White shrimp (Litopenaeus vannamei) recombinant lysozyme has antibacterial activity against Gram negative bacteria: Vibrio alginolyticus, Vibrio parahemolyticus and Vibrio cholerae.

Science.gov (United States)

de-la-Re-Vega, Enrique; García-Galaz, Alfonso; Díaz-Cinco, Martha E; Sotelo-Mundo, Rogerio R

2006-03-01

C-type lysozyme has been described as an antibacterial component of the shrimp innate defence system. We determined quantitatively the antibacterial activity of white shrimp (Litopenaeus vannamei) recombinant lysozyme against three Gram negative bacteria: Vibrio alginolyticus, Vibrio parahemolyticus and Vibrio cholerae, using a turbidimetric assay with live bacteria and differential bacterial viable count after interaction with the protein. In conclusion, the antibacterial activity of recombinant shrimp lysozyme against Vibrio sp. is at least equal to the values against the Gram positive M. luteus and more active against the shrimp pathogens V. alginolyticus and V. parahemolyticus.

Expression and Activity of Lysozyme in Apis Mellifera Carnica Brood Infested with Varroa Destructor

OpenAIRE

Zaobidna Ewa A.; Żółtowska Krystyna; Łopieńska-Biernat Elżbieta

2017-01-01

Varroa destructor is a parasitic mite that attacks the honey bee, and previous studies have suggested that parasitosis caused by this mite is accompanied by immunosuppresion in the host. In this study, the effect of mite infestation on the expression of the lysozyme-1 (lys-1) gene and lysozyme activity in Apis mellifera carnica was determined. The experiment was carried out on the five developmental stages of honey bee workers and drones. Developmental and gender-related differences in gene e...

Resonance scattering spectra of micrococcus lysodeikticus and its application to assay of lysozyme activity.

Science.gov (United States)

Jiang, Zhi-Liang; Huang, Guo-Xia

2007-02-01

Several methods, including turbidimetric and colorimetric methods, have been reported for the detection of lysozyme activity. However, there is no report about the resonance scattering spectral (RSS) assay, which is based on the catalytic effect of lysozyme on the hydrolysis of micrococcus lysodeikticus (ML) and its resonance scattering effect. ML has 5 resonance scattering peaks at 360 400, 420, 470, and 520 nm with the strongest one at 470 nm. The concentration of ML in the range of 2.0x10(6)-9.3x10(8) cells/ml is proportional to the RS intensity at 470 nm (I(470 nm)). A new catalytic RSS method has been proposed for 0.24-40.0 U/ml (or 0.012-2.0 mug/ml) lysozyme activity, with a detection limit (3sigma) of 0.014 U/ml (or 0.0007 microg/ml). Saliva samples were assayed by this method, and it is in agreement with the results of turbidimetric method. The slope, intercept and the correlation coefficient of the regression analysis of the 2 assays were 0.9665, -87.50, and 0.9973, respectively. The assay has high sensitivity and simplicity.

Bio-templated CdSe quantum dots green synthesis in the functional protein, lysozyme, and biological activity investigation

International Nuclear Information System (INIS)

Wang, Qisui; Li, Song; Liu, Peng; Min, Xinmin

2012-01-01

Bifunctional fluorescence (CdSe Quantum Dots) – protein (Lysozyme) nanocomposites were synthesized at room temperature by a protein-directed, solution-phase, green-synthetic method. Fluorescence (FL) and absorption spectra showed that CdSe QDs were prepared successfully with Lyz. The average particle size and crystalline structure of QDs were investigated by high-resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD), respectively. With attenuated total reflection-fourier transform infrared (ATR-FTIR) spectra and thermogravimetric (TG) analysis, it was confirmed that there is interaction between QDs and amide I, amide II groups in Lyz. FL polarization was measured and FL imaging was done to monitor whether QDs could be responsible for possible changes in the conformation and activity of Lyz. Interestingly, the results showed Lyz still retain the biological activity after formation of QDs, but the secondary structure of the Lyz was changed. And the advantage of this synthesis method is producing excellent fluorescent QDs with specifically biological function. -- Highlights: ► Lysozyme-directed green synthesis of CdSe quantum dots. ► Lysozyme still retain the biological activity after formation of CdSe. ► The method is the production of fluorescent QDs with highly specific and functions.

