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Sample records for antibacterial peptide fallaxin

  1. 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...... 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...... 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...

  2. 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.

  3. [Distiller Yeasts Producing Antibacterial Peptides].

    Science.gov (United States)

    Klyachko, E V; Morozkina, E V; Zaitchik, B Ts; Benevolensky, S V

    2015-01-01

    A new method of controlling lactic acid bacteria contamination was developed with the use of recombinant Saccharomyces cerevisiae strains producing antibacterial peptides. Genes encoding the antibacterial peptides pediocin and plantaricin with codons preferable for S. cerevisiae were synthesized, and a system was constructed for their secretory expression. Recombinant S. cerevisiae strains producing antibacterial peptides effectively inhibit the growth of Lactobacillus sakei, Pediacoccus pentasaceus, Pediacoccus acidilactici, etc. The application of distiller yeasts producing antibacterial peptides enhances the ethanol yield in cases of bacterial contamination. Recombinant yeasts producing the antibacterial peptides pediocin and plantaricin can successfully substitute the available industrial yeast strains upon ethanol production.

  4. 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.

  5. 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.

  6. [Cloning, prokaryotic expression and antibacterial assay of Tenecin gene encoding an antibacterial peptide from Tenebrio molitor].

    Science.gov (United States)

    Liu, Ying; Jiang, Yu-xin; Li, Chao-pin

    2011-12-01

    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. The antibacterial peptide was induced from the larvae of Tenebrio molitor by intraperitoneal injection of Escherichia coli DH-5α (1×10(8)/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(+)-Tenecin was constructed and transformed into E. coli BL21(DE3) cells and the expression of tenecin protein was observed after IPTG induction. 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. 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.

  7. Designing Antibacterial Peptides with Enhanced Killing Kinetics

    Directory of Open Access Journals (Sweden)

    Faiza H. Waghu

    2018-02-01

    Full Text Available Antimicrobial peptides (AMPs are gaining attention as substitutes for antibiotics in order to combat the risk posed by multi-drug resistant pathogens. Several research groups are engaged in design of potent anti-infective agents using natural AMPs as templates. In this study, a library of peptides with high sequence similarity to Myeloid Antimicrobial Peptide (MAP family were screened using popular online prediction algorithms. These peptide variants were designed in a manner to retain the conserved residues within the MAP family. The prediction algorithms were found to effectively classify peptides based on their antimicrobial nature. In order to improve the activity of the identified peptides, molecular dynamics (MD simulations, using bilayer and micellar systems could be used to design and predict effect of residue substitution on membranes of microbial and mammalian cells. The inference from MD simulation studies well corroborated with the wet-lab observations indicating that MD-guided rational design could lead to discovery of potent AMPs. The effect of the residue substitution on membrane activity was studied in greater detail using killing kinetic analysis. Killing kinetics studies on Gram-positive, negative and human erythrocytes indicated that a single residue change has a drastic effect on the potency of AMPs. An interesting outcome was a switch from monophasic to biphasic death rate constant of Staphylococcus aureus due to a single residue mutation in the peptide.

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

    DEFF Research Database (Denmark)

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

    2016-01-01

    . In the present study we show that antimicrobial peptides (AMPs) with an intracellular mode of action can be efficient vehicles for bacterial delivery of an antibacterial PNA targeting the essential acpP gene. The results demonstrate that buforin 2-A (BF2-A), drosocin, oncocin 10, Pep-1-K, KLW-9,13-a, (P59→W59...

  9. Antibacterial activity in bovine lactoferrin-derived peptides.

    Science.gov (United States)

    Hoek, K S; Milne, J M; Grieve, P A; Dionysius, D A; Smith, R

    1997-01-01

    Several peptides sharing high sequence homology with lactoferricin B (Lf-cin B) were generated from bovine lactoferrin (Lf) with recombinant chymosin. Two peptides were copurified, one identical to Lf-cin B and another differing from Lf-cin B by the inclusion of a C-terminal alanine (lactoferricin). Two other peptides were copurified from chymosin-hydrolyzed Lf, one differing from Lf-cin B by the inclusion of C-terminal alanyl-leucine and the other being a heterodimer linked by a disulfide bond. These peptides were isolated in a single step from chymosin-hydrolyzed Lf by membrane ion-exchange chromatography and were purified by reverse-phase high-pressure liquid chromatography (HPLC). They were characterized by N-terminal Edman sequencing, mass spectrometry, and antibacterial activity determination. Pure lactoferricin, prepared from pepsin-hydrolyzed Lf, was purified by standard chromatography techniques. This peptide was analyzed against a number of gram-positive and gram-negative bacteria before and after reduction of its disulfide bond or cleavage after its single methionine residue and was found to inhibit the growth of all the test bacteria at a concentration of 8 microM or less. Subfragments of lactoferricin were isolated from reduced and cleaved peptide by reverse-phase HPLC. Subfragment 1 (residues 1 to 10) was active against most of the test microorganisms at concentrations of 10 to 50 microM. Subfragment 2 (residues 11 to 26) was active against only a few microorganisms at concentrations up to 100 microM. These antibacterial studies indicate that the activity of lactoferricin is mainly, but not wholly, due to its N-terminal region. PMID:8980754

  10. Plasmin digest of κ-casein as a source of antibacterial peptides.

    Science.gov (United States)

    Sedaghati, Marjaneh; Ezzatpanah, Hamid; Boojar, Masoud Mashhadi Akbar; Ebrahimi, Maryam Tajabadi; Aminafshar, Mehdi

    2014-05-01

    This study investigated the antibacterial properties of plasmin, the plasmin hydrolysis of bovine κ-casein and the fractions (named κC1, κC2, κC3, κC4, and κC5) liberated from it using RP-HPLC. The target bacteria were Escherichia coli, Staphylococcus aureus (pathogenic), Lactobacillus casei and Lactobacillus acidophilus (probiotic). Three peptides (kC1, kC3, and kC4) were found to have antibacterial activity, with κC3 peptide being the most active. The plasmin digest of bovine κ-casein proved to be stronger than any of its fractions in terms of antibacterial potential. Measurement of the minimum inhibitory concentration (MIC) showed that Gram-positive bacteria are generally more sensitive to antibacterial activity than Gram-negative bacteria. The MIC of nisin, as a bacteriocin peptide, was also measured. The three antibacterial peptides were identified using LC-Mass. The molecular mass of kC1, kC3, and kC4 corresponded to the f(17-21), f(22-24), and f(1-3) of bovine κ-casein, respectively. It was also found that the positive charge and hydrophobicity of a peptide are not key factors in antibacterial activity. On the whole, the present study demonstrated that the plasmin digest of κ-casein has a high antibacterial potential and can be considered as a natural antibacterial agent in the food chain.

  11. New Potent Membrane-Targeting Antibacterial Peptides from Viral Capsid Proteins

    Science.gov (United States)

    Dias, Susana A.; Freire, João M.; Pérez-Peinado, Clara; Domingues, Marco M.; Gaspar, Diana; Vale, Nuno; Gomes, Paula; Andreu, David; Henriques, Sónia T.; Castanho, Miguel A. R. B.; Veiga, Ana S.

    2017-01-01

    The increasing prevalence of multidrug-resistant bacteria urges the development of new antibacterial agents. With a broad spectrum activity, antimicrobial peptides have been considered potential antibacterial drug leads. Using bioinformatic tools we have previously shown that viral structural proteins are a rich source for new bioactive peptide sequences, namely antimicrobial and cell-penetrating peptides. Here, we test the efficacy and mechanism of action of the most promising peptides among those previously identified against both Gram-positive and Gram-negative bacteria. Two cell-penetrating peptides, vCPP 0769 and vCPP 2319, have high antibacterial activity against Staphylococcus aureus, MRSA, Escherichia coli, and Pseudomonas aeruginosa, being thus multifunctional. The antibacterial mechanism of action of the two most active viral protein-derived peptides, vAMP 059 and vCPP 2319, was studied in detail. Both peptides act on both Gram-positive S. aureus and Gram-negative P. aeruginosa, with bacterial cell death occurring within minutes. Also, these peptides cause bacterial membrane permeabilization and damage of the bacterial envelope of P. aeruginosa cells. Overall, the results show that structural viral proteins are an abundant source for membrane-active peptides sequences with strong antibacterial properties. PMID:28522994

  12. Co-expression of apoptin (VP3) and antibacterial peptide cecropin B ...

    African Journals Online (AJOL)

    The antibacterial peptide cecropin B mutant (ABPS1) gene has a broad range of antibacterial and antiproliferative properties. Apoptin (VP3), a chicken anaemia virus-encoded protein is known to induce apoptosis in human transformed cells. To explore drug combination in human tumor cells, apoptin and ABPS1 eukaryotic ...

  13. Efficacy of antibacterial peptides against peptide-resistant MRSA is restored by permeabilisation of bacteria membranes

    Directory of Open Access Journals (Sweden)

    Joshua Thomas Ravensdale

    2016-11-01

    Full Text Available Clinical application of antimicrobial peptides, as with conventional antibiotics, may be compromised by the development of bacterial resistance. This study investigated antimicrobial peptide resistance in methicillin resistant Staphylococcus aureus, including aspects related to the resilience of the resistant bacteria towards the peptides, the stability of resistance when selection pressures are removed, and whether resistance can be overcome by using the peptides with other membrane-permeabilising agents. Genotypically variant strains of S. aureus became equally resistant to the antibacterial peptides melittin and bac8c when grown in sub-lethal concentrations. Subculture of a melittin-resistant strain without melittin for 8 days lowered the minimal lethal concentration of the peptide from 170 µg ml-1 to 30 g ml-1. Growth for 24 h in 12 g ml-1 melittin restored the MLC to 100 g ml-1. Flow cytometry analysis of cationic fluorophore binding to melittin-naïve and melittin-resistant bacteria revealed that resistance coincided with decreased binding of cationic molecules, suggesting a reduction in nett negative charge on the membrane. Melittin was haemolytic at low concentrations but the truncated analogue of melittin, mel12-26, was confirmed to lack haemolytic activity. Although a previous report found that mel12-26 retained full bactericidal activity, we found it to lack significant activity when added to culture medium. However, electroporation in the presence of 50 µg ml-1 of mel12-26, killed 99.3% of the bacteria. Similarly, using a low concentration of the non-ionic detergent Triton X-100 to permeabilize bacteria to mel12-26 markedly increased its bactericidal activity. The observation that bactericidal activity of the non-membranolytic peptide mel12-26 was enhanced when the bacterial membrane was permeablised by detergents or electroporation, suggests that its principal mechanism in reducing bacterial survival may be through

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

    NARCIS (Netherlands)

    Molhoek, E.M.; Dijk, A. van; Veldhuizen, E.J.A.; Dijk-Knijnenburg, H.; Mars-Groenendijk, R.H.; Boele, L.C.L.; Kaman-van Zanten, 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

  15. Generation of Hybrid Peptide-Silver Nanoparticles for Antibacterial and Antifouling Applications

    KAUST Repository

    Seferji, Kholoud

    2018-01-01

    and antifouling agents. Our innovative antibacterial agents are hybrid peptide silver nanoparticles (CH-01-AgNPs) that are created de novo and in situ from a silver nitrate solution (AgNO3) in the presence of ultrashort self-assembling peptides compounds

  16. Hydroxamic acid derivatives as potent peptide deformylase inhibitors and antibacterial agents.

    Science.gov (United States)

    Apfel, C; Banner, D W; Bur, D; Dietz, M; Hirata, T; Hubschwerlen, C; Locher, H; Page, M G; Pirson, W; Rossé, G; Specklin, J L

    2000-06-15

    Low-molecular-weight beta-sulfonyl- and beta-sulfinylhydroxamic acid derivatives have been synthesized and found to be potent inhibitors of Escherichia coli peptide deformylase (PDF). Most of the compounds synthesized and tested displayed antibacterial activities that cover several pathogens found in respiratory tract infections, including Chlamydia pneumoniae, Mycoplasma pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. The potential of these compounds as antibacterial agents is discussed with respect to selectivity, intracellular concentrations in bacteria, and potential for resistance development.

  17. 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.

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

    OpenAIRE

    Barbosa Pelegrini, Patrícia; del Sarto, Rafael Perseghini; Silva, Osmar Nascimento; Franco, Octávio Luiz; Grossi-de-Sa, Maria Fátima

    2011-01-01

    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 evid...

  19. Structure-function characterization and optimization of a plant-derived antibacterial peptide.

    Science.gov (United States)

    Suarez, Mougli; Haenni, Marisa; Canarelli, Stéphane; Fisch, Florian; Chodanowski, Pierre; Servis, Catherine; Michielin, Olivier; Freitag, Ruth; Moreillon, Philippe; Mermod, Nicolas

    2005-09-01

    Crushed seeds of the Moringa oleifera tree have been used traditionally as natural flocculants to clarify drinking water. We previously showed that one of the seed peptides mediates both the sedimentation of suspended particles such as bacterial cells and a direct bactericidal activity, raising the possibility that the two activities might be related. In this study, the conformational modeling of the peptide was coupled to a functional analysis of synthetic derivatives. This indicated that partly overlapping structural determinants mediate the sedimentation and antibacterial activities. Sedimentation requires a positively charged, glutamine-rich portion of the peptide that aggregates bacterial cells. The bactericidal activity was localized to a sequence prone to form a helix-loop-helix structural motif. Amino acid substitution showed that the bactericidal activity requires hydrophobic proline residues within the protruding loop. Vital dye staining indicated that treatment with peptides containing this motif results in bacterial membrane damage. Assembly of multiple copies of this structural motif into a branched peptide enhanced antibacterial activity, since low concentrations effectively kill bacteria such as Pseudomonas aeruginosa and Streptococcus pyogenes without displaying a toxic effect on human red blood cells. This study thus identifies a synthetic peptide with potent antibacterial activity against specific human pathogens. It also suggests partly distinct molecular mechanisms for each activity. Sedimentation may result from coupled flocculation and coagulation effects, while the bactericidal activity would require bacterial membrane destabilization by a hydrophobic loop.

  20. Generation of Hybrid Peptide-Silver Nanoparticles for Antibacterial and Antifouling Applications

    KAUST Repository

    Seferji, Kholoud

    2018-05-01

    An alarming increase of antibiotic-resistant bacterial strains has made the demand for novel antibacterial agents, for example, more effective antibiotics, highly crucial. One of the oldest antimicrobial agents is elementary silver which has been used for thousands of years. Even in our days, elementary silver is used for medical purposes, such as for burns, wounds, and microbial infections. We have taken the effectiveness of elementary silver into consideration to generate novel antibacterial and antifouling agents. Our innovative antibacterial agents are hybrid peptide silver nanoparticles (CH-01-AgNPs) that are created de novo and in situ from a silver nitrate solution (AgNO3) in the presence of ultrashort self-assembling peptides compounds. The nucleation of CH-01-AgNPs is initiated by irradiating the peptide solution mixed with the AgNO3 solution using ultraviolet (UV) light at a wavelength of 254 nm, in the absence of any reducing or capping agents. Obviously, the peptide itself serves as the reducing agent. The ultrashort peptides are four amino acids in length with an innate ability to self-assemble into nanofibrous scaffolds. Using these ultrashort peptides CH-01 we were able to create hybrid peptide silver nanoparticles CH-01-AgNPs with a diameter of 4-6 nm. The synthesized CH-01-AgNPs were further characterized using ultraviolet-visible spectroscopy, transmission electron microscopy, dynamic light scattering, and X-ray photoelectron spectroscopy. The antibacterial and antifouling activity of CH-01-AgNPs were then investigated using either gram-negative bacteria, such as antibiotic-resistant Top10 Escherichia coli and Pseudomonas aeruginosa PDO300, or gram-positive bacteria, such as Staphylococcus aureus CECT 976. The hybrid nanoparticles demonstrated very promising antibacterial and antifouling activity with higher antibacterial and antifouling activity as commercial silver nanoparticles. Quantitative Polymerase Chain Reaction (qPCR) results showed

  1. 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.

  2. Optimization of antibacterial peptides by genetic algorithms and cheminformatics

    DEFF Research Database (Denmark)

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

    2011-01-01

    Pathogens resistant to available drug therapies are a pressing global health problem. Short, cationic peptides represent a novel class of agents that have lower rates of drug resistance than derivatives of current antibiotics. Previously, we created a software system utilizing artificial neural...... 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...

  3. Enterocin X, a novel two-peptide bacteriocin from Enterococcus faecium KU-B5, has an antibacterial spectrum entirely different from those of its component peptides.

    Science.gov (United States)

    Hu, Chih-Bo; Malaphan, Wanna; Zendo, Takeshi; Nakayama, Jiro; Sonomoto, Kenji

    2010-07-01

    Enterocin X, composed of two antibacterial peptides (Xalpha and Xbeta), is a novel class IIb bacteriocin from Enterococcus faecium KU-B5. When combined, Xalpha and Xbeta display variably enhanced or reduced antibacterial activity toward a panel of indicators compared to each peptide individually. In E. faecium strains that produce enterocins A and B, such as KU-B5, only one additional bacteriocin had previously been known.

  4. Collagencin, an antibacterial peptide from fish collagen: Activity, structure and interaction dynamics with membrane

    International Nuclear Information System (INIS)

    Ennaas, Nadia; Hammami, Riadh; Gomaa, Ahmed; Bédard, François; Biron, Éric; Subirade, Muriel; Beaulieu, Lucie; Fliss, Ismail

    2016-01-01

    In this study, we first report characterization of collagencin, an antimicrobial peptide identified from fish collagen hydrolysate. The peptide completely inhibited the growth of Staphylococcus aureus at 1.88 mM. Although non-toxic up to 470 μM, collagencin was hemolytic at higher concentrations. The secondary structure of collagencin was mainly composed by β-sheet and β-turn as determined by CD measurements and molecular dynamics. The peptide is likely to form β-sheet structure under hydrophobic environments and interacts with both anionic (phosphatidylglycerol) and zwitterionic (phosphoethanolamine and phosphatidylcholine) lipids as shown with CD spectroscopy and molecular dynamics. The peptide formed several hydrogen bonds with both POPG and POPE lipids and remained at membrane–water interface, suggesting that collagencin antibacterial action follows a carpet mechanism. Collagenous fish wastes could be processed by enzymatic hydrolysis and transformed into products of high value having functional or biological properties. Marine collagens are a promising source of antimicrobial peptides with new implications in food safety and human health. - Highlights: • Collagencin, an antibacterial (G+ & G-) peptide identified from fish collagen hydrolysate. • The peptide completely inhibited the growth of S. aureus at 1.88 mM and non-toxic at 470 μM. • The secondary structure was mainly composed by β-sheet and turn as determined by CD and MD. • Collagencin interacts with both anionic and zwitterionic lipids as shown with CD and MD. • Collagencin antibacterial action probably follows a carpet mechanism.

  5. Collagencin, an antibacterial peptide from fish collagen: Activity, structure and interaction dynamics with membrane

    Energy Technology Data Exchange (ETDEWEB)

    Ennaas, Nadia [STELA Dairy Research Centre, Institute of Nutrition and Functional Foods, Université Laval, G1V 0A6 Québec, QC (Canada); Hammami, Riadh, E-mail: riadh.hammami@fsaa.ulaval.ca [STELA Dairy Research Centre, Institute of Nutrition and Functional Foods, Université Laval, G1V 0A6 Québec, QC (Canada); Gomaa, Ahmed [STELA Dairy Research Centre, Institute of Nutrition and Functional Foods, Université Laval, G1V 0A6 Québec, QC (Canada); Bédard, François; Biron, Éric [Faculty of Pharmacy, Université Laval and Laboratory of Medicinal Chemistry, CHU de Québec Research Centre, G1V 4G2 Québec, QC (Canada); Subirade, Muriel [STELA Dairy Research Centre, Institute of Nutrition and Functional Foods, Université Laval, G1V 0A6 Québec, QC (Canada); Beaulieu, Lucie, E-mail: lucie.beaulieu@fsaa.ulaval.ca [STELA Dairy Research Centre, Institute of Nutrition and Functional Foods, Université Laval, G1V 0A6 Québec, QC (Canada); Department of Biology, Chemistry and Geography, Université du Québec à Rimouski (UQAR), 300 Allée des Ursulines, Rimouski, QC G5L 3A1 (Canada); Fliss, Ismail, E-mail: ismail.fliss@fsaa.ulaval.ca [STELA Dairy Research Centre, Institute of Nutrition and Functional Foods, Université Laval, G1V 0A6 Québec, QC (Canada)

    2016-04-29

    In this study, we first report characterization of collagencin, an antimicrobial peptide identified from fish collagen hydrolysate. The peptide completely inhibited the growth of Staphylococcus aureus at 1.88 mM. Although non-toxic up to 470 μM, collagencin was hemolytic at higher concentrations. The secondary structure of collagencin was mainly composed by β-sheet and β-turn as determined by CD measurements and molecular dynamics. The peptide is likely to form β-sheet structure under hydrophobic environments and interacts with both anionic (phosphatidylglycerol) and zwitterionic (phosphoethanolamine and phosphatidylcholine) lipids as shown with CD spectroscopy and molecular dynamics. The peptide formed several hydrogen bonds with both POPG and POPE lipids and remained at membrane–water interface, suggesting that collagencin antibacterial action follows a carpet mechanism. Collagenous fish wastes could be processed by enzymatic hydrolysis and transformed into products of high value having functional or biological properties. Marine collagens are a promising source of antimicrobial peptides with new implications in food safety and human health. - Highlights: • Collagencin, an antibacterial (G+ & G-) peptide identified from fish collagen hydrolysate. • The peptide completely inhibited the growth of S. aureus at 1.88 mM and non-toxic at 470 μM. • The secondary structure was mainly composed by β-sheet and turn as determined by CD and MD. • Collagencin interacts with both anionic and zwitterionic lipids as shown with CD and MD. • Collagencin antibacterial action probably follows a carpet mechanism.

  6. Conformational Flexibility Determines Selectivity and Antibacterial, Antiplasmodial, and Anticancer Potency of Cationic α-Helical Peptides*

    Science.gov (United States)

    Vermeer, Louic S.; Lan, Yun; Abbate, Vincenzo; Ruh, Emrah; Bui, Tam T.; Wilkinson, Louise J.; Kanno, Tokuwa; Jumagulova, Elmira; Kozlowska, Justyna; Patel, Jayneil; McIntyre, Caitlin A.; Yam, W. C.; Siu, Gilman; Atkinson, R. Andrew; Lam, Jenny K. W.; Bansal, Sukhvinder S.; Drake, Alex F.; Mitchell, Graham H.; Mason, A. James

    2012-01-01

    We used a combination of fluorescence, circular dichroism (CD), and NMR spectroscopies in conjunction with size exclusion chromatography to help rationalize the relative antibacterial, antiplasmodial, and cytotoxic activities of a series of proline-free and proline-containing model antimicrobial peptides (AMPs) in terms of their structural properties. When compared with proline-free analogs, proline-containing peptides had greater activity against Gram-negative bacteria, two mammalian cancer cell lines, and intraerythrocytic Plasmodium falciparum, which they were capable of killing without causing hemolysis. In contrast, incorporation of proline did not have a consistent effect on peptide activity against Mycobacterium tuberculosis. In membrane-mimicking environments, structures with high α-helix content were adopted by both proline-free and proline-containing peptides. In solution, AMPs generally adopted disordered structures unless their sequences comprised more hydrophobic amino acids or until coordinating phosphate ions were added. Proline-containing peptides resisted ordering induced by either method. The roles of the angle subtended by positively charged amino acids and the positioning of the proline residues were also investigated. Careful positioning of proline residues in AMP sequences is required to enable the peptide to resist ordering and maintain optimal antibacterial activity, whereas varying the angle subtended by positively charged amino acids can attenuate hemolytic potential albeit with a modest reduction in potency. Maintaining conformational flexibility improves AMP potency and selectivity toward bacterial, plasmodial, and cancerous cells while enabling the targeting of intracellular pathogens. PMID:22869378

  7. 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.

  8. Antibacterial peptides from plants: what they are and how they probably work.

    Science.gov (United States)

    Barbosa Pelegrini, Patrícia; Del Sarto, Rafael Perseghini; Silva, Osmar Nascimento; Franco, Octávio Luiz; Grossi-de-Sa, Maria Fátima

    2011-01-01

    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.

  9. Drug forecast - the peptide deformylase inhibitors as antibacterial agents.

    Science.gov (United States)

    Guay, David R P

    2007-08-01

    The relatively rapid development of microbial resistance after the entry of every new antimicrobial into the marketplace necessitates a constant supply of new agents to maintain effective pharmacotherapy. Despite extensive efforts to identify novel lead compounds from molecular targets, only the peptide deformylase inhibitors (PDIs) have shown any real promise, with some advancing to phase I human trials. Bacterial peptide deformylase, which catalyzes the removal of the N-formyl group from N-terminal methionine following translation, is essential for bacterial protein synthesis, growth, and survival. The majority of PDIs are pseudopeptide hydroxamic acids and two of these (IV BB-83698 and oral NVP LBM-415) entered phase I human trials. However, agents to the present have suffered from major potential liabilities. Their in vitro activity has been limited to gram-positive aerobes and some anaerobes and has been quite modest against the majority of such species (MIC(90) values ranging from 1-8 mg/L). They have exerted bacteriostatic, not bacteriocidal, activity, thus reducing their potential usefulness in the management of serious infections in the immunocompromised. The relative ease with which microorganisms have been able to develop resistance and the multiple available mechanisms of resistance (mutations in fmt, defB, folD genes; AcrAB/TolC efflux pump; overexpression of peptide deformylase) are worrisome. These could portend a short timespan of efficacy after marketing. Despite these current liabilities, further pursuit of more potent and broader spectrum PDIs which are less susceptible to bacterial mechanisms of resistance is still warranted.

  10. Targeted separation of antibacterial peptide from protein hydrolysate of anchovy cooking wastewater by equilibrium dialysis.

    Science.gov (United States)

    Tang, Wenting; Zhang, Hui; Wang, Li; Qian, Haifeng; Qi, Xiguang

    2015-02-01

    Anchovy (Engraulis japonicus) cooking wastewater (ACWW) is a by-product resulted from the production of boiled-dried anchovies in the seafood processing industry. In this study, the protein hydrolysate of ACWW (ACWWPH) was found to have antimicrobial activity after enzymatic hydrolysis with Protamex. For the targeted screening of antibacterial peptides, liposomes constructed from Staphylococcus aureus membrane lipids were used in an equilibrium dialysis system. The hydrolysate was further purified by liposome equilibrium dialysis combined with high performance liquid chromatography. The purified antimicrobial peptide (ACWWP1) was determined to be GLSRLFTALK, with a molecular weight of 1104.6622Da. The peptide exhibited no haemolytic activity up to a concentration of 512μg/ml. It displayed a dose-dependent bactericidal effect in reconstituted milk. The change in cell surface hydrophobicity and membrane-permeable action of the purified ACWWP1 may have contributed to the antibacterial effect. This study suggests that liposome equilibrium dialysis can be used for the targeted screening of antimicrobial peptides. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Comparative analysis of internalisation, haemolytic, cytotoxic and antibacterial effect of membrane-active cationic peptides: aspects of experimental setup.

    Science.gov (United States)

    Horváti, Kata; Bacsa, Bernadett; Mlinkó, Tamás; Szabó, Nóra; Hudecz, Ferenc; Zsila, Ferenc; Bősze, Szilvia

    2017-06-01

    Cationic peptides proved fundamental importance as pharmaceutical agents and/or drug carrier moieties functioning in cellular processes. The comparison of the in vitro activity of these peptides is an experimental challenge and a combination of different methods, such as cytotoxicity, internalisation rate, haemolytic and antibacterial effect, is necessary. At the same time, several issues need to be addressed as the assay conditions have a great influence on the measured biological effects and the experimental setup needs to be optimised. Therefore, critical comparison of results from different assays using representative examples of cell penetrating and antimicrobial peptides was performed and optimal test conditions were suggested. Our main goal was to identify carrier peptides for drug delivery systems of antimicrobial drug candidates. Based on the results of internalisation, haemolytic, cytotoxic and antibacterial activity assays, a classification of cationic peptides is advocated. We found eight promising carrier peptides with good penetration ability of which Penetratin, Tat, Buforin and Dhvar4 peptides showed low adverse haemolytic effect. Penetratin, Transportan, Dhvar4 and the hybrid CM15 peptide had the most potent antibacterial activity on Streptococcus pneumoniae (MIC lower than 1.2 μM) and Transportan was effective against Mycobacterium tuberculosis as well. The most selective peptide was the Penetratin, where the effective antimicrobial concentration on pneumococcus was more than 250 times lower than the HC 50 value. Therefore, these peptides and their analogues will be further investigated as drug delivery systems for antimicrobial agents.

  12. 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...... significantly reduced bacterial survival. These results open the possibility of development of antisense antibacterials for treatment of Pseudomonas infections....

  13. The antibacterial activity of peptides derived from human beta-2 glycoprotein I is inhibited by protein H and M1 protein from Streptococcus pyogenes

    NARCIS (Netherlands)

    Nilsson, Maria; Wasylik, Sylwia; Mörgelin, Matthias; Olin, Anders I.; Meijers, Joost C. M.; Derksen, Ronald H. W. M.; de Groot, Philip G.; Herwald, Heiko

    2008-01-01

    During the last years, the importance of antibacterial peptides has attracted considerable attention. We report here that peptides derived from the fifth domain of beta-2 glycoprotein I (beta(2)GPI), a human heparin binding plasma protein, have antibacterial activities against Gram-positive and

  14. Antibacterial and antiproliferative peptides in synbiotic yogurt-Release and stability during refrigerated storage.

    Science.gov (United States)

    Sah, B N P; Vasiljevic, T; McKechnie, S; Donkor, O N

    2016-06-01

    The search for alternative therapeutics is on the rise due to the extensive increase in bacterial resistance to various conventional antibiotics and side effects of conventional cancer therapies. Bioactive peptides released from natural sources such as dairy foods by lactic acid bacteria have received attention as a potential source of biotherapeutic peptides. However, liberation of peptides in yogurt depends on proteolytic activities of the cultures used. Thus, this research was conducted to establish generation of inhibitory peptides in yogurt against pathogenic bacteria and cancer cells during storage at 4°C for 28d. Water-soluble crude peptide extracts were prepared by high-speed centrifugation of plain and probiotic yogurts supplemented with or without pineapple peel powder (PPP). The inhibition zones against Escherichia coli and Staphylococcus aureus by PPP-fortified probiotic yogurt at 28d of storage were, respectively, 25.89 and 11.72mm in diameter, significantly higher than that of nonsupplemented control yogurts. Antiproliferative activity against HT29 colon cancer cells was also significantly higher in probiotic yogurt with PPP than in nonsupplemented probiotic yogurt. Overall, crude water-soluble peptide extracts of the probiotic yogurt with PPP possessed stronger inhibitory activities against bacteria and cancer cells than controls, and these activities were maintained during storage. However, activities were lowered substantially during in vitro gastrointestinal digestion. These findings support the possibility of utilizing dairy-derived bioactive peptides in the development of a superior alternative to the current generation of antibacterial and anticancer agents, as well as a functional ingredient in foods, nutraceuticals, and pharmaceuticals. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  15. Protein-only, antimicrobial peptide-containing recombinant nanoparticles with inherent built-in antibacterial activity.

    Science.gov (United States)

    Serna, Naroa; Sánchez-García, Laura; Sánchez-Chardi, Alejandro; Unzueta, Ugutz; Roldán, Mónica; Mangues, Ramón; Vázquez, Esther; Villaverde, Antonio

    2017-09-15

    The emergence of bacterial antibiotic resistances is a serious concern in human and animal health. In this context, naturally occurring cationic antimicrobial peptides (AMPs) might play a main role in a next generation of drugs against bacterial infections. Taking an innovative approach to design self-organizing functional proteins, we have generated here protein-only nanoparticles with intrinsic AMP microbicide activity. Using a recombinant version of the GWH1 antimicrobial peptide as building block, these materials show a wide antibacterial activity spectrum in absence of detectable toxicity on mammalian cells. The GWH1-based nanoparticles combine clinically appealing properties of nanoscale materials with full biocompatibility, structural and functional plasticity and biological efficacy exhibited by proteins. Because of the largely implemented biological fabrication of recombinant protein drugs, the protein-based platform presented here represents a novel and scalable strategy in antimicrobial drug design, that by solving some of the limitations of AMPs offers a promising alternative to conventional antibiotics. The low molecular weight antimicrobial peptide GWH1 has been engineered to oligomerize as self-assembling protein-only nanoparticles of around 50nm. In this form, the peptide exhibits potent and broad antibacterial activities against both Gram-positive and Gram-negative bacteria, without any harmful effect over mammalian cells. As a solid proof-of-concept, this finding strongly supports the design and biofabrication of nanoscale antimicrobial materials with in-built functionalities. The protein-based homogeneous composition offer advantages over alternative materials explored as antimicrobial agents, regarding biocompatibility, biodegradability and environmental suitability. Beyond the described prototype, this transversal engineering concept has wide applicability in the design of novel nanomedicines for advanced treatments of bacterial infections

  16. 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.

  17. Peptide deformylase as an antibacterial drug target: target validation and resistance development.

    Science.gov (United States)

    Apfel, C M; Locher, H; Evers, S; Takács, B; Hubschwerlen, C; Pirson, W; Page, M G; Keck, W

    2001-04-01

    New inhibitors of peptide deformylase (PDF) which are very potent against the isolated enzyme and show a certain degree of antibacterial activity have recently been synthesized by our group. Several lines of experimental evidence indicate that these inhibitors indeed interfere with the target enzyme in the bacterial cell. (i) The inhibition of Escherichia coli growth could be counteracted by overexpression of PDF from different organisms, including E. coli, Streptococcus pneumoniae, and Haemophilus influenzae. Conversely, reduced expression of PDF in S. pneumoniae resulted in an increased susceptibility to the inhibitors. (ii) Proteome analysis on two-dimensional gels revealed a shift for many proteins towards lower pI in the presence of PDF inhibitors, as would be expected if the proteins still carry their N-formyl-Met terminus. (iii) PDF inhibitors show no antimicrobial activity against E. coli under conditions that make growth independent of formylation and deformylation. The antibacterial activity in E. coli was characterized as bacteriostatic. Furthermore, the development of resistance in E. coli was observed to occur with high frequency (10(-7)). Resistant mutants show a reduced growth rate, and DNA sequence analysis revealed mutations in their formyl transferase gene. Taking all these aspects into account, we conclude that PDF may not be an optimal target for broad-spectrum antibacterial agents.

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

    Science.gov (United States)

    Muhammad, Syed Aun; Ahmed, Safia

    2015-12-01

    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 aerugin osa. 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, 1 H and 13 C 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.

  19. 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

  20. Helical 1:1 α/Sulfono-γ-AA Heterogeneous Peptides with Antibacterial Activity

    Energy Technology Data Exchange (ETDEWEB)

    She, Fengyu; Nimmagadda, Alekhya; Teng, Peng; Su, Ma; Zuo, Xiaobing; Cai, Jianfeng

    2016-05-09

    As one of the greatest threats facing in 21st century, antibiotic resistance is now a major public health concern. Host-defense peptides (HDPs) offer an alternative approach to combat emerging multidrug-resistant bacteria. It is known that helical HDPs such as magainin 2 and its analogs adopt cationic amphipathic conformations upon interaction with bacterial membranes, leading to membrane disruption and subsequent bacterial cell death. We have previously shown that amphipathic sulfono-γ-AApeptides could mimic magainin 2 and exhibit bactericidal activity. In this article, we demonstrate for the first time that amphipathic helical 1:1 α/sulfono-γ-AA heterogeneous peptides, in which regular amino acids and sulfono-γ-AApeptide building blocks are alternatively present in a 1:1 pattern, display potent antibacterial activity against both Gram-positive and Gram-negative bacterial pathogens. Small Angle X-ray Scattering (SAXS) suggests that the lead sequences adopt defined helical structures. The subsequent studies including 2 fluorescence microscopy and time-kill experiments indicate that these hybrid peptides exert antimicrobial activity by mimicking the mechanism of HDPs. Our findings may lead to the development of HDP-mimicking antimicrobial peptidomimetics that combat drug-resistant bacterial pathogens. In addition, our results also demonstrate the effective design of a new class of helical foldamer, which could be employed to interrogate other important biological targets such as protein-protein interactions in the future.

  1. Cytological profile of antibacterial FtsZ inhibitors and synthetic peptide MciZ

    Directory of Open Access Journals (Sweden)

    Lidia Araujo-Bazan

    2016-10-01

    Full Text Available Cell division protein FtsZ is the organizer of the cytokinetic ring in almost all bacteria and a target for the discovery of new antibacterial agents that are needed to counter widespread antibiotic resistance. Bacterial cytological profiling, using quantitative microscopy, is a powerful approach for identifying the mechanism of action of antibacterial molecules affecting different cellular pathways. We have determined the cytological profile on Bacillus subtilis cells of a selection of small molecule inhibitors targeting FtsZ on different binding sites. FtsZ inhibitors lead to long undivided cells, impair the normal assembly of FtsZ into the midcell Z-rings, induce aberrant ring distributions, punctate FtsZ foci, membrane spots and also modify nucleoid length. Quantitative analysis of cell and nucleoid length combined, or the Z-ring distribution, allows categorizing FtsZ inhibitors and to distinguish them from antibiotics with other mechanisms of action, which should be useful for identifying new antibacterial FtsZ inhibitors. Biochemical assays of FtsZ polymerization and GTPase activity combined explain the cellular effects of the FtsZ polymer stabilizing agent PC190723 and its fragments. MciZ is a 40-aminoacid endogenous inhibitor of cell division normally expressed during sporulation in B. subtilis. Using FtsZ cytological profiling we have determined that exogenous synthetic MciZ is an effective inhibitor of B. subtilis cell division, Z-ring formation and localization. This finding supports our cell-based approach to screen for FtsZ inhibitors and opens new possibilities for peptide inhibitors of bacterial cell division.

  2. 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

    2016-07-15

    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.

  3. 2D-QSAR in hydroxamic acid derivatives as peptide deformylase inhibitors and antibacterial agents.

    Science.gov (United States)

    Gupta, Manish K; Mishra, Pradeep; Prathipati, Philip; Saxena, Anil K

    2002-12-01

    Peptide deformylase catalyzes the removal of N-formyl group from the N-formylmethionine of ribosome synthesized polypeptide in eubacteria. Quantitative structure-activity relationship (QSAR) studies have been carried out in a series of beta-sulfonyl and beta-sulfinyl hydroxamic acid derivatives for their PDF enzyme inhibitory and antibacterial activities against Escherichia coli DC2 and Moraxella catarrhalis RA21 which demonstrate that the PDF inhibitory activity in cell free and whole cell system increases with increase in molar refractivity and hydrophobicity. The comparison of the QSARs between the cell free and whole cell system indicate that the active binding sites in PDF isolated from E. coli and in M. catarrhalis RA21 are similar and the whole cell antibacterial activity is mainly due to the inhibition of PDF. Apart from this the QSARs on some matrixmetelloproteins (COL-1, COL-3, MAT and HME) and natural endopeptidase (NEP) indicate the possibilities of introducing selectivity in these hydroxamic acid derivatives for their PDF inhibitory activity.

  4. Production of antibacterial peptide from bee venom via a new strategy for heterologous expression.

    Science.gov (United States)

    Hou, Chunsheng; Guo, Liqiong; Lin, Junfang; You, Linfeng; Wu, Wuhua

    2014-12-01

    Honey bee is important economic insect that not only pollinates fruits and crops but also provides products with various physiological activities. Bee venom is a functional agent that is widely applied in clinical treatment and pharmacy. Secapin is one of these agents that have a significant role in therapy. The functions of secapin from the bee venom have been documented, but little information is known about its heterologous expression under natural condition. Moreover, few scholars verified experimentally the functions of secapin from bee venom in vitro. In this study, we successfully constructed a heterologous expression vector, which is different from conventional expression system. A transgenic approach was established for transformation of secapin gene from the venom of Apis mellifera carnica (Ac-sec) into the edible fungi, Coprinus cinereus. Ac-sec was encoded by a 234 bp nucleotide that contained a signal peptide domain and two potential phosphorylation sites. The sequence exhibited highly homology with various secapins characterized from honey bee and related species. Southern blot data indicated that Ac-sec was present as single or multiple copy loci in the C. cinereus genome. By co-transformation and double-layer active assay, Ac-sec was expressed successfully in C. cinereus and the antibacterial activity of the recombinants was identified, showing notable antibacterial activities on different bacteria. Although Ac-sec is from the venom of Apidae, phylogenetic analysis demonstrated that Ac-sec was more closely related to that of Vespid than to bee species from Apidae. The molecular characteristics of Ac-sec and the potential roles of small peptides in biology were discussed.

  5. Antibacterial activity of synthetic peptides derived from lactoferricin against Escherichia coli ATCC 25922 and Enterococcus faecalis ATCC 29212.

    Science.gov (United States)

    León-Calvijo, María A; Leal-Castro, Aura L; Almanzar-Reina, Giovanni A; Rosas-Pérez, Jaiver E; García-Castañeda, Javier E; Rivera-Monroy, Zuly J

    2015-01-01

    Peptides derived from human and bovine lactoferricin were designed, synthesized, purified, and characterized using RP-HPLC and MALDI-TOF-MS. Specific changes in the sequences were designed as (i) the incorporation of unnatural amino acids in the sequence, the (ii) reduction or (iii) elongation of the peptide chain length, and (iv) synthesis of molecules with different number of branches containing the same sequence. For each peptide, the antibacterial activity against Escherichia coli ATCC 25922 and Enterococcus faecalis ATCC 29212 was evaluated. Our results showed that Peptides I.2 (RWQWRWQWR) and I.4 ((RRWQWR)4K2Ahx2C2) exhibit bigger or similar activity against E. coli (MIC 4-33 μM) and E. faecalis (MIC 10-33 μM) when they were compared with lactoferricin protein (LF) and some of its derivate peptides as II.1 (FKCRRWQWRMKKLGA) and IV.1 (FKCRRWQWRMKKLGAPSITCVRRAE). It should be pointed out that Peptides I.2 and I.4, containing the RWQWR motif, are short and easy to synthesize; our results demonstrate that it is possible to design and obtain synthetic peptides that exhibit enhanced antibacterial activity using a methodology that is fast and low-cost and that allows obtaining products with a high degree of purity and high yield.

  6. Antibacterial Activity of Synthetic Peptides Derived from Lactoferricin against Escherichia coli ATCC 25922 and Enterococcus faecalis ATCC 29212

    Directory of Open Access Journals (Sweden)

    María A. León-Calvijo

    2015-01-01

    Full Text Available Peptides derived from human and bovine lactoferricin were designed, synthesized, purified, and characterized using RP-HPLC and MALDI-TOF-MS. Specific changes in the sequences were designed as (i the incorporation of unnatural amino acids in the sequence, the (ii reduction or (iii elongation of the peptide chain length, and (iv synthesis of molecules with different number of branches containing the same sequence. For each peptide, the antibacterial activity against Escherichia coli ATCC 25922 and Enterococcus faecalis ATCC 29212 was evaluated. Our results showed that Peptides I.2 (RWQWRWQWR and I.4 ((RRWQWR4K2Ahx2C2 exhibit bigger or similar activity against E. coli (MIC 4–33 μM and E. faecalis (MIC 10–33 μM when they were compared with lactoferricin protein (LF and some of its derivate peptides as II.1 (FKCRRWQWRMKKLGA and IV.1 (FKCRRWQWRMKKLGAPSITCVRRAE. It should be pointed out that Peptides I.2 and I.4, containing the RWQWR motif, are short and easy to synthesize; our results demonstrate that it is possible to design and obtain synthetic peptides that exhibit enhanced antibacterial activity using a methodology that is fast and low-cost and that allows obtaining products with a high degree of purity and high yield.

  7. Stable isotope-assisted NMR characterization of interaction between lipid A and sarcotoxin IA, a cecropin-type antibacterial peptide

    Energy Technology Data Exchange (ETDEWEB)

    Yagi-Utsumi, Maho [Institute for Molecular Science and Okazaki Institute for Integrative Bioscience, National Institutes of Natural Sciences, Okazaki 444-8787 (Japan); Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya 467-8603 (Japan); Yamaguchi, Yoshiki [Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya 467-8603 (Japan); Advanced Science Institute, RIKEN, Wako 351-0198 (Japan); Boonsri, Pornthip [Institute for Molecular Science and Okazaki Institute for Integrative Bioscience, National Institutes of Natural Sciences, Okazaki 444-8787 (Japan); Department of Chemistry, Faculty of Science, Kasetsart University, Bangkok 10900 (Thailand); Iguchi, Takeshi [Bioscience Research Laboratory, Fujiya Co., Ltd., Hadano, Kanagawa 257-0031 (Japan); Okemoto, Kazuo [Department of Biochemistry and Cell Biology, National Institute of Infectious Disease, Tokyo 162-8640 (Japan); Natori, Shunji [National Institute of Agrobiological Sciences, Tsukuba 305-8602 (Japan); Kato, Koichi, E-mail: kkatonmr@ims.ac.jp [Institute for Molecular Science and Okazaki Institute for Integrative Bioscience, National Institutes of Natural Sciences, Okazaki 444-8787 (Japan); Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya 467-8603 (Japan); The Glycoscience Institute, Ochanomizu University, Tokyo 135-0064 (Japan); GLYENCE Co., Ltd., Nagoya 474-0858 (Japan)

    2013-02-08

    Highlights: ► Recombinant sarcotoxin IA was successfully produced with {sup 13}C- and {sup 15}N-labeling. ► Sarcotoxin IA adopts an N-terminal α-helix upon binding to lipid A-embedding micelles. ► Two lysine residues are involved in lipid A-mediated antibacterial activities. -- Abstract: Sarcotoxin IA is a 39-residue cecropin-type peptide from Sarcophaga peregrina. This peptide exhibits antibacterial activity against Gram-negative bacteria through its interaction with lipid A, a core component of lipopolysaccharides. To acquire detailed structural information on this specific interaction, we performed NMR analysis using bacterially expressed sarcotoxin IA analogs with {sup 13}C- and {sup 15}N-labeling along with lipid A-embedding micelles composed of dodecylphosphocholine. By inspecting the stable isotope-assisted NMR data, we revealed that the N-terminal segment (Leu3–Arg18) of sarcotoxin IA formed an amphiphilic α-helix upon its interaction with the aqueous micelles. Furthermore, chemical shift perturbation data indicated that the amino acid residues displayed on this α-helix were involved in the specific interaction with lipid A. On the basis of these data, we successfully identified Lys4 and Lys5 as key residues in the interaction with lipid A and the consequent antibacterial activity. Therefore, these results provide unique information for designing chemotherapeutics based on antibacterial peptide structures.

  8. Expression of recombinant antibacterial lactoferricin-related peptides from Pichia pastoris expression system.

    Science.gov (United States)

    Chen, Gen-Hung; Chen, Wei-Ming; Huang, Guo-Ting; Chen, Yu-Wen; Jiang, Shann-Tzong

    2009-10-28

    Four recombinant antimicrobial peptide (rAMP) cDNAs, constructed from two goat lactoferricin-related peptide cDNAs (GLFcin and GLFcin II) with/without (His)(6)-Tag, were cloned into pPICZalphaC and transformed into Pichia pastoris SMD1168H. After methanol induction, these rAMPs were expressed and secreted into broth. They were purified after CM-Sepharose (without His-tg), HisTrap (with His-tg) and Sephadex G-25 chromatographies. The yield of purified rAMP was 0.15 mg/mL of broth. These 4 rAMPs were thermal-stable and with high antibacterial activity against Escherichia coli BCRC 11549, Pseudomonas aeruginosa BCRC 12450, Bacillus cereus BCRC 10603, Staphylococcus aureus BCRC 25923, Propioni bacterium acnes BCRC 10723, and Listera monocytogenes BCRC 14845. The minimum inhibitory concentration (MIC) of rAMPs against these indicators ranged from 4.07 to 16.00 mg/mL.

