic agent widely used by the Amazonian populations, is known for its antibacterial, anti-inflammatory, anesthetic, healing and antitumor medicinal properties. Objective: The aim of this study was to evaluate the in vitro antibacterial activity of copaiba oil (Copaifera multijuga) gel...

  19. Graphene Oxide Reinforced Polylactic Acid/Polyurethane Antibacterial Composites

    OpenAIRE

    Xiaoli An; Haibin Ma; Bin Liu; Jizeng Wang

    2013-01-01

    Nanocomposites from PLA/PU containing small concentrations of graphene oxide (GO) were prepared by simple liquid-phase mixing followed by casting. The as-prepared ternary PLA/PU/GO composite films exhibited good antibacterial activity against the gram-positive Staphylococcus aureus and the gram-negative Escherichia coli, due to the excellent antibacterial property of GO sheets with high specific surface area. The addition of GO inhibited the attachment and proliferation of microbes on the fil...

  20. Synthesis and combinational antibacterial study of 5''-modified neomycin.

    Science.gov (United States)

    Zhang, Jianjun; Keller, Katherine; Takemoto, Jon Y; Bensaci, Mekki; Litke, Anthony; Czyryca, Przemyslaw Greg; Chang, Cheng-Wei Tom

    2009-10-01

    A library of 5''-modified neomycin derivatives were synthesized for an antibacterial structure-activity optimization strategy. Two leads exhibited prominent activity against both methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE). Antibacterial activities were measured when combined with other clinically used antibiotics. Significant synergistic activities were observed, which may lead to the development of novel therapeutic practices in the battle against infectious bacteria.

  1. Bioactive behaviour of sol-gel derived antibacterial bioactive glass

    Energy Technology Data Exchange (ETDEWEB)

    Bellantone, M.; Hench, L.L. [Imperial Coll. of Science, Technology and Medicine, London (United Kingdom). Dept. of Materials

    2001-07-01

    A new four-component bioactive glass containing Ag{sub 2}O was produced via the sol-gel process. This system releases Ag{sup +} which is a powerful antibacterial agent. The work reported herein is a comparative study of the bioactivity levels of conventional bioactive glass and of the new antibacterial glass. On the basis of XRD patterns, FTIR spectra, and ICP data, the bioactive behaviour of the two biomaterials is nearly equivalent. (orig.)

  2. Preparation and Properties of Antibacterial Lyocell Fibers Containing Chitosan Derivative

    Institute of Scientific and Technical Information of China (English)

    ZHUANG Xu-pin; LIU Xiao-fei; CHENG Bo-wen; KANG Wei-min

    2006-01-01

    The O-carboxymethyl chitosan sodium salt, NaCMCh, was initially synthesized and analyzed with better antibacterial activity than chitosan. Then NaCMCh was dissolved in the N-methylmorpholine-N- oxide, NMMO, solution with cellulose for spinning of the lyocell fiber. The results showed that the lyocell fibers modified with over 2 wt% NaCMCh has good antibacterial activity in against the E. coli and with NaCMCh content below 6 wt% has considerable mechanical properties.

  3. Endocrine cells producing regulatory peptides.

    Science.gov (United States)

    Solcia, E; Usellini, L; Buffa, R; Rindi, G; Villani, L; Zampatti, C; Silini, E

    1987-07-15

    Recent data on the immunolocalization of regulatory peptides and related propeptide sequences in endocrine cells and tumors of the gastrointestinal tract, pancreas, lung, thyroid, pituitary (ACTH and opioids), adrenals and paraganglia have been revised and discussed. Gastrin, xenopsin, cholecystokinin (CCK), somatostatin, motilin, secretin, GIP (gastric inhibitory polypeptide), neurotensin, glicentin/glucagon-37 and PYY (peptide tyrosine tyrosine) are the main products of gastrointestinal endocrine cells; glucagon, CRF (corticotropin releasing factor), somatostatin, PP (pancreatic polypeptide) and GRF (growth hormone releasing factor), in addition to insulin, are produced in pancreatic islet cells; bombesin-related peptides are the main markers of pulmonary endocrine cells; calcitonin and CGRP (calcitonin gene-related peptide) occur in thyroid and extrathyroid C cells; ACTH and endorphins in anterior and intermediate lobe pituitary cells, alpha-MSH and CLIP (corticotropin-like intermediate lobe peptide) in intermediate lobe cells; met- and leu-enkephalins and related peptides in adrenal medullary and paraganglionic cells as well as in some gut (enterochromaffin) cells; NPY (neuropeptide Y) in adrenaline-type adrenal medullary cells, etc.. Both tissue-appropriate and tissue-inappropriate regulatory peptides are produced by endocrine tumours, with inappropriate peptides mostly produced by malignant tumours.

  4. Endogenous opioid peptides and epilepsy

    NARCIS (Netherlands)

    J. Haffmans (Judith)

    1985-01-01

    textabstractIn recent years a large number of pept:ides, many of which were originall.y characterized in non-neural tissues, have been reported to be present in the central nervous system ( CNS) . The detection of these peptides within the CNS has raised many questions regarding their source and mec

  5. Urinary Peptides in Rett Syndrome.

    Science.gov (United States)

    Solaas, K. M.; Skjeldal, O.; Gardner, M. L. G.; Kase, B. F.; Reichelt, K. L.

    2002-01-01

    A study found a significantly higher level of peptides in the urine of 53 girls with Rett syndrome compared with controls. The elevation was similar to that in 35 girls with infantile autism. Levels of peptides were lower in girls with classic Rett syndrome than those with congenital Rett syndrome. (Contains references.) (Author/CR)

  6. Peptide Antibiotics for ESKAPE Pathogens

    DEFF Research Database (Denmark)

    Thomsen, Thomas Thyge

    and toxicity by utilizing of the fruit fly Drosophila melanogaster as a whole animal model. This was carried out by testing of antimicrobial peptides targeting Gram-positive bacteria exemplified by the important human pathogen methicillin resistant S. aureus (MRSA). The peptide BP214 was developed from...

  7. Biosynthesis of cardiac natriuretic peptides

    DEFF Research Database (Denmark)

    Goetze, Jens Peter

    2010-01-01

    Cardiac-derived peptide hormones were identified more than 25 years ago. An astonishing amount of clinical studies have established cardiac natriuretic peptides and their molecular precursors as useful markers of heart disease. In contrast to the clinical applications, the biogenesis of cardiac...

  8. Synthetic peptides for antibody production

    NARCIS (Netherlands)

    Zegers, N.D.

    1995-01-01

    Synthetic peptides are useful tools for the generation of antibodies. The use of antibodies as specific reagents in inununochemical assays is widely applied. In this chapter, the application of synthetic peptides for the generation of antibodies is described. The different steps that lead to the uni

  9. Antibacterial properties and mechanisms of gold-silver nanocages

    Science.gov (United States)

    Wang, Yulan; Wan, Jiangshan; Miron, Richard J.; Zhao, Yanbin; Zhang, Yufeng

    2016-05-01

    Despite the number of antibiotics used in routine clinical practice, bacterial infections continue to be one of the most important challenges faced in humans. The main concerns arise from the continuing emergence of antibiotic-resistant bacteria and the difficulties faced with the pharmaceutical development of new antibiotics. Thus, advancements in the avenue of novel antibacterial agents are essential. In this study, gold (Au) was combined with silver (Ag), a well-known antibacterial material, to form silver nanoparticles producing a gold-silver alloy structure with hollow interiors and porous walls (gold-silver nanocage). This novel material was promising in antibacterial applications due to its better biocompatibility than Ag nanoparticles, potential in photothermal effects and drug delivery ability. The gold-silver nanocage was then tested for its antibacterial properties and the mechanism involved leading to its antibacterial properties. This study confirms that this novel gold-silver nanocage has broad-spectrum antibacterial properties exerting its effects through the destruction of the cell membrane, production of reactive oxygen species (ROS) and induction of cell apoptosis. Therefore, we introduce a novel gold-silver nanocage that serves as a potential nanocarrier for the future delivery of antibiotics.