THE PRIMARY STRUCTURE OF HEVAMINE, AN ENZYME WITH LYSOZYME CHITINASE ACTIVITY FROM HEVEA-BRASILIENSIS LATEX

NARCIS (Netherlands)

JEKEL, PA; HARTMANN, JBH; BEINTEMA, JJ

1991-01-01

The primary structure of hevamine, an enzyme with lysozyme/chitinase activity from Hevea brasiliensis latex, has been determined predominantly with conventional non-automatic methods. The positions of three disulfide bridges have been determined. The sequence has about 60% identity with that of a

Assessment of antimicrobial activity of c-type lysozyme from Indian shrimp Fenneropenaeus indicus

Directory of Open Access Journals (Sweden)

Viswanathan Karthik

2014-10-01

Full Text Available Objective: To assess the multitudinal antimicrobial effects of recombinant lysozyme from Fenneropenaeus indicus (rFi-Lyz in comparison with commercially available recombinant hen egg white lysozyme (rHEWL. Methods: Antimicrobial activity of the recombinant rFi-Lyz using several Gram positive, Gram negative bacteria and fungi in comparison with rHEWL has been evaluated. rFi-Lyz was expressed and purified using Ni2+ affinity chromatography. The effect of rFi-Lyz in the growth of yeast Candida krusei, plant molds Rhizoctonia solani and Fusarium solani was assessed by well diffusion assay in petri plates with potato dextrose agar. Results: rFi-Lyz exhibited high inhibitory activity on Gram positive bacteria such as Staphylococcus aureus and Bacillus subtilis. Among various Gram negative bacteria tested Klebsiella pneumoniae exhibited the highest inhibition followed by Pseudomonas aeruginosa and Shigella dysenteriae. rFi-Lyz also exhibited significant inhibition on two marine pathogens Aeromonas veronii and Vibrio alginolyticus. Among the various fungal strains tested, rFi-Lyz inhibited the growth of budding yeast Candida krusei significantly. Further the growth of two other plants fungus Rhizoctonia solani and Fusarium oxysporum were retarded by rFi-Lyz in the plate inhibition assay. Conclusions: rFi-Lyz exhibits a broad spectrum of antimicrobial activity like a natural antibiotic on various pathogenic bacteria and fungal strains.

MUCOADHESIVE GEL WITH IMMOBILIZED LYSOZYME: PREPARATION AND PROPERTIES

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Dekina S. S.

2015-08-01

Full Text Available The study of non-covalent immobilized lysozyme, as well as physico-chemical and biochemical properties of obtained mucoadhesive gel was the aim of the research. Lysozyme activity was determined by bacteriolytic method (Micrococcus lysodeikticus cells acetone powder was a substrate. Lysozyme immobilization was conducted by the method of entrapment in gel. Enzyme carrier interaction was studied by viscometric, spectrophotometric and spectrofluorimetric methods. Mucoadhesive gel with immobilized lysozyme, possessing antiinflammatory and antimicrobial activities, was prepared. Due to immobilization, protein-polymer complex with the original enzymatic activity was formed. The product is characterized by high mucoadhesive properties, quantitative retaining of protein and bacteriolytic activity, prolonged release of the enzyme, improved biochemical characteristics (extended pH-activity profile, stability in acidic medium and during storage for 2 years, and it is perspective for further studies. The proposed method for lysozyme immobilization in the carboxymethyl cellulose sodium salt gel allows to obtain a stable, highly efficient product, with high adhesive properties for attachment to the mucous membranes, that is promising for use in biomedicine.

Influence of lysozyme complexation with purified Aldrich humic acid on lysozyme activity

NARCIS (Netherlands)

Li, Y.; Tan, W.F.; Wang, M.X.; Liu, F.; Weng, L.P.; Norde, W.; Koopal, L.K.

2012-01-01

Humic acid is an important component of dissolved organic matter and in two previous papers it has been shown that purified Aldrich humic acid (PAHA) forms strong complexes with the oppositely charged protein lysozyme (LSZ). The complexation and aggregation of enzymes with humic acids may lead to

Influence of polymers on lysozyme molecules association

Directory of Open Access Journals (Sweden)

Gromovoy T. Yu

2011-12-01

Full Text Available Aim. Study of lysozyme molecules behaviour at immobilization in gelatin and carboxymethyl cellulose sodium salt solutions by matrix-assisted laser desorption/ionization (MALDI. Methods. Determination of the activity of lysozyme, both free and entrapped in gelatin and carboxymethyl cellulose sodium salt (Na-CMC solutions, was conducted by bacteriolytic method. The enzyme interaction with polymers was confirmed by viscometry and mass-spectrometry methods. Results. The occurrence of lysozyme associates in aqueous solution in monomeric and oligomeric forms was shown. A non-valent interaction of the enzyme with solutions of polymers results in the dissociation of oligomeric associates into subunits, which depends on the support nature and mass ratio of lysozyme to polymer. The quantitative retention of immobilized lysozyme hydrolytic activity was established, which favours obtaining mucoadhesive film forms with bacteriolytic action. Conclusions. The lysozyme immobilization by non-valent interactions in gelatin solution and Na-CMC solutions causes dissociation of the enzyme oligomeric structures; a stronger lysozyme coupling with NaCMC was noted.