  9. Antibacterial Efficacy of Gold and Silver Nanoparticles Functionalized with the Ubiquicidin (29–41 Antimicrobial Peptide

    Directory of Open Access Journals (Sweden)

    Enrique Morales-Avila

    2017-01-01

    Full Text Available Recent studies have demonstrated that drug antimicrobial activity is enhanced when metallic nanoparticles are used as an inorganic support, obtaining synergic effects against microorganisms. The cationic antimicrobial peptide ubiquicidin 29–41 (UBI has demonstrated high affinity and sensitivity towards fungal and bacterial infections. The aim of this research was to prepare and evaluate the antimicrobial efficacy of engineered multivalent nanoparticle systems based on silver or gold nanoparticles functionalized with UBI. Spectroscopy techniques demonstrated that NPs were functionalized with UBI mainly through interactions with the -NH2 groups. A significant increase in the antibacterial activity against Escherichia coli and Pseudomonas aeruginosa was obtained with the conjugate AgNP-UBI with regard to that of AgNP. No inhibition of bacterial growth was observed with AuNP and AuNP-UBI using a nanoparticle concentration of up to 182 μg mL−1. Nonetheless, silver nanoparticles conjugated to the UBI antimicrobial peptide may provide an alternative therapy for topical infections.

  10. 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.

  11. Enterocin X, a Novel Two-Peptide Bacteriocin from Enterococcus faecium KU-B5, Has an Antibacterial Spectrum Entirely Different from Those of Its Component Peptides▿

    Science.gov (United States)

    Hu, Chih-Bo; Malaphan, Wanna; Zendo, Takeshi; Nakayama, Jiro; Sonomoto, Kenji

    2010-01-01

    Enterocin X, composed of two antibacterial peptides (Xα and Xβ), is a novel class IIb bacteriocin from Enterococcus faecium KU-B5. When combined, Xα and Xβ display variably enhanced or reduced antibacterial activity toward a panel of indicators compared to each peptide individually. In E. faecium strains that produce enterocins A and B, such as KU-B5, only one additional bacteriocin had previously been known. PMID:20418437

  12. Antibacterial activity of novel peptide derived from Cry1Ab16 toxin and development of LbL films for foodborne pathogens control

    International Nuclear Information System (INIS)

    Plácido, Alexandra; Bragança, Idalina; Marani, Mariela; Rodrigues de Araujo, Alyne; Vasconcelos, Andreanne Gomes; Batziou, Krystallenia; Domingues, Valentina F.

    2017-01-01

    Escherichia coli is one of the most common etiological agents of diarrhea in developing countries. The appearance of resistant E. coli prevents treatment of these infections. Biotechnological products incorporating antimicrobial peptides are currently being considered in applications to prevent intestinal infections by these bacteria. The aim of this study was to evaluate the antibacterial activity of the peptide PcL342-354C, which is derived from the toxin Cry1Ab16 from Bacillus thuringiensis, against E. coli strains. We also report the preparation, characterization and evaluation of the antibacterial activity of LbL films containing PcL342-354C. The results showed that the PcL342-354C peptide inhibited the growth of different strains of E. coli with minimal inhibitory concentration ranging from 15.62–31.25 μg/mL and minimal bactericidal concentration was 250 μg/mL, indicating a potential antibacterial activity. The morphology of an ITO/Cashew gum/PcL342-354C film was analysed using atomic force microscopy which showed an increase of roughness due to the increase in the number of layers. The LbL films showed significant antibacterial activity against E. coli NCTC 9001 in both conditions tested (10 and 20 bilayers). Our results indicate that the peptide exhibits an antibacterial potential that can be tapped to develop biomaterials with antibacterial activity for use against foodborne pathogens. - Highlights: • The PcL342–354C peptide inhibited the growth of E. coli. • The peptide can be simply incorporated into edible films combined with cashew gum. • LbL films incorporating the peptide have antibacterial activity against E. coli. • The PcL342–354C exhibits an antibacterial potential that can be tapped to develop biomaterials.

  13. Antibacterial activity of novel peptide derived from Cry1Ab16 toxin and development of LbL films for foodborne pathogens control

    Energy Technology Data Exchange (ETDEWEB)

    Plácido, Alexandra, E-mail: alexandra.placido@gmail.com [REQUIMTE/LAQV, Instituto Superior de Engenharia do Porto, ISEP, Instituto Politécnico do Porto, Porto (Portugal); Bragança, Idalina, E-mail: linab_20@hotmail.com [REQUIMTE/LAQV, Instituto Superior de Engenharia do Porto, ISEP, Instituto Politécnico do Porto, Porto (Portugal); Marani, Mariela, E-mail: mmarani@cenpat-conicet.gob.ar [IPEEC-CONICET, Consejo Nacional de Investigaciones Científicas y Técnicas, Puerto Madryn, Chubut (Argentina); Rodrigues de Araujo, Alyne, E-mail: alyne_biomed@hotmail.com [Núcleo de Pesquisa em Biodiversidade e Biotecnologia, BIOTEC, Campus Ministro Reis Velloso, CMRV, Universidade Federal do Piauí, UFPI, Parnaíba, PI (Brazil); Vasconcelos, Andreanne Gomes, E-mail: andreannegv@gmail.com [Núcleo de Pesquisa em Biodiversidade e Biotecnologia, BIOTEC, Campus Ministro Reis Velloso, CMRV, Universidade Federal do Piauí, UFPI, Parnaíba, PI (Brazil); Batziou, Krystallenia, E-mail: batkrysta@gmail.com [REQUIMTE/UCIBIO, Departamento de Química e Bioquímica, Faculdade de Ciências da Universidade do Porto, Porto (Portugal); Domingues, Valentina F., E-mail: vfd@isep.ipp.pt [REQUIMTE/LAQV, Instituto Superior de Engenharia do Porto, ISEP, Instituto Politécnico do Porto, Porto (Portugal); and others

    2017-06-01

    Escherichia coli is one of the most common etiological agents of diarrhea in developing countries. The appearance of resistant E. coli prevents treatment of these infections. Biotechnological products incorporating antimicrobial peptides are currently being considered in applications to prevent intestinal infections by these bacteria. The aim of this study was to evaluate the antibacterial activity of the peptide PcL342-354C, which is derived from the toxin Cry1Ab16 from Bacillus thuringiensis, against E. coli strains. We also report the preparation, characterization and evaluation of the antibacterial activity of LbL films containing PcL342-354C. The results showed that the PcL342-354C peptide inhibited the growth of different strains of E. coli with minimal inhibitory concentration ranging from 15.62–31.25 μg/mL and minimal bactericidal concentration was 250 μg/mL, indicating a potential antibacterial activity. The morphology of an ITO/Cashew gum/PcL342-354C film was analysed using atomic force microscopy which showed an increase of roughness due to the increase in the number of layers. The LbL films showed significant antibacterial activity against E. coli NCTC 9001 in both conditions tested (10 and 20 bilayers). Our results indicate that the peptide exhibits an antibacterial potential that can be tapped to develop biomaterials with antibacterial activity for use against foodborne pathogens. - Highlights: • The PcL342–354C peptide inhibited the growth of E. coli. • The peptide can be simply incorporated into edible films combined with cashew gum. • LbL films incorporating the peptide have antibacterial activity against E. coli. • The PcL342–354C exhibits an antibacterial potential that can be tapped to develop biomaterials.

  14. Characterization of a human peptide deformylase: implications for antibacterial drug design.

    Science.gov (United States)

    Nguyen, Kiet T; Hu, Xubo; Colton, Craig; Chakrabarti, Ratna; Zhu, Michael X; Pei, Dehua

    2003-08-26

    Ribosomal protein synthesis in eubacteria and eukaryotic organelles initiates with an N-formylmethionyl-tRNA(i), resulting in N-terminal formylation of all nascent polypeptides. Peptide deformylase (PDF) catalyzes the subsequent removal of the N-terminal formyl group from the majority of bacterial proteins. Deformylation was for a long time thought to be a feature unique to the prokaryotes, making PDF an attractive target for designing novel antibiotics. However, recent genomic sequencing has revealed PDF-like sequences in many eukaryotes, including man. In this work, the cDNA encoding Homo sapiens PDF (HsPDF) has been cloned and a truncated form that lacks the N-terminal 58-amino-acid targeting sequence was overexpressed in Escherichia coli. The recombinant, Co(2+)-substituted protein is catalytically active in deformylating N-formylated peptides, shares many of the properties of bacterial PDF, and is strongly inhibited by specific PDF inhibitors. Expression of HsPDF fused to the enhanced green fluorescence protein in human embryonic kidney cells revealed its location in the mitochondrion. However, HsPDF is much less active than its bacterial counterpart, providing a possible explanation for the apparent lack of deformylation in the mammalian mitochondria. The lower catalytic activity is at least partially due to mutation of a highly conserved residue (Leu-91 in E. coli PDF) in mammalian PDF. PDF inhibitors had no detectable effect on two different human cell lines. These results suggest that HsPDF is likely an evolutional remnant without any functional role in protein formylation/deformylation and validates PDF as an excellent target for antibacterial drug design.

  15. Effects of pig antibacterial peptides on growth performance and intestine mucosal immune of broiler chickens.

    Science.gov (United States)

    Bao, H; She, R; Liu, T; Zhang, Y; Peng, K S; Luo, D; Yue, Z; Ding, Y; Hu, Y; Liu, W; Zhai, L

    2009-02-01

    Currently, substitutions for antibiotic growth promoters in animals are attracting interest. This study investigated the effects of pig antibacterial peptides (PABP) on growth performance and small intestine mucosal immune responses in broilers. Three hundred 1-d-old Arbor Acre male broiler chickens were randomly allocated to 5 groups with 60 birds per group. The groups were control group; PABP administered in drinking water at 20 and 30 mg/L of water; or PABP supplemented in feed at 150 and 200 mg/kg of diet. The birds were fed a corn-soybean based diet for 6 wk. Chickens were weighed weekly and killed after 42 d of feeding, and growth performance was measured. Samples of the duodenum and jejunum were collected. The villus height, mucosa thickness, alkaline phosphatase activity, and numbers of secreting IgA and goblet cells were evaluated. The PABP-treated groups had greater BW and average daily gain, greater height of villus and thickness of gut mucosa, greater activity of alkaline phosphatase, higher ratio of secreting IgA, and a greater number of goblet cells compared with the control group (P<0.05). In conclusion, PABP can improve the growth performance, increase the intestinal ability to absorb nutrients, and improve the mucosal immunity of the intestine.

  16. Antibacterial Synthetic Peptides Derived from Bovine Lactoferricin Exhibit Cytotoxic Effect against MDA-MB-468 and MDA-MB-231 Breast Cancer Cell Lines

    Directory of Open Access Journals (Sweden)

    Yerly Vargas Casanova

    2017-09-01

    Full Text Available Linear, dimeric, tetrameric, and cyclic peptides derived from lactoferricin B, containing the RRWQWR motif, were designed, synthesized, purified, and characterized using RP-HPLC chromatography and MALDI-TOF mass spectrometry. The antibacterial activity of the designed peptides against E. coli (ATCC 11775 and 25922 and their cytotoxic effect against MDA-MB-468 and MDA-MB-231 breast cancer cell lines were evaluated. Dimeric and tetrameric peptides showed higher antibacterial activity in both bacteria strains than linear peptides. The dimeric peptide (RRWQWR2K-Ahx exhibited the highest antibacterial activity against the tested bacterial strains. Furthermore, the peptides with high antibacterial activity exhibited significant cytotoxic effect against the tested breast cancer cell lines. This cytotoxic effect was fast and dependent on the peptide concentration. The tetrameric molecule containing RRWQWR motif has an optimal cytotoxic effect at a concentration of 22 µM. The evaluated dimeric and tetrameric peptides could be considered as candidates for developing new therapeutic agents against breast cancer. Polyvalence of linear sequences could be considered as a novel and versatile strategy for obtaining molecules with high anticancer activity.

  17. Antibacterial Synthetic Peptides Derived from Bovine Lactoferricin Exhibit Cytotoxic Effect against MDA-MB-468 and MDA-MB-231 Breast Cancer Cell Lines.

    Science.gov (United States)

    Vargas Casanova, Yerly; Rodríguez Guerra, Jorge Antonio; Umaña Pérez, Yadi Adriana; Leal Castro, Aura Lucía; Almanzar Reina, Giovanni; García Castañeda, Javier Eduardo; Rivera Monroy, Zuly Jenny

    2017-09-29

    Linear, dimeric, tetrameric, and cyclic peptides derived from lactoferricin B, containing the RRWQWR motif, were designed, synthesized, purified, and characterized using RP-HPLC chromatography and MALDI-TOF mass spectrometry. The antibacterial activity of the designed peptides against E. coli (ATCC 11775 and 25922) and their cytotoxic effect against MDA-MB-468 and MDA-MB-231 breast cancer cell lines were evaluated. Dimeric and tetrameric peptides showed higher antibacterial activity in both bacteria strains than linear peptides. The dimeric peptide (RRWQWR)₂K-Ahx exhibited the highest antibacterial activity against the tested bacterial strains. Furthermore, the peptides with high antibacterial activity exhibited significant cytotoxic effect against the tested breast cancer cell lines. This cytotoxic effect was fast and dependent on the peptide concentration. The tetrameric molecule containing RRWQWR motif has an optimal cytotoxic effect at a concentration of 22 µM. The evaluated dimeric and tetrameric peptides could be considered as candidates for developing new therapeutic agents against breast cancer. Polyvalence of linear sequences could be considered as a novel and versatile strategy for obtaining molecules with high anticancer activity.

  18. 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

  19. Synthesis and in vitro antibacterial activity of oxazolidine LBM-415 analogs as peptide deformylase inhibitors.

    Science.gov (United States)

    Yu, Linliang; Zhou, Weicheng; Wang, Zhenyu

    2011-03-01

    The drug resistant bacteria pose a severe threat to human health. The increasing resistance of those pathogens to traditional antibacterial therapy renders the identification of new antibacterial agents with novel antibacterial mechanisms an urgent need. In this study, a series of (2S)-N-substituted-1-[(formyhydroxyamino)methyl]-1-oxohexyl]-2-oxazolidinecarboxamides were designed, synthesized and evaluated for in vitro antibacterial activity. Most of these compounds displayed good activities against Gram-positive organisms comparable to reference agent LBM-415. Crown Copyright © 2010. Published by Elsevier Ltd. All rights reserved.

  20. Production of Hypoallergenic Antibacterial Peptides from Defatted Soybean Meal in Membrane Bioreactor: A Bioprocess Engineering Study with Comprehensive Product Characterization

    Directory of Open Access Journals (Sweden)

    Arij it Nath

    2017-01-01

    Full Text Available Hypoallergenic antibacterial low-molecular-mass peptides were produced from defatted soybean meal in a membrane bioreactor. In the fi rst step, soybean meal proteins were digested with trypsin in the bioreactor, operated in batch mode. For the tryptic digestion of soybean meal protein, optimum initial soybean meal concentration of 75 g/L, temperature of 40 °C and pH=9.0 were determined. Aft er enzymatic digestion, low-molecular-mass peptides were purifi ed with cross-fl ow fl at sheet membrane (pore size 100 μm and then with tubular ceramic ultrafi ltration membrane (molecular mass cut-off 5 kDa. Eff ects of transmembrane pressure and the use of a static turbulence promoter to reduce the concentration polarization near the ultrafi ltration membrane surface were examined and their positive eff ects were proven. For the fi ltration with ultrafi ltration membrane, transmembrane pressure of 3•105 Pa with 3-stage discontinuous diafi ltration was found optimal. The molecular mass distribution of purifi ed peptides using ultrafi ltration membrane was determined by a liquid chromatography–electrospray ionization quadrupole time-of-fl ight mass spectrometry setup. More than 96 % of the peptides (calculated as relative frequency from the ultrafi ltration membrane permeate had the molecular mass M≤1.7 kDa and the highest molecular mass was found to be 3.1 kDa. The decrease of allergenic property due to the tryptic digestion and membrane fi ltration was determined by an enzyme-linked immunosorbent assay and it was found to exceed 99.9 %. It was also found that the peptides purifi ed in the ultrafi ltration membrane promoted the growth of Pediococcus acidilactici HA6111-2 and they possessed antibacterial activity against Bacillus cereus.

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

    OpenAIRE

    Muhammad, Syed Aun; Ahmed, Safia

    2015-01-01

    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 p...

  2. Selective cytotoxicity of the antibacterial peptide ABP-dHC-Cecropin A and its analog towards leukemia cells.

    Science.gov (United States)

    Sang, Ming; Zhang, Jiaxin; Zhuge, Qiang

    2017-05-15

    Some cationic antibacterial peptides, with typical amphiphilic α-helical conformations in a membrane-mimicking environment, exhibit anticancer properties as a result of a similar mechanism of action towards both bacteria and cancer cells. We previously reported the cDNA sequence of the antimicrobial peptide ABP-dHC-Cecropin A precursor cloned from drury (Hyphantria cunea) (dHC). In the present study, we synthesized and structurally characterized ABP-dHC-Cecropin A and its analog, ABP-dHC-Cecropin A-K(24). Circular dichroism spectroscopy showed that ABP-dHC-Cecropin A and its analog adopt a well-defined α-helical structure in a 50% trifluorethanol solution. The cytotoxicity and cell selectivity of these peptides were further examined in three leukemia cell lines and two non-cancerous cell lines. The MTT assay indicated both of these peptides have a concentration-dependent cytotoxic effect in leukemia cells, although the observed cytotoxicity was greater with ABP-dHC-Cecropin A-K(24) treatment, whereas they were not cytotoxic towards the non-cancerous cell lines. Moreover, ABP-dHC-Cecropin A and its analog had a lower hemolytic effect in human red blood cells. Together, these results suggest the peptides are selectively cytotoxic towards leukemia cells. Confocal laser scanning microscopy determined that the peptides were concentrated at the surface of the leukemia cells, and changes in the cell membrane were determined with a permeability assay, which suggested that the anticancer activity of ABP-dHC-Cecropin A and its analog is a result of its presence at the leukemia cell membrane. ABP-dHC-Cecropin A and its analog may represent a novel anticancer agent for leukemia therapy, considering its cancer cell selectivity and relatively low cytotoxicity in normal cells. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. new caerin-like antibacterial peptide from the venom gland of the ...

    African Journals Online (AJOL)

    Scorpion venom consists of different types of peptides and proteins which are encoded by individual genes. A full length cDNA consisting of 238 base pair nucleotides and encoding 74 amino acids peptide was isolated from the venom gland of the Iranian scorpion Mesobuthus eupeus (Buthidae family). This peptide named ...

  4. 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.

  5. Design, Synthesis and Evaluation of Branched RRWQWR-Based Peptides as Antibacterial Agents Against Clinically Relevant Gram-Positive and Gram-Negative Pathogens

    Directory of Open Access Journals (Sweden)

    Sandra C. Vega

    2018-03-01

    Full Text Available Multidrug resistance of pathogenic bacteria has become a public health crisis that requires the urgent design of new antibacterial drugs such as antimicrobial peptides (AMPs. Seeking to obtain new, lactoferricin B (LfcinB-based synthetic peptides as viable early-stage candidates for future development as AMPs against clinically relevant bacteria, we designed, synthesized and screened three new cationic peptides derived from bovine LfcinB. These peptides contain at least one RRWQWR motif and differ by the copy number (monomeric, dimeric or tetrameric and structure (linear or branched of this motif. They comprise a linear palindromic peptide (RWQWRWQWR, a dimeric peptide (RRWQWR2KAhx and a tetrameric peptide (RRWQWR4K2Ahx2C2. They were screened for antibacterial activity against Enterococcus faecalis (ATCC 29212 and ATCC 51575 strains, Pseudomonas aeruginosa (ATCC 10145 and ATCC 27853 strains and clinical isolates of two Gram-positive bacteria (Enterococcus faecium and Staphylococcus aureus and two Gram-negative bacteria (Klebsiella pneumoniae and Pseudomonas aeruginosa. All three peptides exhibited greater activity than did the reference peptide, LfcinB (17–31, which contains a single linear RRWQWR motif. Against the ATCC reference strains, the three new peptides exhibited minimum inhibitory concentration (MIC50 values of 3.1–198.0 μM and minimum bactericidal concentration (MBC values of 25–200 μM, and against the clinical isolates, MIC50 values of 1.6–75.0 μM and MBC values of 12.5–100 μM. However, the tetrameric peptide was also found to be strongly hemolytic (49.1% at 100 μM. Scanning Electron Microscopy (SEM demonstrated that in the dimeric and tetrameric peptides, the RRWQWR motif is exposed to the pathogen surface. Our results may inform the design of new, RRWQWR-based AMPs.

  6. A new caerin-like antibacterial peptide from the venom gland of the ...

    African Journals Online (AJOL)

    pcnoor1389-4-1

    2012-05-31

    May 31, 2012 ... Scorpion venom consists of different types of peptides and proteins which are encoded by individual genes. A full length cDNA consisting of 238 base pair nucleotides and encoding 74 amino acids peptide was isolated from the venom gland of the Iranian scorpion Mesobuthus eupeus (Buthidae family).

  7. Phylloseptins: a novel class of anti-bacterial and anti-protozoan peptides from the Phyllomedusa genus.

    Science.gov (United States)

    Leite, José Roberto S A; Silva, Luciano P; Rodrigues, Maria Izabel S; Prates, Maura V; Brand, Guilherme D; Lacava, Bruno M; Azevedo, Ricardo B; Bocca, Anamélia L; Albuquerque, Sergio; Bloch, Carlos

    2005-04-01

    Six novel peptides called phylloseptins (PS-1, -2, -3, -4, -5, and -6) showing anti-bacterial (PS-1) and anti-protozoan (PS-4 and -5) activities were isolated from the skin secretion of the Brazilian tree-frogs, Phyllomedusa hypochondrialis and Phyllomedusa oreades. Phylloseptins have a primary structure consisting of 19-21 amino acid residues (1.7-2.1 kDa). They have common structural features, such as a highly conserved N-terminal region and C-terminal amidation. Phylloseptin-1 (FLSLIPHAINAVSAIAKHN-NH2) demonstrated a strong effect against gram-positive and gram-negative bacteria (MICs ranging from 3 to 7.9 microM), without showing significant hemolytic activity (Trypanosoma cruzi.

  8. Dynamic membrane interactions of antibacterial and antifungal biomolecules, and amyloid peptides, revealed by solid-state NMR spectroscopy.

    Science.gov (United States)

    Naito, Akira; Matsumori, Nobuaki; Ramamoorthy, Ayyalusamy

    2018-02-01

    A variety of biomolecules acting on the cell membrane folds into a biologically active structure in the membrane environment. It is, therefore, important to determine the structures and dynamics of such biomolecules in a membrane environment. While several biophysical techniques are used to obtain low-resolution information, solid-state NMR spectroscopy is one of the most powerful means for determining the structure and dynamics of membrane bound biomolecules such as antibacterial biomolecules and amyloidogenic proteins; unlike X-ray crystallography and solution NMR spectroscopy, applications of solid-state NMR spectroscopy are not limited by non-crystalline, non-soluble nature or molecular size of membrane-associated biomolecules. This review article focuses on the applications of solid-state NMR techniques to study a few selected antibacterial and amyloid peptides. Solid-state NMR studies revealing the membrane inserted bent α-helical structure associated with the hemolytic activity of bee venom melittin and the chemical shift oscillation analysis used to determine the transmembrane structure (with α-helix and 3 10 -helix in the N- and C-termini, respectively) of antibiotic peptide alamethicin are discussed in detail. Oligomerization of an amyloidogenic islet amyloid polypeptide (IAPP, or also known as amylin) resulting from its aggregation in a membrane environment, molecular interactions of the antifungal natural product amphotericin B with ergosterol in lipid bilayers, and the mechanism of lipid raft formation by sphingomyelin studied using solid state NMR methods are also discussed in this review article. This article is part of a Special Issue entitled "Biophysical Exploration of Dynamical Ordering of Biomolecular Systems" edited by Dr. Koichi Kato. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Purification and Biochemical Characterization of a Neutral Serine Protease from Trichoderma harzianum. Use in Antibacterial Peptide Production from a Fish By-Product Hydrolysate.

    Science.gov (United States)

    Aissaoui, Neyssene; Chobert, Jean-Marc; Haertlé, Thomas; Marzouki, M Nejib; Abidi, Ferid

    2017-06-01

    This study reports the purification and biochemical characterization of an extracellular neutral protease from the fungus Trichoderma harzianum. The protease (Th-Protease) was purified from the culture supernatant to homogeneity by a three-step procedure with 14.2% recovery and 9.06-fold increase in specific activity. The purified enzyme appeared as a single protein band after sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) with a molecular mass of about 20 kDa. The optimum pH and temperature for the proteolytic activity were pH 7.0 and 40 °C, respectively. The enzyme was then investigated for its potential application in the production of antibacterial peptides. Interestingly, Scorpaena notata viscera protein hydrolysate prepared using the purified serine protease (Th-Protease) showed remarkable in vitro antibacterial activities. A peptide with a high antibacterial activity was further purified by a three-step procedure, and its sequence was identified as FPIGMGHGSRPA. The result of this study offers a promising alternative to produce natural antibacterial peptides from fish protein hydrolysate.

  10. 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.

  11. Anti-endotoxic and antibacterial effects of a dermal substitute coated with host defense peptides.

    Science.gov (United States)

    Kasetty, Gopinath; Kalle, Martina; Mörgelin, Matthias; Brune, Jan C; Schmidtchen, Artur

    2015-01-01

    Biomaterials used during surgery and wound treatment are of increasing importance in modern medical care. In the present study we set out to evaluate the addition of thrombin-derived host defense peptides to human acellular dermis (hAD, i.e. epiflex(®)). Antimicrobial activity of the functionalized hAD was demonstrated using radial diffusion and viable count assays against Gram-negative Escherichia coli, Pseudomonas aeruginosa and Gram-positive Staphylococcus aureus bacteria. Electron microscopy analyses showed that peptide-mediated bacterial killing led to reduced hAD degradation. Furthermore, peptide-functionalized hAD displayed endotoxin-binding activity in vitro, as evidenced by inhibition of NF-κB activation in human monocytic cells (THP-1 cells) and a reduction of pro-inflammatory cytokine production in whole blood in response to lipopolysaccharide stimulation. The dermal substitute retained its anti-endotoxic activity after washing, compatible with results showing that the hAD bound a significant amount of peptide. Furthermore, bacteria-induced contact activation was inhibited by peptide addition to the hAD. E. coli infected hAD, alone, or after treatment with the antiseptic substance polyhexamethylenebiguanide (PHMB), yielded NF-κB activation in THP-1 cells. The activation was abrogated by peptide addition. Thus, thrombin-derived HDPs should be of interest in the further development of new biomaterials with combined antimicrobial and anti-endotoxic functions for use in surgery and wound treatment. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  12. Conformational Flexibility Determines Selectivity and Antibacterial, Antiplasmodial, and Anticancer Potency of Cationic α-Helical Peptides*

    OpenAIRE

    Vermeer, Louic S.; Lan, Yun; Abbate, Vincenzo; Ruh, Emrah; Bui, Tam T.; Wilkinson, Louise J.; Kanno, Tokuwa; Jumagulova, Elmira; Kozlowska, Justyna; Patel, Jayneil; McIntyre, Caitlin A.; Yam, W. C.; Siu, Gilman; Atkinson, R. Andrew; Lam, Jenny K. W.

    2012-01-01

    Background: Antimicrobial peptides (AMPs) have the potential to act against multiple pathogenic targets. Results: AMPs that maintain conformational flexibility are more potent against multiple pathogens and less hemolytic. Conclusion: Antimicrobial action and hemolysis proceed via differing mechanisms. Significance: The potency, selectivity, and ability of AMPs to reach intracellular pathogens can be modulated using general principles.

  13. Antibacterial activity of lactoferrin and a pepsin-derived lactoferrin peptide fragment.

    OpenAIRE

    Yamauchi, K; Tomita, M; Giehl, T J; Ellison, R T

    1993-01-01

    Although the antimicrobial activity of lactoferrin has been well described, its mechanism of action has been poorly characterized. Recent work has indicated that in addition to binding iron, human lactoferrin damages the outer membrane of gram-negative bacteria. In this study, we determined whether bovine lactoferrin and a pepsin-derived bovine lactoferrin peptide (lactoferricin) fragment have similar activities. We found that both 20 microM bovine lactoferrin and 20 microM lactoferricin rele...

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

    OpenAIRE

    Grande Burgos, Mar?a Jos?; P?rez Pulido, Rub?n; L?pez Aguayo, Mar?a del Carmen; G?lvez, 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 ...

  15. 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.

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

    Science.gov (United States)

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

    2014-12-08

    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.

  17. 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.

  18. 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.

  19. Angiotensin I-Converting-Enzyme-Inhibitory and Antibacterial Peptides from Lactobacillus helveticus PR4 Proteinase-Hydrolyzed Caseins of Milk from Six Species

    Science.gov (United States)

    Minervini, F.; Algaron, F.; Rizzello, C. G.; Fox, P. F.; Monnet, V.; Gobbetti, M.

    2003-01-01

    Sodium caseinates prepared from bovine, sheep, goat, pig, buffalo or human milk were hydrolyzed by a partially purified proteinase of Lactobacillus helveticus PR4. Peptides in each hydrolysate were fractionated by reversed-phase fast-protein liquid chromatography. The fractions which showed the highest angiotensin I-converting-enzyme (ACE)-inhibitory or antibacterial activity were sequenced by mass spectrum and Edman degradation analyses. Various ACE-inhibitory peptides were found in the hydrolysates: the bovine αS1-casein (αS1-CN) 24-47 fragment (f24-47), f169-193, and β-CN f58-76; ovine αS1-CN f1-6 and αS2-CN f182-185 and f186-188; caprine β-CN f58-65 and αS2-CN f182-187; buffalo β-CN f58-66; and a mixture of three tripeptides originating from human β-CN. A mixture of peptides with a C-terminal sequence, Pro-Gly-Pro, was found in the most active fraction of the pig sodium caseinate hydrolysate. The highest ACE-inhibitory activity of some peptides corresponded to the concentration of the ACE inhibitor (S)-N-(1-[ethoxycarbonyl]-3-phenylpropyl)-ala-pro maleate (enalapril) of 49.253 μg/ml (100 μmol/liter). Several of the above sequences had features in common with other ACE-inhibitory peptides reported in the literature. The 50% inhibitory concentration (IC50) of some of the crude peptide fractions was very low (16 to 100 μg/ml). Some identified peptides were chemically synthesized, and the ACE-inhibitory activity and IC50s were confirmed. An antibacterial peptide corresponding to β-CN f184-210 was identified in human sodium caseinate hydrolysate. It showed a very large spectrum of inhibition against gram-positive and -negative bacteria, including species of potential clinical interest, such as Enterococcus faecium, Bacillus megaterium, Escherichia coli, Listeria innocua, Salmonella spp., Yersinia enterocolitica, and Staphylococcus aureus. The MIC for E. coli F19 was ca. 50 μg/ml. Once generated, the bioactive peptides were resistant to further

  20. 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.

  1. Identification of a haemolysin-like peptide with antibacterial activity using the draft genome sequence of Staphylococcus epidermidis strain A487.

    Science.gov (United States)

    Al-Mahrous, Mohammed M; Jack, Ralph W; Sandiford, Stephanie K; Tagg, John R; Beatson, Scott A; Upton, Mathew

    2011-08-01

    Our interest in Staphylococcus epidermidis strain A487 was prompted by the unusual nature of its inhibitory activity in screening tests against methicillin-resistant Staphylococcus aureus isolates. The inhibitory activity was detected in deferred antagonism tests only if the agar plate was preheated for at least 35 min at ≥ 55 °C before inoculation of the indicator bacteria, this phenomenon indicating possible involvement of a heat-labile immunity agent or protease. The inhibitor was purified to homogeneity by ammonium sulphate precipitation, followed by cation-exchange and reversed-phase chromatography. Tandem MS revealed a novel peptide of molecular weight 2588.4 Da. The draft genome sequence of strain A487 was determined using 454 GS FLX technology, allowing the identification of the structural gene (hlp) encoding the mature peptide MQFITDLIKKAVDFFKGLFGNK. The deduced amino acid sequence of peptide 487 exhibited 70.8% similarity to that of a putative haemolysin from Staphylococcus cohnii. Analysis of the genome of strain A487 showed several additional inhibitor-encoding genes, including hld, the determinant for staphylococcal δ-lysin. This work indicates that potentially useful inhibitors could be overlooked in agar-based inhibitor screening programmes lacking a heat pretreatment step and also highlights the utility of draft genome sequence examination in antibacterial agent discovery. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  2. 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.

  3. Antibacterial and anti-inflammatory activity of a temporin B peptide analogue on an in vitro model of cystic fibrosis.

    Science.gov (United States)

    Bezzerri, Valentino; Avitabile, Concetta; Dechecchi, Maria Cristina; Lampronti, Ilaria; Borgatti, Monica; Montagner, Giulia; Cabrini, Giulio; Gambari, Roberto; Romanelli, Alessandra

    2014-10-01

    Natural peptides with antimicrobial properties are deeply investigated as tools to fight bacteria resistant to common antibiotics. Small peptides, as those belonging to the temporin family, are very attractive because their activity can easily be tuned after small modification to their primary sequence. Structure-activity studies previously reported by us allowed the identification of one peptide, analogue of temporin B, TB_KKG6A, showing, unlike temporin B, antimicrobial activity against both Gram-positive and Gram-negative bacteria. In this paper, we investigated the antimicrobial and anti-inflammatory activity of the peptide TB_KKG6A against Pseudomonas aeruginosa. Interestingly, we found that the peptide exhibits antimicrobial activity at low concentrations, being able to downregulate the pro-inflammatory chemokines and cytokines interleukin (IL)-8, IL-1β, IL-6 and tumor necrosis factor-α produced downstream infected human bronchial epithelial cells. Experiments were carried out also with temporin B, which was found to show pro-inflammatory activity. Details on the interaction between TB_KKG6A and the P. aeruginosa LPS were obtained by circular dichroism and fluorescence studies. Copyright © 2014 European Peptide Society and John Wiley & Sons, Ltd.

  4. 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 Staphyl......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...

  5. Isolation of dermatoxin from frog skin, an antibacterial peptide encoded by a novel member of the dermaseptin genes family.

    Science.gov (United States)

    Amiche, M; Seon, A A; Wroblewski, H; Nicolas, P

    2000-07-01

    A 32-residue peptide, named dermatoxin, has been extracted from the skin of a single specimen of the tree frog Phyllomedusa bicolor, and purified to homogeneity using a four-step protocol. Mass spectral analysis and sequencing of the purified peptide, as well as chemical synthesis and cDNA analysis were consistent with the structure: SLGSFLKGVGTTLASVGKVVSDQF GKLLQAGQ. This peptide proved to be bactericidal towards mollicutes (wall-less eubacteria) and Gram-positive eubacteria, and also, though to a lesser extent, towards Gram-negative eubacteria. Measurement of the bacterial membrane potential revealed that the plasma membrane is the primary target of dermatoxin. Observation of bacterial cells using reflected light fluorescence microscopy after DNA-staining was consistent with a mechanism of cell killing based upon the alteration of membrane permeability rather than membrane solubilization, very likely by forming ion-conducting channels through the plasma membrane. CD spectroscopy and secondary structure predictions indicated that dermatoxin assumes an amphipathic alpha-helical conformation in low polarity media which mimic the lipophilicity of the membrane of target microorganisms. PCR analysis coupled with cDNA cloning and sequencing revealed that dermatoxin is expressed in the skin, the intestine and the brain. Preprodermatoxin from the brain and the intestine have the same sequence as the skin preproform except for two amino-acid substitutions in the preproregion of the brain precursor. The dermatoxin precursor displayed the characteristic features of preprodermaseptins, a family of peptide precursors found in the skin of Phyllomedusa ssp. Precursors of this family have a common N-terminal preproregion followed by markedly different C-terminal domains that give rise to 19-34-residue peptide antibiotics named dermaseptins B and phylloxin, and to the D-amino-acid-containing opioid heptapeptides dermorphins and deltorphins. Because the structures and cidal

  6. Biosynthetic Tailoring of Microcin E492m: Post-Translational Modification Affords an Antibacterial Siderophore-Peptide Conjugate

    Science.gov (United States)

    Nolan, Elizabeth M.; Fischbach, Michael A.; Koglin, Alexander; Walsh, Christopher T.

    2008-01-01

    The present work reveals that four proteins, MceCDIJ, encoded by the MccE492 gene cluster are responsible for the remarkable post-translational tailoring of Microcin E492 (MccE492), an 84-residue protein toxin secreted by Klebsiella pneumonaie RYC492 that targets neighboring gram-negative species. This modification results in attachment of a linearized and monoglycosylated derivative of enterobactin, a nonribosomal peptide and iron scavenger (siderophore), to the MccE492m C-terminus. MceC and MceD derivatize enterobactin by C-glycosylation at the C5 position of a N-(2,3-dihydroxybenzoyl) serine (DHB-Ser) moiety and regiospecific hydrolysis of an ester linkage in the trilactone scaffold, respectively. MceI and MceJ form a protein complex that attaches C-glycosylated enterobactins to the C-terminal serine residue of both aC10 model peptide and full-length MccE492. In the enzymatic product, the terminal serine residue is covalently attached to the C4′ oxygen of the glucose moiety. Non-enzymatic and base-catalyzed migration of the peptide to the C6′ position affords the C6′ glycosyl ester linkage observed in the mature toxin, MccE492m, isolated from bacterial cultures. PMID:17973380

  7. Dual Targeting of Intracellular Pathogenic Bacteria with a Cleavable Conjugate of Kanamycin and an Antibacterial Cell-Penetrating Peptide.

    Science.gov (United States)

    Brezden, Anna; Mohamed, Mohamed F; Nepal, Manish; Harwood, John S; Kuriakose, Jerrin; Seleem, Mohamed N; Chmielewski, Jean

    2016-08-31

    Bacterial infection caused by intracellular pathogens, such as Mycobacterium, Salmonella, and Brucella, is a burgeoning global health epidemic that necessitates urgent action. However, the therapeutic value of a number of antibiotics, including aminoglycosides, against intracellular pathogenic bacteria is compromised due to their inability to traverse eukaryotic membranes. For this significant problem to be addressed, a cleavable conjugate of the antibiotic kanamycin and a nonmembrane lytic, broad-spectrum antimicrobial peptide with efficient mammalian cell penetration, P14LRR, was prepared. This approach allows kanamycin to enter mammalian cells as a conjugate linked via a tether that breaks down in the reducing environment within cells. Potent antimicrobial activity of the P14KanS conjugate was demonstrated in vitro, and this reducible conjugate effectively cleared intracellular pathogenic bacteria within macrophages more potently than that of a conjugate lacking the disulfide moiety. Notably, successful clearance of Mycobacterium tuberculosis within macrophages was observed with the dual antibiotic conjugate, and Salmonella levels were significantly reduced in an in vivo Caenorhabditis elegans model.

  8. A New Method of Producing a Natural Antibacterial Peptide by Encapsulated Probiotics Internalized with Inulin Nanoparticles as Prebiotics.

    Science.gov (United States)

    Cui, Lian-Hua; Yan, Chang-Guo; Li, Hui-Shan; Kim, Whee-Soo; Hong, Liang; Kang, Sang-Kee; Choi, Yun-Jaie; Cho, Chong-Su

    2018-04-28

    Synbiotics are a combination of probiotics and prebiotics, which lead to synergistic benefits in host welfare. Probiotics have been used as an alternative to antibiotics. Among the probiotics, Pediococcus acidilactici (PA) has shown excellent antimicrobial activity against Salmonella Gallinarum (SG) as a major poultry pathogen and has improved the production performances of animals. Inulin is widely used as a prebiotic for the improvement of animal health and growth. The main aim of this study is to investigate the effect of the antimicrobial activity of inulin nanoparticles (INs)-internalized PA encapsulated into alginate/chitosan/alginate (ACA) microcapsules (MCs) in future in vivo application. The prepared phthalyl INs (PINs) were characterized by DLS and FE-SEM. The contents of phthal groups in phthalyl inulin were estimated by ¹H-NMR measurement as 25.1 mol.-%. The sizes of the PINs measured by DLS were approximately 203 nm. Internalization into PA was confirmed by confocal microscopy and flow cytometry. Antimicrobial activity of PIN-internalized probiotics encapsulated into ACA MCs was measured by co-culture antimicrobial assays on SG. PIN-internalized probiotics had a higher antimicrobial ability than that of ACA MCs loaded with PA/inulin or PA. Interestingly, when PINs were treated with PA and encapsulated into ACA MCs, as a natural antimicrobial peptide, pediocin was produced much more in the culture medium compared with other groups inulin-loaded ACA MCs and PA-encapsulated into ACA MCs.

  9. Antibacterial textiles

    NARCIS (Netherlands)

    Amrit, Usha

    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

  10. Peptide deformylase as an antibacterial drug target: assays for detection of its inhibition in Escherichia coli cell homogenates and intact cells.

    Science.gov (United States)

    Apfel, C M; Evers, S; Hubschwerlen, C; Pirson, W; Page, M G; Keck, W

    2001-04-01

    An assay was developed to determine the activity of peptide deformylase (PDF) inhibitors under conditions as close as possible to the physiological situation. The assay principle is the detection of N-terminal [35S]methionine labeling of a protein that contains no internal methionine. If PDF is active, the deformylation of the methionine renders the peptide a substrate for methionine aminopeptidase, resulting in the removal of the N-terminal methionine label. In the presence of a PDF inhibitor, the deformylation is blocked so that the N-formylated peptide is not processed and the label is detected. Using this assay, it is possible to determine the PDF activity under near-physiological conditions in a cell-free transcription-translation system as well as in intact bacterial cells.

  11. A Diverse Family of Host-Defense Peptides (Piscidins Exhibit Specialized Anti-Bacterial and Anti-Protozoal Activities in Fishes.

    Directory of Open Access Journals (Sweden)

    Scott A Salger

    Full Text Available Conventional antibiotics and other chemical-based drugs are currently one of the most common methods used to control disease-related mortality in animal agriculture. Use of the innate immune system to decrease disease related mortalities is a novel alternative to conventional drugs. One component of the innate immune system is the host-defense peptides, also known as antimicrobial peptides. Host-defense peptides are typically small, amphipathic, α-helical peptides with a broad-spectrum of action against viral, bacterial, fungal, and/or protozoal pathogens. Piscidins are host-defense peptides first discovered in the hybrid striped bass (white bass, Morone chrysops, x striped bass, M. saxatilis. In this paper we identify four new piscidin isoforms in the hybrid striped bass and describe their tissue distributions. We also determine the progenitor species of origin of each piscidin (orthology and propose a revised nomenclature for this newly described piscidin family based on a three class system. The Class I piscidins (22 amino acids in length; striped bass and white bass piscidin 1 and piscidin 3 show broad-spectrum activity against bacteria and ciliated protozoans, while the Class III piscidins (55 amino acids in length; striped bass and white bass piscidin 6 and striped bass piscidin 7 primarily show anti-protozoal activity. The Class II piscidins (44-46 amino acids in length; striped bass and white bass piscidin 4 and white bass piscidin 5 have a level of activity against bacteria and protozoans intermediate to Classes I and III. Knowledge of piscidin function and activity may help in the future development of disease-resistant lines of striped bass and white bass that could be used to produce superior hybrids for aquaculture.

  12. A Diverse Family of Host-Defense Peptides (Piscidins) Exhibit Specialized Anti-Bacterial and Anti-Protozoal Activities in Fishes.

    Science.gov (United States)

    Salger, Scott A; Cassady, Katherine R; Reading, Benjamin J; Noga, Edward J

    2016-01-01

    Conventional antibiotics and other chemical-based drugs are currently one of the most common methods used to control disease-related mortality in animal agriculture. Use of the innate immune system to decrease disease related mortalities is a novel alternative to conventional drugs. One component of the innate immune system is the host-defense peptides, also known as antimicrobial peptides. Host-defense peptides are typically small, amphipathic, α-helical peptides with a broad-spectrum of action against viral, bacterial, fungal, and/or protozoal pathogens. Piscidins are host-defense peptides first discovered in the hybrid striped bass (white bass, Morone chrysops, x striped bass, M. saxatilis). In this paper we identify four new piscidin isoforms in the hybrid striped bass and describe their tissue distributions. We also determine the progenitor species of origin of each piscidin (orthology) and propose a revised nomenclature for this newly described piscidin family based on a three class system. The Class I piscidins (22 amino acids in length; striped bass and white bass piscidin 1 and piscidin 3) show broad-spectrum activity against bacteria and ciliated protozoans, while the Class III piscidins (55 amino acids in length; striped bass and white bass piscidin 6 and striped bass piscidin 7) primarily show anti-protozoal activity. The Class II piscidins (44-46 amino acids in length; striped bass and white bass piscidin 4 and white bass piscidin 5) have a level of activity against bacteria and protozoans intermediate to Classes I and III. Knowledge of piscidin function and activity may help in the future development of disease-resistant lines of striped bass and white bass that could be used to produce superior hybrids for aquaculture.

  13. 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.

  14. Use of the Antimicrobial Peptide Sublancin with Combined Antibacterial and Immunomodulatory Activities To Protect against Methicillin-Resistant Staphylococcus aureus Infection in Mice.

    Science.gov (United States)

    Wang, Shuai; Wang, Qingwei; Zeng, Xiangfang; Ye, Qianhong; Huang, Shuo; Yu, Haitao; Yang, Tianren; Qiao, Shiyan

    2017-10-04

    Methicillin-resistant Staphylococcus aureus (MRSA) is the major pathogen causing serious hospital infections worldwide. With the emergence and rapid spread of drug-resistant bacteria, there is extraordinary interest in antimicrobial peptides (AMPs) as promising candidates for the treatment of antibiotic-resistant bacterial infections. Sublancin, a glycosylated AMP produced by Bacillus subtilis 168, has been reported to possess protective activity against bacterial infection. This study was performed to evaluate the efficacy of sublancin in the prevention of MRSA ATCC43300 intraperitoneal infection in mice. We determined that sublancin had a minimal inhibitory concentration of 15 μM against MRSA ATCC43300. The antimicrobial action of sublancin involved the destruction of the bacterial cell wall. Dosing of mice with sublancin greatly alleviated (p resistant infections and sepsis.

  15. A technology for developing synbodies with antibacterial activity.

    Directory of Open Access Journals (Sweden)

    Valeriy Domenyuk

    Full Text Available The rise in antibiotic resistance has led to an increased research focus on discovery of new antibacterial candidates. While broad-spectrum antibiotics are widely pursued, there is evidence that resistance arises in part from the wide spread use of these antibiotics. Our group has developed a system to produce protein affinity agents, called synbodies, which have high affinity and specificity for their target. In this report, we describe the adaptation of this system to produce new antibacterial candidates towards a target bacterium. The system functions by screening target bacteria against an array of 10,000 random sequence peptides and, using a combination of membrane labeling and intracellular dyes, we identified peptides with target specific binding or killing functions. Binding and lytic peptides were identified in this manner and in vitro tests confirmed the activity of the lead peptides. A peptide with antibacterial activity was linked to a peptide specifically binding Staphylococcus aureus to create a synbody with increased antibacterial activity. Subsequent tests showed that this peptide could block S. aureus induced killing of HEK293 cells in a co-culture experiment. These results demonstrate the feasibility of using the synbody system to discover new antibacterial candidate agents.

  16. Computer-Aided Design of Antimicrobial Peptides

    DEFF Research Database (Denmark)

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

    2010-01-01

    in antimicrobial activity. Consequently, the majority of peptides put into clinical trials have failed at some point, underlining the importance of a thorough peptide optimization. An important tool in peptide design and optimization is quantitative structure-activity relationship (QSAR) analysis, correlating...... 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...

  17. Antimicrobial Peptides in Reptiles

    Science.gov (United States)

    van Hoek, Monique L.