  10. Light-activated polymethylmethacrylate nanofibers with antibacterial activity

    Energy Technology Data Exchange (ETDEWEB)

    Elashnikov, Roman [Department of Solid State Engineering, University of Chemistry and Technology, 16628 Prague (Czech Republic); Lyutakov, Oleksiy, E-mail: lyutakoo@vscht.cz [Department of Solid State Engineering, University of Chemistry and Technology, 16628 Prague (Czech Republic); Ulbrich, Pavel [Department of Biochemistry and Microbiology, University of Chemistry and Technology, 16628 Prague (Czech Republic); Svorcik, Vaclav [Department of Solid State Engineering, University of Chemistry and Technology, 16628 Prague (Czech Republic)

    2016-07-01

    The creation of an antibacterial material with triggerable properties enables us to avoid the overuse or misuse of antibacterial substances and, thus, prevent the emergence of resistant bacterial strains. As a potential light-activated antibacterial material, polymethylmethacrylate (PMMA) nanofibers doped with silver nanoparticles (AgNPs) and meso-tetraphenylporphyrin (TPP) were prepared by electrospinning. TPP was chosen as an effectively reactive oxygen species (ROS) producer. Antibacterial tests on Staphylococcus epidermidis (S. epidermidis) and Enterococcus faecalis (E. faecalis) showed the excellent light-triggerable antibacterial activity of the doped materials. Upon light irradiation at the wavelength corresponding to the TPP absorption peak (405 nm), antibacterial activity dramatically increased, mostly due to the release of AgNPs from the polymer matrix. Furthermore, under prolonged light irradiation, the AgNPs/TPP/PMMA nanofibers, displayed enhanced longevity and photothermal stability. Thus, our results suggest that the proposed material is a promising option for the photodynamic inactivation of bacteria. - Highlights: • The novelty of proposed work can be summared as follow: • Silver nanoparticles/meso-tetraphenylporphyrin embedded polymethylmethacrylate nanofibers were obtained for the first time. • Light triggering of PMMA fibers leads to sufficient release of AgNPs or their agglomeration, depending on the light source. • Release of AgNPs leads to appearance of pronounced antimicrobial activity, which can be switched on/off by the illumination.

  11. Antibacterial Activity of Copper and Cobalt Amino Acids Complexes

    Directory of Open Access Journals (Sweden)

    ANDREEA STĂNILĂ

    2011-11-01

    Full Text Available The antibacterial properties of differently copper and cobalt amino acids complexes on agar plates was investigated in the present study. The antibacterial activity of amino acid complexes was evaluated against on three bacteria strains (Escherichia coli, Bacillus cereus, Micrococcus luteus. Generally, the amino acids complexes were mainly active against gram-positive organisms, species like Micrococcus luteus being the most susceptible strain tested. It was registered a moderate antibacterial activity against Bacillus cereus. The microorganisms Escherichia coli, which are already known to be multi-resistant to drugs, were also resistant to the amino acids complexes but also to the free salts tested. Escherichia coli were susceptible only to the CoCl2 and copper complex with phenylalanine. The complexes with leucine and histidine seem to be more active than the parent free ligand against one or more bacterial species. Moderate activity was registered in the case of complexes with methionine and phenylalanine. From the complexes tested less efficient antibacterial activity was noted in the case of complexes with lysine and valine. These results show that cobalt and copper complexes have an antibacterial activity and suggest their potential application as antibacterial agents.

  12. Polyethyleneimine Capped Silver Nanoclusters as Efficient Antibacterial Agents.

    Science.gov (United States)

    Xu, Dong; Wang, Qingyun; Yang, Tao; Cao, Jianzhong; Lin, Qinlu; Yuan, Zhiqin; Li, Le

    2016-03-18

    Development of efficient antibacterial agents is critical for human health. In the present study, we investigated the antibacterial activity of polyethyleneimine (PEI)-capped silver nanoclusters (PEI-AgNCs), based on the fact that nanoclusters normally have higher surface-to-volume ratios than traditional nanomaterials and PEI itself has a strong antimicrobial capacity. We synthesized stable silver nanoclusters by altering PEI molecular weight from 0.6 kDa to 25 kDa and characterized them by UV-Vis absorption and fluorescence spectroscopy and high resolution transmission electron microscopy. The sizes of AgNCs were around 2 nm in diameter and were little influenced by the molecular weight of PEIs. The antibacterial abilities of the four PEI-AgNCs were explored on agar plate and in liquid systems. Our results revealed that the antibacterial activity of PEI-AgNCs is excellent and the reduction of PEI molecular weight could result in the increased antibacterial capacity of PEI-AgNCs. Such proposed new materials might be useful as efficient antibacterial agents in practical clinical applications.

  13. Antibacterial activity of heavy metal-loaded natural zeolite.

    Science.gov (United States)

    Hrenovic, Jasna; Milenkovic, Jelena; Ivankovic, Tomislav; Rajic, Nevenka

    2012-01-30

    The antibacterial activity of natural zeolitized tuffs containing 2.60wt.% Cu(2+), 1.47 Zn(2+) or 0.52 Ni(2+) were tested. Antibacterial activities of the zeolites against Escherichia coli and Staphylococcus aureus were tested after 1h and 24h of exposure to 1g of the zeolite in 100mL of three different media, namely Luria Bertani, synthetic wastewater and secondary effluent wastewater. The antibacterial activities of the zeolites in Luria Bertani medium were significantly lower than those in the other media and negatively correlated with the chemical oxygen demand of the media. The Ni-loaded zeolite showed high leaching of Ni(2+) (3.44-9.13wt.% of the Ni(2+) loaded) and weak antibacterial activity in the effluent water. Since Cu-loaded zeolite did not leach Cu(2+) and the leaching of Zn(2+) from Zn-loaded zeolite was low (1.07-1.61wt.% of the Zn(2+) loaded), the strong antibacterial activity classified the Cu- and Zn-loaded zeolite as promising antibacterial materials for disinfection of secondary effluent water.

  14. Morpho-phenological and Antibacterial Characteristics of Aconitum spp.

    Directory of Open Access Journals (Sweden)

    Yoirentomba Meetei SINAM

    2013-05-01

    Full Text Available Aconitum species have been traditionally used as ethnomedicine to cure various ailments. The present study reveals the morpho-phenology and antibacterial property of alkaloid extracts of the two Aconitum species. The morpho-phenological characteristics will be helpful for determining the resource availability. Aconitum nagarum is erect type, whereas, Aconitum elwesii is a climber. Aconitum elwesii grows in advance of A. nagarum in terms of growth, flowering and senescence. Towards the end of the year, when the fruits have ripened, the parent tuber dies off. As a result, the daughter tuber becomes independent and in the following spring, takes over the function of the parent tuber. Aconitum nagarum and A. elwesii were found to contain 4-5 aconitine equivalent (AE mg/g of alkaloid. These alkaloids showed antibacterial activity against different bacterial species including human pathogens, namely, Staphylococcus aureus, Salmonella typhimurium, Bordetella bronchiseptica, Escherichia coli, Bacillus subtilis, Pseudomonas putida, Pseudomonas fluorescence and Xanthomonas campestris. However, the extent of antibacterial activity varied among different bacterial species. The antibacterial activity against S. aureus, B. bronchiseptica, and B. subtilis was bactericidal in nature, whereas, against other tested bacterial species was bacteriostatic. Efficacy of the antibacterial activity of these alkaloids was evaluated by comparing with that of standard antibiotics. Differential localization of the antibacterial principle was observed among the Aconitum species studied.

  15. In vitro activity of naturally occurring peptides (defensins against Listeria monocytogenes

    Directory of Open Access Journals (Sweden)

    Nascimento Maria da Graça F.

    1994-01-01

    Full Text Available Autoclaved distilled water samples were inoculated with L. monocytogenes strain V7 and strain VPH-1, and incubated aerobically, at 30 C for 48 hours. Each strain was tested individually, and growth curves were determined at 1, 2, 3, 4, 5, 21, 24, and 48 hours. The growth or survival of L. monocytogenes was similar for both strains, with survivors at 24 hour-incubation. The microbicidal activity of one synthetic cationic peptide (NP-2 was examined against L. monocytogenes strain V7, in a water system. Antibacterial activity of NP-2 (1, 5, and 10 g/ml was best expressed at 60 minute-incubation, with 10 g/ml of peptide, at 30 C.

  16. Antimicrobial Activity of Lactoferrin-Related Peptides and Applications in Human and Veterinary Medicine

    Directory of Open Access Journals (Sweden)

    Natascia Bruni

    2016-06-01

    Full Text Available Antimicrobial peptides (AMPs represent a vast array of molecules produced by virtually all living organisms as natural barriers against infection. Among AMP sources, an interesting class regards the food-derived bioactive agents. The whey protein lactoferrin (Lf is an iron-binding glycoprotein that plays a significant role in the innate immune system, and is considered as an important host defense molecule. In search for novel antimicrobial agents, Lf offers a new source with potential pharmaceutical applications. The Lf-derived peptides Lf(1–11, lactoferricin (Lfcin and lactoferrampin exhibit interesting and more potent antimicrobial actions than intact protein. Particularly, Lfcin has demonstrated strong antibacterial, anti-fungal and antiparasitic activity with promising applications both in human and veterinary diseases (from ocular infections to osteo-articular, gastrointestinal and dermatological diseases.