Antimicrobial activity of some potential active compounds against ...

African Journals Online (AJOL)

Antimicrobial activities of six potential active compounds (acetic acid, chitosan, catechin, gallic acid, lysozyme, and nisin) at the concentration of 500 g/ml against the growth of Escherichia coli, Staphylococcus aureus, Listeria innocua, and Saccharomyces cerevisiae were determined. Lysozyme showed the highest ...

The active site of hen egg-white lysozyme: flexibility and chemical bonding

Energy Technology Data Exchange (ETDEWEB)

Held, Jeanette, E-mail: jeanette.netzel@uni-bayreuth.de; Smaalen, Sander van [University of Bayreuth, D-95440 Bayreuth (Germany)

2014-04-01

Chemical bonding at the active site of lysozyme is analyzed on the basis of a multipole model employing transferable multipole parameters from a database. Large B factors at low temperatures reflect frozen-in disorder, but therefore prevent a meaningful free refinement of multipole parameters. Chemical bonding at the active site of hen egg-white lysozyme (HEWL) is analyzed on the basis of Bader’s quantum theory of atoms in molecules [QTAIM; Bader (1994 ▶), Atoms in Molecules: A Quantum Theory. Oxford University Press] applied to electron-density maps derived from a multipole model. The observation is made that the atomic displacement parameters (ADPs) of HEWL at a temperature of 100 K are larger than ADPs in crystals of small biological molecules at 298 K. This feature shows that the ADPs in the cold crystals of HEWL reflect frozen-in disorder rather than thermal vibrations of the atoms. Directly generalizing the results of multipole studies on small-molecule crystals, the important consequence for electron-density analysis of protein crystals is that multipole parameters cannot be independently varied in a meaningful way in structure refinements. Instead, a multipole model for HEWL has been developed by refinement of atomic coordinates and ADPs against the X-ray diffraction data of Wang and coworkers [Wang et al. (2007), Acta Cryst. D63, 1254–1268], while multipole parameters were fixed to the values for transferable multipole parameters from the ELMAM2 database [Domagala et al. (2012), Acta Cryst. A68, 337–351] . Static and dynamic electron densities based on this multipole model are presented. Analysis of their topological properties according to the QTAIM shows that the covalent bonds possess similar properties to the covalent bonds of small molecules. Hydrogen bonds of intermediate strength are identified for the Glu35 and Asp52 residues, which are considered to be essential parts of the active site of HEWL. Furthermore, a series of weak C�

The active site of hen egg-white lysozyme: flexibility and chemical bonding

International Nuclear Information System (INIS)

Held, Jeanette; Smaalen, Sander van

2014-01-01

Chemical bonding at the active site of lysozyme is analyzed on the basis of a multipole model employing transferable multipole parameters from a database. Large B factors at low temperatures reflect frozen-in disorder, but therefore prevent a meaningful free refinement of multipole parameters. Chemical bonding at the active site of hen egg-white lysozyme (HEWL) is analyzed on the basis of Bader’s quantum theory of atoms in molecules [QTAIM; Bader (1994 ▶), Atoms in Molecules: A Quantum Theory. Oxford University Press] applied to electron-density maps derived from a multipole model. The observation is made that the atomic displacement parameters (ADPs) of HEWL at a temperature of 100 K are larger than ADPs in crystals of small biological molecules at 298 K. This feature shows that the ADPs in the cold crystals of HEWL reflect frozen-in disorder rather than thermal vibrations of the atoms. Directly generalizing the results of multipole studies on small-molecule crystals, the important consequence for electron-density analysis of protein crystals is that multipole parameters cannot be independently varied in a meaningful way in structure refinements. Instead, a multipole model for HEWL has been developed by refinement of atomic coordinates and ADPs against the X-ray diffraction data of Wang and coworkers [Wang et al. (2007), Acta Cryst. D63, 1254–1268], while multipole parameters were fixed to the values for transferable multipole parameters from the ELMAM2 database [Domagala et al. (2012), Acta Cryst. A68, 337–351] . Static and dynamic electron densities based on this multipole model are presented. Analysis of their topological properties according to the QTAIM shows that the covalent bonds possess similar properties to the covalent bonds of small molecules. Hydrogen bonds of intermediate strength are identified for the Glu35 and Asp52 residues, which are considered to be essential parts of the active site of HEWL. Furthermore, a series of weak C�

Stability and activity of lysozyme in stoichiometric and non-stoichiometric protic ionic liquid (PIL)-water systems

Science.gov (United States)

Wijaya, Emmy C.; Separovic, Frances; Drummond, Calum J.; Greaves, Tamar L.