    2014-01-01

    Reptiles are among the oldest known amniotes and are highly diverse in their morphology and ecological niches. These animals have an evolutionarily ancient innate-immune system that is of great interest to scientists trying to identify new and useful antimicrobial peptides. Significant work in the last decade in the fields of biochemistry, proteomics and genomics has begun to reveal the complexity of reptilian antimicrobial peptides. Here, the current knowledge about antimicrobial peptides in reptiles is reviewed, with specific examples in each of the four orders: Testudines (turtles and tortosises), Sphenodontia (tuataras), Squamata (snakes and lizards), and Crocodilia (crocodilans). Examples are presented of the major classes of antimicrobial peptides expressed by reptiles including defensins, cathelicidins, liver-expressed peptides (hepcidin and LEAP-2), lysozyme, crotamine, and others. Some of these peptides have been identified and tested for their antibacterial or antiviral activity; others are only predicted as possible genes from genomic sequencing. Bioinformatic analysis of the reptile genomes is presented, revealing many predicted candidate antimicrobial peptides genes across this diverse class. The study of how these ancient creatures use antimicrobial peptides within their innate immune systems may reveal new understandings of our mammalian innate immune system and may also provide new and powerful antimicrobial peptides as scaffolds for potential therapeutic development. PMID:24918867

  18. Highly Potent Antibacterial Organometallic Peptide Conjugates

    NARCIS (Netherlands)

    Albada, Bauke; Metzler-Nolte, Nils

    2017-01-01

    ConspectusResistance of pathogenic bacteria against currently marketed antibiotics is again increasing. To meet the societal need for effective cures, scientists are faced with the challenge of developing more potent but equally bacteria-specific drugs. Currently, most efforts are directed toward

  19. 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.

  20. Evaluation of the antibacterial spectrum of drosocin analogues

    NARCIS (Netherlands)

    Bikker, F.J.; Kaman-van Zanten, W.E.; Vries-van de Ruit, A.M.B.C. de; Voskamp-Visser, I.; Hooft, P.A.V. van; Mars-Groenendijk, R.H.; Visser, P.C. de; Noort, D.

    2006-01-01

    Drosocin is a 19-mer, cationic antimicrobial peptide from Drosophila melanogaster. The aim of the study was to examine the antibacterial spectrum of unglycosylated drosocin analogues. Furthermore, the amino acid sequence of DnaK, drosocin's intracellular target, from susceptible species was aligned

  1. Design, Synthesis, and Antibacterial Activities of Novel Heterocyclic Arylsulphonamide Derivatives.

    Science.gov (United States)

    Singh, Anuradha; Srivastava, Ritika; Singh, Ramendra K

    2017-02-13

    Design, synthesis, and antibacterial activities of a series of arylsulphonamide derivatives as probable peptide deformylase (PDF) inhibitors have been discussed. Compounds have been designed following Lipinski's rule and after docking into the active site of PDF protein (PDB code: 1G2A) synthesized later on. Furthermore, to assess their antibacterial activity, screening of the compound was done in vitro conditions against Gram-positive and Gram-negative bacterial strains. In silico, studies revealed these compounds as potential antibacterial agents and this fact was also supported by their prominent scoring functions. Antibacterial results indicated that these molecules possessed a significant activity against Staphylococcus aureus, Bacillus cereus, Pseudomonas aeruginosa, and Escherichia coli with MIC values ranging from 0.06 to 0.29 μM. TOPKAT results showed that high LD 50 values and the compounds were assumed non-carcinogenic when various animal models were studied computationally.

  2. Antibacterial components of honey

    NARCIS (Netherlands)

    Kwakman, Paulus H. S.; Zaat, Sebastian A. J.

    2012-01-01

    The antibacterial activity of honey has been known since the 19th century. Recently, the potent activity of honey against antibiotic-resistant bacteria has further increased the interest for application of honey, but incomplete knowledge of the antibacterial activity is a major obstacle for clinical

  3. 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.

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

    KAUST Repository

    Rydberg, Hanna A; Kunze, Angelika; Carlsson, Nils; Altgä rde, Noomi; Svedhem, Sofia; Nordé n, Bengt

    2014-01-01

    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.

  5. Peptide aldehyde inhibitors of bacterial peptide deformylases.

    Science.gov (United States)

    Durand, D J; Gordon Green, B; O'Connell, J F; Grant, S K

    1999-07-15

    Bacterial peptide deformylases (PDF, EC 3.5.1.27) are metalloenzymes that cleave the N-formyl groups from N-blocked methionine polypeptides. Peptide aldehydes containing a methional or norleucinal inhibited recombinant peptide deformylase from gram-negative Escherichia coli and gram-positive Bacillus subtilis. The most potent inhibitor was calpeptin, N-CBZ-Leu-norleucinal, which was a competitive inhibitor of the zinc-containing metalloenzymes, E. coli and B. subtilis PDF with Ki values of 26.0 and 55.6 microM, respectively. Cobalt-substituted E. coli and B. subtilis deformylases were also inhibited by these aldehydes with Ki values for calpeptin of 9.5 and 12.4 microM, respectively. Distinct spectral changes were observed upon binding of calpeptin to the Co(II)-deformylases, consistent with the noncovalent binding of the inhibitor rather than the formation of a covalent complex. In contrast, the chelator 1,10-phenanthroline caused the time-dependent inhibition of B. subtilis Co(II)-PDF activity with the loss of the active site metal. The fact that calpeptin was nearly equipotent against deformylases from both gram-negative and gram-positive bacterial sources lends further support to the idea that a single deformylase inhibitor might have broad-spectrum antibacterial activity. Copyright 1999 Academic Press.

  6. Loop Replacement Enhances the Ancestral Antibacterial Function of a Bifunctional Scorpion Toxin

    Directory of Open Access Journals (Sweden)

    Shangfei Zhang

    2018-06-01

    Full Text Available On the basis of the evolutionary relationship between scorpion toxins targeting K+ channels (KTxs and antibacterial defensins (Zhu S., Peigneur S., Gao B., Umetsu Y., Ohki S., Tytgat J. Experimental conversion of a defensin into a neurotoxin: Implications for origin of toxic function. Mol. Biol. Evol. 2014, 31, 546–559, we performed protein engineering experiments to modify a bifunctional KTx (i.e., weak inhibitory activities on both K+ channels and bacteria via substituting its carboxyl loop with the structurally equivalent loop of contemporary defensins. As expected, the engineered peptide (named MeuTXKα3-KFGGI remarkably improved the antibacterial activity, particularly on some Gram-positive bacteria, including several antibiotic-resistant opportunistic pathogens. Compared with the unmodified toxin, its antibacterial spectrum also enlarged. Our work provides a new method to enhance the antibacterial activity of bifunctional scorpion venom peptides, which might be useful in engineering other proteins with an ancestral activity.

  7. The oxadiazole antibacterials.

    Science.gov (United States)

    Janardhanan, Jeshina; Chang, Mayland; Mobashery, Shahriar

    2016-10-01

    The oxadiazoles are a class of antibacterials discovered by in silico docking and scoring of compounds against the X-ray structure of a penicillin-binding protein. These antibacterials exhibit activity against Gram-positive bacteria, including against methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE). They show in vivo efficacy in murine models of peritonitis/sepsis and neutropenic thigh MRSA infection. They are bactericidal and orally bioavailable. The oxadiazoles show promise in treatment of MRSA infection. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Peptide dendrimers

    Czech Academy of Sciences Publication Activity Database

    Niederhafner, Petr; Šebestík, Jaroslav; Ježek, Jan

    2005-01-01

    Roč. 11, - (2005), 757-788 ISSN 1075-2617 R&D Projects: GA ČR(CZ) GA203/03/1362 Institutional research plan: CEZ:AV0Z40550506 Keywords : multiple antigen peptides * peptide dendrimers * synthetic vaccine * multipleantigenic peptides Subject RIV: CC - Organic Chemistry Impact factor: 1.803, year: 2005

  9. Screening And Optimizing Antimicrobial Peptides By Using SPOT-Synthesis

    Science.gov (United States)

    López-Pérez, Paula M.; Grimsey, Elizabeth; Bourne, Luc; Mikut, Ralf; Hilpert, Kai

    2017-04-01

    Peptide arrays on cellulose are a powerful tool to investigate peptide interactions with a number of different molecules, for examples antibodies, receptors or enzymes. Such peptide arrays can also be used to study interactions with whole cells. In this review, we focus on the interaction of small antimicrobial peptides with bacteria. Antimicrobial peptides (AMPs) can kill multidrug-resistant (MDR) human pathogenic bacteria and therefore could be next generation antibiotics targeting MDR bacteria. We describe the screen and the result of different optimization strategies of peptides cleaved from the membrane. In addition, screening of antibacterial activity of peptides that are tethered to the surface is discussed. Surface-active peptides can be used to protect surfaces from bacterial infections, for example implants.

  10. 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.

  11. 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.

  12. 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.

  13. Antimicrobial Peptide-PNA Conjugates Selectively Targeting Bacterial Genes

    Science.gov (United States)

    2013-07-22

    antibacterial therapy. Initial publications suggest that conjugates of cell penetrating peptides and PNA’s can overcome the barrier in transporting ...Zhou, Y., Hou, Z., Meng, J., and Luo, X. Targeting RNA polymerase primary σ70 as a therapeutic strategy against methicillin - resistant ... Staphylococcus aureus by antisense peptide nucleic acid. PLoS One. 2012; 7(1):e29886. 2. Good, L., Sandberg, R., Larsson, O., Nielsen, P.E., and Wahlestedt, C

  14. 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.

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

    Science.gov (United States)

    Huertas Méndez, Nataly De Jesús; Vargas Casanova, Yerly; Gómez Chimbi, Anyelith Katherine; Hernández, Edith; Leal Castro, Aura Lucia; Melo Diaz, Javier Mauricio; Rivera Monroy, Zuly Jenny; García Castañeda, Javier Eduardo

    2017-03-12

    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 (RRWQWR)₂K-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 .

  16. 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.

  17. 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 flat and rough reference surfaces. Our micro/nanofabrication process is a scalable approach based on cost-efficient self-organization and provides potential for further developing functional surfaces to study the behavior of microbes on nanoscale topographies.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

  18. Antibacterial Au nanostructured surfaces.

    Science.gov (United States)

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

    2016-02-07

    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 flat and rough reference surfaces. Our micro/nanofabrication process is a scalable approach based on cost-efficient self-organization and provides potential for further developing functional surfaces to study the behavior of microbes on nanoscale topographies.

  19. Antibacterial activity of antileukoprotease.

    Science.gov (United States)

    Hiemstra, P S; Maassen, R J; Stolk, J; Heinzel-Wieland, R; Steffens, G J; Dijkman, J H

    1996-01-01

    Antileukoprotease (ALP), or secretory leukocyte proteinase inhibitor, is an endogenous inhibitor of serine proteinases that is present in various external secretions. ALP, one of the major inhibitors of serine proteinases present in the human lung, is a potent reversible inhibitor of elastase and, to a lesser extent, of cathepsin G. In equine neutrophils, an antimicrobial polypeptide that has some of the characteristics of ALP has been identified (M. A. Couto, S. S. L. Harwig, J. S. Cullor, J. P. Hughes, and R. I. Lehrer, Infect. Immun. 60:5042-5047, 1992). This report, together with the cationic nature of ALP, led us to investigate the antimicrobial activity of ALP. ALP was shown to display marked in vitro antibacterial activity against Escherichia coli and Staphylococcus aureus. On a molar basis, the activity of ALP was lower than that of two other cationic antimicrobial polypeptides, lysozyme and defensin. ALP comprises two homologous domains: its proteinase-inhibitory activities are known to be located in the second COOH-terminal domain, and the function of its first NH2-terminal domain is largely unknown. Incubation of intact ALP or its isolated first domain with E. coli or S. aureus resulted in killing of these bacteria, whereas its second domain displayed very little antibacterial activity. Together these data suggest a putative antimicrobial role for the first domain of ALP and indicate that its antimicrobial activity may equip ALP to contribute to host defense against infection. PMID:8890201

  20. Antibacterial Metallic Touch Surfaces

    Directory of Open Access Journals (Sweden)

    Victor M. Villapún

    2016-08-01

    Full Text Available Our aim is to present a comprehensive review of the development of modern antibacterial metallic materials as touch surfaces in healthcare settings. Initially we compare Japanese, European and US standards for the assessment of antimicrobial activity. The variations in methodologies defined in these standards are highlighted. Our review will also cover the most relevant factors that define the antimicrobial performance of metals, namely, the effect of humidity, material geometry, chemistry, physical properties and oxidation of the material. The state of the art in contact-killing materials will be described. Finally, the effect of cleaning products, including disinfectants, on the antimicrobial performance, either by direct contact or by altering the touch surface chemistry on which the microbes attach, will be discussed. We offer our outlook, identifying research areas that require further development and an overview of potential future directions of this exciting field.

  1. Antibacterial activity of Ficus capensis

    African Journals Online (AJOL)

    STORAGESEVER

    2008-05-16

    Allium sativum) is used to reduce cholesterol levels and to boost immune system; it lowers high blood pressure and its oil has been seen to have antibacterial properties (Juurlink, 2001). Milk thistle. Silybum marianum has also ...

  2. 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.

  3. Antibacterial triterpenoids from Melia toosendan

    Directory of Open Access Journals (Sweden)

    Qin Zhu

    2015-01-01

    Full Text Available A new lanostan-type triterpenoid with hydroperoxy group, toosendanin A (1, together with two known triterpenoids, meliastatin 3 (2 and ursolic acid (3, w ere isolated and identified from the stems of Melia toosendan. The structures of these compounds were elucidated by 1D- and 2D-NMR spectra and other spectroscopic studies. These compounds were assayed for the antibacterial activities against some hospital pathogenic bacteria. Toosendanin A (1 exhibited strong antibacterial activity against K. pneumoniae .

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

    NARCIS (Netherlands)

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

    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

  5. Antibacterial Effect of Surface Pretreatment Techniques against ...

    African Journals Online (AJOL)

    2018-02-23

    Feb 23, 2018 ... 2018 Nigerian Journal of Clinical Practice | Published by Wolters Kluwer ... Objective: The aim of this study was to evaluate the antibacterial surface .... glass ionomer cement. ..... resin containing antibacterial monomer MDPB.

  6. 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.

  7. 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. PMID:24949423

  8. 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

  9. Peptide chemistry toolbox - Transforming natural peptides into peptide therapeutics.

    Science.gov (United States)

    Erak, Miloš; Bellmann-Sickert, Kathrin; Els-Heindl, Sylvia; Beck-Sickinger, Annette G

    2018-06-01

    The development of solid phase peptide synthesis has released tremendous opportunities for using synthetic peptides in medicinal applications. In the last decades, peptide therapeutics became an emerging market in pharmaceutical industry. The need for synthetic strategies in order to improve peptidic properties, such as longer half-life, higher bioavailability, increased potency and efficiency is accordingly rising. In this mini-review, we present a toolbox of modifications in peptide chemistry for overcoming the main drawbacks during the transition from natural peptides to peptide therapeutics. Modifications at the level of the peptide backbone, amino acid side chains and higher orders of structures are described. Furthermore, we are discussing the future of peptide therapeutics development and their impact on the pharmaceutical market. Copyright © 2018 Elsevier Ltd. All rights reserved.

  10. 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.

  11. Coiled-coil forming peptides for the induction of silver nanoparticles

    International Nuclear Information System (INIS)

    Božič Abram, Sabina; Aupič, Jana; Dražić, Goran; Gradišar, Helena; Jerala, Roman

    2016-01-01

    Biopolymers with defined sequence patterns offer an attractive alternative for the formation of silver nanoparticle (AgNP). A set of coiled-coil dimer forming peptides was tested for their AgNP formation ability. Seventeen of those peptides mediated the formation of AgNPs in aqueous solution at neutral pH, while the formation of a coiled-coil dimer inhibited the nanoparticle generation. A QSAR regression model on the relationship between sequence and function suggests that in this peptide type the patterns KXQQ and KXEE are favorable, whereas Ala residues appear to have an inhibitory effect. UV–VIS spectra of the obtained nanoparticles gave a peak at around 420 nm, typical for AgNPs in the size range around 40 nm, which was confirmed by dynamic light scattering and transmission electron microscopy. Peptide-induced AgNPs exhibited good antibacterial activity, even after a 15 min contact time, while they had low toxicity to human cells at the same concentrations. These results show that our designed peptides generate AgNPs with antibacterial activity at mild conditions and might be used for antibacterial coatings. - Highlights: • 17 of the 30 tested coiled-coil forming peptides induce AgNP formation. • Coiled-coil dimer formation suppresses AgNP generation of individual peptides. • Size of the peptide-induced silver nanoparticles is around 40 nm. • QSAR analysis points to the importance of KXQQ and KXEE motifs for AgNP generation. • Peptide-induced silver nanoparticles exhibit antibacterial activity.

  12. Coiled-coil forming peptides for the induction of silver nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Božič Abram, Sabina [Department of Synthetic Biology and Immunology, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana (Slovenia); Graduate School of Biomedicine, University of Ljubljana, Ljubljana 1000 (Slovenia); Aupič, Jana [Department of Synthetic Biology and Immunology, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana (Slovenia); Doctoral Programme in Chemical Sciences, Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana 1000 (Slovenia); Dražić, Goran [Laboratory for Materials Chemistry, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana (Slovenia); Gradišar, Helena [Department of Synthetic Biology and Immunology, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana (Slovenia); EN-FIST, Centre of Excellence, Trg Osvobodilne fronte 13, Ljubljana 1000 (Slovenia); Jerala, Roman, E-mail: roman.jerala@ki.si [Department of Synthetic Biology and Immunology, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana (Slovenia); EN-FIST, Centre of Excellence, Trg Osvobodilne fronte 13, Ljubljana 1000 (Slovenia)

    2016-04-08

    Biopolymers with defined sequence patterns offer an attractive alternative for the formation of silver nanoparticle (AgNP). A set of coiled-coil dimer forming peptides was tested for their AgNP formation ability. Seventeen of those peptides mediated the formation of AgNPs in aqueous solution at neutral pH, while the formation of a coiled-coil dimer inhibited the nanoparticle generation. A QSAR regression model on the relationship between sequence and function suggests that in this peptide type the patterns KXQQ and KXEE are favorable, whereas Ala residues appear to have an inhibitory effect. UV–VIS spectra of the obtained nanoparticles gave a peak at around 420 nm, typical for AgNPs in the size range around 40 nm, which was confirmed by dynamic light scattering and transmission electron microscopy. Peptide-induced AgNPs exhibited good antibacterial activity, even after a 15 min contact time, while they had low toxicity to human cells at the same concentrations. These results show that our designed peptides generate AgNPs with antibacterial activity at mild conditions and might be used for antibacterial coatings. - Highlights: • 17 of the 30 tested coiled-coil forming peptides induce AgNP formation. • Coiled-coil dimer formation suppresses AgNP generation of individual peptides. • Size of the peptide-induced silver nanoparticles is around 40 nm. • QSAR analysis points to the importance of KXQQ and KXEE motifs for AgNP generation. • Peptide-induced silver nanoparticles exhibit antibacterial activity.

  13. Antibacterial activity in the hemolymph of the catarina scallop Argopecten ventricosus

    OpenAIRE

    Luna-González, Antonio; Maeda-Martínez, Alfonso; Campa-Córdova, Ángel; Orduña-Rojas, Javier

    2007-01-01

    We conducted a search for antibacterial peptide like activity in hemolymph of Argopecten ventricosus. Pre-purification of peptides was done by reverse phase HPLC. Hemolymph acidic supernatant was loaded into a column packed with C18 matrix. Stepwise elutions were performed with 5, 50, 80, and 100 % acetonitrile (ACN) in 0.05 % trifluoroacetic acid (TFA) over 550 min at a flow rate of 0.2 ml/min. Absorbance was monitored at 280 nm. Eluted fractions were concentrated under vacuum. Vibrio algino...

  14. α-Peptide/ß-Peptoid Chimeras

    DEFF Research Database (Denmark)

    Olsen, Christian Adam; Bonke, Gitte; Vedel, Line

    2007-01-01

    We describe the synthesis and characterization of the first generation of oligomers consisting of alternating repeats of a-amino acids and chiral N-alkyl-ß-alanine (ß-peptoid) residues. These chimeras are stable toward proteolysis, non-hemolytic, and possess antibacterial activity comparable...... to well-known antimicrobial agents. Moreover, the chimeras exhibit length-dependent, concentration-dependent, solvent-dependent, and ion-strength-dependent ellipticity, indicating the presence of a secondary structure in solution. Thus, a-peptide/ß-peptoid oligomers represent a promising novel...

  15. 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.

  16. 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. © 2014 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

  17. Are antimicrobial peptides an alternative for conventional antibiotics?

    International Nuclear Information System (INIS)

    Kamysz, W.

    2005-01-01

    Antimicrobial peptides are widespread in living organisms and constitute an important component of innate immunity to microbial infections. By the early 1980' s , more than 800 different antimicrobial peptides had been isolated from mammals, amphibians, fish, insects, plants and bacterial species. In humans, they are produced by granulocytes, macrophages and most epithelial and endothelial cells. Newly discovered antibiotics have antibacterial, antifungal, antiviral and even antiprotozoal activity. Occasionally, a single antibiotic may have a very wide spectrum of activity and may show activity towards various kinds of microorganisms. Although antimicrobial activity is the most typical function of peptides, they are also characterized by numerous other properties. They stimulate the immune system, have anti-neoplastic properties and participate in cell signalling and proliferation regulation. As antimicrobial peptides from higher eukaryotes differ structurally from conventional antibiotics produced by bacteria and fungi, they offer novel templates for pharmaceutical compounds, which could be used effectively against the increasing number of resistant microbes. (author)

  18. The Antimicrobial Peptide Lysozyme Is Induced after Multiple Trauma

    OpenAIRE

    Klüter, Tim; Fitschen-Oestern, Stefanie; Lippross, Sebastian; Weuster, Matthias; Mentlein, Rolf; Steubesand, Nadine; Neunaber, Claudia; Hildebrand, Frank; Pufe, Thomas; Tohidnezhad, Mersedeh; Beyer, Andreas; Seekamp, Andreas; Varoga, Deike

    2014-01-01

    The antimicrobial peptide lysozyme is an important factor of innate immunity and exerts high potential of antibacterial activity. In the present study we evaluated the lysozyme expression in serum of multiple injured patients and subsequently analyzed their possible sources and signaling pathways. Expression of lysozyme was examined in blood samples of multiple trauma patients from the day of trauma until 14 days after trauma by ELISA. To investigate major sources of lysozyme, its expression ...

  19. Neurotropic and neuroprotective activities of the earthworm peptide Lumbricusin

    International Nuclear Information System (INIS)

    Kim, Dae Hong; Lee, Ik Hwan; Nam, Seung Taek; Hong, Ji; Zhang, Peng; Hwang, Jae Sam; Seok, Heon; Choi, Hyemin; Lee, Dong Gun; Kim, Jae Il; Kim, Ho

    2014-01-01

    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 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 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 Kip1 significantly blocked the antiapoptotic effect of Lumbricusin in 6-hydroxy dopamine-treated SH-SY5Y cells. These results suggest that promotion of p27 Kip1 degradation may be the main mechanism underlying the neuroprotective and neurotropic effects of Lumbricusin

  20. 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.

  1. Antimicrobial Peptides: a promising class of antimicrobial compounds against BWA and multi-drug resistant bacteria: in the spotlight: the lactoferrin chimera

    NARCIS (Netherlands)

    Bikker, F.J.; Sijbrandij, T.; Nazmi, K.; Bolscher, J.G.M.; Veerman, E.C.I.; Jansen, H-J.

    2014-01-01

    Anti-Microbial Peptides (AMPs) are part of the innate immune defense system and considered as promising lead compounds for the development of novel anti-bacterial agents. In general, AMPs are simple, short peptides with broad-spectrum activity against Gram-negative and Gram-positive bacteria, fungi,

  2. Expression, purification, and antibacterial activity of bovine lactoferrampin-lactoferricin in Pichia pastoris.

    Science.gov (United States)

    Tang, Xiang-Shan; Tang, Zhi-Ru; Wang, Sheng-Ping; Feng, Ze-Meng; Zhou, Dong; Li, Tie-Jun; Yin, Yu-Long

    2012-02-01

    Bovine lactoferrampin (LFA) and bovine lactoferricin (LFC) are two antimicrobial peptides located in the N(1) domain of bovine lactoferrin. The bactericidal activity of the fused peptide LFA-LFC is stronger than that of either LFA or LFC. The high cost of peptide production from either native digestion or chemical synthesis limits the clinical application of antimicrobial peptides. The expression of recombinant peptides in yeast may be an effective alternative. In the current study, the expression, purification, and antibacterial activity of LFA-LFC using the Pichia pastoris expression system are reported. The linearized expression vector pPICZaA-LFA-LFC was transformed into P. pastoris KM71 by electroporation, and positive colonies harboring the target genes were screened out and used for fermentation. The recombinant LFA-LFC peptide was purified via two-step column chromatography and identified by tricine-sodium dodecyl sulfate-polyacrylamide gel electrophoresis and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The results indicate that P. pastoris is a suitable system for secreting LFA-LFC. The fermentation supernate and the purified LFA-LFC show high antimicrobial activities. The current study is the first to report on the expression and purification of LFA-LFC in P. pastoris and may have potential practical applications in microbial peptide production.

  3. Antibacterial activity of Artocarpus heterophyllus.

    Science.gov (United States)

    Khan, M R; Omoloso, A D; Kihara, M

    2003-07-01

    The crude methanolic extracts of the stem and root barks, stem and root heart-wood, leaves, fruits and seeds of Artocarpus heterophyllus and their subsequent partitioning with petrol, dichloromethane, ethyl acetate and butanol gave fractions that exhibited a broad spectrum of antibacterial activity. The butanol fractions of the root bark and fruits were found to be the most active. None of the fractions were active against the fungi tested.

  4. 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, wh...

  5. Antimicrobial Peptide from the Eusocial Bee Halictus sexcinctus Interacting with Model Membranes

    Czech Academy of Sciences Publication Activity Database

    Pazderková, Markéta; Kočišová, E.; Pazderka, T.; Maloň, Petr; Kopecký ml., V.; Monincová, Lenka; Čeřovský, Václav; Bednárová, Lucie

    2012-01-01

    Roč. 27, 5-6 (2012), s. 497-502 ISSN 0712-4813 R&D Projects: GA ČR GAP208/10/0376 Institutional research plan: CEZ:AV0Z40550506 Keywords : antibacterial peptides * halictine * micelle * liposome * phospholipid * circular dichroism * fluorescence * infrared spectroscopy Subject RIV: CC - Organic Chemistry Impact factor: 0.530, year: 2012

  6. Dynamics of lipid layers with/without bounded antimicrobial peptide halictine-1

    Czech Academy of Sciences Publication Activity Database

    Tesař, A.; Kopecký, V. Jr.; Kočišová, E.; Bednárová, Lucie

    2017-01-01

    Roč. 93, Nov (2017), s. 42-51 ISSN 0924-2031 R&D Projects: GA ČR GAP208/10/0376 Institutional support: RVO:61388963 Keywords : antibacterial peptide * halictine * liposome * phospholipid bilayer * infrared spectroscopy * attenuated total reflection Subject RIV: BO - Biophysics OBOR OECD: Biophysics Impact factor: 1.740, year: 2016

  7. Design and synthesis of macrocyclic peptidyl hydroxamates as peptide deformylase inhibitors.

    Science.gov (United States)

    Shen, Gang; Zhu, Jinge; Simpson, Anthony M; Pei, Dehua

    2008-05-15

    Macrocyclic peptidyl hydroxamates were designed, synthesized, and evaluated as peptide deformylase (PDF) inhibitors. The most potent compound exhibited tight, slow-binding inhibition of Escherichia coli PDF (K(I)(*)=4.4 nM) and had potent antibacterial activity against Gram-positive bacterium Bacillus subtilis (MIC=2-4 microg/mL).

  8. The route of infection determines Wolbachia antibacterial protection in Drosophila.

    Science.gov (United States)

    Gupta, Vanika; Vasanthakrishnan, Radhakrishnan B; Siva-Jothy, Jonathon; Monteith, Katy M; Brown, Sam P; Vale, Pedro F

    2017-06-14

    Bacterial symbionts are widespread among metazoans and provide a range of beneficial functions. Wolbachia -mediated protection against viral infection has been extensively demonstrated in Drosophila. In mosquitoes that are artificially transinfected with Drosophila melanogaster Wolbachia (wMel), protection from both viral and bacterial infections has been demonstrated. However, no evidence for Wolbachia -mediated antibacterial protection has been demonstrated in Drosophila to date. Here, we show that the route of infection is key for Wolbachia -mediated antibacterial protection. Drosophila melanogaster carrying Wolbachia showed reduced mortality during enteric-but not systemic-infection with the opportunist pathogen Pseudomonas aeruginosa Wolbachia -mediated protection was more pronounced in male flies and is associated with increased early expression of the antimicrobial peptide Attacin A , and also increased expression of a reactive oxygen species detoxification gene ( Gst D8 ). These results highlight that the route of infection is important for symbiont-mediated protection from infection, that Wolbachia can protect hosts by eliciting a combination of resistance and disease tolerance mechanisms, and that these effects are sexually dimorphic. We discuss the importance of using ecologically relevant routes of infection to gain a better understanding of symbiont-mediated protection. © 2017 The Authors.

  9. Antimicrobial Activity of Truncated and Polyvalent Peptides Derived from the FKCRRQWQWRMKKGLA Sequence against Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 25923

    Directory of Open Access Journals (Sweden)

    Nataly de Jesús Huertas

    2017-06-01

    Full Text Available Peptides derived from LfcinB were designed and synthesized, and their antibacterial activity was tested against Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 25923. Specifically, a peptide library was constructed by systemically removing the flanking residues (N or C-terminal of Lfcin 17–31 (17FKCRRWQWRMKKLGA31, maintaining in all peptides the 20RRWQWR25 sequence that corresponds to the minimal antimicrobial motif. For this research, also included were (i a peptide containing an Ala instead of Cys ([Ala19]-LfcinB 17–31 and (ii polyvalent peptides containing the RRWQWR sequence and a non-natural amino acid (aminocaproic acid. We established that the lineal peptides LfcinB 17–25 and LfcinB 17–26 exhibited the greatest activity against E. coli ATCC 25922 and S. aureus ATCC 25923, respectively. On the other hand, polyvalent peptides, a dimer and a tetramer, exhibited the greatest antibacterial activity, indicating that multiple copies of the sequence increase the activity. Our results suggest that the dimeric and tetrameric sequence forms potentiate the antibacterial activity of lineal sequences that have exhibited moderate antibacterial activity.

  10. Anhydrous polymer-based coating with sustainable controlled release functionality for facile, efficacious impregnation, and delivery of antimicrobial peptides.

    Science.gov (United States)

    Lim, Kaiyang; Saravanan, Rathi; Chong, Kelvin K L; Goh, Sharon H M; Chua, Ray R Y; Tambyah, Paul A; Chang, Matthew W; Kline, Kimberly A; Leong, Susanna S J

    2018-04-17

    Anhydrous polymers are actively explored as alternative materials to overcome limitations of conventional hydrogel-based antibacterial coating. However, the requirement for strong organic solvent in polymerization reactions often necessitates extra protection steps for encapsulation of target biomolecules, lowering encapsulation efficiency, and increasing process complexity. This study reports a novel coating strategy that allows direct solvation and encapsulation of antimicrobial peptides (HHC36) into anhydrous polycaprolactone (PCL) polymer-based dual layer coating. A thin 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) film is layered onto the peptide-impregnated PCL as a diffusion barrier, to modulate and enhance release kinetics. The impregnated peptides are eventually released in a controlled fashion. The use of 2,2,2-trifluoroethanol (TFE), as polymerization and solvation medium, induces the impregnated peptides to adopt highly stable turned conformation, conserving peptide integrity, and functionality during both encapsulation and subsequent release processes. The dual layer coating showed sustained antibacterial functionality, lasting for 14 days. In vivo assessment using an experimental mouse wounding model demonstrated good biocompatibility and significant antimicrobial efficacy of the coating under physiological conditions. The coating was translated onto silicone urinary catheters and showed promising antibacterial efficacy, even outperforming commercial silver-based Dover cather. This anhydrous polymer-based platform holds immense potential as an effective antibacterial coating to prevent clinical device-associated infections. The simplicity of the coating process enhances its industrial viability. © 2018 Wiley Periodicals, Inc.

  11. Fast Screening of Antibacterial Compounds from Fusaria

    DEFF Research Database (Denmark)

    Sondergaard, Teis Esben; Fredborg, Marlene; Christensen, Ann-Maria Oppenhagen

    2016-01-01

    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...

  12. Antibacterial effects and toxigenesis of Penicillium aurantiogriseum ...

    African Journals Online (AJOL)

    SERVER

    2007-10-18

    Oct 18, 2007 ... The toxigenesis of one Penicillium aurantiogriseum and one Penicillium viridicatum isolates was investigated. Sterile culture filtrates of both fungi had a clear antibacterial effect only against Bacillus subtilis. The effect on B. subtilis varied with amount of filtrate used and temperature. The antibacterial.

  13. 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.

  14. 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.

  15. 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.

  16. Antibacterial activity of selected Myanmar medicinal plants

    International Nuclear Information System (INIS)

    Nwe Yee Win; Nyunt Wynn; Mar Mar Nyein; Win Myint; Saw Hla Myint; Myint Khine

    2001-01-01

    Thirteen plants which are traditionally used for the treatment of dysentery and diarrhoea in Myanmar were selected and tested for antibacterial activity by using agar disc diffusion technique. Polar and nonpolar solvents were employed for extraction of plants. The minimum inhibitory concentration (MIC) of the extracts with the most significant predominant activity were evaluated by plate dilution method. The plants Eugenia jambolana, Quisqualis indica, Leucaena glauca and Euphorbia splendens var. 1 were found to show significant antibacterial activity. It was also observed that extracts using nonpolar solvents did not show any antibacterial activity and extracts using polar solvents showed antibacterial activity on tested bacteria, indicating that the active chemical compound responsible for the antibacterial action must be a polar soluble compound. (author)

  17. Antibacterial activity of baking soda.

    Science.gov (United States)

    Drake, D

    1997-01-01

    The antibacterial activity of baking soda (sodium bicarbonate) was assessed using three different experimental approaches. Standard minimum inhibitory concentration analyses revealed substantial inhibitory activity against Streptococcus mutans that was not due to ionic strength or high osmolarity. Short-term exposure assays showed significant killing of bacterial suspensions when baking soda was combined with the detergent sodium dodecylsulfate. Multiple, brief exposures of sucrose-colonized S mutans to baking soda and sodium dodecylsulfate caused statistically significant decreases in numbers of viable cells. Use of oral health care products with high concentrations of baking soda could conceivably result in decreased levels of cariogenic S mutans in saliva and plaque.

  18. Antimicrobial Peptides Derived from Fusion Peptides of Influenza A Viruses, a Promising Approach to Designing Potent Antimicrobial Agents.

    Science.gov (United States)

    Wang, Jingyu; Zhong, Wenjing; Lin, Dongguo; Xia, Fan; Wu, Wenjiao; Zhang, Heyuan; Lv, Lin; Liu, Shuwen; He, Jian

    2015-10-01

    The emergence and dissemination of antibiotic-resistant bacterial pathogens have spurred the urgent need to develop novel antimicrobial agents with different mode of action. In this respect, we turned several fusogenic peptides (FPs) derived from the hemagglutinin glycoproteins (HAs) of IAV into potent antibacterials by replacing the negatively or neutrally charged residues of FPs with positively charged lysines. Their antibacterial activities were evaluated by testing the MICs against a panel of bacterial strains including S. aureus, S. mutans, P. aeruginosa, and E. coli. The results showed that peptides HA-FP-1, HA-FP-2-1, and HA-FP-3-1 were effective against both Gram-positive and Gram-negative bacteria with MICs ranging from 1.9 to 16.0 μm, while the toxicities toward mammalian cells were low. In addition, the mode of action and the secondary structure of these peptides were also discussed. These data not only provide several potent peptides displaying promising potential in development as broad antimicrobial agents, but also present a useful strategy in designing new antimicrobial agents. © 2015 John Wiley & Sons A/S.

  19. Lipopolysaccharide induces amyloid formation of antimicrobial peptide HAL-2.

    Science.gov (United States)

    Wang, Jiarong; Li, Yan; Wang, Xiaoming; Chen, Wei; Sun, Hongbin; Wang, Junfeng

    2014-11-01

    Lipopolysaccharide (LPS), the important component of the outer membrane of Gram-negative bacteria, contributes to the integrity of the outer membrane and protects the cell against bactericidal agents, including antimicrobial peptides. However, the mechanisms of interaction between antimicrobial peptides and LPS are not clearly understood. Halictines-2 (HAL-2), one of the novel antimicrobial peptides, was isolated from the venom of the eusocial bee Halictus sexcinctus. HAL-2 has exhibited potent antimicrobial activity against Gram-positive and Gram-negative bacteria and even against cancer cells. Here, we studied the interactions between HAL-2 and LPS to elucidate the antibacterial mechanism of HAL-2 in vitro. Our results show that HAL-2 adopts a significant degree of β-strand structure in the presence of LPS. LPS is capable of inducing HAL-2 amyloid formation, which may play a vital role in its antimicrobial activity. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Recent studies on the antimicrobial peptides lactoferricin and lactoferrampin.

    Science.gov (United States)

    Yin, C; Wong, J H; Ng, T B

    2014-01-01

    Lactoferricin and lactoferrampin, peptides derived from the whey protein lactoferrin, are antimicrobial agents with a promising prospect and are currently one of the research focuses. In this review, a basic introduction including location and solution structures of these two peptides is given. Their biological activities encompassing antiviral, antibacterial, antifungal and anti-inflammatory activities with possible mechanisms are mentioned. In terms of modification studies, research about identification of their active derivatives and crucial amino acid residues is also discussed. Various attempts at modification of lactoferricin and lactoferrampin such as introducing big hydrophobic side-chains; employing special amino acids for synthesis; N-acetylization, amidation, cyclization and peptide chimera are summarized. The studies on lactoferricin-lactoferrampin chimera are discussed in detail. Future prospects of lactoferricin and lactoferrampin are covered.

  1. 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.

  2. 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...

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

    OpenAIRE

    Indarmawan, Taufik; Mustopa, Apon Zaenal; Budiarto, Bugi Ratno; Tarman, Kustiariyah

    2016-01-01

    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 an...

  4. 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....

  5. 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.

  6. 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....

  7. 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....

  8. 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....

  9. 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....

  10. 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.

  11. 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.

  12. 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.

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

    International Nuclear Information System (INIS)

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

    2013-01-01

    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

  14. Bioactive peptides released from in vitro digestion of human milk with or without pasteurization.

    Science.gov (United States)

    Wada, Yasuaki; Lönnerdal, Bo

    2015-04-01

    Pasteurized donor human milk (HM) serves as the best alternative for breast-feeding when availability of mother's milk is limited. Pasteurization is also applied to mother's own milk for very low birth weight infants, who are vulnerable to microbial infection. Whether pasteurization affects protein digestibility and therefore modulates the profile of bioactive peptides released from HM proteins by gastrointestinal digestion, has not been examined to date. HM with and without pasteurization (62.5 °C for 30 min) were subjected to in vitro gastrointestinal digestion, followed by peptidomic analysis to compare the formation of bioactive peptides. Some of the bioactive peptides, such as caseinophosphopeptide homologues, a possible opioid peptide (or propeptide), and an antibacterial peptide, were present in undigested HM and showed resistance to in vitro digestion, suggesting that these peptides are likely to exert their bioactivities in the gastrointestinal lumen, or be stably transported to target organs. In vitro digestion of HM released a large variety of bioactive peptides such as angiotensin I-converting enzyme-inhibitory, antioxidative, and immunomodulatory peptides. Bioactive peptides were released largely in the same manner with and without pasteurization. Provision of pasteurized HM may be as beneficial as breast-feeding in terms of milk protein-derived bioactive peptides.

  15. Antibacterial-induced nephrotoxicity in the newborn.

    Science.gov (United States)

    Fanos, V; Cataldi, L

    1999-03-01

    Antibacterials are the primary cause of drug-induced kidney disease in all age groups and these agents bring about renal damage by 2 main mechanisms, namely, direct and immunologically mediated. For some antibacterials (aminoglycosides and vancomycin) nephrotoxicity is very frequent but generally reversible upon discontinuation of the drug. However, the development of acute renal failure with these agents is possible and its incidence in the newborn seems to be increasing. Antibacterials are very often used in the neonatal period especially in very low birthweight neonates. The role of neonatal age in developing nephrotoxicity has still to be defined. Since the traditional laboratory parameters of nephrotoxicity are abnormal only in the presence of substantial renal damage, the identification of early non-invasive markers of the renal damage (urinary microglobulins, enzymes and growth factors) is of importance. Aminoglycosides and glycopeptides are still frequently used, either alone or in combination, despite their low therapeutic index. Numerous factors intervene in bringing about the kidney damage induced by these 2 classes of antibacterials, such as factors related to the antibacterial itself and others related to the associated pathology as well as pharmacological factors. Nephrotoxicity can be caused by the beta-lactams and related compounds. Their potential to cause nephrotoxicity decreases in the order: carbapenems > cephalosporins > penicillins > monobactams. Third generation cephalosporins are frequently used in neonates. However, they are well tolerated compounds at the renal level. The nephrotoxicity of other classes of antibacterials is not discussed either because they are only used in neonates in exceptional circumstances, for example, chloramphenicol and cotrimoxazole (trimethoprim-sulfamethoxazole) or are not associated with significant nephrotoxicity, for example macrolides, clindamicin, quinolones, rifampicin (rifampin) and metronidazole

  16. Optical control of antibacterial activity

    Science.gov (United States)

    Velema, Willem A.; van der Berg, Jan Pieter; Hansen, Mickel J.; Szymanski, Wiktor; Driessen, Arnold J. M.; Feringa, Ben L.

    2013-11-01

    Bacterial resistance is a major problem in the modern world, stemming in part from the build-up of antibiotics in the environment. Novel molecular approaches that enable an externally triggered increase in antibiotic activity with high spatiotemporal resolution and auto-inactivation are highly desirable. Here we report a responsive, broad-spectrum, antibacterial agent that can be temporally activated with light, whereupon it auto-inactivates on the scale of hours. The use of such a ‘smart’ antibiotic might prevent the build-up of active antimicrobial material in the environment. Reversible optical control over active drug concentration enables us to obtain pharmacodynamic information. Precisely localized control of activity is achieved, allowing the growth of bacteria to be confined to defined patterns, which has potential for the development of treatments that avoid interference with the endogenous microbial population in other parts of the organism.

  17. 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

  18. 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.

  19. SYNTHESIS, STRUCTURAL AND ANTIBACTERIAL STUDY OF ...

    African Journals Online (AJOL)

    diffraction, thermogravimetric analysis, scanning electron microscopy, atomic ... possess interesting biological properties like antibacterial properties [4-7]. ... compounds used for treating mental illness, epilepsy, and nicotine addiction [9, 10].

  20. Antibacterial activity of Mangifera indica L

    African Journals Online (AJOL)

    Dr Steve Ogbonnia

    2011-11-09

    Nov 9, 2011 ... specimens like blood, urine, catheter, stool and pus. Antibacterial ... In addition to this problem, antibiotics ... number of multi-drug resistant microbial strains and the appearance of ... to fine powder and stored in airtight bottles.

  1. Topical Antibacterials and Global Challenges on Resistance ...

    African Journals Online (AJOL)

    skin infections can be easily treated with topical antibacterial medication that is available over the counter or by ... infection in minor cut or burn, eyes and ear infection [5]. .... Sensitive/dry skin ... includes both oral and topical antibiotics, but.

  2. Development and antibacterial performance of silver nanoparticles ...

    Indian Academy of Sciences (India)

    Antibacterial activity; in situ fabrication; polyester fabric; silver nanoparticle. 1. Introduction ... transmitter found in central nervous system which has a vital role in human health. .... finished fabric were higher due to the presence of higher.

  3. Antibacterial and haematological activity of Moringa oleifera ...

    African Journals Online (AJOL)

    The phytochemical, antibacterial and haematologic activity of aqueous seed extract of Moringa oleifera (Moringaceae) were evaluated. Phytochemicals such as tannins, carbohydrates, alkaloids, cardiac glycosides, anthraquinones and flavonoids in low, moderate and high concentrations were present in the seeds.

  4. Antibacterial and haematological activity of Moringa oleifera ...

    African Journals Online (AJOL)

    ADEYEYE

    6Department of Human Anatomy, College of Medical Sciences, University of Maiduguri, Borno ... Keywords: Antibacterial effect, Haematology, Moringa olifera, Phytochemical analysis, Wistar albino rats. ..... Moringa oleifera: A food plant with.

  5. Investigation into the prevalence and antibacterial susceptibility ...

    African Journals Online (AJOL)

    Investigation into the prevalence and antibacterial susceptibility patterns of aeromonas and plesiomonas species isolated from children with diarrhoea in Amuwo-Odofin and Surulere Local Government areas of Lagos, Nigeria.

  6. Antibacterial Titanium Produced Using Selective Laser Melting

    Science.gov (United States)

    Macpherson, Andrew; Li, Xiaopeng; McCormick, Paul; Ren, Ling; Yang, Ke; Sercombe, Timothy B.

    2017-12-01

    Titanium and titanium alloys used in current medical and dental applications do not possess antibacterial properties, and therefore, postoperative infection remains a significant risk. Recently, the addition of silver and copper to conventional biomaterials has been shown to produce a material with good antibacterial properties. In this article, we investigate selective laser melting as a method of producing antibacterial Ti-6Al-4V containing elemental additions of Cu or Ag. The addition of Ag had no effect on the microstructure or strength, but it did result in a 300% increase in the ductility of the alloy. In contrast, the addition of Cu resulted in an increase in strength but in a decrease in ductility, along with a change in the structure of the material. The Cu-containing alloy also showed moderate antibacterial properties and was superior to the Ag-containing alloy.

  7. SHORT COMMUNICATION SYNTHESIS AND ANTIBACTERIAL ...

    African Journals Online (AJOL)

    Admin

    chloroform: methanol: DMF (100+10+05 v/v) as developing solvents and ... mol) was taken as the starting material in a mixture of HCl (8 mL) and water (6 ... Compound 1 (0.002 mol) was dissolved in glacial acetic acid (20 mL) and ..... Suresha, G.P; Prakasha, K.C.; Shivkumara, K.N; Kapfeo W.; Gowda,D.C. Int. J. Peptide.

  8. [Plant signaling peptides. Cysteine-rich peptides].

    Science.gov (United States)

    Ostrowski, Maciej; Kowalczyk, Stanisław

    2015-01-01

    Recent bioinformatic and genetic analyses of several model plant genomes have revealed the existence of a highly abundant group of signaling peptides that are defined as cysteine-rich peptides (CRPs). CRPs are usually in size between 50 and 90 amino acid residues, they are positively charged, and they contain 4-16 cysteine residues that are important for the correct conformational folding. Despite the structural differences among CRP classes, members from each class have striking similarities in their molecular properties and function. The present review presents the recent progress in research on signaling peptides from several families including: EPF/EPFL, SP11/SCR, PrsS, RALF, LURE, and some other peptides belonging to CRP group. There is convincing evidence indicating multiple roles for these CRPs as signaling molecules during the plant life cycle, ranging from stomata development and patterning, self-incompatibility, pollen tube growth and guidance, reproductive processes, and nodule formation.

  9. Novel chimeric peptide with enhanced cell specificity and anti-inflammatory activity.

    Science.gov (United States)

    Kim, Young-Min; Kim, Nam-Hong; Lee, Jong-Wan; Jang, Jin-Sun; Park, Yung-Hoon; Park, Seong-Cheol; Jang, Mi-Kyeong

    2015-07-31

    An antimicrobial peptide (AMP), Hn-Mc, was designed by combining the N-terminus of HPA3NT3 and the C-terminus of melittin. This chimeric AMP exhibited potent antibacterial activity with low minimal inhibitory concentrations (MICs), ranging from 1 to 2 μM against four drug-susceptible bacteria and ten drug-resistant bacteria. Moreover, the hemolysis and cytotoxicity was reduced significantly compared to those of the parent peptides, highlighting its high cell selectivity. The morphological changes in the giant unilamellar vesicles and bacterial cell surfaces caused by the Hn-Mc peptide suggested that it killed the microbial cells by damaging the membrane envelope. An in vivo study also demonstrated the antibacterial activity of the Hn-Mc peptide in a mouse model infected with drug-resistant bacteria. In addition, the chimeric peptide inhibited the expression of lipopolysaccharide (LPS)-induced cytokines in RAW 264.7 cells by preventing the interaction between LPS and Toll-like receptors. These results suggest that this chimeric peptide is an antimicrobial and anti-inflammatory candidate as a pharmaceutic agent. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. 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.