  17. Distinct Signaling Cascades Elicited by Different Formyl Peptide Receptor 2 (FPR2 Agonists

    Directory of Open Access Journals (Sweden)

    Fabio Cattaneo

    2013-04-01

    Full Text Available The formyl peptide receptor 2 (FPR2 is a remarkably versatile transmembrane protein belonging to the G-protein coupled receptor (GPCR family. FPR2 is activated by an array of ligands, which include structurally unrelated lipids and peptide/proteins agonists, resulting in different intracellular responses in a ligand-specific fashion. In addition to the anti-inflammatory lipid, lipoxin A4, several other endogenous agonists also bind FPR2, including serum amyloid A, glucocorticoid-induced annexin 1, urokinase and its receptor, suggesting that the activation of FPR2 may result in potent pro- or anti-inflammatory responses. Other endogenous ligands, also present in biological samples, include resolvins, amyloidogenic proteins, such as beta amyloid (Aβ-42 and prion protein (Prp106–126, the neuroprotective peptide, humanin, antibacterial peptides, annexin 1-derived peptides, chemokine variants, the neuropeptides, vasoactive intestinal peptide (VIP and pituitary adenylate cyclase activating polypeptide (PACAP-27, and mitochondrial peptides. Upon activation, intracellular domains of FPR2 mediate signaling to G-proteins, which trigger several agonist-dependent signal transduction pathways, including activation of phospholipase C (PLC, protein kinase C (PKC isoforms, the phosphoinositide 3-kinase (PI3K/protein kinase B (Akt pathway, the mitogen-activated protein kinase (MAPK pathway, p38MAPK, as well as the phosphorylation of cytosolic tyrosine kinases, tyrosine kinase receptor transactivation, phosphorylation and nuclear translocation of regulatory transcriptional factors, release of calcium and production of oxidants. FPR2 is an attractive therapeutic target, because of its involvement in a range of normal physiological processes and pathological diseases. Here, we review and discuss the most significant findings on the intracellular pathways and on the cross-communication between FPR2 and tyrosine kinase receptors triggered by different FPR2

  18. Peptide-LNA oligonucleotide conjugates

    DEFF Research Database (Denmark)

    Astakhova, I Kira; Hansen, Lykke Haastrup; Vester, Birte

    2013-01-01

    properties, peptides were introduced into oligonucleotides via a 2'-alkyne-2'-amino-LNA scaffold. Derivatives of methionine- and leucine-enkephalins were chosen as model peptides of mixed amino acid content, which were singly and doubly incorporated into LNA/DNA strands using highly efficient copper......Although peptide-oligonucleotide conjugates (POCs) are well-known for nucleic acids delivery and therapy, reports on internal attachment of peptides to oligonucleotides are limited in number. To develop a convenient route for preparation of internally labeled POCs with improved biomedical......(i)-catalyzed azide-alkyne cycloaddition (CuAAC) "click" chemistry. DNA/RNA target binding affinity and selectivity of the resulting POCs were improved in comparison to LNA/DNA mixmers and unmodified DNA controls. This clearly demonstrates that internal attachment of peptides to oligonucleotides can significantly...

  19. 基于人工神经网络的无机抗菌剂抗菌性能预测模型%Predictiong Model of Antibacterial Activities for Inorganic Antibacterial Agents Based on Artificial Neural Networks

    Institute of Scientific and Technical Information of China (English)

    刘雪峰; 张利; 涂铭旌

    2004-01-01

    Quantitatively evaluation of antibacterial activities of inorganic antibacterial agents is an urgent problem to be solved.Using experimental data by an orthogonal design, a prediction model of the relation between conditions of preparing inorganic antibacterial agents and their antibacterial activities has been developed.This is accomplished by introducing BP artificial neural networks in the study of inorganic antibacterial agents.It provides a theoretical support for the development and research on inorganic antibacterial agents.

  20. Purification and use of E. coli peptide deformylase for peptide deprotection in chemoenzymatic peptide synthesis

    NARCIS (Netherlands)

    Di Toma, Claudia; Sonke, Theo; Quaedflieg, Peter J.; Janssen, Dick B.

    2013-01-01

    Peptide deformylases (PDFs) catalyze the removal of the formyl group from the N-terminal methionine residue in nascent polypeptide chains in prokaryotes. Its deformylation activity makes PDF an attractive candidate for the biocatalytic deprotection of formylated peptides that are used in chemoenzyma

  1. Preparation of cellulose fibres with antibacterial Ag-loading nano-SiO2

    Indian Academy of Sciences (India)

    Wang Shuhua; Niu Runlin; Jia Husheng; Wei Liqiao; Daijinming; Liu Xuguang; Xu Bingshe

    2011-07-01

    The antibacterial cellulose fibres with acrylamide polymerization and Ag-loading SiO2 nanoantibacterial materials were successfully prepared. The chemical structures and morphologies of antibacterial cellulose fibres were characterized by Fourier transformation infrared spectrum (FTIR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The results showed that acrylamide was adsorbed on the surface of the cellulose fibres and formed a layer with thickness of 50–100 nm. The nano-SiO2 composite antibacterial materials were combined with cellulose fibres firmly by infiltrating into polyacrylamide layer about 100 nm. The antibacterial cellulose fibres with antibacterial layer owned excellent antibacterial effect.

  2. Antibacterial substance from mucus of a scleractinian coral,Symphyllia gigantea

    Institute of Scientific and Technical Information of China (English)

    CHEN Guohua; HUANG Liangmin; TAN Yehui; YIN Jianqiang; WANG Hankui; HUANG Hui; ZOU Kun; LI Ruiping

    2007-01-01

    Coral mucus covers the surface of coral and contains antibacterial substances as a first line of defense. Coral mucus not only enables the coral itself to resist disease, but also provides antibacterial agents for people. We collected mucus from a scleractinian coral (Symphyllia gigantea) at Sta. Sanya (China), then extracted the antibacterial substances using 10% glacial acetic acid with the help of antiprotease inhibitors, and tested the antibacterial activity by a terrestrial bacterium (Staphylococcus aurevs) and a marine bacterium (Vibrio anguillarum). The result showed that, there were antibacterial agents in the mucus, and their antibacterial activities were lost by treatment of the sample at 90 °C water for 10 min.

  3. Antibacterial and antiviral roles of a fish β-defensin expressed both in pituitary and testis.

    Directory of Open Access Journals (Sweden)

    Jun-Yan Jin

    Full Text Available Defensins are a group of cationic peptides that exhibit broad-spectrum antimicrobial activity. In this study, we cloned and characterized a β-defensin from pituitary cDNA library of a protogynous hermaphroditic orange-spotted grouper (Epinephelus coioides. Interestingly, the β-defensin was shown to be dominantly expressed in pituitary and testis by RT-PCR and Western blot analysis, and its transcript level is significantly upregulated in reproduction organs from intersexual gonad to testis during the natural and artificial sex reversal. Promoter sequence and the responsible activity region analyses revealed the pituitary-specific POU1F1a transcription binding site and testis-specific SRY responsible site, and demonstrated that the pituitary-specific POU1F1a transcription binding site that locates between -180 and -208 bp is the major responsible region of grouper β-defensin promoter activity. Immunofluorescence localization observed its pituicyte expression in pituitary and spermatogonic cell expression in testis. Moreover, both in vitro antibacterial activity assay of the recombinant β-defensin and in vivo embryo microinjection of the β-defensin mRNA were shown to be effective in killing gram-negative bacteria. And, its antiviral role was also demonstrated in EPC cells transfected with the β-defensin construct. Additionally, the antibacterial activity was sensitive to concentrations of Na(+, K(+, Ca(2+ and Mg(2+. The above intriguing findings strongly suggest that the fish β-defensin might play significant roles in both innate immunity defense and reproduction endocrine regulation.

  4. [Comparison of expression and antibacterial activities of recombinant porcine lactoferrin expressed in four Lactobacillus species].

    Science.gov (United States)

    Yu, Hui; Jiang, Yanping; Cui, Wen; Wu, Xiao; He, Jia; Qiao, Xinyuan; Li, Yijing; Tang, Lijie

    2014-09-01

    The coding sequence for the mature peptide of porcine lactoferrin (Plf) was synthesized according to the codon usage of lactobacillus, to establish optimized porcine lactoferrin Lactobacillus expression system. The gene was ligated into the Xho I/BamH I site of Lactobacillus expression vector pPG612.1 and the recombinant plasmid pPG612.1-plf was transformed individually into Lactobacillus casei ATCC393, Lactobacillus pentosus KLDS1.0413, Lactobacillus plantarum KLDS1.0344 or Lactobacillus paracasei KLDS1.0652 by electroporation. After induction with xylose, expression of the recombinant proteins was detected by Western blotting and confocal laser scanning microscopy. Secretion of recombinant Plf proteins from four recombinant species was determined quantitatively by ELISA. The antibacterial activities of recombinant proteins were measured by agar diffusion method. The result shows that Plf was correctly expressed in four species of recombinant lactobacillus, with molecular weight of about 73 kDa. The expression levels in recombinant Lactobacillus casei, Lactobacillus pentosus, Lactobacillus plantarum, Lactobacillus paracasei were 9.6 μg/mL, 10.8 μg/mL, 12.5 μg/mL and 9.9 μg/mL, respectively. Antimicrobial activity experiment shows that the recombinant proteins were active against E. coli, Staphylococcus aureus, Salmonella typhimurium, Listeria, Pasteurella. The recombinant Plf expressed by recombinant Lactobacillus plantarum showed the best antibacterial activity among all recombinant lactobacillus species. These data represent a basis for the development and application of porcine lactoferrin from recombinant lactobacillus.