2018-05-01

There has been a substantial increase in enzyme applications within the biochemical and pharmaceutical industries, for example, as industrial biocatalysts. However, enzymes have narrow marginal stability which makes them prone to become inactive and/or denature with a slight change in the solvent environment. Typically industrial applications require harsher solvent environments than enzyme native environments, and hence there is a need to understand solvent-protein interactions in order to develop strategies to maintain, or enhance, the enzymatic activity under industrially relevant solvent conditions. Previously we have shown that protic ionic liquids (PILs) with water can have a stabilising effect on lysozyme, with a large variation dependent on which PIL ions are present, and the water concentration [E. C. Wijaya et al., Phys. Chem. Chem. Phys. 18(37), 25926-25936 (2016)]. Here we extend on this work using non-stoichiometric aqueous PIL solvents to investigate, and isolate, the role of pH and ionicity on enzymes. We have used the PILs ethylammonium nitrate (EAN) and ethanolammonium formate (EOAF) since our previous work has identified these as good solvents for lysozyme. Solvent libraries were made from these two PILs with an additional precursor acid or base to modify the acidity/basicity of the neutral stoichiometric PIL, and with water added, to have solutions with 4-17 mol. % of the PIL ions in water. Molar ratios of base:acid were varied between 1:1.05 and 2:1 for EAN and 1:1.25 and 2:1 for EOAF, which enabled from highly basic to highly acidic solutions to be obtained. This was to modify the acidity/basicity of the neutral stoichiometric PILs, without the addition of buffers. The structure and stability of hen egg white lysozyme (HEWL) were explored under these solvent conditions using synchrotron small angle X-ray scattering (SAXS), Fourier transform infrared (FTIR), and activity assays. The radius of gyration and Kratky plots obtained from the SAXS data

Solvent freeze out crystallization of lysozyme from a lysozyme-ovalbumin mixture

Energy Technology Data Exchange (ETDEWEB)

Diaz Borbon, V.; Ulrich, J. [Martin-Luther-Universitaet Halle-Wittenberg, Zentrum fuer Ingenieurwissenschaft, Verfahrenstechnik/TVT, 06099 Halle Saale (Germany)

2012-05-15

Hen egg white lysozyme (HEWL) crystallization conditions from an ovalbumin-lysozyme mixture were found by screening tests and further located in pseudo-phase diagrams. This information was used to set up the initial conditions for the solvent freeze out (SFO) process. The process uses the freezing of ice to create the supersaturation for the proteins to crystallize out of the solution. The crystallization of HEWL (15 mg/mL) out of a lysozyme-ovalbumin mixture (1.7 mg/mL) is carried out by SFO. Under the reported conditions, a crystallization yield of 69 % was obtained. A mean crystal size of 77.8 {mu}m was enhanced in a crystallization time of 15.1 h. The lysozyme nature of the crystals is proven by SDS PAGE and enzymatic activity tests. (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Effects of dissolving microneedle fabrication parameters on the activity of encapsulated lysozyme.

Science.gov (United States)

Fakhraei Lahiji, Shayan; Jang, Yoojung; Ma, Yonghao; Dangol, Manita; Yang, Huisuk; Jang, Mingyu; Jung, Hyungil

2018-05-30

Dissolving microneedle (DMN) is referred to a microscale needle that encapsulates drug(s) within a biodegradable polymer matrix and delivers it into the skin in a minimally invasive manner. Although vast majority of studies have emphasized DMN as an efficient drug delivery system, the activity of DMN-encapsulated proteins or antigens can be significantly affected due to a series of thermal, physical and chemical stress factors during DMN fabrication process and storage period. The objective of this study is to evaluate the effects of DMN fabrication parameters including polymer type, polymer concentration, fabrication and storage temperature, and drying conditions on the activity of the encapsulated therapeutic proteins by employing lysozyme (LYS) as a model protein. Our results indicate that a combination of low temperature fabrication, mild drying condition, specific polymer concentration, and addition of protein stabilizer can maintain the activity of encapsulated LYS up to 99.8 ± 3.8%. Overall, findings of this study highlight the importance of optimizing DMN fabrication parameters and paves way for the commercialization of an efficient delivery system for therapeutics. Copyright © 2018 Elsevier B.V. All rights reserved.