  11. Multiaction antibacterial nanofibrous membranes fabricated by electrospinning: an excellent system for antibacterial applications

    International Nuclear Information System (INIS)

    Wu Yiguang; Jia Weijie; An Qi; Li Guangtao; Liu Yuanfeng; Chen Jinchun

    2009-01-01

    In this paper, novel multiaction antibacterial nanofibrous membranes containing apatite, Ag, AgBr and TiO 2 as four active components were fabricated by an electrospinning technique. In this antibacterial membrane, each component serves a different function: the hydroxyapatite acts as the adsorption material for capturing bacteria, the Ag nanoparticles act as the release-active antibacterial agent, the AgBr nanoparticles act as the visible sensitive and release-active antibacterial agent, and the TiO 2 acts as the UV sensitive antibacterial material and substrate for other functional components. Using E. coli as the typical testing organism, such multicomponent membranes exhibit excellent antimicrobial activity under UV light, visible light or in a dark environment. The significant antibacterial properties may be due to the synergetic action of the four major functional components, and the unique porous structure and high surface area of the nanofibrous membrane. It takes only 20 min for the bacteria to be completely (99.9%) destroyed under visible light. Even in a dark environment, about 50 min is enough to kill all of the bacteria. Compared to the four component system in powder form reported previously, the addition of the electrospun membrane could significantly improve the antibacterial inactivation of E. coli under the same evaluation conditions. Besides the superior antimicrobial capability, the permanence of the antibacterial activity of the prepared free-standing membranes was also demonstrated in repeated applications.

  12. ANTIBACTERIAL EFFECTS OF FRESH AND PRESERVED ROYAL JELLY

    Directory of Open Access Journals (Sweden)

    Zinka Maksimović

    2013-10-01

    Full Text Available Antibacterial effects of the fresh royal jelly, royal jelly stored at 4 °C and -40 °C for a period of 12 months against reference and isolated bacterial strains from the different clinical samples, were tested and compared by the diffusion test. Royal jelly shows antibacterial effects against both tested gram-positive and gram-negative bacteria. Fresh royal jelly has the most effective antibacterial activity. Storage temperature at -40 oC slightly affects antibacterial activity of royal jelly, while storage temperature at 4 oC decreases its antibacterial activity.Key words: royal jelly, antibacterial effects, storage temperature, storage duration

  13. Peptide Extracts from Cultures of Certain Lactobacilli Inhibit Helicobacter pylori.

    Science.gov (United States)

    De Vuyst, Luc; Vincent, Pascal; Makras, Eleftherios; Leroy, Frédéric; Pot, Bruno

    2010-03-01

    Helicobacter pylori inhibition by probiotic lactobacilli has been observed in vitro and in vivo. Carefully selected probiotic Lactobacillus strains could therefore play an important role in the treatment of H. pylori infection and eradication. However, the underlying mechanism for this inhibition is not clear. The aim of this study was to examine if peptide extracts, containing bacteriocins or other antibacterial peptides, from six Lactobacillus cultures (Lactobacillus acidophilus La1, Lactobacillus amylovorus DCE 471, Lactobacillus casei YIT 9029, Lactobacillus gasseri K7, Lactobacillus johnsonii La1, and Lactobacillus rhamnosus GG) contribute to the inhibition of H. pylori. Peptide extracts from cultures of Lact. amylovorus DCE 471 and Lact. johnsonii La1 were most active, reducing the viability of H. pylori ATCC 43504 with more than 2 log units within 4 h of incubation (P < 0.001). The four other extracts were less or not active. When six clinical isolates of H. pylori were tested for their susceptibility towards five inhibitory peptide extracts, similar observations were made. Again, the peptide extracts from Lact. amylovorus DCE 471 and Lact. johnsonii La1 were the most inhibitory, while the three other extracts resulted in a much lower inhibition of H. pylori. Protease-treated extracts were inactive towards H. pylori, confirming the proteinaceous nature of the inhibitory substance.

  14. Buwchitin: a ruminal peptide with antimicrobial potential against Enterococcus faecalis

    Science.gov (United States)

    Oyama, Linda B.; Crochet, Jean-Adrien; Edwards, Joan E.; Girdwood, Susan E.; Cookson, Alan R.; Fernandez-Fuentes, Narcis; Hilpert, Kai; Golyshin, Peter N.; Golyshina, Olga V.; Privé, Florence; Hess, Matthias; Mantovani, Hilario C.; Creevey, Christopher J.; Huws, Sharon A.

    2017-07-01

    Antimicrobial peptides (AMPs) are gaining popularity as alternatives for treatment of bacterial infections and recent advances in omics technologies provide new platforms for AMP discovery. We sought to determine the antibacterial activity of a novel antimicrobial peptide, buwchitin, against Enterococcus faecalis. Buwchitin was identified from a rumen bacterial metagenome library, cloned, expressed and purified. The antimicrobial activity of the recombinant peptide was assessed using a broth microdilution susceptibility assay to determine the peptide's killing kinetics against selected bacterial strains. The killing mechanism of buwchitin was investigated further by monitoring its ability to cause membrane depolarization (diSC3(5) method) and morphological changes in E. faecalis cells. Transmission electron micrographs of buwchitin treated E. faecalis cells showed intact outer membranes with blebbing, but no major damaging effects and cell morphology changes. Buwchitin had negligible cytotoxicity against defibrinated sheep erythrocytes. Although no significant membrane leakage and depolarization was observed, buwchitin at minimum inhibitory concentration (MIC) was bacteriostatic against E. faecalis cells and inhibited growth in vitro by 70% when compared to untreated cells. These findings suggest that buwchitin, a rumen derived peptide, has potential for antimicrobial activity against E. faecalis.

  15. Buwchitin: A Ruminal Peptide with Antimicrobial Potential against Enterococcus faecalis

    Directory of Open Access Journals (Sweden)

    Linda B. Oyama

    2017-07-01

    Full Text Available Antimicrobial peptides (AMPs are gaining popularity as alternatives for treatment of bacterial infections and recent advances in omics technologies provide new platforms for AMP discovery. We sought to determine the antibacterial activity of a novel antimicrobial peptide, buwchitin, against Enterococcus faecalis. Buwchitin was identified from a rumen bacterial metagenome library, cloned, expressed and purified. The antimicrobial activity of the recombinant peptide was assessed using a broth microdilution susceptibility assay to determine the peptide's killing kinetics against selected bacterial strains. The killing mechanism of buwchitin was investigated further by monitoring its ability to cause membrane depolarization (diSC3(5 method and morphological changes in E. faecalis cells. Transmission electron micrographs of buwchitin treated E. faecalis cells showed intact outer membranes with blebbing, but no major damaging effects and cell morphology changes. Buwchitin had negligible cytotoxicity against defibrinated sheep erythrocytes. Although no significant membrane leakage and depolarization was observed, buwchitin at minimum inhibitory concentration (MIC was bacteriostatic against E. faecalis cells and inhibited growth in vitro by 70% when compared to untreated cells. These findings suggest that buwchitin, a rumen derived peptide, has potential for antimicrobial activity against E. faecalis.

  16. Peptides in melanoma therapy.

    Science.gov (United States)

    Mocellin, Simone

    2012-01-01

    Peptides derived from tumor associated antigens can be utilized to elicit a therapeutically effective immune response against melanoma in experimental models. However, patient vaccination with peptides - although it is often followed by the induction of melanoma- specific T lymphocytes - is rarely associated with tumor response of clinical relevance. In this review I summarize the principles of peptide design as well as the results so far obtained in the clinical setting while treating cutaneous melanoma by means of this active immunotherapy strategy. I also discuss some immunological and methodological issues that might be helpful for the successful development of peptide-based vaccines.

  17. Bacterial resistance and susceptibility to antimicrobial peptides and peptidomimetics

    DEFF Research Database (Denmark)

    Citterio, Linda

    Bacterial resistance to conventional antibiotics has become a global challenge and there is urgent need for new and alternative compounds. Antimicrobial peptides (AMPs) are under investigation as novel antibiotics. These are part of the immune defense of all living organisms; hence, they represen...... be a threat to our immunity may be overestimated. In conclusion, this PhD project supports the belief that bacteria hold the potential to develop resistance to each novel antibacterial agent. Nevertheless, strategies to circumvent resistance exist and must be pursued....

  18. Dendropsophin 1, a novel antimicrobial peptide from the skin secretion of the endemic Colombian frog Dendropsophus columbianus.

    Science.gov (United States)

    Triana-Vidal, Luz Elena; Castro, Mariana Souza; Pires Júnior, Osmindo Rodrigues; Álvares, Alice Cunha Morales; de Freitas, Sonia Maria; Fontes, Wagner; Vargas, Jimmy Alexander Guerrero; Zúñiga-Baos, Jorge Alberto; Correia Batista, Isabel de Fátima; Grellier, Philippe; Charneau, Sébastien

    2018-06-01

    In efforts to find new antimicrobial peptides (AMPs), we studied the skin secretion of the endemic Colombian frog Dendropsophus columbianus belonging to a genus that has not been investigated previously. From HPLC-fractionated secretion, we identified one peptide with slightly antibacterial activity. Its peptide sequence showed no sequence similarity to current annotated peptides. We named this novel peptide dendropsophin 1 (Dc1). Afterward, two analogues were designed (Dc1.1 and Dc1.2) to improve the cationic and amphipathic features. Then, their antiproliferative and cytotoxic properties were evaluated against several pathogens including bacteria, fungi, protozoa and also mammalian cells. Dc1 and its two analogues exhibited moderate antibacterial activities and no hemolytic and cytotoxic effects on mammalian cells. Analogue Dc1.2 showed slightly improved antibacterial properties. Their secondary structures were characterised using CD spectroscopy and Dc1.2 displayed a higher α-helix content and thermal stability compared to Dc1 and Dc1.1 in hydrophobic experimental conditions.

  19. Antibacterial effects of lactoferricin B.

    Science.gov (United States)

    Vorland, L H; Ulvatne, H; Andersen, J; Haukland, H H; Rekdal, O; Svendsen, J S; Gutteberg, T J

    1999-01-01

    The antimicrobial peptide, lactoferricin, can be generated upon gastric pepsin cleavage of lactoferrin. We have examined the inhibitory efficacy of lactoferricin of bovine origin (Lf-cin B) on Escherichia coli, Proteus mirabilis and Staphylococcus aureus with or without a cell wall. We found that spheroplasts and protoplasts had a lower MIC than their counterparts with a cell wall. We also compared the efficacies of Lf-cin B (17-31) made of all L-amino acids and all D-amino acids. The peptide made of all D-amino acids was more active than the corresponding L-enantiomer. Furthermore, we examined the influence of Lf-cin B on the motility of E. coli and the influence of temperature on the susceptibility of bacteria exposed to Lf-cin B. Bacteria exposed to sub-MIC of Lf-cin B lost their motility. Bacteria exposed to Lf-cin B at 20 degrees C were more sensitive to Lf-cin B than when exposed at 37 degrees C. These findings indicate that the cell envelope is a limiting step for Lf-cin B to exert its antibiotic effect. We cannot rule out a receptor-mediated first step for Lf-cin B (17-31).

  20. 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 ...

  1. antibacterial properties of calyx, stem bark and root of hibiscus ...

    African Journals Online (AJOL)

    HS) were tested for their antibacterial activities. The root of the plant exhibited marked antibacterial activity against gram positive and gram negative organisms of Klebsiella pneumonia, Escherichia coli, Proteus spp., Pseudomonas aureginosa, ...

  2. The antibacterial potential of the seaweeds (Rhodophyceae) of the ...

    African Journals Online (AJOL)

    GREGORY

    2010-09-20

    Sep 20, 2010 ... The antibacterial activity of extracts from 26 marine Rhodophyceae (8 Ceramiales, 7 Gelidiales, 9 ... seaweed extracts as a source of antibacterial compounds. ... Macroalgae are a rich source of natural bioactive products.

  3. Antibacterial action of an aqueous grape seed polyphenolic extract

    African Journals Online (AJOL)

    Jane

    2011-07-06

    Jul 6, 2011 ... The potential of a polyphenolic grape seed extract for use as a natural antibacterial agent was ... electrospray ionisation-mass spectrometry; PBS, phosphate .... The antibacterial tests were carried out by disc diffusion method.

  4. 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. Copyright © 2015 Elsevier B.V. All rights reserved.

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

    International Nuclear Information System (INIS)

    Ribeiro, Marta M.B.; Franquelim, Henri G.; Torcato, Inês M.; Ramu, Vasanthakumar G.; Heras, Montserrat; Bardaji, Eduard R.; Castanho, Miguel A.R.B.

    2012-01-01

    Highlights: ► New kyotorphin derivatives have antimicrobial properties against S. aureus. ► Atomic force microscopy show membrane disturbing effects of KTP–NH 2 and IbKTP–NH 2 . ► None of the KTP derivatives are hemolytic. ► 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 2 , IbKTP, IbKTP–NH 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 and broadens the therapeutic potential and application of kyotorphin peptides.

  6. 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

  7. Enhancement of endotoxin neutralization by coupling of a C12-alkyl chain to a lactoferricin-derived peptide

    Science.gov (United States)

    2004-01-01

    Antibacterial peptide acylation, which mimics the structure of the natural lipopeptide polymyxin B, increases antimicrobial and endotoxin-neutralizing activities. The interaction of the lactoferricin-derived peptide LF11 and its N-terminally acylated analogue, lauryl-LF11, with different chemotypes of bacterial lipopolysaccharide (LPS Re, Ra and smooth S form) was investigated by biophysical means and was related to the peptides' biological activities. Both peptides exhibit high antibacterial activity against the three strains of Salmonella enterica differing in the LPS chemotype. Lauryl-LF11 has one order of magnitude higher activity against Re-type, but activity against Ra- and S-type bacteria is comparable with that of LF11. The alkyl derivative peptide lauryl-LF11 shows a much stronger inhibition of the LPS-induced cytokine induction in human mononuclear cells than LF11. Although peptide–LPS interaction is essentially of electrostatic nature, the lauryl-modified peptide displays a strong hydrophobic component. Such a feature might then explain the fact that saturation of the peptide binding takes place at a much lower peptide/LPS ratio for LF11 than for lauryl-LF11, and that an overcompensation of the negative LPS backbone charges is observed for lauryl-LF11. The influence of LF11 on the gel-to-liquid-crystalline phase-transition of LPS is negligible for LPS Re, but clearly fluidizing for LPS Ra. In contrast, lauryl-LF11 causes a cholesterol-like effect in the two chemotypes, fluidizing in the gel and rigidifying of the hydrocarbon chains in the liquid-crystalline phase. Both peptides convert the mixed unilamellar/non-lamellar aggregate structure of lipid A, the ‘endotoxic principle’ of LPS, into a multilamellar one. These data contribute to the understanding of the mechanisms of the peptide-mediated neutralization of endotoxin and effect of lipid modification of peptides. PMID:15344905

  8. Peptide Vaccines for Leishmaniasis

    Directory of Open Access Journals (Sweden)

    Rory C. F. De Brito

    2018-05-01

    Full Text Available Due to an increase in the incidence of leishmaniases worldwide, the development of new strategies such as prophylactic vaccines to prevent infection and decrease the disease have become a high priority. Classic vaccines against leishmaniases were based on live or attenuated parasites or their subunits. Nevertheless, the use of whole parasite or their subunits for vaccine production has numerous disadvantages. Therefore, the use of Leishmania peptides to design more specific vaccines against leishmaniases seems promising. Moreover, peptides have several benefits in comparison with other kinds of antigens, for instance, good stability, absence of potentially damaging materials, antigen low complexity, and low-cost to scale up. By contrast, peptides are poor immunogenic alone, and they need to be delivered correctly. In this context, several approaches described in this review are useful to solve these drawbacks. Approaches, such as, peptides in combination with potent adjuvants, cellular vaccinations, adenovirus, polyepitopes, or DNA vaccines have been used to develop peptide-based vaccines. Recent advancements in peptide vaccine design, chimeric, or polypeptide vaccines and nanovaccines based on particles attached or formulated with antigenic components or peptides have been increasingly employed to drive a specific immune response. In this review, we briefly summarize the old, current, and future stands on peptide-based vaccines, describing the disadvantages and benefits associated with them. We also propose possible approaches to overcome the related weaknesses of synthetic vaccines and suggest future guidelines for their development.

  9. Peptide Vaccines for Leishmaniasis.

    Science.gov (United States)

    De Brito, Rory C F; Cardoso, Jamille M De O; Reis, Levi E S; Vieira, Joao F; Mathias, Fernando A S; Roatt, Bruno M; Aguiar-Soares, Rodrigo Dian D O; Ruiz, Jeronimo C; Resende, Daniela de M; Reis, Alexandre B

    2018-01-01

    Due to an increase in the incidence of leishmaniases worldwide, the development of new strategies such as prophylactic vaccines to prevent infection and decrease the disease have become a high priority. Classic vaccines against leishmaniases were based on live or attenuated parasites or their subunits. Nevertheless, the use of whole parasite or their subunits for vaccine production has numerous disadvantages. Therefore, the use of Leishmania peptides to design more specific vaccines against leishmaniases seems promising. Moreover, peptides have several benefits in comparison with other kinds of antigens, for instance, good stability, absence of potentially damaging materials, antigen low complexity, and low-cost to scale up. By contrast, peptides are poor immunogenic alone, and they need to be delivered correctly. In this context, several approaches described in this review are useful to solve these drawbacks. Approaches, such as, peptides in combination with potent adjuvants, cellular vaccinations, adenovirus, polyepitopes, or DNA vaccines have been used to develop peptide-based vaccines. Recent advancements in peptide vaccine design, chimeric, or polypeptide vaccines and nanovaccines based on particles attached or formulated with antigenic components or peptides have been increasingly employed to drive a specific immune response. In this review, we briefly summarize the old, current, and future stands on peptide-based vaccines, describing the disadvantages and benefits associated with them. We also propose possible approaches to overcome the related weaknesses of synthetic vaccines and suggest future guidelines for their development.

  10. 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...

  11. Targeted Drug-Carrying Bacteriophages as Antibacterial Nanomedicines▿

    OpenAIRE

    Yacoby, Iftach; Bar, Hagit; Benhar, Itai

    2007-01-01

    While the resistance of bacteria to traditional antibiotics is a major public health concern, the use of extremely potent antibacterial agents is limited by their lack of selectivity. As in cancer therapy, antibacterial targeted therapy could provide an opportunity to reintroduce toxic substances to the antibacterial arsenal. A desirable targeted antibacterial agent should combine binding specificity, a large drug payload per binding event, and a programmed drug release mechanism. Recently, w...

  12. 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)

  13. MgO nanoparticles as antibacterial agent: preparation and activity

    International Nuclear Information System (INIS)

    Tang, Zhen-Xing; Lv, Bin-Feng

    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 reviewed. (author)

  14. A Therapeutic Potential of Animal β-hairpin Antimicrobial Peptides.

    Science.gov (United States)

    Panteleev, Pavel V; Balandin, Sergey V; Ivanov, Vadim T; Ovchinnikova, Tatiana V

    2017-01-01

    Endogenous antimicrobial peptides (AMPs) are evolutionary ancient molecular factors of innate immunity that play the key role in host defense. Because of the low resistance rate, AMPs have caught extensive attention as possible alternatives to conventional antibiotics. Over the last years, it has become evident that biological functions of AMPs are beyond direct killing of microbial cells. This review focuses on a relatively small family of animal host defense peptides with the β-hairpin structure stabilized by disulfide bridges. Their small size, rigid structure, stability to proteases, and plethora of biological functions, including antibacterial, antifungal, antiviral, anticancer, endotoxin-binding, metabolism- and immune- modulating activities, make natural β-hairpin AMPs an attractive molecular basis for drug design. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  15. Engineered chimeric peptides with antimicrobial and titanium-binding functions to inhibit biofilm formation on Ti implants.

    Science.gov (United States)

    Geng, Hongjuan; Yuan, Yang; Adayi, Aidina; Zhang, Xu; Song, Xin; Gong, Lei; Zhang, Xi; Gao, Ping

    2018-01-01

    Titanium (Ti) implants have been commonly used in oral medicine. However, despite their widespread clinical application, these implants are susceptible to failure induced by microbial infection due to bacterial biofilm formation. Immobilization of chimeric peptides with antibacterial properties on the Ti surface may be a promising antimicrobial approach to inhibit biofilm formation. Here, chimeric peptides were designed by connecting three sequences (hBD-3-1/2/3) derived from human β-defensin-3 (hBD-3) with Ti-binding peptide-l (TBP-l: RKLPDAGPMHTW) via a triple glycine (G) linker to modify Ti surfaces. Using X-ray photoelectron spectroscopy (XPS), the properties of individual domains of the chimeric peptides were evaluated for their binding activity toward the Ti surface. The antimicrobial and anti-biofilm efficacy of the peptides against initial settlers, Streptococcus oralis (S. oralis), Streptococcus gordonii (S. gordonii) and Streptococcus sanguinis (S. sanguinis), was evaluated with confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). Transmission electron microscopy (TEM) and real-time quantitative PCR (qRT-PCR) were used to study cell membrane changes and the underlying antimicrobial mechanism. Compared with the other two peptides, TBP-1-GGG-hBD3-3 presented stronger antibacterial activity and remained stable in saliva and serum. Therefore, it was chosen as the best candidate to modify Ti surfaces in this study. This peptide inhibited the growth of initial streptococci and biofilm formation on Ti surfaces with no cytotoxicity to MC3T3-E1 cells. Disruption of the integrity of bacterial membranes and decreased expression of adhesion protein genes from S. gordonii revealed aspects of the antibacterial mechanism of TBP-1-GGG-hBD3-3. We conclude that engineered chimeric peptides with antimicrobial activity provide a potential solution for inhibiting biofilm formation on Ti surfaces to reduce or prevent the occurrence of peri

  16. Novel haemoglobin-derived antimicrobial peptides from chicken (Gallus gallus) blood: purification, structural aspects and biological activity.

    Science.gov (United States)

    Vasilchenko, A S; Rogozhin, E A; Vasilchenko, A V; Kartashova, O L; Sycheva, M V

    2016-12-01

    To purify and characterize antimicrobial peptides derived from the acid extract of Gallus gallus blood cells. Two polypeptides (i.e. CHb-1 and CHb-2) with antibacterial activity were detected in the acidic extract of blood cells from chicken (G. gallus). The isolated peptides that possessed a potent antibacterial activity were purified using a two-step chromatography procedure that involved solid-phase extraction of a total protein/peptide extract followed by thin fractionation by reversed-phase high performance liquid chromatography (RP-HPLC). The molecular masses of the purified peptides were similar and were 4824·4 and 4825·2 Da, which have been measured by matrix-assisted laser desorption/ionization mass spectrometry (MALDI TOF MS). Their amino acid sequences were determined by Edman degradation and showed that the peptides were fully identical to the two fragments of G. gallus α-haemoglobin localized into different subunits (A and D respectively). The peptides were active in micromolar concentrations against Gram-negative Escherichia coli K12 TG1. Using the 1-N-phenylnaphthylamine, the FITC-dextran labelled probes and the live/dead staining allowed to show the hemocidin mode of action and estimate the pore size. In this study, for the first time, α-haemoglobin from chicken (G. gallus) has been investigated as a donor of the two high homologous native peptide fragments that possess potent antibacterial activity in vitro. These are membrane-active peptides and their mechanism of action against E. coli involves a toroidal pore formation. The obtained results expand the perception of the role of haemoglobin in a living system, describing it as a source of multifunction substances. Additionally, the data presented in this paper may contribute to the development of new, cost-effective, antimicrobial agents. © 2016 The Society for Applied Microbiology.

  17. Coupling Plant-Derived Cyclotides to Metal Surfaces: An Antibacterial and Antibiofilm Study

    Directory of Open Access Journals (Sweden)

    Pan Cao

    2018-03-01

    Full Text Available Modification of metal surfaces with antimicrobial peptides is a promising approach to reduce bacterial adhesion. Here, cyclic peptides or cycloids, possessing remarkable stability and antimicrobial activities, were extracted and purified from Viola philippica Cav., and identified using mass spectrometry. Cyclotides were subsequently utilized to modify stainless steel surfaces via polydopamine-mediated coupling. The resulting cyclotide-modified surfaces were characterized by Fourier transform infrared (FTIR spectroscopy and contact angle analysis. The antibacterial capacity of these cyclotides against Staphylococcus aureus was assessed by Alamar blue assay. The antibiofilm capacity of the modified surfaces was assessed by crystal violet assay, and scanning electron microscopy (SEM. A composite of Kalata b1, Varv A, Viba 15 and Viba 17 (P1; Varv E (P2; and Viphi G (P3 were isolated and identified. FTIR analysis of the modified surfaces demonstrated that cyclotides bound to the surfaces and induced reduction of contact angles. Antimicrobial effects showed an order P3 > P1 and P2, with P3-treated surfaces demonstrating the strongest antibiofilm capacity. SEM confirmed reduced biofilm formation for P3-treated surfaces. This study provides novel evidence for cyclotides as a new class for development of antibacterial and antibiofilm agents.

  18. Cloning and expression of antibacterial goat lactoferricin from Escherichia coli AD494(DE3)pLysS expression system.

    Science.gov (United States)

    Chen, Gen-Hung; Yin, Li-Jung; Chiang, I-Hua; Jiang, Shann-Tzong

    2008-12-01

    Goat lactoferricin (GLfcin), an antibacterial peptide, is released from the N terminus of goat lactoferrin by pepsin digestion. Two GLfcin-related cDNAs, GLfcin L and GLfcin S, encoding Ala20-Ser60 and Ser36-Ser60 of goat lactoferrin, respectively, were cloned into the pET-23a(+) expression vector upstream from (His)6-Tag gene and transformed into Escherichia coli AD494(DE3)pLysS expression host. After being induced by isopropyl-beta-D-thiogalactopyranoside (IPTG), two (His)6-Tag fused recombinant lactoferricins, GLfcin L-His*Tag and GLfcin S-His*Tag, were expressed in soluble form within the E. coli cytoplasm. The GLfcin L-His*Tag and GLfcin S-His*Tag were purified using HisTrap affinity chromatography. According to an antibacterial activity assay using the agar diffusion method, GLfcin L-His*Tag had antibacterial activity against E. coli BCRC 11549, Staphylococcus aureus BCRC 25923, and Propionibacterium acnes BCRC 10723, while GLfcin S-His*Tag was able to inhibit the growth of E. coli BCRC 11549 and P. acnes BCRC 10723. These two recombinant lactoferricins behaved as thermostable peptides, which could retain their activity for up to 30 min of exposure at 100 degrees C.

  19. 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. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Antibacterial property of fabrics coated by magnesium-based brucites

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Ying; Sha, Lin; Zhao, Jiao; Li, Qian; Zhu, Yimin, E-mail: ntp@dlmu.edu.cn; Wang, Ninghui

    2017-04-01

    Highlights: • Magnesium-based antibacterial agents composited by brucites with different particle sizes were proposed for the first time. • The coating process for making antibacterial fabrics was easy to operate and apply in industrial application. • The materials used in the antibacterial fabrics were environmental-friendly and cost-effective. • Reduction percentage of as-prepared antibacterial fabrics against E. coli and S. aureus reached to 96.6%, 100% respectively. • The antibacterial fabrics attained excellent washing durability. - Abstract: A kind of environmental-friendly magnesium-based antibacterial agent was reported for the first time, which was composited by brucites with different particle sizes. The antibacterial fabrics were produced by coating the magnesium-based antibacterial agents on the 260T polyester pongee fabrics with waterborne polyurethane. The coating process was simple, low-cost, and harmless to human health and environment. Characteristics of the antibacterial agents and fabrics were studied by particulate size distribution analyzer (PSDA), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The results demonstrated that the coating layer was covered tightly on the fabrics and compositing of different particles by a certain proportion made full filling of the coating layer. Meanwhile, compositing did not change the structure of brucites. The antibacterial fabrics presented strong antibacterial properties against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), with the reduction percentage of 96.6% and 100%, respectively, and the antibacterial fabrics attained excellent washing durability.

  1. Antibacterial activity of indium curcumin and indium diacetylcurcumin

    African Journals Online (AJOL)

    Studies on curcumin, the principal element of turmeric powder, have demonstrated several biological actions such as antibacterial activity. Evaluation of new analogs or new compounds of curcumin for their antibacterial effect is interesting for researchers. In this in vitro study, we attempted to test the antibacterial activity of ...

  2. Antibacterial activity of some selected plants traditionally used as ...

    African Journals Online (AJOL)

    SAM

    2014-03-26

    Mar 26, 2014 ... K. Womens'College, Kongkhampat,Nambol-795134, Manipur, India. 2Department of Life Science and Bioinformatics, Assam University, Silchar, ... antibacterial activity. The study revealed that all extracts show varied degree of antibacterial activity against the tested bacterial pathogens. The antibacterial ...

  3. Antibacterial activity and phospholipid recognition of the recombinant defensin J1-1 from Capsicum genus.

    Science.gov (United States)

    Guillén-Chable, Francisco; Arenas-Sosa, Iván; Islas-Flores, Ignacio; Corzo, Gerardo; Martinez-Liu, Cynthia; Estrada, Georgina

    2017-08-01

    The gene of the four disulfide-bridged defensin J1-1 from Capsicum was cloned into the expression vector pQE30 containing a 6His-tag as fusion protein. This construct was transfected into Origami strain of Escherichia coli and expressed after induction with isopropyl thiogalactoside (IPTG). The level of expression was 4 mg/L of culture medium, and the His-tagged recombinant defensin (HisXarJ1-1) was expressed exclusively into inclusion bodies. After solubilization, HisXarJ1-1 was purified by affinity and hydrophobic interaction chromatography. The reverse-phase HPLC profile of the HisXarJ1-1 product obtained from the affinity chromatography step showed single main peptide fraction of molecular masses of 7050.6 Da and after treatment with DTT a single fraction of 7, 042.6 Da corresponding to the reduced peptide was observed. An in vitro folding step of the HisXarJ1-1 generated a distinct profile of oxidized forms of the peptide this oxidized peptide was capable of binding phosphatidic acid in vitro. Possible dimer and oligomer of HisXarJ1-1 were visible in gel electrophoresis and immunodetected with anti-His antibodies. Pure recombinant defensin HisXarJ1-1 exhibited antibacterial activity against Pseudomonas aeruginosa. Copyright © 2017 Elsevier Inc. All rights reserved.

  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. Identification and characterization of histidine-rich peptides from hard ticks Ixodes ricinus and Ixodes scapularis.

    OpenAIRE

    DORŇÁKOVÁ, Veronika

    2011-01-01

    Antimicrobial (cationic) proteins play an important role in innate imunity. Such proteins can possess antibacterial, antiendotoxic or fungicidal abilities. The rising resistence of microbes to common antibiotics evokes acute need of studying more endogenous proteins to reveal new potential antibiotics. Ticks, the blood-feeding ectoparasites with effectual defense system, present an endless source of newly described and unknown antimicrobial peptides/proteins with significant theurapeutic pote...

  6. Investigation of the antibiofilm capacity of peptide-modified stainless steel.

    Science.gov (United States)

    Cao, Pan; Li, Wen-Wu; Morris, Andrew R; Horrocks, Paul D; Yuan, Cheng-Qing; Yang, Ying

    2018-03-01

    Biofilm formation on surfaces is an important research topic in ship tribology and medical implants. In this study, dopamine and two types of synthetic peptides were designed and attached to 304 stainless steel surfaces, aiming to inhibit the formation of biofilms. A combinatory surface modification procedure was applied in which dopamine was used as a coupling agent, allowing a strong binding ability with the two peptides. X-ray photoelectron spectroscopy (XPS), elemental analysis, contact angle measurement and surface roughness test were used to evaluate the efficiency of the peptide modification. An antibiofilm assay against Staphylococcus aureus was conducted to validate the antibiofilm capacity of the peptide-modified stainless steel samples. XPS analysis confirmed that the optimal dopamine concentration was 40 µg ml -1 in the coupling reaction. Element analysis showed that dopamine and the peptides had bound to the steel surfaces. The robustness assay of the modified surface demonstrated that most peptide molecules had bound on the surface of the stainless steel firmly. The contact angle of the modified surfaces was significantly changed. Modified steel samples exhibited improved antibiofilm properties in comparison to untreated and dopamine-only counterpart, with the peptide 1 modification displaying the best antibiofilm effect. The modified surfaces showed antibacterial capacity. The antibiofilm capacity of the modified surfaces was also surface topography sensitive. The steel sample surfaces polished with 600# sandpaper exhibited stronger antibiofilm capacity than those polished with other types of sandpapers after peptide modification. These findings present valuable information for future antifouling material research.

  7. A simple fragment of cyclic acyldepsipeptides is necessary and sufficient for ClpP activation and antibacterial activity.

    Science.gov (United States)

    Carney, Daniel W; Compton, Corey L; Schmitz, Karl R; Stevens, Julia P; Sauer, Robert T; Sello, Jason K

    2014-10-13

    The development of new antibacterial agents, particularly those with unique biological targets, is essential to keep pace with the inevitable emergence of drug resistance in pathogenic bacteria. We identified the minimal structural component of the cyclic acyldepsipeptide (ADEP) antibiotics that exhibits antibacterial activity. We found that N-acyldifluorophenylalanine fragments function via the same mechanism of action as ADEPs, as evidenced by the requirement of ClpP for the fragments' antibacterial activity, the ability of fragments to activate Bacillus subtilis ClpP in vitro, and the capacity of an N-acyldifluorophenylalanine affinity matrix to capture ClpP from B. subtilis cell lysates. N-acyldifluorophenylalanine fragments are much simpler in structure than the full ADEPs and are also highly amenable to structural diversification. Thus, the stage has been set for the development of non-peptide activators of ClpP that can be used as antibacterial agents. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Probiotic Properties of Lactobacillus fermentum Strains Isolated from Human Oral Samples and Description of their Antibacterial Activity.

    Science.gov (United States)

    Fuochi, Virginia; Volti, Giovanni Li; Furneri, Pio M

    2017-01-01

    Gram positive bacteria produce peptides, defined bacteriocins which exhibit good antibacterial activity. We evaluated the ability of L. fermentum to produce bacteriocins having therefore, good probiotic features and finally, be safe towards microglial cells. Eight wild strains, identified using molecular techniques, were investigated for the evaluation of resistance to bile salts, low pH, H2O2 production, biofilm formation, antibacterial activity and safety on microglia cells (BV2). The determination of the susceptibility/resistance profile showed that the strains are sensitive to the antibiotics tested. All strains showed a good tolerability to extremely low pH as well as resisting in presence of bile salts. In addition, the strains showed excellent activity against pathogens and one of them (LAC 42) showed activity also against Pseudomonas aeruginosa and Klebsiella pneumoniae. Finally, LAC 42 and its active compound did not change microglia cell viability following 24h exposure. Our data on this antibacterial molecule suggest that it is a compound with low molecular weight and with highly hydrophilic component. These results describe the characteristics of Lactobacillus strains and provide evidences for their possible use as new potential probiotic. In addition, other studies are now warranted to exploit the antibacterial activity of the supernatant LAC 42 and for its complete chemical characterization. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  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. Antibacterial and antifungal properties of guanylhydrazones

    Directory of Open Access Journals (Sweden)

    Ajdačić Vladimir

    2017-01-01

    Full Text Available A series of novel guanylhydrazones were designed, synthesized and characterized. All the compounds were screened for their antibacterial and antifungal activity. Compounds 26 and 27 showed excellent antibacterial activities against Staphylococcus aureus ATCC 25923 and Micrococcus luteus ATCC 379 with minimal inhibitory concentrations of 4 μg mL-1, and good antifungal activity against Candida parapsilosis ATCC 22019. These results suggested that the selected guanylhydrazones could serve as promising leads for improved antimicrobial development. [Project of the Ministry of Education, Science and Technological Development of the Republic of Serbia, Grant No. 172008 and Grant No. 173048

  11. Antibacterial Compounds from Red Seaweeds (Rhodophyta

    Directory of Open Access Journals (Sweden)

    Noer Kasanah

    2015-07-01

    Full Text Available Seaweeds produce great variety of metabolites benefit for human. Red seaweeds (Rhodophyta are well known as producer of phycocolloids such agar, agarose, carragenan and great variety of secondary metabolites. This review discusses the red algal secondary metabolites with antibacterial activity. The chemical constituents of red algae are steroid, terpenoid, acetogenin and dominated by halogenated compounds mainly brominated compounds. Novel compounds with intriguing skeleton are also reported such as bromophycolides and neurymenolides. In summary, red seaweeds are potential sources for antibacterial agents and can serve as lead in synthesis of new natural medicines.

  12. Indonesian honey protein isolation Apis dorsata dorsata and Tetragonula sp. as antibacterial and antioxidant agent

    Science.gov (United States)

    Sahlan, Muhamad; Damayanti, Vina; Azizah, Nurul; Hakamada, Kazuaki; Yohda, Masafumi; Hermansyah, Heri; Wijanarko, Anondho; Rohmatin, Etin

    2018-02-01

    Honey is a natural product that has many properties and been widely used for many theurapeutic purposes. Research on honey has been very rapid but not yet for Indonesia. Like local Indonesian honey Apis dorsata dorsata and Tetragonula sp. which has been widely consumed by the public but not yet known for certain efficacy of each content. The function of honey as antibacterial and antioxidant has not been specifically explained by the components contained in honey. Protein is one of the content of honey that turned out to have activity as an antibacterial and antioxidant in certain types of honey because of it antimicrobial peptide. Testing of honey activity as antibacterial and antioxidant through several stages including isolation, SDS-PAGE analysis, Bradford test, antibacterial activity test with well diffusion method and antioxidant activity test by DPPH method. Bacteria used were gram-positive bacteria Staphylococcus aureus and gram negative Escherichia coli. After some experiment finally got protein isolation method that is in the form of further concentration using Millipore membrane for honey Tetragonula sp. and membrane filtration dot blot for honey Apis dorsata dorsata. The Bradford assay showed that Apis dorsata dorsata honey contains protein <5 µg / ml, while honey Tetragonula sp. has a protein content of 97 µg / ml. The characteristic profile of molecular weight of the protein showed honey Tetragonula sp. has 3 protein bands composed of 52, 96 - 61,9 kDa, 63,35 - 65,92 kDa and 86,16 - 91,4 kDa, whereas Apis dorsata dorsata honey has 5 protein bands consisting of 45,2 - 46,6 kDa, 50,2 - 50,9 kDa, 62,5 - 62,9 kDa, 73,1 - 73,9 kDa, 83,9 - 86,9 kDa. Isolate honey protein Apis dorsata dorsata has no antioxidant and antibacterial activity (Staphylococcus aureus and Escherichia coli), whereas honey protein isolates Tetragonula sp. has antibacterial activity against Escherichia coli.

  13. Diversity-oriented peptide stapling

    DEFF Research Database (Denmark)

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

    2017-01-01

    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...

  14. Phytochemical Screening and Antibacterial Activity of Cybopogon ...

    African Journals Online (AJOL)

    Similarly, the results of antibacterial activity testing of the extracts at equal disc concentration of 30@g/disc showed that E. coli was sensitive to all extracts with inhibition zone diameters of 7mm, Klebsiella spp. and Proteus spp. were sensitive to acetone extract of the plant with inhibition zone diameters of 7mm each while ...

  15. Development and antibacterial performance of silver nanoparticles ...

    Indian Academy of Sciences (India)

    Metallization is one of the finishing processes in textile treatment that can produce multifunctional effects. The present study dealt with the development of an antibacterial polyester-knitted fabric via facile and green impregnation of silver nanoparticles (SNPs). This was done by applying a polymeric foundation on the ...

  16. Antibacterial properties of polyaniline-silver films

    Czech Academy of Sciences Publication Activity Database

    Kuceková, Z.; Kašpárková, V.; Humpolíček, P.; Ševčíková, P.; Stejskal, Jaroslav

    2013-01-01

    Roč. 67, č. 8 (2013), s. 1103-1108 ISSN 0366-6352 R&D Projects: GA ČR(CZ) GA13-08944S Institutional support: RVO:61389013 Keywords : polyaniline * silver * antibacterial properties Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.193, year: 2013

  17. Phytochemical Screening and Antibacterial Activities of Hibiscus ...

    African Journals Online (AJOL)

    The phytochemical properties and the antibacterial potency of rosselle (Hibiscus sabdariffa L) leaf extracts were evaluated using the cold maceration method, agar diffusion method and qualitative phytochemical analysis respectively. The methanolic extract was tested against Salmonella typhi, Escherichia coli and ...

  18. Phytochemical screening and antibacterial investigations of crude ...

    African Journals Online (AJOL)

    The objective of this research was to evaluate the presence of phytochemicals present in the different plant parts and their antibacterial activity. Methodology and results: Leaves, flowers, stem bark, immature pods and root barks were collected from Siaya, Nandi and Nakuru Counties. These were dried and ground.

  19. Antibacterial properties and preliminary phytochemical analysis of ...

    African Journals Online (AJOL)

    Partial purification (Thin Layer Chromatography) of the crude extract revealed five (5) components. Characteristics of these components were viewed by Infrared and UV/VIS spectrophotometer showing the presence of alkaloid, saponin, tannin, steroid and flavonoid. The observed antibacterial activity was believed to be due ...

  20. Synthesis and antibacterial activity screening of quaternary ...

    Indian Academy of Sciences (India)

    A series of quaternary ammonium derivatives of triazolyl pyranochromen-2-ones have been synthesized and characterized; their antibacterial potential were investigated against two gram negative (Pseudomonas aeruginosa and Escherichia coli) and two gram positive bacterial strains (Bacillus cereus and Staphylococcus ...

  1. Antibacterial effect of surface pretreatment techniques against ...

    African Journals Online (AJOL)

    Objective: The aim of this study was to evaluate the antibacterial surface pretreatment methods against Streptococcus mutans within the infected dentin surface using a tooth cavity model. Material and Methods: Seventy-two cavities were prepared on caries-free third molars (n = 8). After sterilization, teeth were inoculated ...

  2. Precursor Dependent Structural Properties and Antibacterial Activity ...

    Indian Academy of Sciences (India)

    71

    10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30 ... absorption spectroscopy, Scanning electron microscopy (SEM) and Zeta ... The antibacterial activity of the synthesized CuO were studied against human .... Sample d : Copper oxide synthesized with cupric sulphate as precursor ...... Chem.4 86.

  3. Studies on Buddleja asiatica antibacterial, antifungal, antispasmodic ...

    African Journals Online (AJOL)

    Jane

    2011-07-27

    Jul 27, 2011 ... Studies on Buddleja asiatica antibacterial, antifungal, antispasmodic and Ca. ++ ... strong cyclo-oxygenase inhibitory activities in elicited rat peritoneal ... A resting tension of 1 g was applied to each tissue and kept constant ... Statistical analysis .... through opening of VDCs, thus allowing the influx of extra.

  4. SYNERGISTIC ANTIBACTERIAL EFFECT OF STEM BARK ...

    African Journals Online (AJOL)

    userpc

    ABSTRACT. The study was aimed at screening the stem bark extracts of Faidherbia albida and Psidium guajava for synergistic antibacterial effect against methicillin resistant Staphylococcus aureus (MRSA). The powdered plant materials were extracted with methanol using cold maceration technique and the extracts were ...

  5. Phytochemical Screening, Antibacterial and Toxicological Activities ...

    African Journals Online (AJOL)

    The phytochemical screening, antibacterial and toxicological activities of extracts of the stem bark of Acacia senegal were investigated. The phytochemical analyses according to standard screening tests using conventional protocols revealed the presence of tannins, saponins and sterols in the stem bark of the plant.

  6. antibacterial properties and preliminary phytochemical analysis

    African Journals Online (AJOL)

    DR. AMINU

    IBDF Ministeroida Agricultura, Riode Janesio, 63pp. Edeoja, O.H., Okwu, E.D. and Mbaebie, O.B. (2005). Phytochemical constituents of some Nigerian medicinal plants. African Journal of Biotechnology. 4(7):685-688. Ekhaise, F.O. and Okoruwa, P. (2001). Antibacterial activity of Aloe vera (Aloe barbadensis) extract on.

  7. Purification, Characterization and Antibacterial Mechanism of ...

    African Journals Online (AJOL)

    Purpose: To carry out the extraction, purification and biological characterization, and assess the antibacterial activity of bacteriocin from Lactobacillus acidophilus XH1. Methods: Chloroform extraction method was used for bacteriocin extraction while characterization of bacteriocin was carried out by flat-dug well agar ...

  8. 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,

  9. Preparation, Characterization and Antibacterial Properties of Silver ...

    African Journals Online (AJOL)

    electron microscopy (SEM), differential scanning calorimetry (DSC), dynamic light scattering (DLS) and laser Doppler electrophoresis (LDE). The antibacterial ... silver nanoparticles. The size of the nanoparticles can be modulated by varying both chitosan MW and process conditions such as temperature and stirring speed.

  10. ANTIBACTERIAL ACTIVITIES, DFT AND QSAR STUDIES OF ...

    African Journals Online (AJOL)

    Latif Hesham4. 1Department of ... [5] and characterized, see Figure 1. In the present study, our aim is to investigate the antibacterial activity of 1 and 2. Moreover, ..... in Figure 3. The pink color parts embody the regions of negative electrostatic.

  11. Phytochemical screening and antibacterial activity of Azadiracta ...

    African Journals Online (AJOL)

    Preliminary phytochemical analysis showed that both stem bark and leaf extracts contain alkaloid, tannin, anthraquinone, flavonoid, phenols and terpenoid. The extracts of the plant demonstrated antibacterial activity due to presence of phytochemical constituents hence, the application of the decoction of leaf and stem bark ...

  12. Synthesis, spectral characterization and in vitro antibacterial ...

    African Journals Online (AJOL)

    Shafqat Nadeem

    2015-12-17

    Dec 17, 2015 ... slightly toxic and present a potential for antibacterial activity. Moreover, they ... interaction, in this paper, we describe the coordination of Pal- ladium(II) iodide with .... between steric/electrostatic property and biological activity. Table. 1 ..... properties, affinity to proteins, reactivity, toxicity, metabolic stability and ...

  13. Phytochemical screening, free radical scavenging and antibacterial ...

    African Journals Online (AJOL)

    Cassia sieberiana is a tropical plant, widely distributed throughout Sudan and Guinea savannah. It is used in traditional medicine for the treatment of malarial, cancer and stomach ache. The study was conducted to screen for phytochemicals, free radical scavenging and antibacterial potentials of the root bark.

  14. Antiproliferative and antibacterial activity evaluation of red ...

    African Journals Online (AJOL)

    Antibacterial activity of these extracts was also tested against Salmonella choleraesuis, Listeria monocytogenes and Staphylococcus aureus. All extracts were obtained from lyophilized biomass of red microalgae. Extract A was obtained using 40% ammonium sulfate precipitation and gel filtration chromatography with G-25 ...

  15. Antibacterial evaluation of Anacardium occidentale (Linn ...

    African Journals Online (AJOL)

    aghomotsegin

    has led to the seeking of new antibiotics that are effective and opens paths for the ... to evaluate the antibacterial activity of ethanol extract of the leaves and stem peels of .... radiation intensity and production of phenol compounds such as ...

  16. Evaluation of phytochemical and antibacterial properties of ...

    African Journals Online (AJOL)

    Phytochemical screening of aqueous and ethanol crude extracts of the different plant parts of Terminalia avicennioides was carried out using standard chemical evaluation methods. The antibacterial effects of aqueous and ethanol crude extracts of Terminalia avicennioides against E.coli and S.typhimurium clinical and ...

  17. 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....