  5. Thionin-like peptides from Capsicum annuum fruits with high activity against human pathogenic bacteria and yeasts.

    Science.gov (United States)

    Taveira, Gabriel B; Mathias, Luciana S; da Motta, Olney V; Machado, Olga L T; Rodrigues, Rosana; Carvalho, André O; Teixeira-Ferreira, André; Perales, Jonas; Vasconcelos, Ilka M; Gomes, Valdirene M

    2014-01-01

    Plants defend themselves against pathogens with production of antimicrobial peptides (AMPs). Herein we describe the discovery of a new antifungal and antibacterial peptide from fruits of Capsicum annuum that showed similarity to an already well characterized family of plant AMPs, thionins. Other fraction composed of two peptides, in which the major peptide also showed similarity to thionins. Among the obtained fractions, fraction 1, which is composed of a single peptide of 7 kDa, was sequenced by Edman method and its comparative sequence analysis in database (nr) showed similarity to thionin-like peptides. Tests against microorganisms, fraction 1 presented inhibitory activity to the cells of yeast Saccharomyces cerevisiae, Candida albicans, and Candida tropicalis and caused growth reduction to the bacteria species Escherichia coli and Pseudomonas aeruginosa. Fraction 3 caused inhibitory activity only for C. albicans and C. tropicalis. This fraction was composed of two peptides of ∼7 and 10 kDa, and the main protein band correspondent to the 7 kDa peptide, also showed similarity to thionins. This plasma membrane permeabilization assay demonstrates that the peptides present in the fractions 1 and 3 induced changes in the membranes of all yeast strains, leading to their permeabilization. Fraction 1 was capable of inhibiting acidification of the medium of glucose-induced S. cerevisiae cells 78% after an incubation time of 30 min, and opposite result was obtained for C. albicans. Experiments demonstrate that the fraction 1 and 3 were toxic and induced changes in the membranes of all yeast strains, leading to their permeabilization.

  6. Research Progress in Preparation and Mechanism of Antibactrerial Peptids%抗菌肽的制备方法及作用机理研究进展

    Institute of Scientific and Technical Information of China (English)

    赵学良; 史振霞

    2014-01-01

    抗菌肽是外源微生物入侵时生物体产生的小分子肽类,是生物免疫的第一道防线,成为非特异性免疫的重要组成部分,具有广阔的应用前景,在食品、医学、畜牧业、农业等领域被列为重点研究项目之一。本文简要综述了抗菌肽在不同领域中的研究及应用现状。%As a kind of small molecules molecular which produced by the organisms when the exogenous microbial invade the organisms, antibacterial peptide which had wide application prospect. because it It was the first defensive line for the biological immunity , and was an important part of the Non specific immunity. Antibacterial peptide has been one of the key research project in Medicine, Animal husbandry, Agriculture and Food.This research overviewed the research progress and applications of antibacterial peptids in some of the fields.

  7. Chemical Composition and Antibacterial Effects of

    Directory of Open Access Journals (Sweden)

    SS Saei Dehkordi

    2009-10-01

    Full Text Available Introduction & Objective: Rosmarinus officinalis L. as a member of the Lamiaceae family and lysozyme as a natural antibacterial agent is important in food microbiology, because of its characteristics. The aim of the present study was to determine the chemical composition and anti-listerial activity of Rosmarinus officinalis essential oil (REO alone and in combination with lysozyme for enhancement of anti-listerial activity of both substances. Materials & Methods: Rosmarinus officinalis L. was purchased from a local grocery store at Shahrekord and was identified by the Institute of Medicinal Plants, ACECR. The air-dried aerial parts were subjected to hydrodistillation using a Clevenger apparatus to obtain essential oil and yielded oil was analyzed by GC/MS. Antibacterial activity (on basis of Minimum Inhibitory Concentration (MIC of REO was studied separately and in combination with unheated lysozyme (L and heat-treated lysozyme (HTL on Listeria monocytogenes at different pH (5, 6 and 7 by a micro-broth dilution assay. The collected data were analyzed by SPSS software. Results: In the current study, 98.05% of constituents of the essential oil were identified. The major components were α-pinene (14.06%, 1,8-cineole (13.62%, verbenone (11.2%, camphor (10.51%, borneol (7.3%, 3-octanone (7.02%, camphene (5.46% and linalool (5.07%. The inhibitory action of REO was stronger at lower pH especially 5 (MIC=225 μg/mL. Inhibition by L at pH 5 was 640 μg/mL but no inhibition was seen at pH 7. HTL resulted in more effective inhibition than L, especially at pH 5 and heat-treatment 80˚C (MIC: 160 μg/mL. Conclusion: Combination of L + REO and particularly HTL + REO was led to enhancement of bacterial inhibition. It was concluded that REO by the identified chemical composition was effective alone or in combination with L or HTL on Listeria monocytogenes as a food-borne pathogen.

  8. Clinical pharmacokinetics of antibacterial drugs in neonates.

    Science.gov (United States)

    Paap, C M; Nahata, M C

    1990-10-01

    Neonatal patients are surviving longer due to the rapid advances in medical knowledge and technology. Our understanding of the developmental physiology of both preterm and full term neonates has also increased. It is now apparent that differences in body composition and organ function significantly affect the pharmacokinetics of antibacterial drugs in neonates, and dosage modifications are required to optimise antimicrobial therapy. The penicillins and cephalosporins are frequently used in neonates. Although ampicillin has replaced benzylpenicillin (penicillin G) for empirical treatment of neonatal sepsis, many of the other penicillins may be used in neonates for the management of various infections. Increased volume of distribution (Vd) and decreased total body clearance (CL) affect the disposition of penicillins and cephalosporins. Decreased renal clearance (CLR) due to decreased glomerular filtration and tubular secretion is responsible for the decreased CL for most of the beta-lactams. Aminoglycoside Vd is affected by the increased total body water content and extracellular fluid volume of neonates. The increased Vd, in part, accounts for the extended elimination half-life (t1/2) observed in neonates. Aminoglycoside CL is dependent on renal glomerular filtration which is markedly decreased in neonates, especially those preterm. These drugs appear to be less nephrotoxic and ototoxic in neonates than in older patients, and the role of serum concentration monitoring should be limited to specific neonatal patients. Other antibiotics such as vancomycin, teicoplanin, chloramphenicol, rifampicin, erythromycin, clindamycin, metronidazole and cotrimoxazole (trimethoprim plus sulfamethoxazole) may be used in certain clinical situations. The emergence of staphylococcal resistance to penicillins has increased the need for vancomycin. With the exceptions of vancomycin and chloramphenicol, the efficacy and safety of these other agents in neonates have not been established

  9. Potential of phage-displayed peptide library technology to identify functional targeting peptides

    Science.gov (United States)

    Krumpe, Lauren RH; Mori, Toshiyuki

    2010-01-01

    Combinatorial peptide library technology is a valuable resource for drug discovery and development. Several peptide drugs developed through phage-displayed peptide library technology are presently in clinical trials and the authors envision that phage-displayed peptide library technology will assist in the discovery and development of many more. This review attempts to compile and summarize recent literature on targeting peptides developed through peptide library technology, with special emphasis on novel peptides with targeting capacity evaluated in vivo. PMID:20150977

  10. Antibacterial properties of the Vietnamese cajeput oil and ocimum oil in combination with antibacterial agents.

    Science.gov (United States)

    Jedlicková, Z; Mottl, O; Serý, V

    1992-01-01

    Main antibacterially active agents obtained from plants-Cajeput essential oil--1,8 cineol, linalool, alpha-terpineol and terpinen-4-ol, for example from Melalleuce leucadendron (Myrtaceae) as well as essential oil from Ocimum gratissimum (Labiatae) were combined in tests in vitro with selected antibiotics. Above mentioned plant products were found to be effective medicaments for local application in modern medical practice. Combinations with antibiotics potentiated their therapeutical action. On the basis of tests in vitro the synergistic action of these two kinds of medicaments, i.e., preparations traditionally used for a few last decades--antibiotics--might be well applied for therapeutical needs.

  11. Antibacterial properties of a self-cured acrylic resin composed of a polymer coated with a silver-containing organic composite antibacterial agent.