Suppressive effects of lysozyme on polyphosphate-mediated vascular inflammatory responses

Energy Technology Data Exchange (ETDEWEB)

Chung, Jiwoo [College of Pharmacy, CMRI, Research Institute of Pharmaceutical Sciences, BK21 Plus KNU Multi-Omics Based Creative Drug Research Team, Kyungpook National University, Daegu 41566 (Korea, Republic of); Ku, Sae-Kwang [Department of Anatomy and Histology, College of Korean Medicine, Daegu Haany University, Gyeongsan 38610 (Korea, Republic of); Lee, Suyeon [College of Pharmacy, CMRI, Research Institute of Pharmaceutical Sciences, BK21 Plus KNU Multi-Omics Based Creative Drug Research Team, Kyungpook National University, Daegu 41566 (Korea, Republic of); Bae, Jong-Sup, E-mail: baejs@knu.ac.kr [College of Pharmacy, CMRI, Research Institute of Pharmaceutical Sciences, BK21 Plus KNU Multi-Omics Based Creative Drug Research Team, Kyungpook National University, Daegu 41566 (Korea, Republic of)

2016-06-10

Lysozyme, found in relatively high concentration in blood, saliva, tears, and milk, protects us from the ever-present danger of bacterial infection. Previous studies have reported proinflammatory responses of endothelial cells to the release of polyphosphate(PolyP). In this study, we examined the anti-inflammatory responses and mechanisms of lysozyme and its effects on PolyP-induced septic activities in human umbilical vein endothelial cells (HUVECs) and mice. The survival rates, septic biomarker levels, behavior of human neutrophils, and vascular permeability were determined in PolyP-activated HUVECs and mice. Lysozyme suppressed the PolyP-mediated vascular barrier permeability, upregulation of inflammatory biomarkers, adhesion/migration of leukocytes, and activation and/or production of nuclear factor-κB, tumor necrosis factor-α, and interleukin-6. Furthermore, lysozyme demonstrated protective effects on PolyP-mediated lethal death and the levels of the related septic biomarkers. Therefore, these results indicated the therapeutic potential of lysozyme on various systemic inflammatory diseases, such as sepsis or septic shock. -- Highlights: •PolyP is shown to be an important mediator of vascular inflammation. •Lysozyme inhibited PolyP-mediated hyperpermeability. •Lysozyme inhibited PolyP-mediated septic response. •Lysozyme reduced PolyP-induced septic mortality.

Suppressive effects of lysozyme on polyphosphate-mediated vascular inflammatory responses

International Nuclear Information System (INIS)

Chung, Jiwoo; Ku, Sae-Kwang; Lee, Suyeon; Bae, Jong-Sup

2016-01-01

Lysozyme, found in relatively high concentration in blood, saliva, tears, and milk, protects us from the ever-present danger of bacterial infection. Previous studies have reported proinflammatory responses of endothelial cells to the release of polyphosphate(PolyP). In this study, we examined the anti-inflammatory responses and mechanisms of lysozyme and its effects on PolyP-induced septic activities in human umbilical vein endothelial cells (HUVECs) and mice. The survival rates, septic biomarker levels, behavior of human neutrophils, and vascular permeability were determined in PolyP-activated HUVECs and mice. Lysozyme suppressed the PolyP-mediated vascular barrier permeability, upregulation of inflammatory biomarkers, adhesion/migration of leukocytes, and activation and/or production of nuclear factor-κB, tumor necrosis factor-α, and interleukin-6. Furthermore, lysozyme demonstrated protective effects on PolyP-mediated lethal death and the levels of the related septic biomarkers. Therefore, these results indicated the therapeutic potential of lysozyme on various systemic inflammatory diseases, such as sepsis or septic shock. -- Highlights: •PolyP is shown to be an important mediator of vascular inflammation. •Lysozyme inhibited PolyP-mediated hyperpermeability. •Lysozyme inhibited PolyP-mediated septic response. •Lysozyme reduced PolyP-induced septic mortality.

Aptamer-Based Electrochemical Sensing of Lysozyme

Directory of Open Access Journals (Sweden)

Alina Vasilescu

2016-06-01

Full Text Available Protein analysis and quantification are required daily by thousands of laboratories worldwide for activities ranging from protein characterization to clinical diagnostics. Multiple factors have to be considered when selecting the best detection and quantification assay, including the amount of protein available, its concentration, the presence of interfering molecules, as well as costs and rapidity. This is also the case for lysozyme, a 14.3-kDa protein ubiquitously present in many organisms, that has been identified with a variety of functions: antibacterial activity, a biomarker of several serious medical conditions, a potential allergen in foods or a model of amyloid-type protein aggregation. Since the design of the first lysozyme aptamer in 2001, lysozyme became one of the most intensively-investigated biological target analytes for the design of novel biosensing concepts, particularly with regards to electrochemical aptasensors. In this review, we discuss the state of the art of aptamer-based electrochemical sensing of lysozyme, with emphasis on sensing in serum and real samples.