  18. 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

  19. 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

  20. Nanobiostructure of fibrous-like alumina functionalized with an analog of the BP100 peptide: Synthesis, characterization and biological applications.

    Science.gov (United States)

    Torres, L M F C; Braga, N A; Gomes, I P; Almeida, M T; Santos, T L; de Mesquita, J P; da Silva, L M; Martins, H R; Kato, K C; Dos Santos, W T P; Resende, J M; Pereira, M C; Bemquerer, M P; Rodrigues, M A; Verly, R M

    2018-03-01

    The functionalization of alumina nanoparticles of specific morphology with antimicrobial peptides (AMP) can be a promising strategy for modeling medical devices and packaging materials for cosmetics, medicines or food, since the contamination by pathogens could be reduced. In this paper, we show the synthesis of a fibrous-like alumina nanobiostructure, as well as its functionalization with the peptide EAAA-BP100, an analog of the antimicrobial peptide BP100. The antibacterial activity of the obtained material against some bacterial strains is also investigated. The covalent binding of the peptide to the nanoparticles was promoted by a reaction between the carboxyl group of the glutamate side chain (E1) of the peptide and the amino groups of the alumina nanoparticles, previously modified by reaction with 3-aminopropyltrietoxysilane (APTES). The functionalized nanoparticles were characterized by zeta potential measurements, Fourier transform infrared spectroscopy, and other physicochemical techniques. Although the obtained alumina nanobiostructure shows a relatively low degree of substitution with EAAA-BP100, antibacterial activities against Escherichia coli and Salmonella typhimurium strains are appreciably higher than the activities of the free peptide. The obtained results can affect the design of new hybrid nanobiomaterials based on nanoparticles functionalized with AMP. Copyright © 2018. Published by Elsevier B.V.

  1. Environmental monitoring and assessment of antibacterial metabolite producing actinobacteria screened from marine sediments in south coastal regions of Karnataka, India.

    Science.gov (United States)

    Skariyachan, Sinosh; Garka, Shruthi; Puttaswamy, Sushmitha; Shanbhogue, Shobitha; Devaraju, Raksha; Narayanappa, Rajeswari

    2017-06-01

    Assessment of the therapeutic potential of secondary metabolite producing microorganisms from the marine coastal areas imparts scope and application in the field of environmental monitoring. The present study aims to screen metabolites with antibacterial potential from actionbacteria associated with marine sediments collected from south coastal regions of Karnataka, India. The actinobacteria were isolated and characterized from marine sediments by standard protocol. The metabolites were extracted, and antibacterial potential was analyzed against eight hospital associated bacteria. The selected metabolites were partially characterized by proximate analysis, SDS-PAGE, and FTIR-spectroscopy. The antibiogram of the test clinical isolates revealed that they were emerged as multidrug-resistant strains (P ≤ 0.05). Among six actinobacteria (IS1-1S6) screened, 100 μl -1 metabolite from IS1 showed significant antibacterial activities against all the clinical isolates except Pseudomonas aeruginosa. IS2 demonstrated antimicrobial potential towards Proteus mirabilis, Streptococcus pyogenes, and Escherichia coli. The metabolite from IS3 showed activity against Strep. pyogenes and E. coli. The metabolites from IS4, IS5, and IS6 exhibited antimicrobial activities against Ps. aeruginosa (P ≤ 0.05). The two metabolites that depicted highest antibacterial activities against the test strains were suggested to be antimicrobial peptides with low molecular weight. These isolates were characterized and designated as Streptomyces sp. strain mangaluru01 and Streptomyces sp. mangaloreK01 by 16S ribosomal DNA (rDNA) sequencing. This study suggests that south coastal regions of Karnataka, India, are one of the richest sources of antibacterial metabolites producing actinobacteria and monitoring of these regions for therapeutic intervention plays profound role in healthcare management.

  2. Biosynthesis of 2-aminooctanoic acid and its use to terminally modify a lactoferricin B peptide derivative for improved antimicrobial activity.

    Science.gov (United States)

    Almahboub, Sarah A; Narancic, Tanja; Devocelle, Marc; Kenny, Shane T; Palmer-Brown, William; Murphy, Cormac; Nikodinovic-Runic, Jasmina; O'Connor, Kevin E

    2018-01-01

    Terminal modification of peptides is frequently used to improve their hydrophobicity. While N-terminal modification with fatty acids (lipidation) has been reported previously, C-terminal lipidation is limited as it requires the use of linkers. Here we report the use of a biocatalyst for the production of an unnatural fatty amino acid, (S)-2-aminooctanoic acid (2-AOA) with enantiomeric excess > 98% ee and the subsequent use of 2-AOA to modify and improve the activity of an antimicrobial peptide. A transaminase originating from Chromobacterium violaceum was employed with a conversion efficiency 52-80% depending on the ratio of amino group donor to acceptor. 2-AOA is a fatty acid with amino functionality, which allowed direct C- and N-terminal conjugation respectively to an antimicrobial peptide (AMP) derived from lactoferricin B. The antibacterial activity of the modified peptides was improved by up to 16-fold. Furthermore, minimal inhibitory concentrations (MIC) of C-terminally modified peptide were always lower than N-terminally conjugated peptides. The C-terminally modified peptide exhibited MIC values of 25 μg/ml for Escherichia coli, 50 μg/ml for Bacillus subtilis, 100 μg/ml for Salmonella typhimurium, 200 μg/ml for Pseudomonas aeruginosa and 400 μg/ml for Staphylococcus aureus. The C-terminally modified peptide was the only peptide tested that showed complete inhibition of growth of S. aureus.

  3. 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.

  4. Peptide Integrated Optics.

    Science.gov (United States)

    Handelman, Amir; Lapshina, Nadezda; Apter, Boris; Rosenman, Gil

    2018-02-01

    Bio-nanophotonics is a wide field in which advanced optical materials, biomedicine, fundamental optics, and nanotechnology are combined and result in the development of biomedical optical chips. Silk fibers or synthetic bioabsorbable polymers are the main light-guiding components. In this work, an advanced concept of integrated bio-optics is proposed, which is based on bioinspired peptide optical materials exhibiting wide optical transparency, nonlinear and electrooptical properties, and effective passive and active waveguiding. Developed new technology combining bottom-up controlled deposition of peptide planar wafers of a large area and top-down focus ion beam lithography provides direct fabrication of peptide optical integrated circuits. Finding a deep modification of peptide optical properties by reconformation of biological secondary structure from native phase to β-sheet architecture is followed by the appearance of visible fluorescence and unexpected transition from a native passive optical waveguiding to an active one. Original biocompatibility, switchable regimes of waveguiding, and multifunctional nonlinear optical properties make these new peptide planar optical materials attractive for application in emerging technology of lab-on-biochips, combining biomedical photonic and electronic circuits toward medical diagnosis, light-activated therapy, and health monitoring. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Antimicrobial Peptides from Plants

    Directory of Open Access Journals (Sweden)

    James P. Tam

    2015-11-01

    Full Text Available Plant antimicrobial peptides (AMPs have evolved differently from AMPs from other life forms. They are generally rich in cysteine residues which form multiple disulfides. In turn, the disulfides cross-braced plant AMPs as cystine-rich peptides to confer them with extraordinary high chemical, thermal and proteolytic stability. The cystine-rich or commonly known as cysteine-rich peptides (CRPs of plant AMPs are classified into families based on their sequence similarity, cysteine motifs that determine their distinctive disulfide bond patterns and tertiary structure fold. Cystine-rich plant AMP families include thionins, defensins, hevein-like peptides, knottin-type peptides (linear and cyclic, lipid transfer proteins, α-hairpinin and snakins family. In addition, there are AMPs which are rich in other amino acids. The ability of plant AMPs to organize into specific families with conserved structural folds that enable sequence variation of non-Cys residues encased in the same scaffold within a particular family to play multiple functions. Furthermore, the ability of plant AMPs to tolerate hypervariable sequences using a conserved scaffold provides diversity to recognize different targets by varying the sequence of the non-cysteine residues. These properties bode well for developing plant AMPs as potential therapeutics and for protection of crops through transgenic methods. This review provides an overview of the major families of plant AMPs, including their structures, functions, and putative mechanisms.

  6. Evaluation of in vitro antibacterial effect of room curing polymethylmethacrylate material adding nano-silver base inorganic antibacterial agents

    International Nuclear Information System (INIS)

    Jia Chunli; Wang Xiaorong; Zhang Citong; Sun Shiqun; Yang Yun

    2012-01-01

    Objective: To investigate the antibacterial effect of room curing polymethylmethacrylate (PMMA) material adding nano-silver base inorganic antibacterial agent and to detect the changes of its mechanical property. Methods: Nano-silver base inorganic antibacterial agent was added to the room curing PMMA material in the range of 0.5% -3.0% at an interval of 0.5% by ball milling specimen. Antibacterial rates of the specimens were detected by film method. Bending strength, impact strength, and wear resistance of the specimens were respectively detected on electronic universal testing machine, impact test machine and friction and wear test machine. Results: The antibacterial rates of Streptococcus mutans and Candida albicans were more than 50% when antibiotics content was 1.0% . The antibacterial rates of Streptococcus mutans and Candida albicans were more than 90% when the antibiotics content was 2.5% . The three mechanical properties were increased compared with control group when the antibacterial agents were in the range of 1.0% -1.5% . Then the three mechanical properties were decreased with the increasing of antimicrobial concentration. When the antibiotics content was 2.0% , the wear resistance had significant difference compared with control group (P<0.05); when the antibiotics content was 2.5% , the bending strength and impact strength had significant difference compared with control group (P<0.05). Conclusion: The antibacterial effect of room curing PMMA adding nano-silver base inorganic antibacterial agent is ideal. The antibacterial rate is increased gradually with the increasing content of antibacterial agents. There is no significant effect on the mechanical properties of room curing PMMA material, but the antibacterial effects are satisfied when the content of antibacterial agents is 2.0% . (authors)

  7. Antibacterial and Antifungal Activities of Spices

    Science.gov (United States)

    Liu, Qing; Meng, Xiao; Li, Ya; Zhao, Cai-Ning; Tang, Guo-Yi; Li, Hua-Bin

    2017-01-01

    Infectious diseases caused by pathogens and food poisoning caused by spoilage microorganisms are threatening human health all over the world. The efficacies of some antimicrobial agents, which are currently used to extend shelf-life and increase the safety of food products in food industry and to inhibit disease-causing microorganisms in medicine, have been weakened by microbial resistance. Therefore, new antimicrobial agents that could overcome this resistance need to be discovered. Many spices—such as clove, oregano, thyme, cinnamon, and cumin—possessed significant antibacterial and antifungal activities against food spoilage bacteria like Bacillus subtilis and Pseudomonas fluorescens, pathogens like Staphylococcus aureus and Vibrio parahaemolyticus, harmful fungi like Aspergillus flavus, even antibiotic resistant microorganisms such as methicillin resistant Staphylococcus aureus. Therefore, spices have a great potential to be developed as new and safe antimicrobial agents. This review summarizes scientific studies on the antibacterial and antifungal activities of several spices and their derivatives. PMID:28621716

  8. 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.

  9. Antimicrobial peptides from Capsicum sp.

    African Journals Online (AJOL)

    ajl yemi

    2011-12-30

    Dec 30, 2011 ... are regarded as waste after plants' fruits or seeds have been harvested. AMPs from ... including bacteria, fungi, viruses and oomycetes causing ..... Antibacterial effect of protein fraction from seeds of Capsicum chinense Jacq.

  10. Acylation of Therapeutic Peptides

    DEFF Research Database (Denmark)

    Trier, Sofie; Henriksen, Jonas Rosager; Jensen, Simon Bjerregaard

    ) , which promotes intestinal growth and is used to treat bowel disorders such as inflammatory bowel diseases and short bowel syndrome, and the 32 amino acid salmon calcitonin (sCT), which lowers blood calcium and is employed in the treatment of post-menopausal osteoporosis and hypercalcemia. The two...... peptides are similar in size and structure, but oppositely charged at physiological pH. Both peptides were acylated with linear acyl chains of systematically increasing length, where sCT was furthermore acylated at two different positions on the peptide backbone. For GLP-2, we found that increasing acyl...... remained optimal overall. The results indicate that rational acylation of GLP-2 can increase its in vitro intestinal absorption, alone or in combination with permeation enhancers, and are consistent with the initial project hypothesis. For sCT, an unpredicted effect of acylation largely superseded...

  11. Antibacterial biodegradable Mg-Ag alloys

    Directory of Open Access Journals (Sweden)

    D Tie

    2013-06-01

    Full Text Available The use of magnesium alloys as degradable metals for biomedical applications is a topic of ongoing research and the demand for multifunctional materials is increasing. Hence, binary Mg-Ag alloys were designed as implant materials to combine the favourable properties of magnesium with the well-known antibacterial property of silver. In this study, three Mg-Ag alloys, Mg2Ag, Mg4Ag and Mg6Ag that contain 1.87 %, 3.82 % and 6.00 % silver by weight, respectively, were cast and processed with solution (T4 and aging (T6 heat treatment.The metallurgical analysis and phase identification showed that all alloys contained Mg4Ag as the dominant β phase. After heat treatment, the mechanical properties of all Mg-Ag alloys were significantly improved and the corrosion rate was also significantly reduced, due to presence of silver. Mg(OH2 and MgO present the main magnesium corrosion products, while AgCl was found as the corresponding primary silver corrosion product. Immersion tests, under cell culture conditions, demonstrated that the silver content did not significantly shift the pH and magnesium ion release. In vitro tests, with both primary osteoblasts and cell lines (MG63, RAW 264.7, revealed that Mg-Ag alloys show negligible cytotoxicity and sound cytocompatibility. Antibacterial assays, performed in a dynamic bioreactor system, proved that the alloys reduce the viability of two common pathogenic bacteria, Staphylococcus aureus (DSMZ 20231 and Staphylococcus epidermidis (DSMZ 3269, and the results showed that the killing rate of the alloys against tested bacteria exceeded 90%. In summary, biodegradable Mg-Ag alloys are cytocompatible materials with adjustable mechanical and corrosion properties and show promising antibacterial activity, which indicates their potential as antibacterial biodegradable implant materials.

  12. Antibacterial phenolics from the mangrove Lumnitzera racemosa

    Digital Repository Service at National Institute of Oceanography (India)

    DeSouza, L.; Wahidullah, S.; PrabhaDevi

    -(4- hydroxyphenyl)-propyl-3′-(3,4-dihydroxyphenyl)- propionate1. This communication relates to the identification of antibacterial principle in L. racemosa which is associated with polyphenolic constituents. The efficacy of this mangrove has been studied... be necessary for a full evaluation of their practical usefulness in the field of modern medicine. Acknowledgements The authors thank Dr. S. R. Shetye, Director, NIO for his keen interest in the work. Financial support by Ministry of Earth Sciences under...

  13. Antibacterial nanofiber materials activated by light

    Czech Academy of Sciences Publication Activity Database

    Jesenská, S.; Plištil, L.; Kubát, Pavel; Lang, Kamil; Brožová, Libuše; Popelka, Štěpán; Szatmáry, Lórant; Mosinger, Jiří

    99A, č. 4 (2011), s. 676-683 ISSN 1549-3296 R&D Projects: GA ČR GAP208/10/1678 Institutional research plan: CEZ:AV0Z40400503; CEZ:AV0Z40320502; CEZ:AV0Z40500505 Keywords : antibacterial nanofiber materials * photoactive * singlet oxygen Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.625, year: 2011

  14. Antibacterial Compounds from Red Seaweeds (Rhodophyta)

    OpenAIRE

    Noer Kasanah; Triyanto Triyanto; Drajad Sarwo Seto; Windi Amelia; Alim Isnansetyo

    2015-01-01

    Seaweeds produce great variety of metabolites benefit for human. Red seaweeds (Rhodophyta) are well known as producer of phycocolloids such agar, agarose, carragenan and great variety of secondary metabolites. This review discusses the red algal secondary metabolites with antibacterial activity. The chemical constituents of red algae are steroid, terpenoid, acetogenin and dominated by halogenated compounds mainly brominated compounds. Novel compounds with intriguing skeleton are also reported...

  15. 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; Poret-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 (clay minerals in the bactericidal process is to buffer the aqueous pH and oxidation state to conditions that promote Fe2+ solubility. Chemical analyses of E. coli killed by aqueous leachates of an antibacterial clay show that intracellular concentrations of Fe and P are elevated relative to controls. Phosphorus uptake by the cells supports a regulatory role of polyphosphate or phospholipids in controlling Fe2+. Fenton reaction products can degrade critical cell components, but we deduce that extracellular processes do not cause cell death. Rather, Fe2+ overwhelms outer membrane regulatory proteins and is oxidized when it enters the cell, precipitating Fe3+ and producing lethal hydroxyl radicals. PMID:21413758

  16. Antibacterial Functionalization of PVD Coatings on Ceramics

    Directory of Open Access Journals (Sweden)

    Javier Osés

    2018-05-01

    Full Text Available The application of surface treatments that incorporate silver or copper as antibacterial elements has become a common practice for a wide variety of medical devices and materials because of their effective activity against nosocomial infections. Ceramic tiles are choice materials for cladding the floors and walls of operation rooms and other hospital spaces. This study is focused on the deposition of biocide physical vapor deposition (PVD coatings on glazed ceramic tiles. The objective was to provide antibacterial activity to the surfaces without worsening their mechanical properties. Silver and copper-doped chromium nitride (CrN and titanium nitride (TiN coatings were deposited on samples of tiles. A complete characterization was carried out in order to determine the composition and structure of the coatings, as well as their topographical and mechanical properties. The distribution of Ag and Cu within the coating was analyzed using glow discharge optical emission spectrometry (GD-OES and field emission scanning electron microscope (FE-SEM. Roughness, microhardness, and scratch resistance were measured for all of the combinations of coatings and dopants, as well as their wettability. Finally, tests of antibacterial efficacy against Staphylococcus aureus and Escherichia coli were carried out, showing that all of the doped coatings had pronounced biocide activity.

  17. Antibacterial properties of laser spinning glass nanofibers.

    Science.gov (United States)

    Echezarreta-López, M M; De Miguel, T; Quintero, F; Pou, J; Landin, M

    2014-12-30

    A laser-spinning technique has been used to produce amorphous, dense and flexible glass nanofibers of two different compositions with potential utility as reinforcement materials in composites, fillers in bone defects or scaffolds (3D structures) for tissue engineering. Morphological and microstructural analyses have been carried out using SEM-EDX, ATR-FTIR and TEM. Bioactivity studies allow the nanofibers with high proportion in SiO2 (S18/12) to be classified as a bioinert glass and the nanofibers with high proportion of calcium (ICIE16) as a bioactive glass. The cell viability tests (MTT) show high biocompatibility of the laser spinning glass nanofibers. Results from the antibacterial activity study carried out using dynamic conditions revealed that the bioactive glass nanofibers show a dose-dependent bactericidal effect on Sthaphylococcus aureus (S. aureus) while the bioinert glass nanofibers show a bacteriostatic effect also dose-dependent. The antibacterial activity has been related to the release of alkaline ions, the increase of pH of the medium and also the formation of needle-like aggregates of calcium phosphate at the surface of the bioactive glass nanofibers which act as a physical mechanism against bacteria. The antibacterial properties give an additional value to the laser-spinning glass nanofibers for different biomedical applications, such as treating or preventing surgery-associated infections. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. 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...

  19. Descriptors for antimicrobial peptides

    DEFF Research Database (Denmark)

    Jenssen, Håvard

    2011-01-01

    of these are currently being used in quantitative structure--activity relationship (QSAR) studies for AMP optimization. Additionally, some key commercial computational tools are discussed, and both successful and less successful studies are referenced, illustrating some of the challenges facing AMP scientists. Through...... examples of different peptide QSAR studies, this review highlights some of the missing links and illuminates some of the questions that would be interesting to challenge in a more systematic fashion. Expert opinion: Computer-aided peptide QSAR using molecular descriptors may provide the necessary edge...

  20. Antimicrobial Peptides in Biomedical Device Manufacturing

    Directory of Open Access Journals (Sweden)

    Martijn Riool

    2017-08-01

    Full Text Available Over the past decades the use of medical devices, such as catheters, artificial heart valves, prosthetic joints, and other implants, has grown significantly. Despite continuous improvements in device design, surgical procedures, and wound care, biomaterial-associated infections (BAI are still a major problem in modern medicine. Conventional antibiotic treatment often fails due to the low levels of antibiotic at the site of infection. The presence of biofilms on the biomaterial and/or the multidrug-resistant phenotype of the bacteria further impair the efficacy of antibiotic treatment. Removal of the biomaterial is then the last option to control the infection. Clearly, there is a pressing need for alternative strategies to prevent and treat BAI. Synthetic antimicrobial peptides (AMPs are considered promising candidates as they are active against a broad spectrum of (antibiotic-resistant planktonic bacteria and biofilms. Moreover, bacteria are less likely to develop resistance to these rapidly-acting peptides. In this review we highlight the four main strategies, three of which applying AMPs, in biomedical device manufacturing to prevent BAI. The first involves modification of the physicochemical characteristics of the surface of implants. Immobilization of AMPs on surfaces of medical devices with a variety of chemical techniques is essential in the second strategy. The main disadvantage of these two strategies relates to the limited antibacterial effect in the tissue surrounding the implant. This limitation is addressed by the third strategy that releases AMPs from a coating in a controlled fashion. Lastly, AMPs can be integrated in the design and manufacturing of additively manufactured/3D-printed implants, owing to the physicochemical characteristics of the implant material and the versatile manufacturing technologies compatible with antimicrobials incorporation. These novel technologies utilizing AMPs will contribute to development of novel

  1. Antimicrobial Peptides in Biomedical Device Manufacturing

    Science.gov (United States)

    Riool, Martijn; de Breij, Anna; Drijfhout, Jan W.; Nibbering, Peter H.; Zaat, Sebastian A. J.

    2017-08-01

    Over the past decades the use of medical devices, such as catheters, artificial heart valves, prosthetic joints and other implants, has grown significantly. Despite continuous improvements in device design, surgical procedures and wound care, biomaterial-associated infections (BAI) are still a major problem in modern medicine. Conventional antibiotic treatment often fails due to the low levels of antibiotic at the site of infection. The presence of biofilms on the biomaterial and/or the multidrug-resistant phenotype of the bacteria further impair the efficacy of antibiotic treatment. Removal of the biomaterial is then the last option to control the infection. Clearly, there is a pressing need for alternative strategies to prevent and treat BAI. Synthetic antimicrobial peptides (AMPs) are considered promising candidates as they are active against a broad spectrum of (antibiotic-resistant) planktonic bacteria and biofilms. Moreover, bacteria are less likely to develop resistance to these rapidly-acting peptides. In this review we highlight the four main strategies, three of which applying AMPs, in biomedical device manufacturing to prevent BAI. The first involves modification of the physicochemical characteristics of the surface of implants. Immobilization of AMPs on surfaces of medical devices with a variety of chemical techniques is essential in the second strategy. The main disadvantage of these two strategies relates to the limited antibacterial effect in the tissue surrounding the implant. This limitation is addressed by the third strategy that releases AMPs from a coating in a controlled fashion. Lastly, AMPs can be integrated in the design and manufacturing of additively manufactured / 3D-printed implants, owing to the physicochemical characteristics of the implant material and the versatile manufacturing technologies compatible with antimicrobials incorporation. These novel technologies utilizing AMPs will contribute to development of novel and safe

  2. Presence of chromogranin-derived antimicrobial peptides in plasma during coronary artery bypass surgery and evidence of an immune origin of these peptides.

    Science.gov (United States)

    Tasiemski, Aurélie; Hammad, Hamida; Vandenbulcke, Franck; Breton, Christophe; Bilfinger, Thomas J; Pestel, Joel; Salzet, Michel

    2002-07-15

    Chromogranin A (CGA) and chromogranin B (CGB) are acidic proteins stored in secretory organelles of endocrine cells and neurons. In addition to their roles as helper proteins in the packaging of peptides, they may serve as prohormones to generate biologically active peptides such as vasostatin-1 and secretolytin. These molecules derived from CGA and CGB, respectively, possess antimicrobial properties. The present study demonstrates that plasmatic levels of both vasostatin-1 and secretolytin increase during surgery in patients undergoing cardiopulmonary bypass (CPB). Vasostatin-1 and secretolytin, initially present in plasma at low levels, are released just after skin incision. Consequently, they can be added to enkelytin, an antibacterial peptide derived from proenkephalin A, for the panoply of components acting as a first protective barrier against hypothetical invasion of pathogens, which may occur during surgery. CGA and CGB, more commonly viewed as markers for endocrine and neuronal cells, were also found to have an immune origin. RNA messengers coding for CGB were amplified by reverse transcription-polymerase chain reaction in human monocytes, and immunocytochemical analysis by confocal microscopy revealed the presence of CGA or CGB or both in monocytes and neutrophils. A combination of techniques including confocal microscopic analysis, mass spectrometry measurement, and antibacterial tests allowed for the identification of the positive role of interleukin 6 (IL-6) in the secretolytin release from monocytes in vitro. Because IL-6 release is known to be strongly enhanced during CPB, we suggest a possible relationship between IL-6 and the increased level of secretolytin in patients undergoing CPB.

  3. 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.

  4. Tissue factor pathway inhibitor 2 is found in skin and its C-terminal region encodes for antibacterial activity.

    Science.gov (United States)

    Papareddy, Praveen; Kalle, Martina; Sørensen, Ole E; Lundqvist, Katarina; Mörgelin, Matthias; Malmsten, Martin; Schmidtchen, Artur

    2012-01-01

    Tissue factor pathway inhibitor 2 (TFPI-2) is a matrix-associated serine protease inhibitor with an enigmatic function in vivo. Here, we describe that TFPI-2 is present in fibrin of wounds and also expressed in skin, where it is up-regulated upon wounding. Neutrophil elastase cleaved TFPI-2, and a C-terminal fragment was found to bind to bacteria. Similarly, a prototypic peptide representing this C-terminal part, EDC34, bound to bacteria and bacterial lipopolysaccharide, and induced bacterial permeabilization. The peptide also induced leakage in artificial liposomes, and displayed a random coil conformation upon interactions with liposomes as well as lipopolysaccharide. EDC34 was antibacterial against both Gram-negative and Gram-positive bacteria in physiological buffer conditions. The results demonstrate that the C-terminus of TFPI-2 encodes for antimicrobial activity, and may be released during wounding.

  5. Komodo dragon-inspired synthetic peptide DRGN-1 promotes wound-healing of a mixed-biofilm infected wound.

    Science.gov (United States)

    M C Chung, Ezra; Dean, Scott N; Propst, Crystal N; Bishop, Barney M; van Hoek, Monique L

    2017-01-01

    determined to be via anti-biofilm activity and antibacterial activity through membrane permeabilization. This novel peptide may have potential as a future therapeutic for treating infected wounds.

  6. Antimicrobial Peptides: An Introduction.

    Science.gov (United States)

    Haney, Evan F; Mansour, Sarah C; Hancock, Robert E W

    2017-01-01

    The "golden era" of antibiotic discovery has long passed, but the need for new antibiotics has never been greater due to the emerging threat of antibiotic resistance. This urgency to develop new antibiotics has motivated researchers to find new methods to combat pathogenic microorganisms resulting in a surge of research focused around antimicrobial peptides (AMPs; also termed host defense peptides) and their potential as therapeutics. During the past few decades, more than 2000 AMPs have been identified from a diverse range of organisms (animals, fungi, plants, and bacteria). While these AMPs share a number of common features and a limited number of structural motifs; their sequences, activities, and targets differ considerably. In addition to their antimicrobial effects, AMPs can also exhibit immunomodulatory, anti-biofilm, and anticancer activities. These diverse functions have spurred tremendous interest in research aimed at understanding the activity of AMPs, and various protocols have been described to assess different aspects of AMP function including screening and evaluating the activities of natural and synthetic AMPs, measuring interactions with membranes, optimizing peptide function, and scaling up peptide production. Here, we provide a general overview of AMPs and introduce some of the methodologies that have been used to advance AMP research.

  7. 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.

  8. Cationic antimicrobial peptides in penaeid shrimp.

    Science.gov (United States)

    Tassanakajon, Anchalee; Amparyup, Piti; Somboonwiwat, Kunlaya; Supungul, Premruethai

    2011-08-01

    Penaeid shrimp aquaculture has been consistently affected worldwide by devastating diseases that cause a severe loss in production. To fight a variety of harmful microbes in the surrounding environment, particularly at high densities (of which intensive farming represents an extreme example), shrimps have evolved and use a diverse array of antimicrobial peptides (AMPs) as part of an important first-line response of the host defense system. Cationic AMPs in penaeid shrimps composed of penaeidins, crustins, and anti-lipopolysaccharide factors are comprised of multiple classes or isoforms and possess antibacterial and antifungal activities against different strains of bacteria and fungi. Shrimp AMPs are primarily expressed in circulating hemocytes, which is the main site of the immune response, and hemocytes expressing AMPs probably migrate to infection sites to fight against pathogen invasion. Indeed, most AMPs are produced as early as the nauplii developmental stage to protect shrimp larvae from infections. In this review, we discuss the sequence diversity, expression, gene structure, and antimicrobial activities of cationic AMPs in penaeid shrimps. The information available on antimicrobial activities indicates that these shrimp AMPs have potential therapeutic applications in the control of disease problems in aquaculture.

  9. Design, Synthesis, and Biological Evaluation of Vanillin Hydroxamic Acid Derivatives as Novel Peptide Deformylase Inhibitors.

    Science.gov (United States)

    Gao, Jian; Qiu, Shengzhi; Liang, Li; Hao, Zhixiang; Zhou, Qianqian; Wang, Fanfan; Mou, Jie; Lin, Qisi

    2018-01-01

    Infectious disease is increasingly hampering human health, which challenge the discovery of new antibacterial target. Peptide deformylase (PDF), a metalloenzyme responsible for catalyzing the removal of the N-formyl group from nascent proteins, was considered as an important target in antibacterial drug discovery. Reported here are the design, synthesis and biological evaluation of vanillin hydroxamic acid derivatives. Analysis of the structure-activity relationships lead to the discovery of compound 8, which exhibits promising antibacterial activity against Escherichia coli, Staphylococcus aureus, Aspergillus oryzae, and Aspergillus foetidus with the MIC value of 0.32 µg/ml, 0.32 µg/ml, 0.16 µg/ml and 0.16 µg/ml, respectively. Furthermore, molecular docking study was applied to elucidate binding interaction between compound 8 and PDF, which indicate that compound 8 not only shares the same binding pocket with actinonin, but also has a similar binding pattern. In silico pharmacokinetic and toxicity prediction studies also suggested that compound 8 has a relatively high drug score of 0.80, and has no risk of toxicity. Compound 8 might represent a promising scaffold for the further development of novel antibacterial drugs. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  10. 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. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Actinonin, a naturally occurring antibacterial agent, is a potent deformylase inhibitor.

    Science.gov (United States)

    Chen, D Z; Patel, D V; Hackbarth, C J; Wang, W; Dreyer, G; Young, D C; Margolis, P S; Wu, C; Ni, Z J; Trias, J; White, R J; Yuan, Z

    2000-02-15

    Peptide deformylase (PDF) is essential in prokaryotes and absent in mammalian cells, thus making it an attractive target for the discovery of novel antibiotics. We have identified actinonin, a naturally occurring antibacterial agent, as a potent PDF inhibitor. The dissociation constant for this compound was 0.3 x 10(-)(9) M against Ni-PDF from Escherichia coli; the PDF from Staphylococcus aureus gave a similar value. Microbiological evaluation revealed that actinonin is a bacteriostatic agent with activity against Gram-positive and fastidious Gram-negative microorganisms. The PDF gene, def, was placed under control of P(BAD) in E. coli tolC, permitting regulation of PDF expression levels in the cell by varying the external arabinose concentration. The susceptibility of this strain to actinonin increases with decreased levels of PDF expression, indicating that actinonin inhibits bacterial growth by targeting this enzyme. Actinonin provides an excellent starting point from which to derive a more potent PDF inhibitor that has a broader spectrum of antibacterial activity.

  12. Structural and biophysical characterization of an antimicrobial peptide chimera comprised of lactoferricin and lactoferrampin.

    Science.gov (United States)

    Haney, Evan F; Nazmi, Kamran; Bolscher, Jan G M; Vogel, Hans J

    2012-03-01

    Lactoferricin and lactoferrampin are two antimicrobial peptides found in the N-terminal lobe of bovine lactoferrin with broad spectrum antimicrobial activity against a range of Gram-positive and Gram-negative bacteria as well as Candida albicans. A heterodimer comprised of lactoferrampin joined to a fragment of lactoferricin was recently reported in which these two peptides were joined at their C-termini through the two amino groups of a single Lys residue (Bolscher et al., 2009, Biochimie 91(1):123-132). This hybrid peptide, termed LFchimera, has significantly higher antimicrobial activity compared to the individual peptides or an equimolar mixture of the two. In this work, the underlying mechanism behind the increased antibacterial activity of LFchimera was investigated. Differential scanning calorimetry studies demonstrated that all the peptides influenced the thermotropic phase behaviour of anionic phospholipid suspensions. Calcein leakage and vesicle fusion experiments with anionic liposomes revealed that LFchimera had enhanced membrane perturbing properties compared to the individual peptides. Peptide structures were evaluated using circular dichroism and NMR spectroscopy to gain insight into the structural features of LFchimera that contribute to the increased antimicrobial activity. The NMR solution structure, determined in a miscible co-solvent mixture of chloroform, methanol and water, revealed that the Lys linkage increased the helical content in LFchimera compared to the individual peptides, but it did not fix the relative orientations of lactoferricin and lactoferrampin with respect to each other. The structure of LFchimera provides insight into the conformation of this peptide in a membranous environment and improves our understanding of its antimicrobial mechanism of action. Copyright © 2011 Elsevier B.V. All rights reserved.

  13. Alanine scan of the peptide antibiotic feglymycin: assessment of amino acid side chains contributing to antimicrobial activity.

    Science.gov (United States)

    Hänchen, Anne; Rausch, Saskia; Landmann, Benjamin; Toti, Luigi; Nusser, Antje; Süssmuth, Roderich D

    2013-03-18

    The antibiotic feglymycin is a linear 13-mer peptide synthesized by the bacterium Streptomyces sp. DSM 11171. It mainly consists of the nonproteinogenic amino acids 4-hydroxyphenylglycine and 3,5-dihydroxyphenylglycine. An alanine scan of feglymycin was performed by solution-phase peptide synthesis in order to assess the significance of individual amino acid side chains for biological activity. Hence, 13 peptides were synthesized from di- and tripeptide building blocks, and subsequently tested for antibacterial activity against Staphylococcus aureus strains. Furthermore we tested the inhibition of peptidoglycan biosynthesis enzymes MurA and MurC, which are inhibited by feglymycin. Whereas the antibacterial activity is significantly based on the three amino acids D-Hpg1, L-Hpg5, and L-Phe12, the inhibitory activity against MurA and MurC depends mainly on L-Asp13. The difference in the position dependence for antibacterial activity and enzyme inhibition suggests multiple molecular targets in the modes of action of feglymycin. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Microwave synthesis and antibacterial studies of bioceramics doped with antibacterial metal

    Science.gov (United States)

    Iqbal, Nida; Kadir, M. R. Abdul

    2017-12-01

    The aim of this work was to evaluate the effect of zinc metal ion on the antibacterial properties of bioceramics i.e. hydroxyapatite for the protection of bacterial infections. In this paper, rapid icrowave synthesis of hydroxyapatite with different weightages of antibacterial ions zinc (2 and 4 wt%) at 850 watts via microwave irradiation method at 10 mins was reported. The synthesized bioceramics were chemically characterized using energy dispersive X-ray (EDAX) and Fourier transform infrared spectroscopy (FTIR) studies. FT-IR analysis revealed the presence of Zn into HA lattices due to the increasing in the vibrational modes corresponds to phosphates and hydroxyl groups and EDAX analysis confirmed the presence of oxygen (O), calcium (Ca), phosphor (P), and zinc (Zn) in the ZnHA samples. Antibacterial studies have demonstrated that each of the Zn-bearing bioceramics samples exhibits marked antibacterial effects against Bacillus subtilis and Pseudomonas aeruginosa. Based on the results, it can be concluded that the synthesized Zn HA bioceramics have potential to prevent the bacterial infections and can be used as bone tissue regeneration.

  15. Ligand-regulated peptide aptamers.

    Science.gov (United States)

    Miller, Russell A

    2009-01-01

    The peptide aptamer approach employs high-throughput selection to identify members of a randomized peptide library displayed from a scaffold protein by virtue of their interaction with a target molecule. Extending this approach, we have developed a peptide aptamer scaffold protein that can impart small-molecule control over the aptamer-target interaction. This ligand-regulated peptide (LiRP) scaffold, consisting of the protein domains FKBP12, FRB, and GST, binds to the cell-permeable small-molecule rapamycin and the binding of this molecule can prevent the interaction of the randomizable linker region connecting FKBP12 with FRB. Here we present a detailed protocol for the creation of a peptide aptamer plasmid library, selection of peptide aptamers using the LiRP scaffold in a yeast two-hybrid system, and the screening of those peptide aptamers for a ligand-regulated interaction.

  16. 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...... peptides has only been elucidated during the last decade. The cellular synthesis including amino acid modifications and proteolytic cleavages has proven considerably more complex than initially perceived. Consequently, the elimination phase of the peptide products in circulation is not yet well....... 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...

  17. 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.)

  18. Studies on Antibacterial Effect of The Leaves Of Phyllanthus Niruri ...

    African Journals Online (AJOL)

    USER

    Statistical analysis revealed that the mean diameter zones of inhibition for gentamycin was significantly higher than those of the plant extracts at 0.05 level of probability though, 400mg/ml concentration exhibited high antibacterial activities in both extracts. This study has established the antibacterial effect of P. niruri leaves.

  19. Anti-bacterial activities and phytochemical screening of extracts of ...

    African Journals Online (AJOL)

    Anti-bacterial activity tests were carried out using disc diffusion assay and tube dilution technique, and phytochemical screening was carried out through Thin Layer Chromatography. The crude extracts showed antibacterial effects on M. vaccae, P. aeruginosa and B. subtilis. M. vaccae was most sensitive, particularly to the ...

  20. CRISPR-Based Antibacterials: Transforming Bacterial Defense into Offense.

    Science.gov (United States)

    Greene, Adrienne C

    2018-02-01

    The development of antimicrobial-resistant (AMR) bacteria poses a serious worldwide health concern. CRISPR-based antibacterials are a novel and adaptable method for building an arsenal of antibacterials potentially capable of targeting any pathogenic bacteria. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Evaluation of in vitro antibacterial property of seaweeds of southeast ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-06-17

    Jun 17, 2008 ... high antibacterial activity than other members of the algae tested in the present ... study confirmed the potential use of seaweed extracts as a source of antibacterial compounds. ... marine algae belonging to families such as Chlorphyceae .... seasons, method, organic solvents used for extraction of bioactive ...

  2. Antibacterial Activity and Mode of Action of Mentha arvensis Ethanol ...

    African Journals Online (AJOL)

    Antibacterial Activity and Mode of Action of Mentha arvensis Ethanol Extract against ... the antibacterial effect of ethanol extract of Mentha arvensis against multi-drug ... Reactive oxygen species (ROS) generation and protein leakage from the ... A. baumannii and acts by inducing lethal cellular damage to the bacterium.

  3. Antibacterial compounds from marine Vibrionaceae isolated on a global expedition

    DEFF Research Database (Denmark)

    Wietz, Matthias; Månsson, Maria; Gotfredsen, Charlotte Held

    2010-01-01

    known antibiotics as being responsible for the antibacterial activity; andrimid (from V. coralliilyticus) and holomycin (from P. halotolerans). Despite the isolation of already known antibiotics, our findings show that marine Vibrionaceae are a resource of antibacterial compounds and may have potential...

  4. The phytochemical, antibacterial and antioxidant activity of five ...

    African Journals Online (AJOL)

    The phytochemical, antibacterial and antioxidant activity of five medicinal plants against the wound infecting bacteria. ... Phytochemical analyses of the extracts were performed using thin layer chromatography (TLC). ... Antibacterial activity of the plants was evaluated using micro-dilution and bioautography methods.

  5. Antibacterial activity of the crude extract of Chinese green tea ...

    African Journals Online (AJOL)

    Antibacterial activity of the crude extract of Chinese green tea (Camellia sinensis) on Listeria monocytogenes. TI Mbata, LU Debiao, A Saikia. Abstract. The antibacterial activity of the methanol and aqueous extract of Camellia sinensis on Listeria monocytogenes were investigated using agar-gel diffusion, paper disk ...

  6. Antibacterial action of an aqueous grape seed polyphenolic extract ...

    African Journals Online (AJOL)

    The potential of a polyphenolic grape seed extract for use as a natural antibacterial agent was evaluated. Pure catechin (CS) and a previously LC-MS characterized grape seed phenolic extract (PE) were evaluated as antibacterial agents against Escherichia coli and Brevibacterium linens on solid and in liquid culture media ...

  7. Economic Evaluation pf Antibacterial Usage in Ear, Nose and Throat ...

    African Journals Online (AJOL)

    Purpose: To carry out economic evaluation of antibacterial usage for Ear, Nose and Throat infections in a tertiary health care facility in Nigeria. Methods: Antibacterial utilisation evaluation was carried out retrospectively over one year period by reviewing 122 case notes containing 182 prescriptions of patient with Ear Nose ...

  8. Evaluation of phytochemical and antibacterial potential of Helicteres ...

    African Journals Online (AJOL)

    Antibacterial activities of aqueous, acetone, ethanol and methanol extracts of fruits of Helicteres isora (Mororphali) were studied. The fruit aqueous extracts of H. isora showed prominent antibacterial activities against E.coli, Staphylococcus epidermidis, Salmonella typhimurium and Proteus vulgaris; moderate activity against ...

  9. Antibacterial activities of PHU - AgNO3 nanocomposite

    International Nuclear Information System (INIS)

    Panzaru, Carmen; Danciu, M; Mihailovici, Maria-Sultana; Ciobanu, C

    2009-01-01

    Objective was to characterize the antibacterial action for six combination of PHU-AgNO 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.

  10. Investigation Into The Antibacterial And Antidiarrhoeal Properties Of ...

    African Journals Online (AJOL)

    Objective: The water extract (WE) and ethanol extract (EE) of Psidium guava Leaf were carried out for antibacterial and antidiarrhoeal effects using patients stool and animal models. The antibacterial sensitivity tests were based on their zone of inhibition for six species of bacteria which include: Aeromonas hydrophila, ...

  11. Fumaric acid, an antibacterial component of Aloe vera L. | He ...

    African Journals Online (AJOL)

    The acetoacetate fraction partitioned from Aloe vera L. showed an effective antibacterial activity against four clinically frequent pathogenic bacteria. Through a series of chromatographic methods and activity assays, one compound was obtained and it has potent antibacterial activity. Based on the data of mass spectrometry, ...

  12. Antibacterial activity of Mangifera indica L. seeds against some ...

    African Journals Online (AJOL)

    Antibacterial activity of methanol extract of Mangifera indica L. seeds was done against 41 clinically isolated and 20 standard bacterial strains. Clinical bacterial strains were isolated from different specimens like blood, urine, catheter, stool and pus. Antibacterial activity was done by agar disc diffusion method at two different ...

  13. Antibacterial activity and probiotic properties of some lactic acid ...

    African Journals Online (AJOL)

    Several lactic acid bacteria strains were screened for the production of antibacterial substances active against some pathogenic bacteria. The inhibitory mechanism was investigated and was shown to be dependant of bacteriocin production. The objective was to isolate LAB with antibacterial activity from raib and to select ...

  14. Evaluation of Antibacterial Activity of Prosopis Juliflora (Sw.) Dc ...

    African Journals Online (AJOL)

    Background: The ethnobotanical importance of Prosopis juliflora is well-known in the folkloric system of medicine for the treatment of various ailments. Although, the study related to the antibacterial potential of this plant, from Central India is scanty. Material and methods: The in vitro antibacterial activity of Prosopis juliflora ...

  15. Antifungal and antibacterial activities of the ethanolic and aqueous ...

    African Journals Online (AJOL)

    SERVER

    2007-07-18

    Jul 18, 2007 ... psoriasis and eczema, through to the more serious disease like leprosy, syphilis and skin cancer (Burkill,. 1985). Previous studies of the fruits of K. africana showed some antibacterial activity (Grace et al., 2002). However there is no report on the antibacterial and antifungal properties of the stem bark of this ...

  16. Antibacterial activity of some selected plants traditionally used as ...

    African Journals Online (AJOL)

    Antibacterial activity of some selected plants traditionally used as medicine in Manipur. ... Hence these plants can be used to discover bioactive natural products that may serve as leads in the development of the new pharmaceuticals. Keywords: Antibacterial, human pathogens, methanolic extract, traditional medicine

  17. Antibacterial properties and toxicity from metallic nanomaterials

    Directory of Open Access Journals (Sweden)

    Vimbela GV

    2017-05-01

    Full Text Available Gina V Vimbela,1,* Sang M Ngo,2,* Carolyn Fraze,3 Lei Yang,4,5 David A Stout5–7 1Department of Chemical Engineering, 2Department of Electrical Engineering, California State University, Long Beach, CA, 3Brigham Young University Idaho, Rexburg, ID, USA; 4Department of Orthopaedics, Orthopaedic Institute, The First Affiliated Hospital, 5International Research Center for Translational Orthopaedics (IRCTO, Soochow University, Suzhou, Jiangsu, People’s Republic of China; 6Department of Mechanical and Aerospace Engineering, 7Department of Biomedical Engineering, California State University, Long Beach, CA, USA *These authors contributed equally to this work Abstract: The era of antibiotic resistance is a cause of increasing concern as bacteria continue to develop adaptive countermeasures against current antibiotics at an alarming rate. In recent years, studies have reported nanoparticles as a promising alternative to antibacterial reagents because of their exhibited antibacterial activity in several biomedical applications, including drug and gene delivery, tissue engineering, and imaging. Moreover, nanomaterial research has led to reports of a possible relationship between the morphological characteristics of a nanomaterial and the magnitude of its delivered toxicity. However, conventional synthesis of nanoparticles requires harsh chemicals and costly energy consumption. Additionally, the exact relationship between toxicity and morphology of nanomaterials has not been well established. Here, we review the recent advancements in synthesis techniques for silver, gold, copper, titanium, zinc oxide, and magnesium oxide nanomaterials and composites, with a focus on the toxicity exhibited by nanomaterials of multidimensions. This article highlights the benefits of selecting each material or metal-based composite for certain applications while also addressing possible setbacks and the toxic effects of the nanomaterials on the environment. Keywords

  18. Antibacterial characteristics of thermal plasma spray system.

    Science.gov (United States)

    Goudarzi, M; Saviz, Sh; Ghoranneviss, M; Salar Elahi, A

    2018-03-15

    The objective of this study is to investigate antibacterial characteristics of a thermal plasma spray system. For this purpose, copper powder was coated on a handmade atmospheric plasma spraying system made by the stainless steel 316 substrate, which is preheated at different temperatures before spraying. A number of deposition characteristics such as antibacterial characteristics, adhesion strength and hardness of coating, was investigated. All of the spray parameters are fixed except the substrate temperature. The chemical composition was analyzed by X-ray diffraction (XRD). A scanning electron microscopy (SEM) and back scattering electron microscopy (BSE) were used to show the coating microstructure, its thickness and also the powder micrograph. The energy dispersive X-ray spectroscopy (EDX) was used to analyze the coating particles. Hardness of the deposition was examined by Vickers tester (HV0.1). Its adhesion strength was declared by cross cut tester (TQC). In addition, the percentage of bactericidal coating was evidenced with Staphylococcus aurous and Escherichia coli bacteria. Study results show that as the substrates temperature increases, the number of splats in the shape of pancake increases, the greatness and percentage of the deposition porosity both decrease. The increment of the substrate temperature leads to more oxidation and makes thicker dendrites on the splat. The enhancement of the substrate temperature also enlarges thickness and efficiency of coating. The interesting results are that antibacterial properties of coatings against the Escherichia coli are more than Staphylococcus aurous bacteria. However the bactericidal percentage of the coatings against Staphylococcus aurous and Escherichia coli bacteria roughly does not change with increasing the substrate temperature. Furthermore, by increment of the substrate temperature, coatings with both high adhesion and hardness are obtained. Accordingly, the temperature of substrate can be an

  19. Trace elements and antibacterial activity in amniotic fluid.

    Science.gov (United States)

    Honkonen, E; Näntö, V; Hyörä, H; Vuorinen, K; Erkkola, R

    1986-01-01

    Antibacterial activity and trace element concentrations in amniotic fluid (AF) were determined in a population of 39 pregnant women in the second half of gestation. Antibacterial activity in each AF was measured by a spectrophotometric micromethod after 18 h incubation at 37 degrees C using Escherichia coli K 12 as a reference bacterium. Concentrations of zinc, iron, copper, calcium, potassium and bromine were measured by particle-induced X-ray emission method and the zinc concentration was also measured by atomic absorption spectrophotometry. Phosphate concentration was determined by direct albumin adding method. In AFs with good antibacterial activity significantly lower concentrations of potassium and bromine were found when compared to AFs with lower antibacterial activity. Concentrations of zinc, iron, copper, calcium or phosphate did not correlate with antibacterial activity in AF.