    Science.gov (United States)

    Kiriyama, Takashi; Kuroki, Kenjiro; Sasaki, Keisuke; Tomino, Masahumi; Asakura, Masaki; Kominami, Yoshiko; Takahashi, Yoshihumi; Kawai, Tatsushi

    2013-01-01

    A novel antibacterial polymer, coated with a silver-containing organic composite antibacterial agent, was dispersed in a self-cured acrylic resin. Residual viable cell count of each oral bacterial and fungal species cultivated on acrylic resin specimens containing the antibacterial polymer was significantly decreased when compared to those cultivated on specimens prepared from untreated polymer. A strong inverse correlation was found between the amount of eluted silver ions and the residual viable cell count of all species grown on the antibacterial polymer: the lower the viable cell count, the higher the amount of eluted silver ions. This clearly indicated the antibacterial activity of silver ions. As the content of organic composite antibacterial agent added to the polymer increased from 0.5% to 1.5% in 0.5% increments, amount of eluted silver ions significantly increased with each 0.5% increment to exert greater antibacterial effect.

  12. Antibacterial and anticandidal activity of Tylosema esculentum (marama extracts

    Directory of Open Access Journals (Sweden)

    Amanda Minnaar

    2011-03-01

    . Marama seed coat soluble-esterified fraction (MSCS had closer activity to that of cefsulodin against M. terrae. High amounts of phenolic substances, such as gallic acid, especially in the seed coats, as well as high amounts of phytosterols, lignans, certain fatty acids and peptides (specifically protease inhibitors in the cotyledons contributed to the observed antibacterial and anticandidal activities. Marama extracts, especially phenolic and crude seed coat extracts, had high multi-species antibacterial and anticandidal activities at concentrations comparable to that of some conventional drugs; these extracts have potential use as microbicides.

  13. Improved in vitro evaluation of novel antimicrobials: potential synergy between human plasma and antibacterial peptidomimetics, AMPs and antibiotics against human pathogenic bacteria

    DEFF Research Database (Denmark)

    Citterio, Linda; Franzyk, Henrik; Palarasah, Yaseelan;

    2016-01-01

    Stable peptidomimetics mimicking natural antimicrobial peptides (AMPs) have emerged as a promising class of potential novel antibiotics. In the present study, we aimed at determining whether the antibacterial activity of two α-peptide/β-peptoid peptidomimetics against a range of bacterial pathogens...... was affected by conditions mimicking in vivo settings. Their activity was enhanced to an unexpected degree in the presence of human blood plasma for thirteen pathogenic Gram-positive and Gram-negative bacteria. MIC values typically decreased 2- to 16-fold in the presence of a human plasma concentration...... treatments might be lower than traditionally deduced from MICs determined in laboratory media. Thus, antibiotics previously considered too toxic could be developed into usable last-resort drugs, due to ensuing lowered risk of side effects. In contrast, the activity of the compounds was significantly...

  14. Radiopharmaceutical development of radiolabelled peptides

    Energy Technology Data Exchange (ETDEWEB)

    Fani, Melpomeni; Maecke, Helmut R. [University Hospital Freiburg, Department of Nuclear Medicine, Freiburg (Germany)

    2012-02-15

    Receptor targeting with radiolabelled peptides has become very important in nuclear medicine and oncology in the past few years. The overexpression of many peptide receptors in numerous cancers, compared to their relatively low density in physiological organs, represents the molecular basis for in vivo imaging and targeted radionuclide therapy with radiolabelled peptide-based probes. The prototypes are analogs of somatostatin which are routinely used in the clinic. More recent developments include somatostatin analogs with a broader receptor subtype profile or with antagonistic properties. Many other peptide families such as bombesin, cholecystokinin/gastrin, glucagon-like peptide-1 (GLP-1)/exendin, arginine-glycine-aspartic acid (RGD) etc. have been explored during the last few years and quite a number of potential radiolabelled probes have been derived from them. On the other hand, a variety of strategies and optimized protocols for efficient labelling of peptides with clinically relevant radionuclides such as {sup 99m}Tc, M{sup 3+} radiometals ({sup 111}In, {sup 86/90}Y, {sup 177}Lu, {sup 67/68}Ga), {sup 64/67}Cu, {sup 18}F or radioisotopes of iodine have been developed. The labelling approaches include direct labelling, the use of bifunctional chelators or prosthetic groups. The choice of the labelling approach is driven by the nature and the chemical properties of the radionuclide. Additionally, chemical strategies, including modification of the amino acid sequence and introduction of linkers/spacers with different characteristics, have been explored for the improvement of the overall performance of the radiopeptides, e.g. metabolic stability and pharmacokinetics. Herein, we discuss the development of peptides as radiopharmaceuticals starting from the choice of the labelling method and the conditions to the design and optimization of the peptide probe, as well as some recent developments, focusing on a selected list of peptide families, including somatostatin

  15. Preparation, Characterization and Antibacterial Property of Cerium Substituted Hydroxyapatite Nanoparticles

    Institute of Scientific and Technical Information of China (English)

    Lin Yingguang; Yang Zhuoru; Cheng Jiang

    2007-01-01

    Nanoparticles of hydroxyapatite (HAP) and cerium substituted hydroxyapatite (CeHAP) with the atomic ratio of Ce/[Ca+Ce] (xCe) from 0 to 0.2 were prepared by sol-gel-supercritical fluid drying (SCFD) method. The nanoparticles were characterized by TEM, XRD, and FT-IR, and the effects of cerium on crystal structure, crystallinity, and particle shape were discussed. With the tests of bacterial inhibition zone and antibacterial ratio, the antibacterial property of HAP and CeHAP nanoparticles on Escherichia coli, Staphylococcus aureus, Lactobacillus were researched. Results showed that the nanoparticles of HAP and CeHAP could be made by sol-gel-SCFD, cerium could partially substitute for calcium and enter the structure of HAP. After substitution, the crystallinity, the IR wavenumbers of bonds in CeHAP decreased gradually with increase of cerium substitution, and the morphology of the nanoparticles changed from the short rod-shaped HAP to the needle-shaped CeHAP. The nanoparticles of HAP and CeHAP with xCe below 0.08 had antibacterial property only forcibly contacting with the test bacteria at the test concentration of 0.1 g·ml-1, however, the CeHAP nanoparticles had antibacterial ability at that concentration no matter statically or dynamically contacting with the test bacteria when xCe was above 0.08, and the antibacterial ability gets better with the increase of xCe, indicating that the antibacterial property was improved after calcium was partially substituted by cerium. The improved antibacterial effects of CeHAP nanoparticle on Lactobacillus showed its potential ability to anticaries.

  16. Peptide primary messengers in plants

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The peptide primary messengers regulate embryonic development,cell growth and many other activities in animal cells. But recent evidence verified that peptide primary messengers are also involved in plant defense responses, the recognition between pollen and stigma and keep the balance between cell proliferation and differentiations in shoot apical meristems. Those results suggest that plants may actually make wide use of peptide primary messengers, both in embryonic development and late life when they rally their cells to defend against pathogens and insect pests. The recent advance in those aspects is reviewed.

  17. Next generation natriuretic peptide measurement

    DEFF Research Database (Denmark)

    Hunter, Ingrid; Goetze, Jens P

    2012-01-01

    Plasma measurement of natriuretic peptides is a "must" for clinical laboratories. For the next generation measurement, the unraveling of the molecular complexity of the peptides points toward a more qualitative assessment, as the posttranslational processing also changes with disease. Changes...... in the molecular heterogeneity could in itself contain valuable information of clinical status, and the time seems right for industry and dedicated researchers in the field to get together and discuss the next generation natriuretic peptide measurement. In such an environment, new strategies can be developed...

  18. New vasoactive peptides in cirrhosis

    DEFF Research Database (Denmark)

    Kimer, Nina; Goetze, Jens Peter; Bendtsen, Flemming;

    2014-01-01

    BACKGROUND: Patients with cirrhosis have substantial circulatory imbalance between vasoconstrictive and vasodilating forces. The study of circulatory vasoactive peptides may provide important pathophysiological information. This study aimed to assess concentrations, organ extraction and relations...... to haemodynamic changes in the pro-peptides copeptin, proadrenomedullin and pro-atrial natriuretic peptide (proANP) in patients with cirrhosis. MATERIALS AND METHODS: Fifty-four cirrhotic patients and 15 controls were characterized haemodynamically during a liver vein catheterization. Copeptin, proadrenomedullin...... found no extraction of copeptin, proadrenomedullin or proANP over the liver. Copeptin correlated with portal pressure (R=0·50, P

  19. Targeting the Eph System with Peptides and Peptide Conjugates.

    Science.gov (United States)

    Riedl, Stefan J; Pasquale, Elena B

    2015-01-01

    Eph receptor tyrosine kinases and ephrin ligands constitute an important cell communication system that controls development, tissue homeostasis and many pathological processes. Various Eph receptors/ephrins are present in essentially all cell types and their expression is often dysregulated by injury and disease. Thus, the 14 Eph receptors are attracting increasing attention as a major class of potential drug targets. In particular, agents that bind to the extracellular ephrin-binding pocket of these receptors show promise for medical applications. This pocket comprises a broad and shallow groove surrounded by several flexible loops, which makes peptides particularly suitable to target it with high affinity and selectivity. Accordingly, a number of peptides that bind to Eph receptors with micromolar affinity have been identified using phage display and other approaches. These peptides are generally antagonists that inhibit ephrin binding and Eph receptor/ ephrin signaling, but some are agonists mimicking ephrin-induced Eph receptor activation. Importantly, some of the peptides are exquisitely selective for single Eph receptors. Most identified peptides are linear, but recently the considerable advantages of cyclic scaffolds have been recognized, particularly in light of potential optimization towards drug leads. To date, peptide improvements have yielded derivatives with low nanomolar Eph receptor binding affinity, high resistance to plasma proteases and/or long in vivo half-life, exemplifying the merits of peptides for Eph receptor targeting. Besides their modulation of Eph receptor/ephrin function, peptides can also serve to deliver conjugated imaging and therapeutic agents or various types of nanoparticles to tumors and other diseased tissues presenting target Eph receptors.