Identification of lysozyme activity from two edible bivalves - Perna viridis (Linnaeus) and Meretrix casta (Chemnitz)

Digital Repository Service at National Institute of Oceanography (India)

Sharma, S.; Tanu; Chatterji, A.

on the column. Fractions of 1 ml each were collected. The absorbance of these fractions was also monitored at 280 nm. The lysozyme activity was checked against Micrococcus luteus. Ion exchange chromatography - The lyophilized active samples (McL2 and PvL2... in the case of M. casta – McL1, McL2 (fr 7), McL3, McL4, McL5 and McL6, and 7 in the case of P. viridis - PvL1, PvL2 (fr 5), PvL3, PvL4, PvL5, PvL6, PvL 7. Fig. 2: Absorbance of Sephadex fractions of M. casta at 280 nm Absorbance at 280 nm Fig. 3...

Shift in aggregation, ROS generation, antioxidative defense, lysozyme and acetylcholinesterase activities in the cells of an Indian freshwater sponge exposed to washing soda (sodium carbonate).

Science.gov (United States)

Mukherjee, Soumalya; Ray, Mitali; Ray, Sajal

2016-09-01

Washing soda, chemically identified as anhydrous sodium carbonate, is a popular cleaning agent among the rural and urban populations of India which often contaminates the freshwater ponds and lakes, the natural habitat of sponge Eunapius carteri. Present investigation deals with estimation of cellular aggregation, generation of ROS and activities of antioxidant enzymes, lysozyme and acetylcholinesterase in the cells of E. carteri under the environmentally realistic concentrations of washing soda. Prolonged treatment of washing soda inhibited the degree of cellular aggregation. Experimental exposure of 8 and 16mg/l of sodium carbonate for 48h elevated the physiological level of reactive oxygen species (ROS) generation in the agranulocytes, semigranulocytes and granulocytes of E. carteri, whereas, treatment of 192h inhibited the ROS generation in three cellular morphotypes. Activities of superoxide dismutase, catalase and glutathione-S-transferase were recorded to be inhibited under prolonged exposure of washing soda. Washing soda mediated inhibition of ROS generation and depletion in the activities of antioxidant enzymes were indicative to an undesirable shift in cytotoxic status and antioxidative defense in E. carteri. Inhibition in the activity of lysozyme under the treatment of sodium carbonate was suggestive to a severe impairment of the innate immunological efficiency of E. carteri distributed in the washing soda contaminated habitat. Washing soda mediated inhibition in the activity of acetylcholinesterase indicated its neurotoxicity in E. carteri. Washing soda, a reported environmental contaminant, affected adversely the immunophysiological status of E. carteri with reference to cellular aggregation, oxidative stress, antioxidative defense, lysozyme and acetylcholinesterase activity. Copyright © 2016 Elsevier Inc. All rights reserved.

Serum lysozyme determinations, April-June 1961

Energy Technology Data Exchange (ETDEWEB)

Finch, S C; Lamphere, J P; Jablon, S

1963-04-18

Serum lysozyme levels were determined on 670 consecutive subjects seen for regularly scheduled clinic examinations of the Adult Health Study in Hiroshima. Serum lysozyme levels were found to vary significantly with the absolute peripheral granulocyte count, age, sex, and month of study. A high level of correlation also was noted between serum lysozyme and diabetes mellitus. This was at least in part attributable to greater average age in patients with diabetes. Suggestive relationship was established between serum lysozyme levels, respiratory diseases, and tuberculosis. These changes are believed to reflect active inflammation with excessive destruction of granulocytes and parenchymal tissues in those patients with the more acute processes. No relationship was found between serum lysozyme and previous exposure to ionizing radiation. These studies indicate that the serum lysozyme level may be useful in the study of the kinetics of leukopoiesis, the aging process, and in the detection of subtle inflammatory processes. 21 references, 5 tables.

Lysozyme-immobilized electrospun PAMA/PVA and PSSA-MA/PVA ion-exchange nanofiber for wound healing.