  20. 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.

  1. Alteration of the mode of antibacterial action of a defensin by the amino-terminal loop substitution

    International Nuclear Information System (INIS)

    Gao, Bin; Zhu, Shunyi

    2012-01-01

    Highlights: ► Al-M is an engineered fungal defensin with the n-loop of an insect defensin. ► Al-M adopts a native defensin-like structure with high antibacterial potency. ► Al-M kills bacteria through a membrane disruptive mechanism. ► This work sheds light on the functional evolution of CSαβ-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 α-helical and β-sheet (CSαβ) 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 μM. 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.

  2. 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.

  3. Carbon nanotubes as anti-bacterial agents.

    Science.gov (United States)

    Mocan, Teodora; Matea, Cristian T; Pop, Teodora; Mosteanu, Ofelia; Buzoianu, Anca Dana; Suciu, Soimita; Puia, Cosmin; Zdrehus, Claudiu; Iancu, Cornel; Mocan, Lucian

    2017-10-01

    Multidrug-resistant bacterial infections that have evolved via natural selection have increased alarmingly at a global level. Thus, there is a strong need for the development of novel antibiotics for the treatment of these infections. Functionalized carbon nanotubes through their unique properties hold great promise in the fight against multidrug-resistant bacterial infections. This new family of nanovectors for therapeutic delivery proved to be innovative and efficient for the transport and cellular translocation of therapeutic molecules. The current review examines the latest progress in the antibacterial activity of carbon nanotubes and their composites.

  4. 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.

  5. METAL OXIDE DOPED ANTIBACTERIAL POLYMERIC COATED TEXTILE MATERIALS AND ASSESSEMENT OF ANTIBACTERIAL ACTIVITY WITH ELECTRON SPIN RESONANCE

    Directory of Open Access Journals (Sweden)

    GEDIK Gorkem

    2017-05-01

    Full Text Available Antibacterial activity of a food conveyor belt is an essential property in some cases. However, every antibacterial chemical is not suitable to contact with food materials. Many metal oxides are suitable option for this purpose. The aim of this study was to investigate antibacterial properties of zinc oxide doped PVC polymer coated with electron spin resonance technique. Therefore, optimum zinc oxide containing PVC paste was prepared and applied to textile surface. Coating construction was designed as double layered, first layer did not contain antibacterial agent, thin second layer contained zinc oxide at 10-35% concentration. Oxygen radicals released from zinc oxide containing polymeric coated surface were spin trapped with DMPO (dimethylpyrroline-N-oxide spin trap and measured with Electron Spin Resonance (ESR. Besides conveyor belt samples, oxygen radical release from zinc oxide surface was measured with ESR under UV light and dark conditions. Oxygen radical release was determined even at dark conditions. Antibacterial properties were tested with ISO 22196 standard using Listeria innocua species. Measured antibacterial properties were related with ESR results. Higher concentration of zinc oxide resulted in higher antibacterial efficiency. DCFH-DA flourometric assay was carried out to determine oxidative stress insidebacteria. It is tought that, this technique will lead to decrease on the labour and time needed for conventional antibacterial tests.

  6. Metabolic fate of lactoferricin-based antimicrobial peptides: effect of truncation and incorporation of amino acid analogs on the in vitro metabolic stability.

    Science.gov (United States)

    Svenson, Johan; Vergote, Valentijn; Karstad, Rasmus; Burvenich, Christian; Svendsen, John S; De Spiegeleer, Bart

    2010-03-01

    A series of promising truncated antibacterial tripeptides derived from lactoferricin has been prepared, and their in vitro metabolic stability in the main metabolic compartments, plasma, liver, kidney, stomach, duodenum, and brain, has been investigated for the first time. The potential stabilizing effect of truncation, C-terminal capping, and introduction of the bulky synthetic amino acid biphenylalanine is also investigated. The drug-like peptides displayed large differences in half-lives in the different matrixes ranging from 4.2 min in stomach and duodenum to 355.9 min in liver. Kinetic analysis of the metabolites revealed that several different degrading enzymes simultaneously target the different peptide bonds and that the outcome of the tested strategies to increase the stability is clearly enzyme-specific. Some of the metabolic enzymes even prefer the synthetic modifications incorporated over the natural counterparts. Collectively, it is shown that the necessary antibacterial pharmacophore generates compounds that are not only potent antibacterial peptides, but excellent substrates for the main degrading enzymes. All the amide bonds are thus rapidly targeted by different enzymes despite the short peptidic sequences of the tested compounds. Hence, our results illustrate that several structural changes are needed before these compounds can be considered for oral administration. Strategies to overcome such metabolic challenges are discussed.

  7. Towards the Development of Synthetic Antibiotics: Designs Inspired by Natural Antimicrobial Peptides.

    Science.gov (United States)

    Azmi, Fazren; Skwarczynski, Mariusz; Toth, Istvan

    2016-01-01

    Virtually every living organism produces gene-encoded antimicrobial peptides (AMPs) that provide an immediate defence against pathogen invasion. Many AMPs have been isolated and used as antibiotics that are effective against multidrug-resistant bacteria. Although encouraging, AMPs have such poor drug-like properties that their application for clinical use is restricted. In turn, this has diverted research to the development of synthetic molecules that retain the therapeutic efficacy of AMPs but are endowed with greater biological stability and safety profiles. Most of the synthetic molecules, either based on a peptidic or non-peptidic scaffold, have been designed to mimic the amphiphilic properties of native AMPs, which are widely believed to be the key determinant of their antibacterial activity. In this review, the structural, chemical and biophysical features that govern the biological activities of various synthetic designs are discussed extensively. Recent innovative approaches from the literature that exhibit novel concepts towards the development of new synthetic antibacterial agents, including the engineered delivery platform incorporated with AMP mimetics, are also emphasised.

  8. Empirical comparison of web-based antimicrobial peptide prediction tools.

    Science.gov (United States)

    Gabere, Musa Nur; Noble, William Stafford

    2017-07-01

    Antimicrobial peptides (AMPs) are innate immune molecules that exhibit activities against a range of microbes, including bacteria, fungi, viruses and protozoa. Recent increases in microbial resistance against current drugs has led to a concomitant increase in the need for novel antimicrobial agents. Over the last decade, a number of AMP prediction tools have been designed and made freely available online. These AMP prediction tools show potential to discriminate AMPs from non-AMPs, but the relative quality of the predictions produced by the various tools is difficult to quantify. We compiled two sets of AMP and non-AMP peptides, separated into three categories-antimicrobial, antibacterial and bacteriocins. Using these benchmark data sets, we carried out a systematic evaluation of ten publicly available AMP prediction methods. Among the six general AMP prediction tools-ADAM, CAMPR3(RF), CAMPR3(SVM), MLAMP, DBAASP and MLAMP-we find that CAMPR3(RF) provides a statistically significant improvement in performance, as measured by the area under the receiver operating characteristic (ROC) curve, relative to the other five methods. Surprisingly, for antibacterial prediction, the original AntiBP method significantly outperforms its successor, AntiBP2 based on one benchmark dataset. The two bacteriocin prediction tools, BAGEL3 and BACTIBASE, both provide very good performance and BAGEL3 outperforms its predecessor, BACTIBASE, on the larger of the two benchmarks. gaberemu@ngha.med.sa or william-noble@uw.edu. Supplementary data are available at Bioinformatics online. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

  9. New Potent Membrane-Targeting Antibacterial Peptides from Viral Capsid Proteins

    OpenAIRE

    Dias, Susana A.; Freire, Jo?o M.; P?rez-Peinado, Clara; Domingues, Marco M.; Gaspar, Diana; Vale, Nuno; Gomes, Paula; Andreu, David; Henriques, S?nia T.; Castanho, Miguel A. R. B.; Veiga, Ana S.

    2017-01-01

    Copyright © 2017 Dias, Freire, Pérez-Peinado, Domingues, Gaspar, Vale, Gomes, Andreu, Henriques, Castanho and Veiga. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction...

  10. 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.

  11. 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.

  12. Antibacterial Nanoparticles in Endodontics: A Review.

    Science.gov (United States)

    Shrestha, Annie; Kishen, Anil

    2016-10-01

    A major challenge in root canal treatment is the inability of the current cleaning and shaping procedures to eliminate bacterial biofilms surviving within the anatomic complexities and uninstrumented portions of the root canal system. Nanoparticles with their enhanced and unique physicochemical properties, such as ultrasmall sizes, large surface area/mass ratio, and increased chemical reactivity, have led research toward new prospects of treating and preventing dental infections. This article presents a comprehensive review on the scientific knowledge that is available on the application of antibacterial nanoparticles in endodontics. The application of nanoparticles in the form of solutions for irrigation, medication, and as an additive within sealers/restorative materials has been evaluated to primarily improve the antibiofilm efficacy in root canal and restorative treatments. In addition, antibiotic or photosensitizer functionalized nanoparticles have been proposed recently to provide more potent antibacterial efficacy. The increasing interest in this field warrants sound research based on scientific and clinical collaborations to emphasize the near future potential of nanoparticles in clinical endodontics. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  13. Quaternary Ammonium Polyethyleneimine: Antibacterial Activity Ira

    International Nuclear Information System (INIS)

    Farber, Y.; Domb, A.G.; Golenser, J.; Beyth, N.; Weiss, E.I.

    2010-01-01

    Quaternary ammonium polyethyleneimine- (QA-PEI-) based nanoparticles were synthesized using two synthetic methods, reductive amination and N-alkylation. According to the first method, QA-PEI nanoparticles were synthesized by cross-linking with glutaraldehyde followed by reductive amination with octanal and further N-methylation with methyl iodide. The second method is based on crosslinking with dialkyl halide followed by N-alkylation with octyl halide and further N-methylation with methyl iodide. QA-PEI nanoparticles completely inhibited bacterial growth (>106 bacteria), including both Gram-positive, that is, Staphylococcus aureus at 80 μ/mL, and Gram-negative, that is, Escherichia coli at 320 μ/mL. Activity analysis revealed that the degree of alkylation and N-methylation of the QA-PEI nanoparticles plays a significant role in antibacterial activity of the reagent. The most potent compound was octyl alkylated QA-PEI alkylated at 1 : 1 mole ratio (primary amine of PEI monomer units/alkylating agent). Also, cytotoxicity studies on MAT-LyLu and MBT cell lines were performed with QA-PEI nanoparticles. These findings confirm previous reports that poly cations bearing quaternary ammonium moieties inhibit bacterial growth in vitro and have a potential use as additives in medical devices which need antibacterial properties.

  14. Silver nanoparticles as potential antibacterial agents.

    Science.gov (United States)

    Franci, Gianluigi; Falanga, Annarita; Galdiero, Stefania; Palomba, Luciana; Rai, Mahendra; Morelli, Giancarlo; Galdiero, Massimiliano

    2015-05-18

    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.

  15. 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

  16. Therapeutic peptides for cancer therapy. Part II - cell cycle inhibitory peptides and apoptosis-inducing peptides.

    Science.gov (United States)

    Raucher, Drazen; Moktan, Shama; Massodi, Iqbal; Bidwell, Gene L

    2009-10-01

    Therapeutic peptides have great potential as anticancer agents owing to their ease of rational design and target specificity. However, their utility in vivo is limited by low stability and poor tumor penetration. The authors review the development of peptide inhibitors with potential for cancer therapy. Peptides that arrest the cell cycle by mimicking CDK inhibitors or induce apoptosis directly are discussed. The authors searched Medline for articles concerning the development of therapeutic peptides and their delivery. Inhibition of cancer cell proliferation directly using peptides that arrest the cell cycle or induce apoptosis is a promising strategy. Peptides can be designed that interact very specifically with cyclins and/or cyclin-dependent kinases and with members of apoptotic cascades. Use of these peptides is not limited by their design, as a rational approach to peptide design is much less challenging than the design of small molecule inhibitors of specific protein-protein interactions. However, the limitations of peptide therapy lie in the poor pharmacokinetic properties of these large, often charged molecules. Therefore, overcoming the drug delivery hurdles could open the door for effective peptide therapy, thus making an entirely new class of molecules useful as anticancer drugs.

  17. Antibacterial Activity of Dental Cements Containing Quaternary Ammonium Polyethylenimine Nanoparticles

    International Nuclear Information System (INIS)

    Beyth, N.; Weiss, E.I.; Pilo, R.

    2012-01-01

    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 micro leakage may occur, resulting in secondary caries. As micro leakage cannot be completely prevented, GCS possessing antibacterial properties are in demand. In the present study the antibacterial activity of insoluble, cross-linked quaternary ammonium polyethylenimine (Qp) nanoparticles incorporated at 1% w/w in two clinically available GCS were studied. The antibacterial activity was tested against Streptococcus mutans and Lactobacillus casei using the direct contact test (Dct) and the agar diffusion test (Ad). Using the direct contact test, antibacterial activity (P<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.

  18. Future prospects of antibacterial metal nanoparticles as enzyme inhibitor

    International Nuclear Information System (INIS)

    Ahmed, Khan Behlol Ayaz; Raman, Thiagarajan; Veerappan, Anbazhagan

    2016-01-01

    Nanoparticles are being widely used as antibacterial agents with metal nanoparticles emerging as the most efficient antibacterial agents. There have been many studies which have reported the mechanism of antibacterial activity of nanoparticles on bacteria. In this review we aim to emphasize on all the possible mechanisms which are involved in the antibacterial activity of nanoparticles and also to understand their mode of action and role as bacterial enzyme inhibitor by comparing their antibacterial mechanism to that of antibiotics with enzyme inhibition as a major mechanism. With the emergence of widespread antibiotic resistance, nanoparticles offer a better alternative to our conventional arsenal of antibiotics. Once the biological safety of these nanoparticles is addressed, these nanoparticles can be of great medical importance in our fight against bacterial infections. - Highlights: • Mechanisms of antibiotics and metal nanoparticles resemble one another. • Bactericidal mechanisms of NPs are cell wall damage, and ROS generation. • Metal NPs inhibit membrane synthesis enzyme. • NPs can be used as antibacterial agents. • NP as antibacterial strategy important due to widespread antibiotic resistance

  19. Antibacterial Activity of Garlic Extract Against some Pathogenic Animal Bacteria

    Directory of Open Access Journals (Sweden)

    M. Safithri

    2011-12-01

    Full Text Available The antimicrobial activity of garlic extract against Gram-positive and Gram-negative bacterial isolates was well studied. However, reports on antibacterial activity of garlic extract against some pathogenic bacteria in animals in Indonesia, are still limited. Therefore, the aim of this study was to evaluate the antibacterial activity of water and ethanol extracts of garlic against Salmonella typhimurium in chickens, and Streptococcus agalactie, Escherichia coli, and Staphylococcus aureus causing mastitis in dairy cows in Indonesia. A filtrate of fresh garlic was used to determine the antibacterial activity against S. typhimurium at concentrations of 5%, 10%, 20%, 30%, and 40% w/v, whereas, the antibacterial activity of water and ethanol extracts was determined against S. agalactie, E. coli, and S. aureus at concentrations of 5%, 10%, 15%, 20%, and 25% w/v. Results showed that antibacterial activity of 30% garlic filtrate was equivalent to 10% tetracycline. Meanwhile, antibacterial activity of garlic aqueous extract on mastitis bacteria was better than that of the garlic ethanol extract. Aqueous extract of garlic at 20% had the same antibacterial activity as 0.01% ampicillin on mastitis bacteria. Filtrates of fresh garlic can be used to inhibit growth of S. typhimurium and mastitis bacteria.

  20. 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.

  1. Studies on antibacterial screening of corm of Amorphophallus campanulatus (Roxb.

    Directory of Open Access Journals (Sweden)

    Bhagwan Mariba Waghmare

    2017-05-01

    Full Text Available Objective: To study the antibacterial screening of corm of Amorphophallus campanulatus (Roxb. (A. campanulatus. Methods: Antibacterial activities of methanolic, petroleum ether and ethyl acetate extracts of corm of A. campanulatus were studied by agar diffusion technique to determine in vitro antibacterial activities. The antibacterial activity was measured with respect to the standard antibacterial drug. In addition, minimum inhibitory concentration was also determined by using serial dilution method to determine and evaluate antibacterial potency of test corm extracts of A. campanulatus. Results: The results showed significant antibacterial activities against four pathogenic bacteria. The minimum inhibitory concentration values against test bacteria were found to be remarkable range in bacteria like methicillin-resistant Staphylococcus aureus at concentration 0.25 mg/ well, in Pseudomonas aeruginosa at 0.5 mg/well concentration, in Vibrio cholerae was 2 mg/ well, Streptococcus pyogenes at concentration of 0.5 mg/well and Proteus mirabilis was at concentration of 2 mg/well. Conclusions: The methanolic and petroleum ether extracts are capable to maximum inhibition of the tested pathogenic bacteria.

  2. Antibacterial Effect of Diclofenac Sodium on Enterococcus faecalis

    Directory of Open Access Journals (Sweden)

    Amin Salemmilani

    2013-01-01

    Full Text Available Objective: Non-steroidal anti-inflammatory drugs (NSAIDs have shown antibacterial activity in some recent studies. The aim of this study was to evaluate the antibacterial effect of diclofenac against Enterococcus faecalis (E. faecalis as a resistant endodontic bacterium in comparison with ibuprofen, calcium hydroxide and amoxicillin.Materials and Methods: The antibacterial activity of materials was evaluated using agar diffusion test and tube dilution method. Mixtures of 400 mg/ml of materials were prepared. The bacteria were seeded on 10 Muller-Hinton agar culture plates. Thirty microliter of each test material was placed in each well punched in agar plates. After incubation, the zone of bacterial inhibition was measured. Minimum inhibitory concentration (MIC of the test materials was determined by agar dilution method. One-way Analysis of Variance (ANOVA followed by Sidak post hoc test was used to compare the mean zone of microbial growth in the groups.Results: There were significant differences between the two groups (p< 0.05. Results of the agar diffusion test showed that antibiotics (amoxicillin, gentamycin had the greatest antibacterial activity followed by NSAIDs (ibuprofen, diclofenac. Ca(OH2 failed to show antibacterial activity. Diclofenac and ibuprofen showed distinct antibacterial activity against E. faecalis in 50 µg/ml and above concentrations.Conclusion: Within the limitations of this in vitro study, it is concluded that diclofenac and ibuprofen have significantly more pronounced antibacterial activity against E. faecalis in comparison with Ca(OH2.

  3. Future prospects of antibacterial metal nanoparticles as enzyme inhibitor

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Khan Behlol Ayaz; Raman, Thiagarajan, E-mail: raman@biotech.sastra.edu; Veerappan, Anbazhagan, E-mail: anbazhagan@scbt.sastra.edu

    2016-11-01

    Nanoparticles are being widely used as antibacterial agents with metal nanoparticles emerging as the most efficient antibacterial agents. There have been many studies which have reported the mechanism of antibacterial activity of nanoparticles on bacteria. In this review we aim to emphasize on all the possible mechanisms which are involved in the antibacterial activity of nanoparticles and also to understand their mode of action and role as bacterial enzyme inhibitor by comparing their antibacterial mechanism to that of antibiotics with enzyme inhibition as a major mechanism. With the emergence of widespread antibiotic resistance, nanoparticles offer a better alternative to our conventional arsenal of antibiotics. Once the biological safety of these nanoparticles is addressed, these nanoparticles can be of great medical importance in our fight against bacterial infections. - Highlights: • Mechanisms of antibiotics and metal nanoparticles resemble one another. • Bactericidal mechanisms of NPs are cell wall damage, and ROS generation. • Metal NPs inhibit membrane synthesis enzyme. • NPs can be used as antibacterial agents. • NP as antibacterial strategy important due to widespread antibiotic resistance.

  4. 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.

  5. Isolation and partial purification of antimicrobial peptides/proteins from dung beetle, Onthophagus taurus immune hemolymph

    International Nuclear Information System (INIS)

    Vasanth Patil, H.B.; Sathish Kumar, B.Y.

    2012-01-01

    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 and not against eukaryotes. These properties reveal its unique characteristics and therapeutic application. (author)

  6. Rational Design of Cyclic Antimicrobial Peptides Based on BPC194 and BPC198

    Directory of Open Access Journals (Sweden)

    Anna D. Cirac

    2017-06-01

    Full Text Available A strategy for the design of antimicrobial cyclic peptides derived from the lead compounds c(KKLKKFKKLQ (BPC194 and c(KLKKKFKKLQ (BPC198 is reported. First, the secondary β-structure of BPC194 and BPC198 was analyzed by carrying out molecular dynamics (MD simulations. Then, based on the sequence pattern and the β-structure of BPC194 or BPC198, fifteen analogues were designed and synthesized on solid-phase. The best peptides (BPC490, BPC918, and BPC924 showed minimum inhibitory concentration (MIC values <6.2 μM against Pseudomonas syringae pv. syringae and Xanthomonas axonopodis pv. vesicatoria, and an MIC value of 12.5 to 25 μM against Erwinia amylovora, being as active as BPC194 and BPC198. Interestingly, these three analogues followed the structural pattern defined from the MD simulations of the parent peptides. Thus, BPC490 maintained the parallel alignment of the hydrophilic pairs K1–K8, K2–K7, and K4–K5, whereas BPC918 and BPC924 included the two hydrophilic interactions K3–Q10 and K5–K8. In short, MD simulations have proved to be very useful for ascertaining the structural features of cyclic peptides that are crucial for their biological activity. Such approaches could be further employed for the development of new antibacterial cyclic peptides.

  7. 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....

  8. 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.

  9. Comparative mode of action of novel hybrid peptide CS-1a and its rearranged amphipathic analogue CS-2a.

    Science.gov (United States)

    Joshi, Seema; Bisht, Gopal S; Rawat, Diwan S; Maiti, Souvik; Pasha, Santosh

    2012-10-01

    Cell selective, naturally occurring, host defence cationic peptides present a good template for the design of novel peptides with the aim of achieving a short length with improved antimicrobial potency and selectivity. A novel, short peptide CS-1a (14 residues) was derived using a sequence hybridization approach on sarcotoxin I (39 residues) and cecropin B (35 residues). The sequence of CS-1a was rearranged to enhance amphipathicity with the help of a Schiffer-Edmundson diagram to obtain CS-2a. Both peptides showed good antibacterial activity in the concentration range 4-16 μg·mL(-1) against susceptible as well as drug-resistant bacterial strains, including the clinically relevant pathogens Acenatobacter sp. and methicillin-resistant Staphylococcus aureus. The major thrust of these peptides is their nonhaemolytic activity against human red blood cells up to a high concentration of 512 μg·mL(-1). Compared to CS-1a, amphipathic peptide CS-2a showed a more pronounced α-helical conformation, along with a better membrane insertion depth in bacterial mimic 1,2-dipalmitoyl-sn-glycero-3-phosphocholine/1,2-dipalmitoyl-sn-glycero-3-phospho-(1'-rac-glycerol) small unilamellar vesicles. With equivalent lipid-binding affinity, the two peptides assumed different pathways of membrane disruption, as demonstrated by calcein leakage and the results of transmission electron microscopy on model bacterial mimic large unilamellar vesicles. Extending the work from model membranes to intact Escherichia coli cells, differences in membrane perturbation were visible in microscopic images of peptide-treated E. coli. The present study describes two novel short peptides with potent activity, cell selectivity and divergent modes of action that will aid in the future design of peptides with better therapeutic potential. © 2012 The Authors Journal compilation © 2012 FEBS.

  10. Antibacterial Activity of Oenothera rosea (L 'Her) Leaf Extracts

    OpenAIRE

    Gomez-Flores, Ricardo; Reyna-Martínez, Raúl; Tamez-Guerra, Patricia; Quintanilla-Licea, Ramiro

    2012-01-01

    Aims: To determine the antibacterial effect of Oenothera rosea against Escherichia coli, Salmonella enteritidis and Vibrio cholerae. Study Design: In vitro antibacterial study. Place and Duration of Study: Universidad Autónoma de Nuevo León, Facultad de Ciencias Biológicas, Departamento de Microbiología e Inmunología and Departamento de Química, San Nicolás de los Garza, NL. México, from June 2010 to June 2011. Methodology: The antibacterial in vitro effect of methanol and aqueous extracts of...

  11. 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.

  12. Towards a Scalable, Biomimetic, Antibacterial Coating

    Science.gov (United States)

    Dickson, Mary Nora

    Corneal afflictions are the second leading cause of blindness worldwide. When a corneal transplant is unavailable or contraindicated, an artificial cornea device is the only chance to save sight. Bacterial or fungal biofilm build up on artificial cornea devices can lead to serious complications including the need for systemic antibiotic treatment and even explantation. As a result, much emphasis has been placed on anti-adhesion chemical coatings and antibiotic leeching coatings. These methods are not long-lasting, and microorganisms can eventually circumvent these measures. Thus, I have developed a surface topographical antimicrobial coating. Various surface structures including rough surfaces, superhydrophobic surfaces, and the natural surfaces of insects' wings and sharks' skin are promising anti-biofilm candidates, however none meet the criteria necessary for implementation on the surface of an artificial cornea device. In this thesis I: 1) developed scalable fabrication protocols for a library of biomimetic nanostructure polymer surfaces 2) assessed the potential these for poly(methyl methacrylate) nanopillars to kill or prevent formation of biofilm by E. coli bacteria and species of Pseudomonas and Staphylococcus bacteria and improved upon a proposed mechanism for the rupture of Gram-negative bacterial cell walls 3) developed a scalable, commercially viable method for producing antibacterial nanopillars on a curved, PMMA artificial cornea device and 4) developed scalable fabrication protocols for implantation of antibacterial nanopatterned surfaces on the surfaces of thermoplastic polyurethane materials, commonly used in catheter tubings. This project constitutes a first step towards fabrication of the first entirely PMMA artificial cornea device. The major finding of this work is that by precisely controlling the topography of a polymer surface at the nano-scale, we can kill adherent bacteria and prevent biofilm formation of certain pathogenic bacteria

  13. 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.

  14. 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.

  15. Antibacterial iodine-supported titanium implants.

    Science.gov (United States)

    Shirai, T; Shimizu, T; Ohtani, K; Zen, Y; Takaya, M; Tsuchiya, H

    2011-04-01

    Deep infection remains a serious complication in orthopedic implant surgery. In order to reduce the incidence of implant-associated infections, several biomaterial surface treatments have been proposed. This study focused on evaluating the antibacterial activity of iodine-supported titanium (Ti-I(2)) and its impact on post-implant infection, as well as determining the potential suitability of Ti-I(2) as a biomaterial. External fixation pins were used in this experiment as trial implants because of the ease of making the septic models. The antibacterial activity of the metal was measured using a modification of the Japanese Industrial Standards method. Activity was evaluated by exposing the implants to Staphylococcus aureus or Escherichia coli and comparing reaction of pathogens to Ti-I(2) vs. stainless steel and titanium controls. Ti-I(2) clearly inhibited bacterial colonization more than the control metals. In addition, cytocompatibility was assessed by counting the number of colonies that formed on the metals. The three metals showed the same amount of fibroblast colony formation. Japanese white rabbits were used as an in vivo model. Three pins were inserted into both femora of six rabbits for histological analysis. Pin sites were inspected and graded for infection and inflammation. Fewer signs of infection and inflammatory changes were observed in conjunction with the Ti-I(2) pins. Furthermore, osteoconductivity of the implant was evaluated with osteoid formation surface of the pin. Consecutive bone formation was observed around the Ti-I(2) and titanium pins, while little osteoid formation was found around the stainless steel pins. These findings suggest that Ti-I(2) has antimicrobial activity and exhibits cytocompatibility. Therefore, Ti-I(2) substantially reduces the incidence of implant infection and shows particular promise as a biomaterial. Copyright © 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  16. Antibacterial properties of 3-(phenylsulfonyl)-2-pyrazinecarbonitrile.

    Science.gov (United States)

    Rajamuthiah, Rajmohan; Jayamani, Elamparithi; Majed, Hiwa; Conery, Annie L; Kim, Wooseong; Kwon, Bumsup; Fuchs, Beth Burgwyn; Kelso, Michael J; Ausubel, Frederick M; Mylonakis, Eleftherios

    2015-11-15

    The emergence of multidrug-resistant bacterial strains has heightened the need for new antimicrobial agents based on novel chemical scaffolds that are able to circumvent current modes of resistance. We recently developed a whole-animal drug-screening methodology in pursuit of this goal and now report the discovery of 3-(phenylsulfonyl)-2-pyrazinecarbonitrile (PSPC) as a novel antibacterial effective against resistant nosocomial pathogens. The minimum inhibitory concentrations (MIC) of PSPC against Staphylococcus aureus and Enterococcus faecium were 4 μg/mL and 8 μg/mL, respectively, whereas the MICs were higher against the Gram-negative bacteria Klebsiella pneumoniae (64 μg/mL), Acinetobacter baumannii (32 μg/mL), Pseudomonas aeruginosa (>64 μg/mL), and Enterobacter spp. (>64 μg/mL). However, co-treatment of PSPC with the efflux pump inhibitor phenylalanine arginyl β-naphthylamide (PAβN) or with sub-inhibitory concentrations of the lipopeptide antibiotic polymyxin B reduced the MICs of PSPC against the Gram-negative strains by >4-fold. A sulfide analog of PSPC (PSPC-1S) showed no antibacterial activity, whereas the sulfoxide analog (PSPC-6S) showed identical activity as PSPC across all strains, confirming structure-dependent activity for PSPC and suggesting a target-based mechanism of action. PSPC displayed dose dependent toxicity to both Caenorhabditis elegans and HEK-293 mammalian cells, culminating with a survival rate of 16% (100 μg/mL) and 8.5% (64 μg/mL), respectively, at the maximum tested concentration. However, PSPC did not result in hemolysis of erythrocytes, even at a concentration of 64 μg/mL. Together these results support PSPC as a new chemotype suitable for further development of new antibiotics against Gram-positive and Gram-negative bacteria. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. 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

  18. Synthetic peptides for antibody production

    NARCIS (Netherlands)

    N.D. Zegers (Netty)

    1995-01-01

    textabstractSynthetic 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

  19. Peptide radiopharmaceuticals in nuclear medicine

    International Nuclear Information System (INIS)

    Blok, D.; Vermeij, P.; Feitsma, R.I.J.; Pauwels, E.J.K.

    1999-01-01

    This article reviews the labelling of peptides that are recognised to be of interest for nuclear medicine or are the subject of ongoing nuclear medicine research. Applications and approaches to the labelling of peptide radiopharmaceuticals are discussed, and drawbacks in their development considered. (orig.)

  20. Green synthesis, characterization and antibacterial activity of copper ...

    African Journals Online (AJOL)

    Green synthesis, characterization and antibacterial activity of copper nanoparticles using L -ascorbic ... Journal Home > Vol 10, No 3 (2017) > ... In this study, simple, economical, convenient and environmentally-friendly chemical reduction ...

  1. A new screening method for discovering antibacterial agents from ...

    African Journals Online (AJOL)

    A new screening method for discovering antibacterial agents from filamentous fungi. ... African Journal of Biotechnology ... Keywords: Drug-resistant bacterial pathogens, novel antibiotics; screening method, filamentous fungi products ...

  2. Antioxidant and antibacterial properties of Ziziphus mucronata and ...

    African Journals Online (AJOL)

    sulphuric acid reagent, Fehling's solution, concentrated sulphuric acid, ferric chloride, Drangendorff's reagent, acetic anhydride, 2, 2-diphenyl-1-picrylhydrazyl (DPPH), p-iodonitrotetrazolium violet, Methods: Antibacterial activity was evaluated using ...

  3. Antibacterial properties of palladium nanostructures sputtered on polyethylene naphthalate

    Czech Academy of Sciences Publication Activity Database

    Polívková, M.; Válová, M.; Siegel, J.; Rimpelová, S.; Hubáček, Tomáš; Lyutakov, O.; Švorčík, V.

    2015-01-01

    Roč. 5, č. 90 (2015), s. 73767-73774 ISSN 2046-2069 Institutional support: RVO:60077344 Keywords : polymer * palladium sputtering * annealing * nanostructure * antibacterial effect Subject RIV: JJ - Other Materials Impact factor: 3.289, year: 2015

  4. A new screening method for discovering antibacterial agents from ...

    African Journals Online (AJOL)

    DR. NJ TONUKARI

    2012-04-26

    Apr 26, 2012 ... 1College of Chemistry & Life Science, China Three Gorges University, Yichang ... However, antibacterial drug discovery and development ... Untapped biological ..... gratefully thank Professor David M. Johnson for helpful.

  5. Evaluation of antioxidant, antihemolytic and antibacterial potential of six

    Directory of Open Access Journals (Sweden)

    Eimad dine Tariq Bouhlali

    2016-04-01

    These results suggested that date fruit extract, especially Jihl and Bousrdon extract, is not only an important source of antioxidants, which possess a high protective effect of membrane against free radical, but also a potential source of antibacterial components.

  6. Screening of antibacterial potentials of some medicinal plants from ...

    African Journals Online (AJOL)

    Out of these medicinal plants Caesalpinia bonducella, Gardenia gummifera and ... arabica, Gardenia gummifera and ethanol, methanol extracts of Caesalpinia ... Key words: Antibacterial activity, Melghat, Medicinal Plants, Phytochemical ...

  7. Phytochemicals, antioxidant and antibacterial properties of a lichen ...

    African Journals Online (AJOL)

    MARSHYMARGGIE

    2012-04-17

    Apr 17, 2012 ... done using chemical tests. Antibacterial activities of Cladonia digitata were determined by a disk ... of antimicrobial therapeutics or lead compounds to synthesis of new .... ingredients used in cosmetics. J. Am. Acad. Dermatol ...

  8. antibacterial properties of mangifera indica on staphylococcus aureus.

    African Journals Online (AJOL)

    boaz

    Antibacterial activity of Mangifera indica stem bark extracts was determined using disk ... In disk diffusion method, inhibition zone sizes were used to determine the ...... There is need for lead compounds ... pharmaceutical and cosmetics.

  9. Antibacterial efficacy of raw and commercially available honey

    African Journals Online (AJOL)

    Administrator

    2011-09-19

    Sep 19, 2011 ... Key words: Honey, antibacterial activity, raw honey, commercially available honey, minimum inhibitory ... against pathogenic bacteria, oral bacteria as well as food .... explore the possible benefits of the use of honey among.

  10. Research Note: Comparative antibacterial activities of oil-palm ...

    African Journals Online (AJOL)

    Research Note: Comparative antibacterial activities of oil-palm Elaeis ... The antimicrobial activities liquid pyrolysates (obtained by destructive distillation), their ... respective chloroform fractions which showed higher activities than the crude ...

  11. Antibacterial Properties of Marine Sponges from Mauritius Waters

    African Journals Online (AJOL)

    assay. The extracts were screened for the presence of compounds that could be responsible for bioactivity. ... Keywords: Biemna tubulosa, Stylissa spp., Antibacterial activity, Marine sponges, MIC. Tropical ..... Bio-organic and Med. Chem 2003 ...

  12. Synthesis, characterization and antibacterial activity of new fluorescent chitosan derivatives

    Czech Academy of Sciences Publication Activity Database

    Přichystalová, H.; Almonasy, N.; Abdel-Mohsen, A. M.; Abdel-Rahman, R. M.; Fouda, M. M. G.; Vojtova, L.; Kobera, Libor; Spotz, Z.; Burgert, L.; Jancar, J.

    2014-01-01

    Roč. 65, April (2014), s. 234-240 ISSN 0141-8130 Institutional support: RVO:61389013 Keywords : chitosan derivatives * fluorescence * antibacterial activity Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.858, year: 2014

  13. Antibacterial activity and phytochemical analysis of leaf extracts of ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-01-05

    Jan 5, 2009 ... medicinal plant Lasienthera africanum (“Editan”) and their antibacterial activities against clinical isolates ... parts of Nigeria and many of the herbal remedies have ... drugs abound in various markets today, there is need for.

  14. Chemical composition and antibacterial activity of the essential oil of ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-07-18

    Jul 18, 2008 ... essential oil of Pinus caribaea from Nigeria. O. Oluwadayo ... Key words: Pinus caribbea, Pinaceae, essential oil, β-phellandrene, β-caryophyllene, antibacterial. .... cones of Pinus. Pinea, P. halepensis, P. pinaster and P. nigra.

  15. Antibacterial activity of eight medicinal plants against Diarrhoea ...

    African Journals Online (AJOL)

    The studies involve the phytochemical screening and antibacterial activity of leaf extracts eight medicinal plants. The selected plants were Timarindus indica, Guiera senegalensis, Prosopis africana, Deterium microcarpum, Citrus aurantifolia, Psidium guajava, Acacia nilotica and Momordica charantia. Methanolics and ...

  16. Antibacterial activity of some selected plants traditionally used as ...

    African Journals Online (AJOL)

    SAM

    2014-03-26

    Mar 26, 2014 ... The antibacterial activity was determined using agar well diffusion ... antimicrobial chemotherapeutic agents, but the cost of production of .... Hamilton ex D Don. in the traditional system of medicine ... Based on this, further.

  17. Synthesis, characterization and in vitro antibacterial activity of novel ...

    Indian Academy of Sciences (India)

    MARZIEH ABBASI

    The prepared compounds were screened for antibacterial activity against. Escherichia coli (E. ..... HCl in the presence of phenol phthalein as an indicator. The number of H. + ... correspond to the symmetric and asymmetric SO2 and also C-S ...

  18. Antibacterial activities of three medicinal plants against some gastro ...

    African Journals Online (AJOL)

    ... Klebsiella pneumoniae, Proteus mirabilis, Salmonella typhi, and Shigella ... The antibacterial assay showed that the three plants significantly inhibited all the test ... Bambusa vulgaris, Erigeron floribundus, Fluerya aestuans, medicinal plants ...

  19. Antibacterial activity of watermelon (Citrullus lanatus) seed against ...

    African Journals Online (AJOL)

    Engr Akande

    2015-04-08

    Apr 8, 2015 ... Also, saponins which have been implicated in antimicrobial activity were found to be ... Key words: Watermelon seed, antibacterial, Soxhlet extraction, cold ..... International Centre for Science and High Technology, Trieste, pp.

  20. Antibacterial activities of the crude ethanol extracts of medicinal ...

    African Journals Online (AJOL)

    STORAGESEVER

    2010-07-05

    Jul 5, 2010 ... extract. On the other hand, the antimicrobial activity was mainly a function of their chemical ... determine antibacterial properties of these plants extracts .... vancomycin (30 µg); PEN= penicillin G (10 unit); AMP = ampicillin (5.

  1. Screening for antibacterial and antiprotozoal activities of crude ...

    African Journals Online (AJOL)

    The antibacterial properties of organic and aqueous extracts of these plants were determined by the microdilution method and the microplate alamar blue assay against Stenotrophomonas maltophilia, Escherichia coli, Acinetobacter baumannii, Pseudomonas aeruginosa, Klebsiella pneumoniae, Enterobacter cloacae, ...

  2. The biology of Mur ligases as an antibacterial target.

    Science.gov (United States)

    Kouidmi, Imène; Levesque, Roger C; Paradis-Bleau, Catherine

    2014-10-01

    With antibiotic resistance mechanisms increasing in diversity and spreading among bacterial pathogens, the development of new classes of antibacterial agents against judiciously chosen targets is a high-priority task. The biochemical pathway for peptidoglycan biosynthesis is one of the best sources of antibacterial targets. Within this pathway are the Mur ligases, described in this review as highly suitable targets for the development of new classes of antibacterial agents. The amide ligases MurC, MurD, MurE and MurF function with the same catalytic mechanism and share conserved amino acid regions and structural features that can conceivably be exploited for the design of inhibitors that simultaneously target more than one enzyme. This would provide multi-target antibacterial weapons with minimized likelihood of target-mediated resistance development. © 2014 John Wiley & Sons Ltd.

  3. Antibacterial activity of seed extracts of Argemone mexicana L. on ...

    African Journals Online (AJOL)

    PRECIOUS

    2009-12-15

    Dec 15, 2009 ... Chloroform extract of seeds exhibited varying level of antibacterial activity, with minimum ... et al., 1999; Scheck et al.,. 2006). The glycoside and saponins from Quillaja saponaria and Acacia auriculoformis were found to be.

  4. Antioxidant and antibacterial activities of ethanolic extracts of ...

    African Journals Online (AJOL)

    Antioxidant and antibacterial activities of ethanolic extracts of Asparagus officinalis cv. Mary Washington: Comparison of in vivo and in vitro grown plant bioactivities. Arash Khorasani, Wirakarnain Sani, Koshy Philip, Rosna Mat Taha, Arash Rafat ...

  5. Antibacterial activity of six indigenous Indian plants: Acacia nilotica ...

    African Journals Online (AJOL)

    sunny t

    2016-04-20

    Apr 20, 2016 ... The antibacterial activity of extracts (water, acetone and methanol) from six indigenous Indian plants: Acacia ... attention to traditional methods, looking for novel ... Five grams powder of each plant was equally divided into.

  6. Fabrication and Antibacterial Performance of Nano-silver-Doped ...

    African Journals Online (AJOL)

    NICO

    Human beings are often infected by microorganisms like bacteria, moulds, yeast ... However, antibacterial materials such as zeolites covered with silver ions ... copy (TEM) was recorded using LEO-912 AB and scanning tunnelling microscopy ...

  7. Comparison of antibacterial activity of parent plant of Tylophora ...

    African Journals Online (AJOL)

    Valued Acer Customer

    2013-07-31

    Jul 31, 2013 ... raised plant and its callus. Key words: Tylophora indica, in vitro raised plant and callus, antibacterial activity. .... Callusing was initiated from the cut ends of the explants after 25 days of ..... Glossary of Indian Medicinal. Plants,.

  8. Antibacterial activity and medicinal properties of ginger ( Zingiber ...

    African Journals Online (AJOL)

    . Ginger extracts were obtained using solvents, n-hexane, ethyl acetate, ethanolic soxhlet and water. The extracts were assayed for antibacterial activity and bacterial growth inhibition activity. The results showed that all the extracts except the ...

  9. Phytochemical screening and antibacterial activity of Garcinia kola ...

    African Journals Online (AJOL)

    , Tannin, Saponin, and Cardiac glycoside, Flavonoid, Terpenoid, Phenols, Anthraquinone and Steroid. However, reducing sugar is absent. The antibacterial activity of the extracts against the isolates showed that ethanol extract is more ...

  10. An evaluation of antibacterial activities of Seidenfia rheedii (Sw ...

    African Journals Online (AJOL)

    PRECIOUS

    2009-12-01

    Dec 1, 2009 ... Key words: Seidenfia rheedii, drug resistance, antibacterial activity. INTRODUCTION ... The plant materials (leaves) were shade dried at 31°C for 10 days. ... purchased from Microbial Type Culture Collection (MTCC), Institute.

  11. Titanium Dioxide-Based Antibacterial Surfaces for Water Treatment

    Science.gov (United States)

    The field of water disinfection is gaining much interest since waterborne diseases caused by pathogenic microorganisms directly endanger human health. Antibacterial surfaces offer a new, ecofriendly technique to reduce the harmful disinfection byproducts that form in medical and ...

  12. Antibacterial and Cytotoxic Activities of Acacia nilotica Lam ...

    African Journals Online (AJOL)

    Erah

    Keywords: Acacia nilotica, ESBLs, MRSA, E. coli, Klebsiella, Antibacterial resistance, Cytotoxicity. Received: ... infectious diseases, is an age-long practice, especially ... used in a variety of infections. ... E. coli K1 [14] and MRSA [15] were used.

  13. 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

  14. The Equine PeptideAtlas

    DEFF Research Database (Denmark)

    Bundgaard, Louise; Jacobsen, Stine; Sørensen, Mette Aamand

    2014-01-01

    Progress in MS-based methods for veterinary research and diagnostics is lagging behind compared to the human research, and proteome data of domestic animals is still not well represented in open source data repositories. This is particularly true for the equine species. Here we present a first...... Equine PeptideAtlas encompassing high-resolution tandem MS analyses of 51 samples representing a selection of equine tissues and body fluids from healthy and diseased animals. The raw data were processed through the Trans-Proteomic Pipeline to yield high quality identification of proteins and peptides....... The current release comprises 24 131 distinct peptides representing 2636 canonical proteins observed at false discovery rates of 0.2% at the peptide level and 1.4% at the protein level. Data from the Equine PeptideAtlas are available for experimental planning, validation of new datasets, and as a proteomic...

  15. Vascular targeting with peptide libraries

    Energy Technology Data Exchange (ETDEWEB)

    Pasqualini, R. [La Jolla Cancer Research Center The Burnham Inst., La Jolla CA (United States)

    1999-06-01

    The authors have developed an 'in vivo' selection system in which phage capable of selective homing to different tissues are recovered from a phage display peptide library following intravenous administration. Using this strategy, they have isolate several organ and tumor-homing peptides. They have shown that each of those peptides binds of different receptors that are selectively expressed on the vasculature of the target tissue. The tumor-homing peptides bind to receptors that are up regulated in tumor angiogenic vasculature. Targeted delivery of doxorubicin to angiogenic vasculature using these peptides in animals models decrease toxicity and increased the therapeutic efficacy of the drug. Vascular targeting may facilitate the development of other treatment strategies that rely on inhibition of angio genesis and lead to advances to extend the potential for targeting of drugs, genes and radionuclides in the context of many diseases.

  16. Natriuretic peptides and cerebral hemodynamics

    DEFF Research Database (Denmark)

    Guo, Song; Barringer, Filippa; Zois, Nora Elisabeth

    2014-01-01

    Natriuretic peptides have emerged as important diagnostic and prognostic tools for cardiovascular disease. Plasma measurement of the bioactive peptides as well as precursor-derived fragments is a sensitive tool in assessing heart failure. In heart failure, the peptides are used as treatment...... in decompensated disease. In contrast, their biological effects on the cerebral hemodynamics are poorly understood. In this mini-review, we summarize the hemodynamic effects of the natriuretic peptides with a focus on the cerebral hemodynamics. In addition, we will discuss its potential implications in diseases...... where alteration of the cerebral hemodynamics plays a role such as migraine and acute brain injury including stroke. We conclude that a possible role of the peptides is feasible as evaluated from animal and in vitro studies, but more research is needed in humans to determine the precise response...

  17. Maize Bioactive Peptides against Cancer

    Science.gov (United States)

    Díaz-Gómez, Jorge L.; Castorena-Torres, Fabiola; Preciado-Ortiz, Ricardo E.; García-Lara, Silverio

    2017-06-01

    Cancer is one of the main chronic degenerative diseases worldwide. In recent years, consumption of whole-grain cereals and their derived food products has been associated with reduction risks of various types of cancer. Cereals main biomolecules includes proteins, peptides, and amino acids present in different quantities within the grain. The nutraceutical properties associated with peptides exerts biological functions that promote health and prevent this disease. In this review, we report the current status and advances on maize peptides regarding bioactive properties that have been reported such as antioxidant, antihypertensive, hepatoprotective, and anti-tumour activities. We also highlighted its biological potential through which maize bioactive peptides exert anti-cancer activity. Finally, we analyse and emphasize the possible areas of application for maize peptides.