  20. Antibacterial Curcuma xanthorrhiza Extract and Fractions

    Directory of Open Access Journals (Sweden)

    Hartiwi Diastuti

    2014-12-01

    Full Text Available An acetone extract of Curcuma xanthorrhiza rhizomes and the nhexane and chloroform fractions obtained from it were tested on eight pathogenic bacteria. The results showed that the acetone extract and the nhexane fraction exhibited significant activities against Bacillus subtilis, Pseudomonas aeruginosa, and Staphylococcus aureus, and weak activities against Shigella dysenteriae and Vibrio cholerae. They were inactive against Escherichia coli, Enterobacter aerogenes and Salmonella thypi, while the chloroform fraction was devoid of activities. NMR analysis disclosed the presence of α-curcumene, xanthorrhizol and an unknown monoterpene in the nhexane fraction. In the chloroform fraction, curcumin was found to be the main compound, together with xanthorrhizol as a minor compound. These results suggest that the antibacterial potency of acetone extract of C. xanthorrhiza is contained in the n-hexane fraction, in which the active constituents are terpenoid compounds. This is the first report of the use of NMR analysis for compound identification contained in an extract or fractions of C. xanthorrhiza.

  1. Antibacterial Effect of Five Zingiberaceae Essential Oils

    Directory of Open Access Journals (Sweden)

    Orapin Kerdchoechuen

    2007-08-01

    Full Text Available Essential oil obtained by hydrodistillation and two different solvent extractions (petroleum ether and ethanol from five Zingiberaceae species: ginger (Zingiber officinale Roscoe., galanga (Alpinia galanga Sw., turmeric (Curcuma longa L., kaempferia (Boesenbergia pandurata Holtt. and bastard cardamom (Amomum xanthioides Wall. was characterized. Volatile components of all extracts were analyzed by gas chromatographymass spectrometry (GC-MS. The major components of ginger, turmeric, galangal, bastard cardamom and kaempferia were zingiberene, turmerone, methyl chavicol, and γ-terpinene, respectively. Their antibacterial effects towards Escherichia coli, Staphylococcus aureus, Bacillus cereus and Listeria monocytogenes were tested by a disc diffusion assay. Essential oil of kaempferia and bastard cardamom obtained by hydrodistillation extraction could inhibit growth of all tested bacteria. Essential oil of ginger extracted by hydrodistillation had the highest efficiency against three positive strains of bacteria (S. aureus, B. cereus and L. monocytogenes, with a minimum concentration to inhibit B. cereus and L. monocytogenes of 6.25 mg/mL.

  2. Antibacterial and Antibiofilm Activities of Makaluvamine Analogs

    Directory of Open Access Journals (Sweden)

    Bhavitavya Nijampatnam

    2014-09-01

    Full Text Available Streptococcus mutans is a key etiological agent in the formation of dental caries. The major virulence factor is its ability to form biofilms. Inhibition of S. mutans biofilms offers therapeutic prospects for the treatment and the prevention of dental caries. In this study, 14 analogs of makaluvamine, a marine alkaloid, were evaluated for their antibacterial activity against S. mutans and for their ability to inhibit S. mutans biofilm formation. All analogs contained the tricyclic pyrroloiminoquinone core of makaluvamines. The structural variations of the analogs are on the amino substituents at the 7-position of the ring and the inclusion of a tosyl group on the pyrrole ring N of the makaluvamine core. The makaluvamine analogs displayed biofilm inhibition with IC50 values ranging from 0.4 μM to 88 μM. Further, the observed bactericidal activity of the majority of the analogs was found to be consistent with the anti-biofilm activity, leading to the conclusion that the anti-biofilm activity of these analogs stems from their ability to kill S. mutans. However, three of the most potent N-tosyl analogs showed biofilm IC50 values at least an order of magnitude lower than that of bactericidal activity, indicating that the biofilm activity of these analogs is more selective and perhaps independent of bactericidal activity.

  3. Antibacterial activity and genotypic-phenotypic characteristics of bacteriocin-producing Bacillus subtilis KKU213: potential as a probiotic strain.

    Science.gov (United States)

    Khochamit, Nalisa; Siripornadulsil, Surasak; Sukon, Peerapol; Siripornadulsil, Wilailak

    2015-01-01

    The antimicrobial activity and probiotic properties of Bacillus subtilis strain KKU213, isolated from local soil, were investigated. The cell-free supernatant (CFS) of a KKU213 culture containing crude bacteriocins exhibited inhibitory effects on Gram-positive bacteria, including Bacillus cereus, Listeria monocytogenes, Micrococcus luteus, and Staphylococcus aureus. The antibacterial activity of the CFS precipitated with 40% ammonium sulfate (AS) remained even after treatment at 60 and 100 °C, at pH 4 and 10 and with proteolytic enzymes, detergents and heavy metals. When analyzed by SDS-PAGE and overlaid with the indicator strains B. cereus and S. aureus, the 40% AS precipitate exhibited inhibitory activity on proteins smaller than 10 kDa. However, proteins larger than 25 kDa and smaller than 10 kDa were still observed on a native protein gel. Purified subtilosin A was prepared by Amberlite XAD-16 bead extraction and HPLC and analyzed by Nano-LC-QTOF-MS. Its molecular mass was found to be 3.4 kDa, and it retained its antibacterial activity. These results are consistent with the detection of the anti-listerial subtilosin A gene of the sbo/alb cluster in the KKU213 strain, which is 100% identical to that of B. subtilis subsp. subtilis 168. In addition to stable and cyclic subtilosin A, a mixture of many extracellular antibacterial peptides was also detected in the KKU213 culture. The KKU213 strain produced extracellular amylase, cellulase, lipase and protease, is highly acid-resistant (pH 2) when cultured in inulin and promotes health and reduces infection of intestinally colonized broiler chickens. Therefore, we propose that bacteriocin-producing B. subtilis KKU213 could be used as a potential probiotic strain or protective culture.

  4. Screening of TACE Peptide Inhibitors from Phage Display Peptide Library

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    To obtain the recombinant tumor necrosis factor-α converting enzyme (TACE) ectodomain and use it as a selective molecule for the screening of TACE peptide inhibitors, the cDNA coding catalytic domain (T800) and full-length ectodomain (T1300) of TACE were amplified by RTPCR, and the expression plasmids were constructed by inserting T800 and T1300 into plasmid pET28a and pET-28c respectively. The recombinant T800 and T1300 were induced by IPTG, and SDSPAGE and Western blotting analysis results revealed that T800 and T1300 were highly expressed in the form of inclusion body. After Ni2+-NTA resin affinity chromatography, the recombinant proteins were used in the screening of TACE-binding peptides from phage display peptide library respectively. After 4 rounds of biopanning, the positive phage clones were analyzed by ELISA, competitive inhibition assay and DNA sequencing. A common amino acid sequence (TRWLVYFSRPYLVAT) was found and synthesized. The synthetic peptide could inhibit the TNF-α release from LPS-stimulated human peripheral blood mononuclear cells (PBMC) up to 60.3 %. FACS analysis revealed that the peptide mediated the accumulation of TNF-α on the cell surface. These results demonstrate that the TACE-binding peptide is an effective antagonist of TACE.