Science.gov (United States)

Tonglairoum, Prasopchai; Ngawhirunpat, Tanasait; Rojanarata, Theerasak; Opanasopit, Praneet

2014-08-27

Abstract This research was aimed to develop the lysozyme immobilized ion-exchange nanofiber mats for wound healing. To promote the healing process, the PSSA-MA/PVA and PAMA ion-exchange nanofiber mats were fabricated to mimic the extracellular matrix structure using electrospinning process followed by thermally crosslinked. Lysozyme was immobilized on the ion-exchane nanofibers by an adsorption method. The ion-exchange nanofibers were investigated using SEM, FTIR and XRPD. Moreover, the lysozyme-immobilized ion-exchange nanofibers were further investigated for lysozyme content and activity, lysozyme release and wound healing activity. The fiber diameters of the mats were in the nanometer range. Lysozyme was gradually absorbed into the PSSA-MA/PVA nanofiber with higher extend than that is absorbed on the PAMA/PVA nanofiber and exhibited higher activity than lysozyme-immobilized PAMA/PVA nanofiber. The total contents of lysozyme on the PSSA-MA/PVA and PAMA/PVA nanofiber were 648 and 166 µg/g, respectively. FTIR and lysozyme activity results confirmed the presence of lysozyme on the nanofiber mats. The lysozyme was released from the PSSA-MA/PVA and PAMA/PVA nanofiber in the same manner. The lysozyme-immobilized PSSA-MA/PVA nanofiber mats and lysozyme-immobilized PAMA/PVA nanofiber mats exhibited significantly faster healing rate than gauze and similar to the commercial antibacterial gauze dressing. These results suggest that these nanofiber mats could provide the promising candidate for wound healing application.

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 ...

Evaluating the antimicrobial activity of Nisin, Lysozyme and Ethylenediaminetetraacetate incorporated in starch based active food packaging film.

Science.gov (United States)

Bhatia, Sugandha; Bharti, Anoop

2015-06-01

The pleothera of micro organisms obtained from contaminated food cultured in a starch broth was effectively tested against antibacterial agents, i.e. nisin, lysozyme and chelating agent EDTA. A variety of combination treatments of these antimicrobial agents and their incorporation in Starch based active packaging film according to their permissibility standards was done. 4 variables of Nisin concentration (ranging from 0 to 750 IU/ml), 3 variables of lysozyme concentration (ranging from 0 to 500 IU/ml) and 3 variables of EDTA concentration from (0 to 20 μM) were chosen. Bacterial inhibition by combination of different levels of different factors without antimicrobial films was evaluated using a liquid incubation method. The samples were assayed for turbidity at interval of 2, 4 and 24 h to check effectiveness of combined effects of antimicrobial agents which proved a transitory bactericidal effect for short incubation times. Zone of Inhibition was observed in the antimicrobial films prepared by agar diffusion method. Statistical analysis of experimental data for their antimicrobial spectrum was carried out by multi regression analysis and ANOVA using Design-Expert software to plot the final equation in terms of coded factors as antimicrobial agents. The experimental data indicated that the model was highly significant. Results were also evaluated graphically using response surface showing interactions between two factors, keeping other factor fixed at values at the center of domain. Synergy was also determined among antibacterial agents using the fractional inhibitory concentration (FIC) index which was observed to be 0.56 supporting the hypothesis that nisin and EDTA function as partial synergistically. The presented work aimed to screen in quick fashion the combinatorial effect of three antimicrobial agents and evaluating their efficacy in anti microbial film development.

ISOLATION AND PURIFICATION OF LYSOZYME FROM THE HEN EGG WHITE

Directory of Open Access Journals (Sweden)

S. S.

2015-12-01

Full Text Available The aim of the research was the development of the method of lysozyme isolation from hen egg proteins. Lysozyme was isolated by differential heat denaturation of proteins with changing of the medium pH value, followed by neutralization, dialysis and additional purification by gel chromatography on Sephadex G-50. Activity was determined by bacteriolytic method (with Micrococcus lysodeikticus 4698 as a substrate. The enzyme purity and molecular mass were determined using SDS-electrophoresis and massspectrometry. The method of lysozyme isolation from hen egg proteins with the enzyme yield of 3.2 ± 0.2% and bacteriolytic activity of 22 025 ± 1 500 U/mg is modified. According to electrophoresis data, the isolated enzyme is characterized by high degree of purity (~95–98% and is comparable with lysozyme of AppliChem company by main physical and chemical characteristics. The obtaining product is stored in a crystalline form at low temperature (–24 оC for 9 months. The proposed method allows obtaining active and stable lysozyme with high purity from hen egg protein in laboratory conditions for the usage in biotechnology.