  18. 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.

  19. Synthesis and comparative antibacterial studies of some benzylidene monosaccharide benzoates

    Directory of Open Access Journals (Sweden)

    Mohammed Matin

    2015-03-01

    Full Text Available Some 4,6-O-benzylidene protected 2,3-di-O-benzoates of methyl a-D-glucopyranoside and methyl a-D-mannopyranoside were prepared. All the compounds (1-7 were screened for in vitro antibacterial activity study against ten human pathogenic bacteria. The study revealed that the benzoylated mannopyranosides (5-7 are more prone towards antibacterial functionalities than that of the glucopyranosides (2-3.

  20. Antibacterial marine bacterium deter luminous vibriosis in shrimp larvae

    OpenAIRE

    Abraham, T.J.

    2004-01-01

    Inhibitory activity of a marine pigmented bacterium - Alteromonas sp. - isolated from Penaeus monodon Fabricius larva against pathogenic and environmental isolates of Vibrio harveyi was studied. All the isolates were inhibited to varying degrees by Alteromonas sp. in vitro. The antibacterial substance produced by the Alteromonas sp. was soluble in organic solvent and closely bound to the external surface of bacterial cells. The antibacterial Alteromonas sp., when allowed to colonize on shrimp...

  1. Antibacterial performance of bovine lactoferrin-fish gelatine electrospun nanocomposites

    OpenAIRE

    Padrão, Jorge; Machado, Raul; Casal, Margarida; Rodrigues, L. R.; Dourado, Fernando; Lanceros-Méndez, S.; Sencadas, V.

    2014-01-01

    Antibacterial performance of bovine lactoferrin-fish gelatine electrospun nanocomposites The alarming increase of antibiotic resistant microorganisms urged the development and synthesis of novel antimicrobial biomaterials, to be employed in a broad range of applications, ranging from food casings to medical devices [1 – 3]. This work describes the processing and characterization of an innovative fully biobased eletrctrospun nanocomposite material displaying antibacterial properties. Its c...

  2. Antibacterial and antiadherent properties of silver dioxide-coated brackets

    OpenAIRE

    Rizwan A Gilani; S M Laxmikanth; C S Ramachandra; Sangeeta L Prasad; Sushruth Shetty; S D Vasudevan

    2017-01-01

    Introduction: Enamel demineralization after fixed orthodontic treatment can occur in 50% of patients. Brackets play a significant role in enamel demineralization. Silver has already been prooved to have antibacterial properties. Hence the present study is conducted to assess the antiadherent and antibacterial properties of photocatalytic silver dioxide (AgO2) surface modified stainless steel orthodontic brackets against S. mutans. Materials and Methods: 80 stainless steel brackets of maxillar...

  3. PRODUCTION OF ANTIBACTERIAL FILTER PAPER FROM WOOD CELLULOSE

    OpenAIRE

    Reza Imani; Mohammad Talaiepour; Joydeep Dutta; Mohammad R. Ghobadinezhad; Amir H. Hemmasi; Mousa M. Nazhad

    2011-01-01

    Paper has a visible market-share in hygiene products either in the form of personal hygiene or as food packaging. The designation “hygiene”, though it suggests cleanliness, does not imply antibacterial properties; rather it can be stated that hygiene products do not initiate microorganism growth. Antibacterial products could restrict propagation of pathogenic bacteria either by holding bacteria or by trapping and neutralizing them. Most research in this field has been conducted using textile ...

  4. Honey Antibacterial Effect Boosting Using Origanum vulgare L. Essential Oil

    OpenAIRE

    Imtara, Hamada; Elamine, Youssef; Lyoussi, Badiâa

    2018-01-01

    The appearance of new bacterial strains which cause pathogenic diseases and which are resistant to the most used antibiotics requires probing new antibacterial agents sources. Therefore, the main aim of the present work was to follow the antibacterial activity of honey samples from Palestine and Morocco, after the combination with Origanum vulgare L. essential oil, and figure out whether the honey physicochemical parameters and geographic origin influence the final activity. The results of th...

  5. Endogenous and Exogenous KdpF Peptide Increases Susceptibility of Mycobacterium bovis BCG to Nitrosative Stress and Reduces Intramacrophage Replication

    Science.gov (United States)

    Rosas Olvera, Mariana; Vivès, Eric; Molle, Virginie; Blanc-Potard, Anne-Béatrice; Gannoun-Zaki, Laila

    2017-01-01

    Emerging antibiotic resistance in pathogenic bacteria like Mycobacterium sp., poses a threat to human health and therefore calls for the development of novel antibacterial strategies. We have recently discovered that bacterial membrane peptides, such as KdpF, possess anti-virulence properties when overproduced in pathogenic bacterial species. Overproduction of the KdpF peptide in Mycobacterium bovis BCG decreased bacterial replication within macrophages, without presenting antibacterial activity. We propose that KdpF functions as a regulatory molecule and interferes with bacterial virulence, potentially through interaction with the PDIM transporter MmpL7. We demonstrate here that KdpF overproduction in M. bovis BCG, increased bacterial susceptibility to nitrosative stress and thereby was responsible for lower replication rate within macrophages. Moreover, in a bacterial two-hybrid system, KdpF was able to interact not only with MmpL7 but also with two membrane proteins involved in nitrosative stress detoxification (NarI and NarK2), and a membrane protein of unknown function that is highly induced upon nitrosative stress (Rv2617c). Interestingly, we showed that the exogenous addition of KdpF synthetic peptide could affect the stability of proteins that interact with this peptide. Finally, the exogenous KdpF peptide presented similar biological effects as the endogenously expressed peptide including nitrosative stress susceptibility and reduced intramacrophage replication rate for M. bovis BCG. Taken together, our results establish a link between high levels of KdpF and nitrosative stress susceptibility to further highlight KdpF as a potent molecule with anti-virulence properties. PMID:28428950

  6. Characterization and antibacterial properties of porous fibers containing silver ions

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Zhaoyang; Fan, Chenxu; Tang, Xiaopeng; Zhao, Jianghui; Song, Yanhua; Shao, Zhongbiao [National Engineering Laboratory for Modern Silk, College of Textile and Engineering, Soochow University, 199 Ren-ai Road, Suzhou 215123 (China); Xu, Lan, E-mail: lanxu@suda.edu.cn [National Engineering Laboratory for Modern Silk, College of Textile and Engineering, Soochow University, 199 Ren-ai Road, Suzhou 215123 (China); Nantong Textile Institute of Soochow University, 58 Chong-chuan Road, Nantong 226018 (China)

    2016-11-30

    Highlights: • Antibacterial electrospun PLA porous fibers containing silver ions were prepared. • Porous structure and porosity of PLA/Ag{sup +} porous fibers were investigated. • The antibacterial effects of PLA/Ag{sup +} porous fibers were studied. • The released mechanism of silver ions in the porous fibers was illustrated. • The porous structure could improve the antibacterial properties. - Abstract: Materials prepared on the base of bioactive silver compounds have become more and more popular. In the present work, the surface morphology, structure and properties, of electrospun Polylactide Polylactic acid (PLA) porous fibers containing various ratios of silver ions were investigated by a combination of X-ray photoelectron spectroscopy (XPS), universal testing machine, thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and et al. The biological activities of the proposed porous fibers were discussed in view of the released silver ions concentration. Antibacterial properties of these porous fibers were studied using two bacterial strains: Escherichia coli (E. coli) and Methicillin-resistant Staphylococcus aureus (MRSA). Results of the antibacterial testing suggested that PLA porous fibers containing silver ions could be used as potent antibacterial wound dressing materials in the biomedical field.

  7. 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.

  8. 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.

  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. Antibacterial activity of propolins from Taiwanese green propolis

    Directory of Open Access Journals (Sweden)

    Yue-Wen Chen

    2018-04-01

    Full Text Available Taiwanese green propolis is a prenylated flavonoid rich honeybee product and propolins isolated from Taiwanese green propolis exert a broad spectrum of biological activities, such as anti-cancer and anti-oxidant. However, the anti-bacterial effects of Taiwanese green propolis or propolins are still poorly understood. In the current study, the antibacterial effects of Taiwanese green propolis and propolins were evaluated. Results show that the maximum dry matter yields of Taiwanese green propolis were observed in the 95% and 99.5% ethanol extracts compared to other extraction methods. Consistently, the highest concentration of propolins C, D, F and G from Taiwanese green propolis was obtained in 95% and 99.5% ethanol extracts. Propolins inhibited the growth of gram-positive bacterial strains (Staphylococcus aureus, Bacillus subtilis, Listeria monocytogenes and Paenibacillus larvae. The average minimum inhibitory concentration (MIC and minimum bactericidal concentration (MBC of propolins from ethanol extracts were 20 μg/ml. Among the propolins, propolin C had the highest antibacterial activity. Furthermore, Taiwanese green propolis also showed antibacterial activity against methicillin-resistant S. aureus (MRSA. In conclusion, these results demonstrate that Taiwanese green propolis and propolins have significant antibacterial activity, particularly against gram-positive bacterial strains. Keywords: Antibacterial activity, Propolins, Taiwan, Green propolis

  11. Antibacterial properties of modified biodegradable PHB non-woven fabric.

    Science.gov (United States)

    Slepička, P; Malá, Z; Rimpelová, S; Švorčík, V

    2016-08-01

    The antibacterial properties of poly(hydroxybutyrate) (PHB) non-woven fabric were explored in this study. The PHB was activated by plasma modification and subsequently processed with either immersion into a solution of nanoparticles or direct metallization. The wettability and surface chemistry of the PHB surface was determined. The thickness of the sputtered nanolayer on PHB fabric was characterized. It was found that plasma modification led to a formation of strongly hydrophilic surface, while the subsequent metallization by silver or gold resulted in a significantly increased water contact angle. Further, it was found that antibacterial activity may be controlled by the type of a metal and deposition method used. The immersion of plasma modified fabric into Ag nanoparticle solution led to enhanced antibacterial efficiency of PHB against Escherichia coli (E. coli). Direct silver sputtering on PHB fabric was proved to be a simple method for construction of a surface with strong antibacterial potency against both Escherichia coli (E. coli) and Staphylococcus epidermidis (S. epidermidis). We demonstrated the antibacterial activity of PHB fabric modified by plasma activation and consecutive selection of a treatment method for an effective antibacterial surface construction. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Antibacterial effects and dissolution behavior of six bioactive glasses.

    Science.gov (United States)

    Zhang, Di; Leppäranta, Outi; Munukka, Eveliina; Ylänen, Heimo; Viljanen, Matti K; Eerola, Erkki; Hupa, Mikko; Hupa, Leena

    2010-05-01

    Dissolution behavior of six bioactive glasses was correlated with the antibacterial effects of the same glasses against sixteen clinically important bacterial species. Powdered glasses (<45 microm) were immersed in simulated body fluid (SBF) for 48 h. The pH in the solution inside the glass powder was measured in situ with a microelectrode. After 2, 4, 27, and 48 h, the pH and concentration of ions after removing the particles and mixing the SBF were measured with a normal glass pH electrode and ICP-OES. The bacteria were cultured in broth with the glass powder for up to 4 days, after which the viability of the bacteria was determined. The antibacterial effect of the glasses increased with increasing pH and concentration of alkali ions and thus with increased dissolution tendency of the glasses, but it also depended on the bacterium type. The changes in the concentrations of Si, Ca, Mg, P, and B ions in SBF did not show statistically significant influence on the antibacterial property. Bioactive glasses showed strong antibacterial effects for a wide selection of aerobic bacteria at a high sample concentration (100 mg/mL). The antibacterial effects increased with glass concentration and a concentration of 50 mg/mL (SA/V 185 cm(-1)) was required to generate the bactericidal effects. Understanding the dissolution mechanisms of bioactive glasses is essential when assessing their antibacterial effects. Copyright 2009 Wiley Periodicals, Inc.

  13. Evaluation of antibacterial activity of Prosopis juliflora (SW.) DC. leaves.

    Science.gov (United States)

    Thakur, Rupesh; Singh, Rupal; Saxena, Pooja; Mani, Abin

    2014-01-01

    The ethnobotanical importance of Prosopis juliflora is well-known in the folkloric system of medicine for the treatment of various ailments. Although, the study related to the antibacterial potential of this plant, from Central India is scanty. The in vitro antibacterial activity of Prosopis juliflora leaves collected from the local area was evaluated against ten bacterial type cultures by agar well diffusion assay. The crude extracts prepared by two methods separately with three different solvents were examined for the preliminary antibacterial activity and phytochemical screening, the results of which were used for the choice of solvent and mass extraction of crude extract. Solvent fractionation of crude extract was done employing two sets of solvents namely Set-PCE and Set-HDB which resulted in total, six organic and two aqueous fractions, which were finally subjected to antibacterial activities. Varying degrees of growth inhibition was shown by all the fractions against tested microorganisms. The highest antibacterial activity was observed in aqueous fractions as compared to solvent fractions. Isolation and characterization of the bioactive components can be further done by systematic screening of the most active solvent fraction which could lead to the possible source of new antibacterial agents.

  14. Characterization and antibacterial properties of porous fibers containing silver ions

    International Nuclear Information System (INIS)

    Sun, Zhaoyang; Fan, Chenxu; Tang, Xiaopeng; Zhao, Jianghui; Song, Yanhua; Shao, Zhongbiao; Xu, Lan

    2016-01-01

    Highlights: • Antibacterial electrospun PLA porous fibers containing silver ions were prepared. • Porous structure and porosity of PLA/Ag + porous fibers were investigated. • The antibacterial effects of PLA/Ag + porous fibers were studied. • The released mechanism of silver ions in the porous fibers was illustrated. • The porous structure could improve the antibacterial properties. - Abstract: Materials prepared on the base of bioactive silver compounds have become more and more popular. In the present work, the surface morphology, structure and properties, of electrospun Polylactide Polylactic acid (PLA) porous fibers containing various ratios of silver ions were investigated by a combination of X-ray photoelectron spectroscopy (XPS), universal testing machine, thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and et al. The biological activities of the proposed porous fibers were discussed in view of the released silver ions concentration. Antibacterial properties of these porous fibers were studied using two bacterial strains: Escherichia coli (E. coli) and Methicillin-resistant Staphylococcus aureus (MRSA). Results of the antibacterial testing suggested that PLA porous fibers containing silver ions could be used as potent antibacterial wound dressing materials in the biomedical field.

  15. 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.

    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

  16. Cathepsin-Mediated Cleavage of Peptides from Peptide Amphiphiles Leads to Enhanced Intracellular Peptide Accumulation

    Energy Technology Data Exchange (ETDEWEB)

    Acar, Handan [Institute; Department; Samaeekia, Ravand [Institute; Department; Schnorenberg, Mathew R. [Institute; Department; Medical; Sasmal, Dibyendu K. [Institute; Huang, Jun [Institute; Tirrell, Matthew V. [Institute; Institute; LaBelle, James L. [Department

    2017-08-24

    Peptides synthesized in the likeness of their native interaction domain(s) are natural choices to target protein protein interactions (PPIs) due to their fidelity of orthostatic contact points between binding partners. Despite therapeutic promise, intracellular delivery of biofunctional peptides at concentrations necessary for efficacy remains a formidable challenge. Peptide amphiphiles (PAs) provide a facile method of intracellular delivery and stabilization of bioactive peptides. PAs consisting of biofunctional peptide headgroups linked to hydrophobic alkyl lipid-like tails prevent peptide hydrolysis and proteolysis in circulation, and PA monomers are internalized via endocytosis. However, endocytotic sequestration and steric hindrance from the lipid tail are two major mechanisms that limit PA efficacy to target intracellular PPIs. To address these problems, we have constructed a PA platform consisting of cathepsin-B cleavable PAs in which a selective p53-based inhibitory peptide is cleaved from its lipid tail within endosomes, allowing for intracellular peptide accumulation and extracellular recycling of the lipid moiety. We monitor for cleavage and follow individual PA components in real time using a resonance energy transfer (FRET)-based tracking system. Using this platform, components in real time using a Forster we provide a better understanding and quantification of cellular internalization, trafficking, and endosomal cleavage of PAs and of the ultimate fates of each component.

  17. Preclinical advantages of intramuscularly administered peptide A3-APO over existing therapies in Acinetobacter baumannii wound infections.

    Science.gov (United States)

    Ostorhazi, Eszter; Rozgonyi, Ferenc; Sztodola, Andras; Harmos, Ferenc; Kovalszky, Ilona; Szabo, Dora; Knappe, Daniel; Hoffmann, Ralf; Cassone, Marco; Wade, John D; Bonomo, Robert A; Otvos, Laszlo

    2010-11-01

    The designer antibacterial peptide A3-APO is efficacious in mouse models of Escherichia coli and Acinetobacter baumannii systemic infections. Here we compare the efficacy of the peptide with that of imipenem and colistin in A. baumannii wound infections after burn injury. CD-1 mice were inflicted with burn wounds and different inocula of A. baumannii, isolated from an injured soldier, were placed into the wound sites. The antibiotics were given intramuscularly (im) one to five times. Available free peptide in the blood and the systemic toxicity of colistin and A3-APO were studied in healthy mice. While toxicity of colistin was observed at 25 mg/kg bolus drug administration, the lowest toxic dose of A3-APO was 75 mg/kg. In the A. baumannii blast injury models, 5 mg/kg A3-APO improved survival and reduced bacterial counts in the blood as well as in the wounds and improved wound appearance significantly better than any other antibiotic treatment. The free peptide concentration in the blood did not reach 1 µg/mL. Peptide A3-APO, with an intramuscular therapeutic index of 15, is more efficacious and less toxic than any existing burn injury infection therapy modality against multidrug-resistant Gram-negative pathogens. A3-APO administered by the im route probably binds to a biopolymer that promotes the peptide's biodistribution.

  18. Antimicrobial activity and mechanism of the human milk-sourced peptide Casein201

    International Nuclear Information System (INIS)

    Zhang, Fan; Cui, Xianwei; Fu, Yanrong; Zhang, Jun; Zhou, Yahui; Sun, Yazhou; Wang, Xing; Li, Yun; Liu, Qianqi; Chen, Ting

    2017-01-01

    Introduction: Casein201 is one of the human milk sourced peptides that differed significantly in preterm and full-term mothers. This study is designed to demonstrate the biological characteristics, antibacterial activity and mechanisms of Casein201 against common pathogens in neonatal infection. Methodology: The analysis of biological characteristics was done by bioinformatics. Disk diffusion method and flow cytometry were used to detect the antimicrobial activity of Casein201. Killing kinetics of Casein201 was measured using microplate reader. The antimicrobial mechanism of Casein201 was studied by electron microscopy and electrophoresis. Results: Bioinformatics analysis indicates that Casein201 derived from β-casein and showed significant sequence overlap. Antibacterial assays showed Casein201 inhibited the growth of S taphylococcus aureus and Y ersinia enterocolitica. Ultrastructural analyses revealed that the antibacterial activity of Casein201 is through cytoplasmic structures disintegration and bacterial cell envelope alterations but not combination with DNA. Conclusion: We conclude the antimicrobial activity and mechanism of Casein201. Our data demonstrate that Casein201 has potential therapeutic value for the prevention and treatment of pathogens in neonatal infection.

  19. 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.

  20. Antibacterial and antiviral roles of a fish β-defensin expressed both in pituitary and testis.

    Science.gov (United States)

    Jin, Jun-Yan; Zhou, Li; Wang, Yang; Li, Zhi; Zhao, Jiu-Gang; Zhang, Qi-Ya; Gui, Jian-Fang

    2010-12-20

    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.

  1. 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

  2. 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......(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...

  3. 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...... pressure (R=0·32, P0·31, Ppeptide is elevated in cirrhosis. Copeptin, proadrenomedullin and proANP are related to portal pressure and seem associated with systemic haemodynamics. These propeptides may...

  4. 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.

  5. Transition metal ions mediated tyrosine based short peptide amphiphile nanostructures inhibit bacterial growth.

    Science.gov (United States)

    Joshi, Khashti Ballabh; Singh, Ramesh; Mishra, Narendra Kumar; Kumar, Vikas; Vinayak, Vandana

    2018-05-17

    We report the design and synthesis of biocompatible small peptide based molecule for the controlled and targeted delivery of the encapsulated bioactive metal ions via transforming their internal nanostructures. Tyrosine based short peptide amphiphile (sPA) was synthesized which self-assembled into β-sheet like secondary structures. The self assembly of the designed sPA was modulated by using different bioactive transition metal ions which is confirmed by spectroscopic and microscopic techniques. These bioactive metal ions conjugated sPA hybrid structures are further used to develop antibacterial materials. It is due to the excellent antibacterial activity of zinc ions that the growth of clinically relevant bacteria such as E. Coli was inhibited in the presence of zinc-sPA conjugate. The bacterial test demonstrated that owing to high biocompatibility with bacterial cell, the designed sPA worked as metal ions delivery agent and therefore it can show great potential in locally addressing bacterial infections. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. ANTIBACTERIAL ACTIVITY OF GINGER OIL AGAINST FOOD BORN PATHOGENS

    International Nuclear Information System (INIS)

    TAHA, S.M.A.

    2008-01-01

    This study was carried out to investigate the antibacterial activity of ginger oil against Food Born pathogens and the effect of heating, microwave heating and gamma irradiation on microbiological quality and antibacterial activity of ginger oil. Growth and survival of A. hydrophila and L. monocytogenes in broth media and carrot juice with different concentrations of ginger oil was also studied. Gram-negative bacteria were more resistant than gram-positive bacteria. Heating at 80 0 C for 10 min did not change the antibacterial activity of ginger oil, whereas heating at 100 0 C for 5 min and autoclaving at 121 0 C for 15 min caused slight reduction in antibacterial activity in most microorganisms tested. Heating by microwave of ginger oil destroyed its antibacterial activity against B. cereus although it still works against other microorganisms tested. The dose 6 kGy caused slight reduction in antibacterial activity of ginger oil, whereas the dose 10 kGy caused markedly reduction in antibacterial activity of ginger oil against most microorganisms tested. Ginger oil was more effective on L. monocytogenes as compared with its effect on A. hydrophila in tryptone soya broth at 4 0 C or 25 0 C. Supplementation of ginger oil with carrot juice was more effective on A. hydrophila and L. monocytogenes than in tryptone soya broth and this effect was increased with increasing the time of incubation and the concentration of ginger oil. These results support the notion that plant essential oils may have an important role as pharmaceuticals and food preservatives

  7. Povidone-Iodine-Based Polymeric Nanoparticles for Antibacterial Applications.

    Science.gov (United States)

    Gao, Tianyi; Fan, Hongbo; Wang, Xinjie; Gao, Yangyang; Liu, Wenxin; Chen, Wanjun; Dong, Alideertu; Wang, Yan-Jie

    2017-08-09

    As microbial contamination is becoming more and more serious, antibacterial agents play an important role in preventing and removing bacterial pathogens from microbial pollution in our daily life. To solve the issues with water solubility and antibacterial stability of PVP-I 2 (povidone-iodine) as a strong antibacterial agent, we successfully obtain hydrophobic povidone-iodine nanoparticles (povidone-iodine NPs) by a two-step method related to the advantage of nanotechnology. First, the synthesis of poly(N-vinyl-2-pyrrolidone-co-methyl methacrylate) nanoparticles, i.e., P(NVP-MMA) NPs, was controlled by tuning a feed ratio of NVP to MMA. Then, the products P(NVP-MMA) NPs were allowed to undergo a complexation reaction with iodine, resulting in the formation of a water-insoluble antibacterial material, povidone-iodine NPs. It is found that the feed ratio of NVP to MMA has an active effect on morphology, chemical composition, molecular weight, and hydrophilic-hydrophobic properties of the P(NVP-MMA) copolymer after some technologies, such as SEM, DLS, elemental analysis, 1 H NMR, GPC, and the contact angle test, were used in the characterizations. The antibacterial property of povidone-iodine NPs was investigated by using Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and Pseudomonas aeruginosa (P. aeruginosa) as model bacteria with the colony count method. Interestingly, three products, such as glue, ink, and dye, after the incorporation of povidone-iodine NPs, show significant antibacterial properties. It is believed that, with the advantage of nanoscale morphology, the final povidone-iodine NPs should have great potential for utilization in various fields where antifouling and antibacterial properties are highly required.

  8. Characterization of synthetic peptides by mass spectrometry

    DEFF Research Database (Denmark)

    Prabhala, Bala Krishna; Mirza, Osman Asghar; Højrup, Peter

    2015-01-01

    Mass spectrometry (MS) is well suited for analysis of the identity and purity of synthetic peptides. The sequence of a synthetic peptide is most often known, so the analysis is mainly used to confirm the identity and purity of the peptide. Here, simple procedures are described for MALDI......-TOF-MS and LC-MS of synthetic peptides....

  9. 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.

  10. NLF20: an antimicrobial peptide with therapeutic potential against invasive Pseudomonas aeruginosa infection.

    Science.gov (United States)

    Papareddy, Praveen; Kasetty, Gopinath; Kalle, Martina; Bhongir, Ravi K V; Mörgelin, Matthias; Schmidtchen, Artur; Malmsten, Martin

    2016-01-01

    Increasing resistance to antibiotics makes antimicrobial peptides interesting as novel therapeutics. Here, we report on studies of the peptide NLF20 (NLFRKLTHRLFRRNFGYTLR), corresponding to an epitope of the D helix of heparin cofactor II (HCII), a plasma protein mediating bacterial clearance. Peptide effects were evaluated by a combination of in vitro and in vivo methods, including antibacterial, anti-inflammatory and cytotoxicity assays, fluorescence and electron microscopy, and experimental models of endotoxin shock and Pseudomonas aeruginosa sepsis. The results showed that NLF20 displayed potent antimicrobial effects against the Gram-negative bacteria Escherichia coli and P. aeruginosa, the Gram-positive Bacillus subtilis and Staphylococcus aureus and the fungi Candida albicans and Candida parapsilosis. Importantly, this antimicrobial effect was retained in human blood, particularly for P. aeruginosa. Fluorescence and electron microscopy studies showed that the peptide exerted membrane-breaking effects. In an animal model of P. aeruginosa sepsis, NLF20 reduced bacterial levels, resulting in improved survival. Reduced mortality was also observed in experimental animal models of endotoxin shock, which was paralleled with modulated IFN-γ, IL-10 and coagulation responses. Together, these results indicate that functional epitopes of HCII may have therapeutic potential against bacterial infection. © The Author 2015. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  11. Antiseptic mouthwashes: in vitro antibacterial activity.

    Science.gov (United States)

    Watanabe, Evandro; Nascimento, Andresa P; Guerreiro-Tanomaru, Juliane M; Razaboni, Ana M; de Andrade, Denise; Tanomaru-Filho, Mário

    2015-01-01

    Mouthwashes are used as an adjunct to tooth brushing for improving breath and preventing oral diseases. The aim of this study was to compare the in vitro Maximum Inhibitory Dilution (MID) of 3 mouthwashes with different active ingredients against mutans streptococci (MS). The products analyzed were Periogard®, Cepacol® and Plax® Fresh Mint. Their antibacterial activity was assessed in duplicate in 96-well microtiter plates against 36 clinical isolates of MS. Each mouthwash was submitted to a serial two-fold dilution (1/2.5 to 1/5120) using double concentration of Tryptose Soy Broth with 1.0% yeast extract. The final volume in each well was 100 mL plus 5 mL of a bacterial suspension, equivalent to 107 CFU/mL. They were incubated microaerobically at 37 °C for 48 hours and the MIDs determined. MID was 1/320 for Periogard® and Cepacol®, and 1/20 for PlaxR® Statistical analysis revealed that the MID of Periogard® MID did not differ from that of Cepacol® (p>0.05), and was higher than that of Plax® (pantiseptic mouthwashes containing chlorhexidine (Periogard®) and cetylpyridinium chloride (Cepacol®) had higher in vitroantibacterial activity (MID) against MS than the antiseptic mouthwash containing triclosan (Plax®), according to microbiological method employed.

  12. Antibacterial mechanism of fraxetin against Staphylococcus aureus

    Science.gov (United States)

    WANG, HAITING; ZOU, DAN; XIE, KUNPEING; XIE, MINGJIE

    2014-01-01

    Fraxetin is one of the main constituents of the traditional medicinal plant Fraxinus rhynchophylla. The inhibitory effect of fraxetin on various bacterial strains has been extensively reported, however, its mechanism of action on bacterial cells remains to be elucidated. In the present study, the antibacterial mechanism of fraxetin on Staphylococcus aureus was systematically investigated by examining its effect on cell membranes, protein synthesis, nucleic acid content and topoisomerase activity. The results indicated that fraxetin increased the permeability of the cell membrane but did not render it permeable to macromolecules, such as DNA and RNA. Additionally, the quantity of protein, DNA and RNA decreased to 55.74, 33.86 and 48.96%, respectively following treatment with fraxetin for 16 h. The activity of topoisomerase I and topoisomerase II were also markedly inhibited as fraxetin concentration increased. The result of the ultraviolet-visible spectrophotometry demonstrated that the DNA characteristics exhibited a blue shift and hypochromic effect following treatment with fraxetin. These results indicated that fraxetin had a marked inhibitory effect on S.aureus proliferation. Further mechanistic studies showed that fraxetin could disrupt nucleic acid and protein synthesis by preventing topoisomerase from binding to DNA. PMID:25189268

  13. Marine Peptides: Bioactivities and Applications

    Directory of Open Access Journals (Sweden)

    Randy Chi Fai Cheung

    2015-06-01

    Full Text Available Peptides are important bioactive natural products which are present in many marine species. These marine peptides have high potential nutraceutical and medicinal values because of their broad spectra of bioactivities. Their antimicrobial, antiviral, antitumor, antioxidative, cardioprotective (antihypertensive, antiatherosclerotic and anticoagulant, immunomodulatory, analgesic, anxiolytic anti-diabetic, appetite suppressing and neuroprotective activities have attracted the attention of the pharmaceutical industry, which attempts to design them for use in the treatment or prevention of various diseases. Some marine peptides or their derivatives have high commercial values and had reached the pharmaceutical and nutraceutical markets. A large number of them are already in different phases of the clinical and preclinical pipeline. This review highlights the recent research in marine peptides and the trends and prospects for the future, with special emphasis on nutraceutical and pharmaceutical development into marketed products.

  14. Cardioprotective peptides from marine sources.

    Science.gov (United States)

    Harnedy, Padraigín A; FitzGerald, Richard J

    2013-05-01

    Elevated blood pressure or hypertension is one of the fastest growing health problems worldwide. Although the etiology of essential hypertension has a genetic component, dietary factors play an important role. With the high costs and adverse side-effects associated with synthetic antihypertensive drugs and the awareness of the link between diet and health there has been increased focus on identification of food components that may contribute to cardiovascular health. In recent years special interest has been paid to the cardioprotective activity of peptides derived from food proteins including marine proteins. These peptides are latent within the sequence of the parent protein and only become active when released by proteolytic digestion during gastrointestinal digestion or through food processing. Current data on antihypertensive activity of marine-derived protein hydrolysates/peptides in animal and human studies is reviewed herein. Furthermore, products containing protein hydrolysates/peptides from marine origin with antihypertensive effects are discussed.

  15. Antimicrobial peptides from Capsicum sp.

    African Journals Online (AJOL)

    ajl yemi

    2011-12-30

    Dec 30, 2011 ... Key words: Antimicrobial peptides, Capsicum sp, Capsicum chinense, chili pepper, agronomical options, ..... of this human activity is resumed by the simple phrase: produce .... It will be interesting to scale the AMPs extraction.

  16. Production and characterization of peptide antibodies

    DEFF Research Database (Denmark)

    Trier, Nicole Hartwig; Hansen, Paul Robert; Houen, Gunnar

    2012-01-01

    Proteins are effective immunogens for generation of antibodies. However, occasionally the native protein is known but not available for antibody production. In such cases synthetic peptides derived from the native protein are good alternatives for antibody production. These peptide antibodies...... are powerful tools in experimental biology and are easily produced to any peptide of choice. A widely used approach for production of peptide antibodies is to immunize animals with a synthetic peptide coupled to a carrier protein. Very important is the selection of the synthetic peptide, where factors......, including solid-phase peptide-carrier conjugation and peptide-carrier conjugation in solution. Upon immunization, adjuvants such as Al(OH)(3) are added together with the immunogenic peptide-carrier conjugate, which usually leads to high-titred antisera. Following immunization and peptide antibody...

  17. Peptides and proteins

    Energy Technology Data Exchange (ETDEWEB)

    Bachovchin, W.W.; Unkefer, C.J.

    1994-12-01

    Advances in magnetic resonance and vibrational spectroscopy make it possible to derive detailed structural information about biomolecular structures in solution. These techniques are critically dependent on the availability of labeled compounds. For example, NMR techniques used today to derive peptide and protein structures require uniformity {sup 13}C-and {sup 15}N-labeled samples that are derived biosynthetically from (U-6-{sup 13}C) glucose. These experiments are possible now because, during the 1970s, the National Stable Isotope Resource developed algal methods for producing (U-6-{sup 13}C) glucose. If NMR techniques are to be used to study larger proteins, we will need sophisticated labelling patterns in amino acids that employ a combination of {sup 2}H, {sup 13}C, and {sup 15}N labeling. The availability of these specifically labeled amino acids requires a renewed investment in new methods for chemical synthesis of labeled amino acids. The development of new magnetic resonance or vibrational techniques to elucidate biomolecular structure will be seriously impeded if we do not see rapid progress in labeling technology. Investment in labeling chemistry is as important as investment in the development of advanced spectroscopic tools.

  18. Matrix-assisted peptide synthesis on nanoparticles.

    Science.gov (United States)

    Khandadash, Raz; Machtey, Victoria; Weiss, Aryeh; Byk, Gerardo

    2014-09-01

    We report a new method for multistep peptide synthesis on polymeric nanoparticles of differing sizes. Polymeric nanoparticles were functionalized via their temporary embedment into a magnetic inorganic matrix that allows multistep peptide synthesis. The matrix is removed at the end of the process for obtaining nanoparticles functionalized with peptides. The matrix-assisted synthesis on nanoparticles was proved by generating various biologically relevant peptides. Copyright © 2014 European Peptide Society and John Wiley & Sons, Ltd.

  19. High-resolution mass spectrometry driven discovery of peptidic danger signals in insect immunity.

    Directory of Open Access Journals (Sweden)

    Arton Berisha

    Full Text Available The 'danger model' is an alternative concept for immune response postulating that the immune system reacts to entities that do damage (danger associated molecular patterns, DAMP and not only to entities that are foreign (pathogen-associated molecular patterns, PAMP as proposed by classical immunology concepts. In this study we used Galleria mellonella to validate the danger model in insects. Hemolymph of G. mellonella was digested with thermolysin (as a representative for virulence-associated metalloproteinases produced by humanpathogens followed by chromatographic fractionation. Immune-stimulatory activity was tested by measuring lysozyme activity with the lytic zone assays against Micrococcus luteus cell wall components. Peptides were analyzed by nano-scale liquid chromatography coupled to high-resolution Fourier transform mass spectrometers. Addressing the lack of a genome sequence we complemented the rudimentary NCBI protein database with a recently established transcriptome and de novo sequencing methods for peptide identification. This approach led to identification of 127 peptides, 9 of which were identified in bioactive fractions. Detailed MS/MS experiments in comparison with synthetic analogues confirmed the amino acid sequence of all 9 peptides. To test the potential of these putative danger signals to induce immune responses we injected the synthetic analogues into G. mellonella and monitored the anti-bacterial activity against living Micrococcus luteus. Six out of 9 peptides identified in the bioactive fractions exhibited immune-stimulatory activity when injected. Hence, we provide evidence that small peptides resulting from thermolysin-mediated digestion of hemolymph proteins function as endogenous danger signals which can set the immune system into alarm. Consequently, our study indicates that the danger model also plays a role in insect immunity.

  20. Chimeric Peptides as Implant Functionalization Agents for Titanium Alloy Implants with Antimicrobial Properties

    Science.gov (United States)

    Yucesoy, Deniz T.; Hnilova, Marketa; Boone, Kyle; Arnold, Paul M.; Snead, Malcolm L.; Tamerler, Candan

    2015-04-01

    Implant-associated infections can have severe effects on the longevity of implant devices and they also represent a major cause of implant failures. Treating these infections associated with implants by antibiotics is not always an effective strategy due to poor penetration rates of antibiotics into biofilms. Additionally, emerging antibiotic resistance poses serious concerns. There is an urge to develop effective antibacterial surfaces that prevent bacterial adhesion and proliferation. A novel class of bacterial therapeutic agents, known as antimicrobial peptides (AMPs), are receiving increasing attention as an unconventional option to treat septic infection, partly due to their capacity to stimulate innate immune responses and for the difficulty of microorganisms to develop resistance towards them. While host and bacterial cells compete in determining the ultimate fate of the implant, functionalization of implant surfaces with AMPs can shift the balance and prevent implant infections. In the present study, we developed a novel chimeric peptide to functionalize the implant material surface. The chimeric peptide simultaneously presents two functionalities, with one domain binding to a titanium alloy implant surface through a titanium-binding domain while the other domain displays an antimicrobial property. This approach gains strength through control over the bio-material interfaces, a property built upon molecular recognition and self-assembly through a titanium alloy binding domain in the chimeric peptide. The efficiency of chimeric peptide both in-solution and absorbed onto titanium alloy surface was evaluated in vitro against three common human host infectious bacteria, Streptococcus mutans, Staphylococcus epidermidis, and Escherichia coli. In biological interactions such as occur on implants, it is the surface and the interface that dictate the ultimate outcome. Controlling the implant surface by creating an interface composed chimeric peptides may therefore

  1. Material Binding Peptides for Nanotechnology

    Directory of Open Access Journals (Sweden)

    Urartu Ozgur Safak Seker

    2011-02-01

    Full Text Available Remarkable progress has been made to date in the discovery of material binding peptides and their utilization in nanotechnology, which has brought new challenges and opportunities. Nowadays phage display is a versatile tool, important for the selection of ligands for proteins and peptides. This combinatorial approach has also been adapted over the past decade to select material-specific peptides. Screening and selection of such phage displayed material binding peptides has attracted great interest, in particular because of their use in nanotechnology. Phage display selected peptides are either synthesized independently or expressed on phage coat protein. Selected phage particles are subsequently utilized in the synthesis of nanoparticles, in the assembly of nanostructures on inorganic surfaces, and oriented protein immobilization as fusion partners of proteins. In this paper, we present an overview on the research conducted on this area. In this review we not only focus on the selection process, but also on molecular binding characterization and utilization of peptides as molecular linkers, molecular assemblers and material synthesizers.

  2. 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

  3. 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...

  4. 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.

  5. Chemical Composition and Antibacterial Effect of Medicinal Plants against Some Food-Borne Pathogen

    Directory of Open Access Journals (Sweden)

    Hassan Habibi

    2017-05-01

    Conclusion: Antibacterial efficacy shown by these plants provides a scientific basis and thus validates their use as medicinal remedies. Isolation and purification of different phytochemicals may further yield significant antibacterial agents.

  6. Antibacterial activity of the latex of Argemone ochroleuca Sweet

    International Nuclear Information System (INIS)

    Saad A. Alamri; Mahmoud F. Moustafa

    2010-01-01

    To investigate the antibacterial effect of the crude latex of Argemone ochroleuca (A. ochroleuca) as antibacterial potential against a range of human pathogenic bacteria. This study was carried out at King Khalid University, Abha, Kingdom of Saudi Arabia from January to March 2010. Seventeen ml of fresh latex from A. ochroleuca Sweet was collected, and the antibacterial activity of crude and diluted latex were examined using one ml of standardized inoculum suspension, and using the agar diffusion method test against Bacillus subtilis, Enterobacter aerogenes, Micrococcus luteus, Escherichia coli, and Staphylococcus aureus. All inoculated plates were incubated aerobically at 290C for 48 hours. The diameter of the zones of inhibition was measured to the nearest mm. The crude latex of A. ochroleuca exhibited a potent antibacterial effect on all bacterial strains examined. The zones of inhibition against the tested bacteria were found in the range of 9.30 - 40.3 mm along with their respective minimum inhibitory concentration values 100 ul/ml. The observable inhibition on selected bacteria by latex of A. ochroleuca makes it a promising alternative as a potential source of natural antibacterial (Author).

  7. Antibacterial Properties of Silver-Loaded Plasma Polymer Coatings

    International Nuclear Information System (INIS)

    Ploux, L.; Mateescu, M.; Anselme, K.; Vasilev, K.

    2012-01-01

    In a previous paper, we proposed new silver nanoparticles (SNPs) based antibacterial coatings able to protect eukaryotic cells from SNPs related toxic effects, while preserving antibacterial efficiency. A SNPs containing n-heptylamine (HA) polymer matrix was deposited by plasma polymerization and coated by a second HA layer. In this paper, we elucidate the antibacterial action of these new coatings. We demonstrated that SNPs-loaded material can be covered by thin HA polymer layer without losing the antibacterial activity to planktonic bacteria living in the near surroundings of the material. SNPs-containing materials also revealed antibacterial effect on adhered bacteria. Adhered bacteria number was significantly reduced compared to pure HA plasma polymer and the physiology of the bacteria was affected. The number of adhered bacteria directly decreased with thickness of the second HA layer. Surprisingly, the quantity of cultivable bacteria harvested by transfer to nutritive agar decreased not only with the presence of SNPs, but also in relation to the covering HA layer thickness, that is, oppositely to the increase in adhered bacteria number. Two hypotheses are proposed for this surprising result (stronger attachment or weaker vitality), which raises the question of the diverse potential ways of action of SNPs entrapped in a polymer matrix.

  8. Antibacterial Activity of Germacrane Type Sesquiterpenes from Curcuma heyneana Rhizomes

    Directory of Open Access Journals (Sweden)

    Hartiwi Diastuti

    2014-03-01

    Full Text Available The isolation of terpenoids from C. heyneana rhizomes and their antibacterial activity have been conducted. The terpenoids were isolated by using vacuum liquid chromatography and radial chromatography. The structures of the compounds were determined based on spectroscopic data (1H-NMR, 13C-NMR (1D and 2D. The antibacterial activity was carried out by using microdilution method and evaluated against eight bacteria. Three germacrane type sesquiterpenes have been isolated from C. heyneana rhizhomes and were identified as germacrone, dehydrocurdione, and 1(10,4(5-diepoxygermacrone. Germacrone showed highest antibacterial activity against P. aeruginosa with MIC values of 15.6 µg/mL and MBC values 31.2 µg/mL. Dehydrocurdione showed highest antibacterial activity against B. subtilis with MIC values of 31.2 µg/mL and MBC values of 31.2 µg/mL. However, 1(10,4(5-diepoxygermacrone showed a weak antibacterial activity.

  9. Antibacterial activity of ethanolic extracts of some moss species

    Directory of Open Access Journals (Sweden)

    Karpiński Tomasz M.

    2017-09-01

    Full Text Available Introduction: For centuries, mosses have been used in traditional medicine due to their antibacterial, antifungal, and antiviral activities. Objective: The present study was designed to evaluate the antibacterial activity of ethanolic extracts obtained from 12 moss species: Brachythecium albicans, Bryum argenteum, Ceratodon purpureus, Dicranum scoparium, Dryptodon pulvinatus, Orthotrichum anomalum, Oxyrrhynchium hians, Plagiomnium undulatum, Polytrichum juniperinum, P. piliferum, Schistidium crassipilum, and Syntrichia ruralis. Methods: The antimicrobial activity of extracts was investigated against three Gram(+ bacteria (Enterococcus faecalis, Staphylococcus aureus, and Streptococcus pyogenes and two Gram(- bacteria (Escherichia coli and Klebsiella pneumoniae, using the agar disc-diffusion method. Results: The high activity against all investigated bacteria was determined for extracts of D. pulvinatus, P. undulatum, B. argenteum, S. crassipilum, O. anomalum (mean inhibition zone: 11.3-13.1 mm and to a lesser extent in the case of D. scoparium (8.3 mm. Extracts from P. juniperinum and P. piliferum showed activity only against Gram-positive bacteria, with an inhibition zone from 7.3 to 9.7 mm. Four species: B. albicans, C. purpureus, O. hians, and S. ruralis had not antibacterial properties. Conclusions: The obtained results indicate that mosses could be a significant source of antibacterial agents. For the first time, we presented antibacterial activity of ethanolic extracts from S. crassipilum and O. anomalum.

  10. Analogues of the Frog-skin Antimicrobial Peptide Temporin 1Tb Exhibit a Wider Spectrum of Activity and a Stronger Antibiofilm Potential as Compared to the Parental Peptide

    Science.gov (United States)

    Grassi, Lucia; Maisetta, Giuseppantonio; Maccari, Giuseppe; Esin, Semih; Batoni, Giovanna

    2017-04-01

    The frog skin-derived peptide Temporin 1Tb (TB) has gained increasing attention as novel antimicrobial agent for the treatment of antibiotic-resistant and/or biofilm-mediated infections. Nevertheless, such a peptide possesses a preferential spectrum of action against Gram-positive bacteria. In order to improve the therapeutic potential of TB, the present study evaluated the antibacterial and antibiofilm activities of two TB analogues against medically relevant bacterial species. Of the two analogues, TB_KKG6A has been previously described in the literature, while TB_L1FK is a new analogue designed by us through statistical-based computational strategies. Both TB analogues displayed a faster and stronger bactericidal activity than the parental peptide, especially against Gram-negative bacteria in planktonic form. Differently from the parental peptide, TB_KKG6A and TB_L1FK were able to inhibit the formation of Staphylococcus aureus biofilms by more than 50% at 12 μM, while only TB_KKG6A prevented the formation of Pseudomonas aeruginosa biofilms at 24 μM. A marked antibiofilm activity against preformed biofilms of both bacterial species was observed for the two TB analogues when used in combination with EDTA. Analysis of synergism at the cellular level suggested that the antibiofilm activity exerted by the peptide-EDTA combinations against mature biofilms might be due mainly to a disaggregating effect on the extracellular matrix in the case of S. aureus, and to a direct activity on biofilm-embedded cells in the case of P. aeruginosa. Both analogues displayed a low hemolytic effect at the active concentrations and, overall, TB_L1FK resulted less cytotoxic towards mammalian cells. Collectively, the results obtained demonstrated that subtle changes in the primary sequence of TB may provide TB analogues that, used alone or in combination with adjuvant molecules such as EDTA, exhibit promising features against both planktonic and biofilm cells of medically relevant

  11. The Wound Healing and Antibacterial Activity of Five Ethnomedical Calophyllum inophyllum Oils: An Alternative Therapeutic Strategy to Treat Infected Wounds.

    Directory of Open Access Journals (Sweden)

    Teddy Léguillier

    showed that CIO exhibit two distinct antibacterial effects: one against Gram+ bacteria by direct inhibition of mitotic growth and another potent effect against Gram- bacteria due to increased release of β-defensin 2 peptide by macrophages. Interestingly, the needed concentrations of CIO to inhibit bacteria growth and to promote wound healing are lower than concentrations exhibiting cytotoxic effects on keratinocyte cells. Finally, we performed bioautography assay against Staphylococcus aureus to determine polarity profile of the components responsible for CIO antibacterial activity. Our results showed for the five tested CIO that components responsible of the bacterial growth inhibition are the more polar one on the TLC chromatographic profile and are contained in the resinous fraction of the oil.This study was conducted to evaluate cytotoxicity, wound healing and antibacterial properties of five CIO traditionally used to treat infected wounds. Using cell and bacteria cultures, we confirmed the pharmacological effects of CIO as wound healing and antimicrobial agent. Moreover, we showed that concentration of CIO needed to exhibit therapeutic effects are lower than concentrations exhibiting cytotoxic effects in vitro. For the first time, this study provides support for traditional uses of CIO. These wound healing and antibiotic properties make CIO a valuable candidate to treat infected wounds especially in tropical areas.