  5. Peptide-Mediated Delivery of Chemical Probes and Therapeutics to Mitochondria.

    Science.gov (United States)

    Jean, Sae Rin; Ahmed, Marya; Lei, Eric K; Wisnovsky, Simon P; Kelley, Shana O

    2016-09-20

    poorly understood mitochondrial DNA repair and replication pathways. In this work, a variety of novel proteins were identified that are essential for the maintenance of mitochondrial nucleic acids. Mitochondria-targeted peptides have also been used to increase the therapeutic window of antibacterial drugs with significant mammalian toxicity. Given the evolutionary similarity of mitochondria and bacteria, peptides are effective transporters that can target both of these entities. These antimicrobial peptides are highly effective even in difficult to target intracellular bacteria which reside within host cells. This peptide-based approach to targeting mitochondria has provided a variety of insights into the "druggability" of mitochondria and new biological processes that could be future drug targets. Nevertheless, the mitochondrial-targeting field is quite nascent and many exciting applications of organelle-specific conjugates remain to be explored. In this Account, we highlight the development and optimization of the mitochondria-penetrating peptides that our laboratory has developed, the unique applications of mitochondria-targeted bioactive cargo, and offer a perspective on important directions for the field.

  6. Antiviral activity of a Bacillus sp. P34 peptide against pathogenic viruses of domestic animals

    Science.gov (United States)

    Silva, Débora Scopel e; de Castro, Clarissa Caetano; Silva, Fábio da Silva e; Sant’anna, Voltaire; Vargas, Gilberto D’Avila; de Lima, Marcelo; Fischer, Geferson; Brandelli, Adriano; da Motta, Amanda de Souza; Hübner, Silvia de Oliveira

    2014-01-01

    P34 is an antimicrobial peptide produced by a Bacillus sp. strain isolated from the intestinal contents of a fish in the Brazilian Amazon basin with reported antibacterial activity. The aim of this work was to evaluate the peptide P34 for its in vitro antiviral properties against canine adenovirus type 2 (CAV-2), canine coronavirus (CCoV), canine distemper virus (CDV), canine parvovirus type 2 (CPV-2), equine arteritis virus (EAV), equine influenza virus (EIV), feline calicivirus (FCV) and feline herpesvirus type 1 (FHV-1). The results showed that the peptide P34 exhibited antiviral activity against EAV and FHV-1. The peptide P34 inhibited the replication of EAV by 99.9% and FHV-1 by 94.4%. Virucidal activity was detected only against EAV. When P34 and EAV were incubated for 6 h at 37 °C the viral titer reduced from 104.5 TCID50 to 102.75 TCID50, showing a percent of inhibition of 98.6%. In conclusion, our results demonstrated that P34 inhibited EAV and FHV-1 replication in infected cell cultures and it showed virucidal activity against EAV. Since there is documented resistance to the current drugs used against herpesviruses and there is no treatment for equine viral arteritis, it is advisable to search for new antiviral compounds to overcome these infections. PMID:25477947

  7. Antiviral activity of a Bacillus sp: P34 peptide against pathogenic viruses of domestic animals

    Directory of Open Access Journals (Sweden)

    Débora Scopel e Silva

    2014-09-01

    Full Text Available P34 is an antimicrobial peptide produced by a Bacillus sp. strain isolated from the intestinal contents of a fish in the Brazilian Amazon basin with reported antibacterial activity. The aim of this work was to evaluate the peptide P34 for its in vitro antiviral properties against canine adenovirus type 2 (CAV-2, canine coronavirus (CCoV, canine distemper virus (CDV, canine parvovirus type 2 (CPV-2, equine arteritis virus (EAV, equine influenza virus (EIV, feline calicivirus (FCV and feline herpesvirus type 1 (FHV-1. The results showed that the peptide P34 exhibited antiviral activity against EAV and FHV-1. The peptide P34 inhibited the replication of EAV by 99.9% and FHV-1 by 94.4%. Virucidal activity was detected only against EAV. When P34 and EAV were incubated for 6 h at 37 °C the viral titer reduced from 10(4.5 TCID50 to 10(2.75 TCID50, showing a percent of inhibition of 98.6%. In conclusion, our results demonstrated that P34 inhibited EAV and FHV-1 replication in infected cell cultures and it showed virucidal activity against EAV. Since there is documented resistance to the current drugs used against herpesviruses and there is no treatment for equine viral arteritis, it is advisable to search for new antiviral compounds to overcome these infections.

  8. Trichoplaxin - a new membrane-active antimicrobial peptide from placozoan cDNA.

    Science.gov (United States)

    Simunić, Juraj; Petrov, Dražen; Bouceba, Tahar; Kamech, Nédia; Benincasa, Monica; Juretić, Davor

    2014-05-01

    A method based on the use of signal peptide sequences from antimicrobial peptide (AMP) precursors was used to mine a placozoa expressed sequence tag database and identified a potential antimicrobial peptide from Trichoplax adhaerens. This peptide, with predicted sequence FFGRLKSVWSAVKHGWKAAKSR is the first AMP from a placozoan species, and was named trichoplaxin. It was chemically synthesized and its structural properties, biological activities and membrane selectivity were investigated. It adopts an α-helical structure in contact with membrane-like environments and is active against both Gram-negative and Gram-positive bacterial species (including MRSA), as well as yeasts from the Candida genus. The cytotoxic activity, as assessed by the haemolytic activity against rat erythrocytes, U937 cell permeabilization to propidium iodide and MCF7 cell mitochondrial activity, is significantly lower than the antimicrobial activity. In tests with membrane models, trichoplaxin shows high affinity for anionic prokaryote-like membranes with good fit in kinetic studies. Conversely, there is a low affinity for neutral eukaryote-like membranes and absence of a dose dependent response. With high selectivity for bacterial cells and no homologous sequence in the UniProt, trichoplaxin is a new potential lead compound for development of broad-spectrum antibacterial drugs.

  9. Viral O-GalNAc peptide epitopes

    DEFF Research Database (Denmark)

    Olofsson, Sigvard; Blixt, Klas Ola; Bergström, Tomas

    2016-01-01

    on a novel three-step procedure that identifies any reactive viral O-glycosyl peptide epitope with respect to (i) relevant peptide sequence, (ii) the reactive glycoform out of several possible glycopeptide isomers of that peptide sequence, and (iii) possibly tolerated carbohydrate or peptide structural...

  10. Fas-associated factor 1 plays a negative regulatory role in the antibacterial immunity of Locusta migratoria.

    Science.gov (United States)

    He, Z; Wang, P; Shi, H; Si, F; Hao, Y; Chen, B

    2013-08-01

    Insect immune responses are precisely regulated to maintain immune balance. In this study, the Fas-associated factor 1 (FAF1) gene of Locusta migratoria manilensis, a homologue of the caspar gene that functions as a specific negative regulator in the antibacterial immunity pathway, was cloned. Gene expression analysis showed that FAF1 was expressed throughout the developmental stages and in all tested tissues, but its transcription levels varied significantly. Thus, FAF1 appears to be tightly regulated and is probably involved in multiple physiological processes. In addition, the antimicrobial peptide gene prolixicin was cloned and characterized. After bacterial challenge, prolixicin was rapidly up-regulated, whereas FAF1 was markedly down-regulated. This result was consistent with the observation that prolixicin was hyperactivated when FAF1 was suppressed by RNA interference. Moreover, after bacterial infection, the survival rate of FAF1-knockdown locusts was much higher than that of the wild-type. Taken together, these findings strongly suggest that FAF1 shares a similar function as caspar in Drosophila and may be involved in the negative regulation of antibacterial immunity in locusts.

  11. Antibacterial activity of TiO2 nanotubes: Influence of crystal phase, morphology and Ag deposition

    Science.gov (United States)

    Li, Huirong; Cui, Qiang; Feng, Bo; Wang, Jianxin; Lu, Xiong; Weng, Jie

    2013-11-01

    TiO2 nanotubes on Ti substrate were fabricated by electrochemical anodization. Ag nanoparticles were deposited on the TiO2 nanotubes by a silver mirror reaction. Antibacterial activity of the nanotubes with different structural features was evaluated by a culture test with Escherichia coli bacteria. The anatase nanotubes showed the highest antibacterial activity among three crystal phases including anatase, rutile and amorphous titania. The diameters of the nanotubes affected the antibacterial activity. The two nanotubes with 200 nm and 50 nm diameters had higher antibacterial rate than those with other diameters. The antibacterial activity of the nanotubes was independent on their lengths. Ag-deposited nanotubes exhibited excellent antibacterial activity and its antibacterial rate was up to approximately 100%. TiO2 nanotubes and Ag-deposited nanotubes on titanium should be potential for antibacterial applications in clinics and industry, especially regarding with their reusability.

  12. Characterization of antibacterial polyethersulfone membranes using the respiration activity monitoring system (RAMOS)

    NARCIS (Netherlands)

    Kochan, J.; Scheidle, M.; Erkel, J. van; Bikel, M.; Büchs, J.; Wong, J.E.; Melin, T.; Wessling, M.

    2012-01-01

    Membranes with antibacterial properties were developed using surface modification of polyethersulfone ultrafiltration membranes. Three different modification strategies using polyelectrolyte layer-by-layer (LbL) technique are described. The first strategy relying on the intrinsic antibacterial prope

  13. Antibacterial characteristics of anthocyanins extracted from wild blueberries against foodborne pathogens

    Science.gov (United States)

    Wild blueberries have rich bioactive compounds, such as polyphenols, phenolics and organic acids. Previous studies demonstrated the antibacterial activity of blueberries against the growth of pathogenic bacteria. The objective of this study was to evaluate the antibacterial characteristics and mech...

  14. Comparative analysis of antibacterial activity of povidone iodine and homoeopathic mother tinctures as antiseptics

    Directory of Open Access Journals (Sweden)

    Muhammad Mohsin Zaman

    2016-01-01

    Conclusion: This study confirms the antibacterial activity and more effectiveness of Thuja occidentalis and Rhus glabra mother tinctures than povidone iodine. The other tested mother tinctures also have antibacterial activity against tested bacteria, except Echinacea.

  15. Neoglycolipidation for modulating peptide properties

    DEFF Research Database (Denmark)

    van Witteloostuijn, Søren Blok

    The alarming increase in the prevalence of obesity and associated comorbidities such as type 2 diabetes emphasizes the urgent need for new drugs with both anorectic and antidiabetic eects. Several peptide hormones secreted from the gastrointestinal tract play an important role in the physiological...... regulation of appetite, food intake, and glucose homeostasis, and many of these peptides display a signicant potential for treatment of obesity and/or type 2 diabetes. This Ph.D. thesis describes three novel approaches for utilizing gut peptides as the starting point for developing obesity and diabetes drugs...... of food intake, which was enhanced compared to native NMU. Project II explored the design, synthesis, and characterization of neoglycolipidated analogs of glucagon-like peptide 1 (GLP-1). Neoglycolipidation reduced lipophilicity and maintained or even improved in vitro potency towards the GLP-1 receptor...

  16. Study of antibacterial mechanism of graphene oxide using Raman spectroscopy

    Science.gov (United States)

    Nanda, Sitansu Sekhar; Yi, Dong Kee; Kim, Kwangmeyung

    2016-01-01

    Graphene oxide (GO) is extensively proposed as an effective antibacterial agent in commercial product packaging and for various biomedical applications. However, the antibacterial mode of action of GO is yet hypothetical and unclear. Here we developed a new and sensitive fingerprint approach to study the antibacterial activity of GO and underlying mechanism, using Raman spectroscopy. Spectroscopic signatures obtained from biomolecules such as Adenine and proteins from bacterial cultures with different concentrations of GO, allowed us to probe the antibacterial activity of GO with its mechanism at the molecular level. Escherichia coli (E. coli) and Enterococcus faecalis (E. faecalis) were used as model micro-organisms for all the experiments performed. The observation of higher intensity Raman peaks from Adenine and proteins in GO treated E. coli and E. faecalis; correlated with induced death, confirmed by Scanning electron Microscopy (SEM) and Biological Atomic Force Microscopy (Bio-AFM). Our findings open the way for future investigations of the antibacterial properties of different nanomaterial/GO composites using Raman spectroscopy. PMID:27324288

  17. Acylated flavonol glycosides from Tagetes minuta with antibacterial activity

    Directory of Open Access Journals (Sweden)

    Irum eShahzadi

    2015-09-01

    Full Text Available Wild marigold (Tagetes minuta, a flowering plant of the family Asteraceae contains compounds of pharmaceutical and nutritional importance especially essential oils and flavonols. Identification, characterization of flavonols and determination of their antibacterial activity were major objectives of the current study. The isolation and purification of flavonols was accomplished using chromatographic techniques while structural elucidation was completed by LC-MS and NMR spectroscopy. The extracts and purified compounds were tested against various bacterial strains for antibacterial activity. A total of nineteen flavonols were isolated from this species. Of these, seventeen were of butanol and two of ethyl acetate extracts. Based on the concentration and purity, eight potential flavonols were selected and structurally elucidated. Four flavonols, 6-hydroxyquercetin 7-O-β-(6''-galloylglucopyranoside (2, 6-hydroxykaempferol 7-O-β-glucopyranoside (5, 6-hydroxykaempferol 7-O-β-(6''-galloylglucopyranoside (7, 6-hydroxyquercetin 7-O-β-(6''-caffeoylglucopyranoside (9, were identified for the first time from T. minuta. Butanol and ethyl acetate extracts of flowers and seeds showed significant antibacterial activity against Micrococcus leteus, Staphylococcus aureus, Bacillus subtilis and Pseudomonas piket. Among the isolated flavonols only 1, 2 and 18 were found to possess significant antibacterial activity against M. luteus. The extracts and purified flavonols from T. minuta can be potential candidates for antibacterial drug discovery and support to ethnopharmacological use.

  18. Antibacterial polyelectrolyte-coated Mg alloys for biomedical applications

    Science.gov (United States)

    Seraz, Md. S.; Asmatulu, R.; Chen, Z.; Ceylan, M.; Mahapatro, A.; Yang, S. Y.

    2014-04-01

    This study deals with two biomedical subjects: corrosion rates of polyelectrolyte-coated magnesium (Mg) alloys, mainly used for biomedical purposes, and antibacterial properties of these alloys. Thin sheets of Mg alloys were coated with cationic polyelectrolyte chitosan (CHI) and anionic polyelectrolyte carboxymethyl cellulose (CMC) using a layer-by-layer coating method and then embedded with antibacterial agents under vacuum. Electrochemical impedance spectroscopy was employed to analyze these samples in order to detect their corrosion properties at different conditions. In the electrochemical analysis section, a corrosion rate of 72 mille inches per year was found in a salt solution for the sample coated with a 12 phosphonic acid self-assembled monolayer and 9 CHI/CMC multilayers. In the antibacterial tests, gentamicin was used to investigate the effects of the drug embedded with the coated surfaces against the Escherichia coli (E. coli) bacteria. Antibacterial studies were tested using the disk diffusion method. Based on the standard diameter of the zone of inhibition chart, the antibacterial diffusion from the surface strongly inhibited bacterial growth in the regions. The largest recorded diameter of the zone of inhibition was 50 mm for the pre-UV treated and gentamicin-loaded sample, which is more than three times the standard diameter.

  19. Study of antibacterial mechanism of graphene oxide using Raman spectroscopy

    Science.gov (United States)

    Nanda, Sitansu Sekhar; Yi, Dong Kee; Kim, Kwangmeyung

    2016-06-01

    Graphene oxide (GO) is extensively proposed as an effective antibacterial agent in commercial product packaging and for various biomedical applications. However, the antibacterial mode of action of GO is yet hypothetical and unclear. Here we developed a new and sensitive fingerprint approach to study the antibacterial activity of GO and underlying mechanism, using Raman spectroscopy. Spectroscopic signatures obtained from biomolecules such as Adenine and proteins from bacterial cultures with different concentrations of GO, allowed us to probe the antibacterial activity of GO with its mechanism at the molecular level. Escherichia coli (E. coli) and Enterococcus faecalis (E. faecalis) were used as model micro-organisms for all the experiments performed. The observation of higher intensity Raman peaks from Adenine and proteins in GO treated E. coli and E. faecalis; correlated with induced death, confirmed by Scanning electron Microscopy (SEM) and Biological Atomic Force Microscopy (Bio-AFM). Our findings open the way for future investigations of the antibacterial properties of different nanomaterial/GO composites using Raman spectroscopy.

  20. Antibacterial activity of graphene supported FeAg bimetallic nanocomposites.

    Science.gov (United States)

    Ahmad, Ayyaz; Qureshi, Abdul Sattar; Li, Li; Bao, Jie; Jia, Xin; Xu, Yisheng; Guo, Xuhong

    2016-07-01

    We report the simple one pot synthesis of iron-silver (FeAg) bimetallic nanoparticles with different compositions on graphene support. The nanoparticles are well dispersed on the graphene sheet as revealed by the TEM, XRD, and Raman spectra. The antibacterial activity of graphene-FeAg nanocomposite (NC) towards Bacillus subtilis, Escherichia coli, and Staphylococcus aureus was investigated by colony counting method. Graphene-FeAg NC demonstrates excellent antibacterial activity as compared to FeAg bimetallic without graphene. To understand the antibacterial mechanism of the NC, oxidative stress caused by reactive oxygen species (ROS) and the glutathione (GSH) oxidation were investigated in the system. It has been observed that ROS production and GSH oxidation are concentration dependent while the increase in silver content up to 50% generally enhances the ROS production while ROS decreases on further increase in silver content. Graphene loaded FeAg NC demonstrates higher GSH oxidation capacity than bare FeAg bimetallic nanocomposite. The mechanism study suggests that the antibacterial activity is probably due to membrane and oxidative stress produced by the nanocomposites. The possible antibacterial pathway mainly includes the non-ROS oxidative stress (GSH oxidation) while ROS play minor role.