  12. Flanking signal and mature peptide residues influence signal peptide cleavage

    Directory of Open Access Journals (Sweden)

    Ranganathan Shoba

    2008-12-01

    Full Text Available Abstract Background Signal peptides (SPs mediate the targeting of secretory precursor proteins to the correct subcellular compartments in prokaryotes and eukaryotes. Identifying these transient peptides is crucial to the medical, food and beverage and biotechnology industries yet our understanding of these peptides remains limited. This paper examines the most common type of signal peptides cleavable by the endoprotease signal peptidase I (SPase I, and the residues flanking the cleavage sites of three groups of signal peptide sequences, namely (i eukaryotes (Euk (ii Gram-positive (Gram+ bacteria, and (iii Gram-negative (Gram- bacteria. Results In this study, 2352 secretory peptide sequences from a variety of organisms with amino-terminal SPs are extracted from the manually curated SPdb database for analysis based on physicochemical properties such as pI, aliphatic index, GRAVY score, hydrophobicity, net charge and position-specific residue preferences. Our findings show that the three groups share several similarities in general, but they display distinctive features upon examination in terms of their amino acid compositions and frequencies, and various physico-chemical properties. Thus, analysis or prediction of their sequences should be separated and treated as distinct groups. Conclusion We conclude that the peptide segment recognized by SPase I extends to the start of the mature protein to a limited extent, upon our survey of the amino acid residues surrounding the cleavage processing site. These flanking residues possibly influence the cleavage processing and contribute to non-canonical cleavage sites. Our findings are applicable in defining more accurate prediction tools for recognition and identification of cleavage site of SPs.

  13. Plaque-left-behind after brushing: intra-oral reservoir for antibacterial toothpaste ingredients

    OpenAIRE

    Otten, Marieke P. T.; Busscher, Henk J.; Abbas, Frank; van der Mei, Henny C.; van Hoogmoed, Chris G.

    2012-01-01

    Objectives Plaque is never fully removed by brushing and may act as a reservoir for antibacterial ingredients, contributing to their substantive action. This study investigates the contribution of plaque-left-behind and saliva towards substantivity of three antibacterial toothpastes versus a control paste without antibacterial claims. Materials and methods First, volunteers brushed 2 weeks with a control or antibacterial toothpaste. Next, plaque and saliva samples were collected 6 and 12 h af...

  14. Synthesis and evaluation of amphiphilic peptides as nanostructures and drug delivery tools

    Science.gov (United States)

    Sayeh, Naser Ali

    the well-known, highly cationic CPPs, such as TAT and Arg9, which do not translocate across phospholipid bilayers, and enter cells mostly by active endocytosis. Alternatively, researchers have found that an effective cellular delivery vector can be improved developed by conjugating a CPP with a fatty acid chain. Amphiphilic peptides have also become a subject of major interest as potent antibacterial agents. Antimicrobial peptides (AMPs) are produced naturally by bacteria and are considered as the first line of host defense protecting living organisms from microorganisms. Various types of AMPs has been discovered, such as defensins, cecropins, magainins and cathelicidins, with significant different structures and bioactivity profiles. The mechanism of actions for these peptides were reported as effectors and regulators of the innate immune system by increasing production and release of chemokine, and enhancing wound healing and angiogenesis. They were able to suppress biofilm formation and induce the dissolution of existing biofilms. Thus, design of new AMPs and more cost effective sequences with highly activity are urgently needed. Although a number of cyclic peptides were discovered and reported as efficient cellular delivery agents or antimicrobial agent, a more systematic investigation is required to identify design rules for optimal entrapment, drug loading, and stability. The balance of many small forces determines the overall morphology, size, and functionality of the structures. A deeper understanding of these factors is required for guiding future research, and for customizing cyclic peptides for drug loading and cellular delivery applications. Thus, additional amphiphilic cyclic and linear peptides were designed with variable electrostatic and hydrophobic residues to optimize drug encapsulation. The diversity in ring size, amino acid number, position and sequences, number of rings, net charge, and hydrophobicity of side chains in cyclic peptides will allow

  15. Peptides and Anti-peptide Antibodies for Small and Medium Scale Peptide and Anti-peptide Affinity Microarrays: Antigenic Peptide Selection, Immobilization, and Processing.

    Science.gov (United States)

    Zhang, Fan; Briones, Andrea; Soloviev, Mikhail

    2016-01-01

    This chapter describes the principles of selection of antigenic peptides for the development of anti-peptide antibodies for use in microarray-based multiplex affinity assays and also with mass-spectrometry detection. The methods described here are mostly applicable to small to medium scale arrays. Although the same principles of peptide selection would be suitable for larger scale arrays (with 100+ features) the actual informatics software and printing methods may well be different. Because of the sheer number of proteins/peptides to be processed and analyzed dedicated software capable of processing all the proteins and an enterprise level array robotics may be necessary for larger scale efforts. This report aims to provide practical advice to those who develop or use arrays with up to ~100 different peptide or protein features.

  16. Symbiotic Plant Peptides Eliminate Candida albicans Both In Vitro and in an Epithelial Infection Model and Inhibit the Proliferation of Immortalized Human Cells

    Directory of Open Access Journals (Sweden)

    Lilla Ördögh

    2014-01-01

    Full Text Available The increasing number of multidrug-resistant microbes now emerging necessitates the identification of novel antimicrobial agents. Plants produce a great variety of antimicrobial peptides including hundreds of small, nodule-specific cysteine-rich NCR peptides that, in the legume Medicago truncatula, govern the differentiation of endosymbiotic nitrogen fixing bacteria and, in vitro, can display potent antibacterial activities. In this study, the potential candidacidal activity of 19 NCR peptides was investigated. Cationic NCR peptides having an isoelectric point above 9 were efficient in killing Candida albicans, one of the most common fungal pathogens of humans. None of the tested NCR peptides were toxic for immortalized human epithelial cells at concentrations that effectively killed the fungus; however, at higher concentrations, some of them inhibited the division of the cells. Furthermore, the cationic peptides successfully inhibited C. albicans induced human epithelial cell death in an in vitro coculture model. These results highlight the therapeutic potential of cationic NCR peptides in the treatment of candidiasis.

  17. ANTIBACTERIAL PROPERTIES OF PHARMACEUTICAL COMPOSITION OF HEPATOPROTECTORS

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    Aslanian MA

    2016-12-01

    Full Text Available Pathology problemof hepatobiliary system (HBS of contagious origin becomes relevant with the increase of disturbance and complications of lipid metabolism and bile pigments among young people. Leading role in prophylaxis and treatment in the context of this pathology belongs to antibacterialc hemotherapeutic agents. However, along with antimicrobial activity, numerous side effects can be observed during treatment with antibacterial agents. According to the recent study on hepatobiliary system (HBS, therapeutic effect can be seen only while using herbal medicine with choleretic action as well as their various compositions.Amountof medicine with the appropriate effect is insufficient, that is why the study was conducted towards finding effective combinations of plant substances of different groups for the purpose of creatingan effective medicine for treatment of hepatobiliary system (HBS of contagious origin. Aim of the work The purpose of study was to examine antibacterial properties of different combinations with flamin and lavender oil in combined medicine during the course of treatment of cholecystitis and cholangitis. Materials and methods. It the result of study 61 microbial strains were distinguished and identified from the pathological material taken from 53 patients with cholecystitis and cholangitis. All distinguished clinical microbial strains taken from the patients were tested for sensitivity to combined medicine in the form of tablets with flamin and lavender oil. Minimal inhibitory concentration for S. aureus АТСС 25923 amounted to 250-350 ug/ml, for E. coli АТСС 25922 - 350±50,0 ug/ml, for P. aeruginosa АТСС 27853 750±100,0 ug/ml, for Р. vulgaris АТСС 4636 - 850±100,0 ug/ml, minimal inhibitory concentration to the tablets № 2 та № 3 amounted to > 1000 мкг/мл. Minimal inhibitory concentration for B. subtilis АТСС 6633 amounted to 250±50,0 ug/ml, for C. albicans ATCC 885/653 300±50,0 ug

  18. Preparation and antibacterial activity of Ag–TiO 2 composite film by ...

    Indian Academy of Sciences (India)

    From these analyses, it was found that silver ions were trapped in TiO2 matrix and their reduction could be achieved at 600°C annealing temperature. The antibacterial activity against S. aureus and . coli has been studied applying the so called antibacterial-drop test. The Ag–TiO2 thin films exhibited a high antibacterial ...

  19. Studies on the antibacterial activity of dodecylglycerol

    International Nuclear Information System (INIS)

    Brissette, J.L.

    1985-01-01

    The antimicrobial activity of lipids has been known for many years, with dodecanoylglycerol (dodecanoic acid esterified to glycerol) being one of the most potential. However, the antibacterial potency of dodecylglycerol (DDG), the corresponding 1-O-alkyl glycerol ether, is considerably greater. The superior efficacy of DDG can be attributed, at least in part, to the greater chemical and metabolic stability of the ether bond as compared to esters. In an attempt towards elucidating the mode of action of DDG, the effect of DDG on bacterial lipid metabolism was examined using Streptococcus mutans BHT, a tolerant bacterium. The metabolic fate of the ether was also determined with the use of three radioactive tracers, 14 C-glycerol, 32 Pi, and 14 C-DDG. Treatment of exponentially growing cultures of S. mutans BHI with growth inhibitory concentrations of DDG (10 and 20 μg/ml) inhibited the incorporation of 14 C-glycerol into lipid. In vivo studies using 14 C-DDG showed that the 14 C-ether was readily incorporated almost exclusively into phosphatidic (PA) and lysophosphatidic (LPA) acids. When cells prelabelled with either 14 C-glycerol or 32 Pi were exposed to 10 and 20 + g/ml DDG for 2 h, the accumulation of PA and diphosphatidylglycerol (diPG) was greatly stimulated. However, diPG accumulated at the expense of its precursor, glycerol, which greatly decreased. These data suggest that the ether-containing PA inhibits the synthesis of CDP-diglyceride. Moreover, these results clearly demonstrate that DDG functions as a metabolic rather than physical effector, disputing the conventional notion that bactericidal lipids act as detergents, physically dissolving the cellular envelope

  20. Automated solid-phase peptide synthesis to obtain therapeutic peptides

    Directory of Open Access Journals (Sweden)

    Veronika Mäde

    2014-05-01

    Full Text Available The great versatility and the inherent high affinities of peptides for their respective targets have led to tremendous progress for therapeutic applications in the last years. In order to increase the drugability of these frequently unstable and rapidly cleared molecules, chemical modifications are of great interest. Automated solid-phase peptide synthesis (SPPS offers a suitable technology to produce chemically engineered peptides. This review concentrates on the application of SPPS by Fmoc/t-Bu protecting-group strategy, which is most commonly used. Critical issues and suggestions for the synthesis are covered. The development of automated methods from conventional to essentially improved microwave-assisted instruments is discussed. In order to improve pharmacokinetic properties of peptides, lipidation and PEGylation are described as covalent conjugation methods, which can be applied by a combination of automated and manual synthesis approaches. The synthesis and application of SPPS is described for neuropeptide Y receptor analogs as an example for bioactive hormones. The applied strategies represent innovative and potent methods for the development of novel peptide drug candidates that can be manufactured with optimized automated synthesis technologies.

  1. Facts and myths of antibacterial properties of silk.

    Science.gov (United States)

    Kaur, Jasjeet; Rajkhowa, Rangam; Afrin, Tarannum; Tsuzuki, Takuya; Wang, Xungai

    2014-03-01

    Silk cocoons provide protection to silkworm from biotic and abiotic hazards during the immobile pupal phase of the lifecycle of silkworms. Protection is particularly important for the wild silk cocoons reared in an open and harsh environment. To understand whether some of the cocoon components resist growth of microorganisms, in vitro studies were performed using gram negative bacteria Escherichia coli (E. coli) to investigate antibacterial properties of silk fiber, silk gum, and calcium oxalate crystals embedded inside some cocoons. The results show that the previously reported antibacterial properties of silk cocoons are actually due to residues of chemicals used to isolate/purify cocoon elements, and properly isolated silk fiber, gum, and embedded crystals free from such residues do not have inherent resistance to E. coli. This study removes the uncertainty created by previous studies over the presence of antibacterial properties of silk cocoons, particularly the silk gum and sericin. Copyright © 2013 Wiley Periodicals, Inc.

  2. Antibacterial gold nanoparticles-biomass assisted synthesis and characterization.

    Science.gov (United States)

    Badwaik, Vivek D; Willis, Chad B; Pender, Dillon S; Paripelly, Rammohan; Shah, Monic; Kherde, Yogesh A; Vangala, Lakshmisri M; Gonzalez, Matthew S; Dakshinamurthy, Rajalingam

    2013-10-01

    Xylose is a natural monosaccharide found in biomass such as straw, pecan shells, cottonseed hulls, and corncobs. Using this monosaccharide, we report the facile, green synthesis and characterization of stable xylose encapsulated gold nanoparticles (Xyl-GNPs) with potent antibacterial activity. Xyl-GNPs were synthesized using the reduction property of xylose in an aqueous solution containing choloraurate anions carried out at room temperature and atmospheric pressure. These nanoparticles were stable and near spherical in shape with an average diameter of 15 +/- 5 nm. Microbiological assay results showed the concentration dependent antibacterial activity of these particles against both Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus epidermidis) bacteria. Thus the facile, environmentally friendly Xyl-GNPs have many potential applications in chemical and biomedical industries, particularly in the development of antibacterial agents in the field of biomedicine.

  3. Antibacterial and antioxidant activities of Licania tomentosa (Benth. fritsch (crhysobalanaceae

    Directory of Open Access Journals (Sweden)

    Silva J.B.N.F.

    2012-01-01

    Full Text Available This work describes the chemical composition, and evaluates the antimicrobial and antioxidant activities of a hydroalcoholic extract from the leaves of the Licania tomentosa. Gram positive and negative bacterial strains were used in this work. Examination of the phytochemical composition of L. tomentosa revealed the presence of secondary metabolites such as tannins, flavonoids, saponins, alkaloids, steroids and triterpenoids. An antibacterial assay pointed out that the extract had a lower minimal inhibitory concentration (MIC - 32 μg/mL towards Staphylococcus aureus (ATCC12692. The extract also presented antibacterial activity against other assayed bacteria, with the MIC varying between 64 and 512 μg/ mL. Our findings reveal that the extract presented an antioxidative capacity lower than that of BHT at the same concentration, used as positive control. Our results suggest that the levels and combinations between the secondary metabolites of this plant should be investigated to explain the demonstrated antibacterial activity.

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

    Directory of Open Access Journals (Sweden)

    Claudia Pasca

    2016-11-01

    Full Text Available 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 show the best antibacterial effect with  Arctium lappa ethanol extracts, having inhibition areas of 6.3 to 17.5 mm, with an average of 9.0 mm and the highest determined mineral being Calcium. The results obtained open the prospect of using these medicinal plants as an alternative to be used for the control and cure of some mineral deficiencies or for preventing various diseases of the animals.

  5. Antibacterial effect of composite resins containing quaternary ammonium polyethyleneimine nanoparticles

    International Nuclear Information System (INIS)

    Yudovin-Farber, Ira; Beyth, Nurit; Weiss, Ervin I.; Domb, Abraham J.

    2010-01-01

    Quaternary ammonium polyethyleneimine (QA-PEI)-based nanoparticles were synthesized by crosslinking with dibromopentane followed by N-alkylation with various alkyl halides and further N-methylation with methyl iodide. Insoluble pyridinium-type particles were prepared by suspension polymerization of 4-vinyl pyridine followed by N-alkylation with alkyl halides. Polyamine-based nanoparticles embedded in restorative composite resin at 1% w/w were tested for antibacterial activity against Streptococcus mutans using direct contact test. Activity analysis revealed that the alkyl chain length of the QA-PEI nanoparticles plays a significant role in antibacterial activity of the reagent. The most potent compound was octyl-alkylated QA-PEI embedded in restorative composite resin at 1% w/w that totally inhibited S. mutans growth in 3-month-aged samples. This data indicates that restorative composite resin with antibacterial properties can be produced by the incorporation of QA-PEI nanoparticles.

  6. Antibacterial effect of composite resins containing quaternary ammonium polyethyleneimine nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Yudovin-Farber, Ira [Hebrew University of Jerusalem, Department of Medicinal Chemistry and Natural Products, School of Pharmacy, Faculty of Medicine (Israel); Beyth, Nurit; Weiss, Ervin I. [Hebrew University of Jerusalem, Department of Prosthodontics, Faculty of Dentistry (Israel); Domb, Abraham J., E-mail: avid@ekmd.huji.ac.i [Hebrew University of Jerusalem, Department of Medicinal Chemistry and Natural Products, School of Pharmacy, Faculty of Medicine (Israel)

    2010-02-15

    Quaternary ammonium polyethyleneimine (QA-PEI)-based nanoparticles were synthesized by crosslinking with dibromopentane followed by N-alkylation with various alkyl halides and further N-methylation with methyl iodide. Insoluble pyridinium-type particles were prepared by suspension polymerization of 4-vinyl pyridine followed by N-alkylation with alkyl halides. Polyamine-based nanoparticles embedded in restorative composite resin at 1% w/w were tested for antibacterial activity against Streptococcus mutans using direct contact test. Activity analysis revealed that the alkyl chain length of the QA-PEI nanoparticles plays a significant role in antibacterial activity of the reagent. The most potent compound was octyl-alkylated QA-PEI embedded in restorative composite resin at 1% w/w that totally inhibited S. mutans growth in 3-month-aged samples. This data indicates that restorative composite resin with antibacterial properties can be produced by the incorporation of QA-PEI nanoparticles.

  7. Novel orthodontic cement containing dimethylaminohexadecyl methacrylate with strong antibacterial capability.

    Science.gov (United States)

    Feng, Xiaodong; Zhang, Ning; Xu, Hockin H K; Weir, Michael D; Melo, Mary Anne S; Bai, Yuxing; Zhang, Ke

    2017-09-26

    Orthodontic treatments increase the incidence of white spot lesions. The objectives of this study were to develop an antibacterial orthodontic cement to inhibit demineralization, and to evaluate its enamel shear bond strength and anti-biofilm properties. Novel antibacterial monomer dimethylaminohexadecyl methacrylate (DMAHDM) was synthesized and incorporated into Transbond XT at 0, 1.5 and 3% by mass. Anti-biofilm activity was assessed using a human dental plaque microcosm biofilm model. Shear bond strength and adhesive remnant index were also tested. Biofilm activity precipitously dropped when contacting orthodontic cement with DMAHDM. Orthodontic cement containing 3% DMAHDM significantly reduced biofilm metabolic activity and lactic acid production (p0.1). By incorporating DMAHDM into Transbond XT for the first time, the modified orthodontic cement obtained a strong antibacterial capability without compromising the enamel bond strength.

  8. What peptides these deltorphins be.

    Science.gov (United States)

    Lazarus, L H; Bryant, S D; Cooper, P S; Salvadori, S

    1999-02-01

    The deltorphins are a class of highly selective delta-opioid heptapeptides from the skin of the Amazonian frogs Phyllomedusa sauvagei and P. bicolor. The first of these fascinating peptides came to light in 1987 by cloning of the cDNA of from frog skins, while the other members of this family were identified either by cDNA or isolation of the peptides. The distinctive feature of deltorphins is the presence of a naturally occurring D-enantiomer at the second position in their common N-terminal sequence, Tyr-D-Xaa-Phe, comparable to dermorphin, which is the prototype of a group of mu-selective opioids from the same source. The D-amino acid and the anionic residues, either Glu or Asp, as well as their unique amino acid compositions are responsible for the remarkable biostability, high delta-receptor affinity, bioactivity and peptide conformation. This review summarizes a decade of research from many laboratories that defined which residues and substituents in the deltorphins interact with the delta-receptor and characterized pharmacological and physiological activities in vitro and in vivo. It begins with a historical description of the topic and presents general schema for the synthesis of peptide analogues of deltorphins A, B and C as a means to document the methods employed in producing a myriad of analogues. Structure activity studies of the peptides and their pharmacological activities in vitro are detailed in abundantly tabulated data. A brief compendium of the current level of knowledge of the delta-receptor assists the reader to appreciate the rationale for the design of these analogues. Discussion of the conformation of these peptides addresses how structure leads to further hypotheses regarding ligand receptor interaction. The review ends with a broad discussion of the potential applications of these peptides in clinical and therapeutic settings.

  9. Lateral dimension-dependent antibacterial activity of graphene oxide sheets.

    Science.gov (United States)

    Liu, Shaobin; Hu, Ming; Zeng, Tingying Helen; Wu, Ran; Jiang, Rongrong; Wei, Jun; Wang, Liang; Kong, Jing; Chen, Yuan

    2012-08-21

    Graphene oxide (GO) is a promising precursor to produce graphene-family nanomaterials for various applications. Their potential health and environmental impacts need a good understanding of their cellular interactions. Many factors may influence their biological interactions with cells, and the lateral dimension of GO sheets is one of the most relevant material properties. In this study, a model bacterium, Escherichia coli ( E. coli ), was used to evaluate the antibacterial activity of well-dispersed GO sheets, whose lateral size differs by more than 100 times. Our results show that the antibacterial activity of GO sheets toward E. coli cells is lateral size dependent. Larger GO sheets show stronger antibacterial activity than do smaller ones, and they have different time- and concentration-dependent antibacterial activities. Large GO sheets lead to most cell loss after 1 h incubation, and their concentration strongly influences antibacterial activity at relative low concentration (oxidation capacity toward glutathione is similar, consistent with X-ray photoelectron spectroscopy and ultraviolet-visible absorption spectroscopy results. This suggests the lateral size-dependent antibacterial activity of GO sheets is caused by neither their aggregation states, nor oxidation capacity. Atomic force microscope analysis of GO sheets and cells shows that GO sheets interact strongly with cells. Large GO sheets more easily cover cells, and cells cannot proliferate once fully covered, resulting in the cell viability loss observed in the followed colony counting test. In contrast, small GO sheets adhere to the bacterial surfaces, which cannot effectively isolate cells from environment. This study highlights the importance of tailoring the lateral dimension of GO sheets to optimize the application potential with minimal risks for environmental health and safety.

  10. Consumption of antibacterial molecules in broiler production in Morocco.

    Science.gov (United States)

    Rahmatallah, Naoufal; El Rhaffouli, Hicham; Lahlou Amine, Idriss; Sekhsokh, Yassine; Fassi Fihri, Ouafaa; El Houadfi, Mohammed

    2018-05-01

    Monitoring the use of antibacterial agents in food-producing animals is crucial in order to reduce antimicrobial resistance, selection and dissemination of resistant bacterial strains, and drug residues in the animal food products. The broiler production sector is considered a great consumer of antibacterials and incriminated in the rise of antimicrobial resistance level in zoonotic bacterial pathogens such as Escherichia coli, Salmonella and Campylobacter. Following recommendations from the OIE and WHO, a survey was conducted about the use and consumption of several antibacterial agents in Moroccan broiler flocks. More than 5 million broilers were randomly surveyed at the prescriber level, that is, via the veterinary clinics involved in their health management. The results showed that 93% of the flocks received at least one antibacterial treatment of minimum 3 days duration. Enrofloxacin, colistin and trimethoprim/sulphonamides were the most used antibacterials followed by oxytetracycline, florfenicol and amoxicillin. Oxytetracycline, enrofloxacin and colistin were overdosed in most of the administration, while amoxicillin and the combination of trimethoprim/sulphonamides were under-dosed. The total amount of antibacterial consumed in the survey was 63.48 mg/kg and the Animal Level of Exposure to Antimicrobials (ALEA) was 94.45%. The reasons for this frequent use were related mainly to the poor quality of broiler production management. Chicks and animal feed provided to producers were of variable quality. Management of rearing stock density was often poor and biosecurity inadequate, and broilers were challenged by a high prevalence of infectious diseases. © 2018 The Authors. Veterinary Medicine and Science Published by John Wiley & Sons Ltd.

  11. Sequencing Cyclic Peptides by Multistage Mass Spectrometry

    Science.gov (United States)

    Mohimani, Hosein; Yang, Yu-Liang; Liu, Wei-Ting; Hsieh, Pei-Wen; Dorrestein, Pieter C.; Pevzner, Pavel A.

    2012-01-01

    Some of the most effective antibiotics (e.g., Vancomycin and Daptomycin) are cyclic peptides produced by non-ribosomal biosynthetic pathways. While hundreds of biomedically important cyclic peptides have been sequenced, the computational techniques for sequencing cyclic peptides are still in their infancy. Previous methods for sequencing peptide antibiotics and other cyclic peptides are based on Nuclear Magnetic Resonance spectroscopy, and require large amount (miligrams) of purified materials that, for most compounds, are not possible to obtain. Recently, development of mass spectrometry based methods has provided some hope for accurate sequencing of cyclic peptides using picograms of materials. In this paper we develop a method for sequencing of cyclic peptides by multistage mass spectrometry, and show its advantages over single stage mass spectrometry. The method is tested on known and new cyclic peptides from Bacillus brevis, Dianthus superbus and Streptomyces griseus, as well as a new family of cyclic peptides produced by marine bacteria. PMID:21751357

  12. Cyclic peptide therapeutics: past, present and future.

    Science.gov (United States)

    Zorzi, Alessandro; Deyle, Kaycie; Heinis, Christian

    2017-06-01

    Cyclic peptides combine several favorable properties such as good binding affinity, target selectivity and low toxicity that make them an attractive modality for the development of therapeutics. Over 40 cyclic peptide drugs are currently in clinical use and around one new cyclic peptide drug enters the market every year on average. The vast majority of clinically approved cyclic peptides are derived from natural products, such as antimicrobials or human peptide hormones. New powerful techniques based on rational design and in vitro evolution have enabled the de novo development of cyclic peptide ligands to targets for which nature does not offer solutions. A look at the cyclic peptides currently under clinical evaluation shows that several have been developed using such techniques. This new source for cyclic peptide ligands introduces a freshness to the field, and it is likely that de novo developed cyclic peptides will be in clinical use in the near future. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Reverse engineering truncations of an antimicrobial peptide dimer to identify the origins of potency and broad spectrum of action.

    Science.gov (United States)

    Anantharaman, Aparna; Sahal, Dinkar

    2010-08-26

    Antimicrobial peptides hold promise against antibiotic resistant pathogens. Here, to find the physicochemical origins of potency and broad spectrum antimicrobial action, we report the structure-activity relationships of synthetic intermediates (peptides A-D) of a potent lysine branched dimeric antibacterial peptide DeltaFd. Our studies show that a tetracationic character in a weak helical fold (peptide C) elicits potent but narrow spectrum antimicrobial activity [Minimum inhibitory concentrations (MICs) E. coli 10 microM, S. aureus>100 microM]. In contrast, a hexacationic character in a strong, amphipathic helix (DeltaFd) confers potent and broad spectrum action [MICs E. coli 2.5 microM, S. aureus 5 microM]. While DeltaFd caused rapid and potent permeabilization of the E. coli membranes, the less helical intermediates (peptides A-D) showed slow and weak to no responses. Two seminal findings that may aid future drug design are (a) at identical helicity, increasing charge enhanced outer membrane permeabilization, and (b) at identical charge, increasing helicity stimulated rate of outer membrane permeabilization and kill kinetics besides enhancing potency leading to broad spectrum action.

  14. Emerging trends in the discovery of natural product antibacterials

    DEFF Research Database (Denmark)

    Bologa, Cristian G; Ursu, Oleg; Oprea, Tudor

    2013-01-01

    This article highlights current trends and advances in exploiting natural sources for the deployment of novel and potent anti-infective countermeasures. The key challenge is to therapeutically target bacterial pathogens that exhibit a variety of puzzling and evolutionarily complex resistance...... 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....

  15. Synthesis, Antibacterial and Antifungal Activities of s Derivatives

    Directory of Open Access Journals (Sweden)

    B. B. Baldaniya

    2009-01-01

    Full Text Available Several Nʹ-{4-[(3-chloro-4-fluorophenyl amino]-6-[(-aryl amino] -1, 3, 5-triazin-2-yl} isonicotinohydrazides (6a-r and N2-(Aryl-N4, N6-dipyrimidin-2-yl-1,3,5-triazine-2,4,6-triamines (4a-o were prepared. All newly synthesized compounds have been tested for their antibacterial activity against gram (+ve and gram (-ve bacteria and also on different strains of fungi. Introduction of -OH, -OCH3, -NO2, -Cl and -Br groups to the heterocyclic frame work enhanced antibacterial and antifungal activities.

  16. Optimizing the extraction of antibacterial compounds from pineapple leaf fiber

    Directory of Open Access Journals (Sweden)

    Zhuang Zhikai

    2016-01-01

    Full Text Available Five different solvents (petroleum ether, chloroform, ethyl acetate, acetone, and distilled water were used to extract antibacterial compounds from pineapple leaf fiber. Compounds extracted using acetone showed the greatest antibacterial effect against Escherichia coli, measured by inhibition zone diameter. Three extraction parameters including temperature, time and solid-liquid ratio were optimized through orthogonal experiment based on single factor investigations for achieving maximum active substance extraction rate and bacteriostatic effect. Results showed that using acetone, the optimum extraction conditions for temperature, time and solid-liquid ratio were 45°C, 8 h, and 1:40 (g/ml, respectively.

  17. Synthesis, construction, and evaluation of self-assembled nano-bacitracin A as an efficient antibacterial agent in vitro and in vivo

    Directory of Open Access Journals (Sweden)

    Hong W

    2017-06-01

    greater antibacterial activities. In addition, Nano-BA5K was found to be effective in vivo, and it served as an anti-infective agent for wound healing. Collectively, this study provides a cost-effective means of developing self-assembling nano-polypeptide antibiotic candidates with a broader antibacterial spectrum and a lower toxicity than commercially available peptide antibiotics, owing to their modification with biodegradable copolymers. Keywords: bacitracin A, poly (D,L-lactide-co-glycolide, nano-BAs, broader antibacterial spectrum, wound healing

  18. Peptide Vaccine: Progress and Challenges

    Directory of Open Access Journals (Sweden)

    Weidang Li

    2014-07-01

    Full Text Available Conventional vaccine strategies have been highly efficacious for several decades in reducing mortality and morbidity due to infectious diseases. The bane of conventional vaccines, such as those that include whole organisms or large proteins, appear to be the inclusion of unnecessary antigenic load that, not only contributes little to the protective immune response, but complicates the situation by inducing allergenic and/or reactogenic responses. Peptide vaccines are an attractive alternative strategy that relies on usage of short peptide fragments to engineer the induction of highly targeted immune responses, consequently avoiding allergenic and/or reactogenic sequences. Conversely, peptide vaccines used in isolation are often weakly immunogenic and require particulate carriers for delivery and adjuvanting. In this article, we discuss the specific advantages and considerations in targeted induction of immune responses by peptide vaccines and progresses in the development of such vaccines against various diseases. Additionally, we also discuss the development of particulate carrier strategies and the inherent challenges with regard to safety when combining such technologies with peptide vaccines.

  19. Double-Stranded Peptide Nucleic Acids

    DEFF Research Database (Denmark)

    2001-01-01

    A novel class of compounds, known as peptide nucleic acids, form double-stranded structures with one another and with ssDNA. The peptide nucleic acids generally comprise ligands such as naturally occurring DNA bases attached to a peptide backbone through a suitable linker.......A novel class of compounds, known as peptide nucleic acids, form double-stranded structures with one another and with ssDNA. The peptide nucleic acids generally comprise ligands such as naturally occurring DNA bases attached to a peptide backbone through a suitable linker....

  20. Comparison of the antibacterial activity and synergistic activity towards antibiotics of different mammalian sera.

    Science.gov (United States)

    Miglioli, P A; Pea, F; Mazzo, M; Berti, T

    1993-02-01

    The antibacterial activity against Escherichia coli ATCC 10798 and Staphylococcus aureus Mag 90 of normal sera from nine species of mammals was investigated by Avantage (Abbott). Human and rat sera showed the highest antibacterial activity against E. coli ATCC 10798, while all investigated sera did not exhibit, till the maximum concentration tested (20%), spontaneous antibacterial activity against S. aureus Mag 90. Heat inactivated sera (56 degrees C for 30 min) of all investigated species lost their antibacterial activity, but maintained their synergistic effect with sub-MICs of some antibacterial drugs, principally against E. coli ATCC 10798.

  1. 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....... To better understand the underlying mechanisms of antibody-antigen interaction here we present a pipeline developed by us to structurally classify immunoglobulin antigen binding sites and to infer key sequence residues and other variables that have a prominent role in each structural class....

  2. Self-assembling peptide semiconductors

    Science.gov (United States)

    Tao, Kai; Makam, Pandeeswar; Aizen, Ruth; Gazit, Ehud

    2017-01-01

    Semiconductors are central to the modern electronics and optics industries. Conventional semiconductive materials bear inherent limitations, especially in emerging fields such as interfacing with biological systems and bottom-up fabrication. A promising candidate for bioinspired and durable nanoscale semiconductors is the family of self-assembled nanostructures comprising short peptides. The highly ordered and directional intermolecular π-π interactions and hydrogen-bonding network allow the formation of quantum confined structures within the peptide self-assemblies, thus decreasing the band gaps of the superstructures into semiconductor regions. As a result of the diverse architectures and ease of modification of peptide self-assemblies, their semiconductivity can be readily tuned, doped, and functionalized. Therefore, this family of electroactive supramolecular materials may bridge the gap between the inorganic semiconductor world and biological systems. PMID:29146781

  3. Antimicrobial Peptide Production and Purification.

    Science.gov (United States)

    Suda, Srinivas; Field, Des; Barron, Niall

    2017-01-01

    Antimicrobial peptides (AMPs) are natural defense compounds which are synthesized as ribosomal gene-encoded pre-peptides and produced by all living organisms. AMPs are small peptides, usually cationic and typically have hydrophobic residues which interact with cell membranes and have either a narrow or broad spectrum of biological activity. AMPs are isolated from the natural host or heterologously expressed in other hosts such as Escherichia coli. The proto-typical lantibiotic Nisin is a widely used AMP that is produced by the food-grade organism Lactococcus lactis. Although AMP production and purification procedures require optimization for individual AMPs, the Nisin production and purification protocol outlined in this chapter can be easily applied with minor modifications for the production and purification of other lantibiotics or AMPs. While Nisin is produced and secreted into the supernatant, steps to recover Nisin from both cell-free supernatant and cell pellet are outlined in detail.

  4. Delivery systems for antimicrobial peptides

    DEFF Research Database (Denmark)

    Nordström, Randi; Malmsten, Martin

    2017-01-01

    Due to rapidly increasing resistance development against conventional antibiotics, finding novel approaches for the treatment of infections has emerged as a key health issue. Antimicrobial peptides (AMPs) have attracted interest in this context, and there is by now a considerable literature...... on the identification such peptides, as well as on their optimization to reach potent antimicrobial and anti-inflammatory effects at simultaneously low toxicity against human cells. In comparison, delivery systems for antimicrobial peptides have attracted considerably less interest. However, such delivery systems...... are likely to play a key role in the development of potent and safe AMP-based therapeutics, e.g., through reducing chemical or biological degradation of AMPs either in the formulation or after administration, by reducing adverse side-effects, by controlling AMP release rate, by promoting biofilm penetration...

  5. Radioactive labelling of peptidic hormones

    International Nuclear Information System (INIS)

    Fromageot, P.; Pradelles, P.; Morgat, J.L.; Levine, H.

    1976-01-01

    The labelling of peptidic hormones requires stability, specificity and sensitivity of the label. Introduction of a radioactive atome is one way to satisfy these criteria. Several processes have been described to prepare radioactive TRF: synthesis of the peptide with labelled aminoacids or introduction of the label into the hormone. In that approach, tritium can be substituted in the imidazole ring, via precursors activating the proper carbon. Monoiodo TRF leads essentially to tritium labelling of the 5 positions whereas monoazo TRF allows the preparation of 3 H TRF labelled in the 2 positions. Di-substituted TRF leads to labelling into the 2 and 5 carbons. Labelled analogs of TRF can be prepared with labelled iodine; further developments of peptide labelling, will be presented. In particular, the homolytic scission of the C-iodine, bond by photochemical activation. The nascent carbon radical can be stabilized by a tritiated scavenger. This approach eliminates the use of heavy metal catalysts

  6. The Pig PeptideAtlas

    DEFF Research Database (Denmark)

    Hesselager, Marianne Overgaard; Codrea, Marius; Sun, Zhi

    2016-01-01

    Biological research of Sus scrofa, the domestic pig, is of immediate relevance for food production sciences, and for developing pig as a model organism for human biomedical research. Publicly available data repositories play a fundamental role for all biological sciences, and protein data...... repositories are in particular essential for the successful development of new proteomic methods. Cumulative proteome data repositories, including the PeptideAtlas, provide the means for targeted proteomics, system-wide observations, and cross-species observational studies, but pigs have so far been...... 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...

  7. Novel Formulations for Antimicrobial Peptides

    Directory of Open Access Journals (Sweden)

    Ana Maria Carmona-Ribeiro

    2014-10-01

    Full Text Available Peptides in general hold much promise as a major ingredient in novel supramolecular assemblies. They may become essential in vaccine design, antimicrobial chemotherapy, cancer immunotherapy, food preservation, organs transplants, design of novel materials for dentistry, formulations against diabetes and other important strategical applications. This review discusses how novel formulations may improve the therapeutic index of antimicrobial peptides by protecting their activity and improving their bioavailability. The diversity of novel formulations using lipids, liposomes, nanoparticles, polymers, micelles, etc., within the limits of nanotechnology may also provide novel applications going beyond antimicrobial chemotherapy.

  8. Peptides and the new endocrinology

    Science.gov (United States)

    Schwyzer, Robert

    1982-01-01

    The discovery of regulatory peptides common to the nervous and the endocrine systems (brain, gut, and skin) has brought about a revolution in our concepts of endocrinology and neurology. We are beginning to understand some of the complex interrelationships between soma and psyche that might, someday, be important for an integrated treatment of diseases. Examples of the actions of certain peptides in the periphery and in the central nervous system are given, and their biosynthesis and molecular anatomy as carriers for information are discussed.

  9. Novel Formulations for Antimicrobial Peptides

    Science.gov (United States)

    Carmona-Ribeiro, Ana Maria; Carrasco, Letícia Dias de Melo

    2014-01-01

    Peptides in general hold much promise as a major ingredient in novel supramolecular assemblies. They may become essential in vaccine design, antimicrobial chemotherapy, cancer immunotherapy, food preservation, organs transplants, design of novel materials for dentistry, formulations against diabetes and other important strategical applications. This review discusses how novel formulations may improve the therapeutic index of antimicrobial peptides by protecting their activity and improving their bioavailability. The diversity of novel formulations using lipids, liposomes, nanoparticles, polymers, micelles, etc., within the limits of nanotechnology may also provide novel applications going beyond antimicrobial chemotherapy. PMID:25302615

  10. Isolation and Preliminary Characterization of Proteinaceous Toxins with Insecticidal and Antibacterial Activities from Black Widow Spider (L. tredecimguttatus Eggs

    Directory of Open Access Journals (Sweden)

    Qian Lei

    2015-03-01

    Full Text Available The eggs of black widow spider (L. tredecimguttatus have been demonstrated to be rich in toxic proteinaceous components. The study on such active components is of theoretical and practical importance. In the present work, using a combination of multiple biochemical and biological strategies, we isolated and characterized the proteinaceous components from the aqueous extract of the black widow spider eggs. After gel filtration of the egg extract, the resulting main protein and peptide peaks were further fractionated by ion exchange chromatography and reversed-phase high performance liquid chromatography. Two proteinaceous components, named latroeggtoxin-III and latroeggtoxin-IV, respectively, were purified to homogeneity. Latroeggtoxin-III was demonstrated to have a molecular weight of about 36 kDa. Activity analysis indicated that latroeggtoxin-III exhibited neurotoxicity against cockroaches but had no obvious effect on mice, suggesting that it is an insect-specific toxin. Latroeggtoxin-IV, with a molecular weight of 3.6 kDa, was shown to be a broad-spectrum antibacterial peptide, showing inhibitory activity against all five species of bacteria tested, with the highest activity against Staphylococcus aureus. Finally, the implications of the proteinaceous toxins in egg protection and their potential applications were analyzed and discussed.

  11. Dendroaspis natriuretic peptide binds to the natriuretic peptide clearance receptor

    International Nuclear Information System (INIS)

    Johns, Douglas G.; Ao, Zhaohui; Heidrich, Bradley J.; Hunsberger, Gerald E.; Graham, Taylor; Payne, Lisa; Elshourbagy, Nabil; Lu, Quinn; Aiyar, Nambi; Douglas, Stephen A.

    2007-01-01

    Dendroaspis natriuretic peptide (DNP) is a newly-described natriuretic peptide which lowers blood pressure via vasodilation. The natriuretic peptide clearance receptor (NPR-C) removes natriuretic peptides from the circulation, but whether DNP interacts with human NPR-C directly is unknown. The purpose of this study was to test the hypothesis that DNP binds to NPR-C. ANP, BNP, CNP, and the NPR-C ligands AP-811 and cANP(4-23) displaced [ 125 I]-ANP from NPR-C with pM-to-nM K i values. DNP displaced [ 125 I]-ANP from NPR-C with nM potency, which represents the first direct demonstration of binding of DNP to human NPR-C. DNP showed high pM affinity for the GC-A receptor and no affinity for GC-B (K i > 1000 nM). DNP was nearly 10-fold more potent than ANP at stimulating cGMP production in GC-A expressing cells. Blockade of NPR-C might represent a novel therapeutic approach in augmenting the known beneficial actions of DNP in cardiovascular diseases such as hypertension and heart failure

  12. Recent advances in engineering topography mediated antibacterial surfaces

    Science.gov (United States)

    Hasan, Jafar; Chatterjee, Kaushik

    2015-09-01

    The tendency of bacterial cells to adhere and colonize a material surface leading to biofilm formation is a fundamental challenge underlying many different applications including microbial infections associated with biomedical devices and products. Although, bacterial attachment to surfaces has been extensively studied in the past, the effect of surface topography on bacteria-material interactions has received little attention until more recently. We review the recent progress in surface topography based approaches for engineering antibacterial surfaces. Biomimicry of antibacterial surfaces in nature is a popular strategy. Whereas earlier endeavors in the field aimed at minimizing cell attachment, more recent efforts have focused on developing bactericidal surfaces. However, not all such topography mediated bactericidal surfaces are necessarily cytocompatible thus underscoring the need for continued efforts for research in this area for developing antibacterial and yet cytocompatible surfaces for use in implantable biomedical applications. This mini-review provides a brief overview of the current strategies and challenges in the emerging field of topography mediated antibacterial surfaces.

  13. In Vitro antibacterial activity of rumex nervosus, plantago lanceolata ...

    African Journals Online (AJOL)

    The finding indicated that Rumex nervosus showed have the highest zone of inhibition (20mm) against the genus Salmonella followed by Plantago lanceolata with the zone of inhibition (16mm) against L. monocytogenes. On the other hand, Lepidium sativum and Solanum incanum did not have any antibacterial activity ...

  14. Assessment of antibacterial activity of three plants used in Pakistan ...

    African Journals Online (AJOL)

    The in vitro antimicrobial activity of Justicia adhatoda, Glycyrrhiza glabra and Hyssopus officinalis extracts were studied against selected bacteria by using agar well diffusion assay. Methanol, ethanol, chloroform, diethyl-ether and aqueous extracts were tested in crude form for antibacterial activity against Bacillus subtillus, ...

  15. Antibacterial effects of zinc oxide nanoparticles on Escherichia coli ...

    African Journals Online (AJOL)

    To study the antibacterial mechanisms, atomic force microscopy (AFM) and scanning electron microscopy (SEM) were used to observe morphological changes of E. coli K88 treated with 0.8 μg/ml zinc oxide nanoparticles. The results reveal that zinc oxide nanoparticles could damage cell membranes, lead to leakage of ...

  16. Antibacterial and antioxidant activities of Vaccinium corymbosum L. leaf extract

    Directory of Open Access Journals (Sweden)

    Mehnaz Pervin

    2013-12-01

    Full Text Available Objective: To investigate antibacterial and antioxidant activity of the leaf extract of tropical medicinal herb and food plant Vaccinium corymbosum L. (V. corymbosum . Methods: Free radical scavenging activity on DPPH, ABTS, and nitrites were used to analyse phenolic and flavonoid contents of leaf extract. Other focuses included the determination of antioxidant enzymatic activity (SOD, CAT and GPx, metal chelating activity, reduction power, lipid peroxidation inhibition and the prevention of oxidative DNA damage. Antibacterial activity was determined by using disc diffusion method against seven strains of bacteria. Results: Results found that V. corymbosum leaf extract had significant antibacterial activity. The tested extract displayed the highest activity (about 23.18 mm inhibition zone against Salmonella typhymurium and the lowest antibacterial activity was observed against Enterococcus faecalis (about 14.08 mm inhibition zone at 10 mg/ disc. The IC 50 values for DPPH, ABTS and radical scavenging activity were 0.120, 0.049 and 1.160 mg/mL, respectively. V. corymbosum leaf extract also showed dose dependent reduction power, lipid peroxidation, DNA damage prevention and significant antioxidant enzymatic activity. Conclusions: These findings demonstrate that leaf extract of V. corymbosum could be used as an alternative therapy for antibiotic-resistant bacteria and help prevent various free radical related diseases.

  17. Antibacterial and antioxidant activities of Vaccinium corymbosum L. leaf extract

    Science.gov (United States)

    Pervin, Mehnaz; Hasnat, Md Abul; Lim, Beong Ou

    2013-01-01

    Objective To investigate antibacterial and antioxidant activity of the leaf extract of tropical medicinal herb and food plant Vaccinium corymbosum L. (V. corymbosum). Methods Free radical scavenging activity on DPPH, ABTS, and nitrites were used to analyse phenoic and flavonoid contents of leaf extract. Other focuses included the determination of antioxidant enzymatic activity (SOD, CAT and GPx), metal chelating activity, reduction power, lipid peroxidation inhibition and the prevention of oxidative DNA damage. Antibacterial activity was determined by using disc diffusion for seven strains of bacteria. Results Results found that V. corymbosum leaf extract had significant antibacterial activity. The tested extract displayed the highest activity (about 23.18 mm inhibition zone) against Salmonella typhymurium and the lowest antibacterial activity was observed against Enterococcus faecalis (about 14.08 mm inhibition zone) at 10 mg/ disc. The IC50 values for DPPH, ABTS and radical scavenging activity were 0.120, 0.049 and 1.160 mg/mL, respectively. V. corymbosum leaf extract also showed dose dependent reduction power, lipid peroxidation, DNA damage prevention and significant antioxidant enzymatic activity. Conclusions These findings demonstrate that leaf extract of V. corymbosum could be used as an alternative therapy for antibiotic-resistant bacteria and help prevent various free radical related diseases.

  18. Antibacterial, antioxidant and cytotoxic activities of extracts from the ...

    African Journals Online (AJOL)

    Unicellular green algal strains, identified as Cosmarium (Chlorophyta), were isolated from Ain-Echeffa hot spring in north Tunisia. Different extracts (methanol, hexane, acetone, acetone: methanol and water) obtained from both biomass and extracellular polysaccharides (EPS) were evaluated for their antibacterial, ...

  19. Antibacterial activity of Eucalpytus citriodora Hk. oil on few clinically ...

    African Journals Online (AJOL)

    SERVER

    2008-01-04

    Jan 4, 2008 ... The antibacterial activity of Eucalyptus citriodora oil was evaluated. The volatile oil was extracted by steam distillation method. The tested bacterial strains were Escherichia coli ATCC 25922,. Staphylococcus aureus, Proteus mirabilis NCIM2241, Pseudomonas aeruginosa ATCC27853, Proteus vulgaris ...

  20. Antioxidant, Antibacterial and Cell Toxicity Effects of Polyphenols

    African Journals Online (AJOL)

    Z. Ghouila, S. Laurent, S. Boutry, L. Vander Elst, F. Nateche, R. N. Muller, A. Baaliouamer

    2017-01-01

    Jan 1, 2017 ... At 100 μg/mL, GSE induced a moderate toxicity of the order of ... the many phytochemical compounds consumed in our diet, polyphenols are the most ... action of grape seed extract in many health related areas due to its antioxidant effect [11]. In ...... antibacterial activities of southern Serbian red wines.