The interaction of the protein lysozyme with bacteria E. coli observed using nanodiamond labelling

International Nuclear Information System (INIS)

Perevedentseva, Elena; Cheng, C-Y; Chung, P-H; Tu, J-S; Hsieh, Y-H; Cheng, C-L

2007-01-01

The application of a nanometre-sized diamond in Raman-detectable biolabelling is demonstrated in this study. The interaction of a lysozyme-nanodiamond complex with bacteria E. coli was observed via Raman mapping using the diamond Raman signal as the labelling marker. The results are compared with scanning electron microscope observations, and the adsorbed lysozyme's functionality is analysed. High antibacterial activity of lysozyme-nanodiamond complex was observed, equivalent to active lysozyme in solution. The results suggest that nanodiamond labelling can be effective and that it can be applied in ambient conditions without complicated sample pre-treatments

Production of active lysozyme films by matrix assisted pulsed laser evaporation at 355 nm

DEFF Research Database (Denmark)

Purice, Andreea; Schou, Jørgen; Kingshott, P.

2007-01-01

Thin lysozyme films have been produced in a dry environment by MAPLE (matrix assisted pulsed laser evaporation) from a water ice matrix irradiated by laser light at 355 nm above the absorption threshold of the protein. A significant part of the lysozyme molecules are transferred to the film without...

Reversible aggregation of lysozyme in a biodegradable amphiphilic multiblock copolymer.

Science.gov (United States)

van de Weert, Marco; van Dijkhuizen-Radersma, Riemke; Bezemer, Jeroen M; Hennink, Wim E; Crommelin, Daan J A

2002-07-01

Lysozyme-loaded poly(ethylene glycol terephthalate)-poly(butylene terephthalate) (PEGT/PBT) films were prepared using a water-in-oil emulsification solvent evaporation method. Infrared spectroscopic analysis of the dried films indicated the presence of non-covalent lysozyme aggregates in the polymer matrix. The use of methanol to enhance the drying rate of the films increased the relative amount of aggregates. Surprisingly, quantitative in-vitro release of fully active, non-aggregated lysozyme was observed, indicating that lysozyme forms reversible aggregates during encapsulation in PEGT/PBT films.

Isolation and characterization of a c-type lysozyme from the nurse shark.

Science.gov (United States)

Hinds Vaughan, Nichole; Smith, Sylvia L

2013-12-01

Lysozyme is a ubiquitous antibacterial enzyme that occurs in numerous invertebrate and vertebrate species. Three forms have been described c-type, g-type and i-type which differ in primary structure. Shark lysozyme has not been characterized; here we report on the isolation and characterization of lysozyme from unstimulated shark (Ginglymostoma cirratum) leukocytes and provide amino acid sequence data across the highly conserved active site of the molecule identifying it to be a c-type lysozyme. A leukocyte lysate was applied either (a) to the first of two sequential DE-52 cellulose columns or alternatively, (b) to a DEAE-Sepharose column. Lysozyme activity in lysate and active fractions was identified by zones of lysis of Micrococcus lysodeikticus cell walls on lysoplates and zones of growth inhibition in agar diffusion assays using Planococcus citreus as the target organism. SDS-PAGE analysis revealed a 14 kDa protein which was identified as lysozyme by mass spectroscopic analysis of peptides, reactivity against anti-HEWL antibodies on a Western blot, hydrolysis of M. lysodeikticus cell walls, and inhibition of growth of P. citreus on AU-gel blots in which the area of growth inhibition correlated to a 14 kDa protein. Copyright © 2013 Elsevier Ltd. All rights reserved.

The interaction of the protein lysozyme with bacteria E. coli observed using nanodiamond labelling

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Perevedentseva, Elena; Cheng, C-Y; Chung, P-H; Tu, J-S; Hsieh, Y-H; Cheng, C-L [Department of Physics, National Dong Hwa University, Hualien 97401, Taiwan (China)

2007-08-08

The application of a nanometre-sized diamond in Raman-detectable biolabelling is demonstrated in this study. The interaction of a lysozyme-nanodiamond complex with bacteria E. coli was observed via Raman mapping using the diamond Raman signal as the labelling marker. The results are compared with scanning electron microscope observations, and the adsorbed lysozyme's functionality is analysed. High antibacterial activity of lysozyme-nanodiamond complex was observed, equivalent to active lysozyme in solution. The results suggest that nanodiamond labelling can be effective and that it can be applied in ambient conditions without complicated sample pre-treatments.

The Antimicrobial Peptide Lysozyme Is Induced after Multiple Trauma

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Tim Klüter

2014-01-01

Full Text Available 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 and regulation in serum samples, different blood cells, and tissue samples were analysed by ELISA and real-time PCR. Neutrophils and hepatocytes were stimulated with cytokines and supernatant of Staphylococcus aureus. The present study demonstrates the induction and release of lysozyme in serum of multiple injured patients. The highest lysozyme expression of all tested cells and tissues was detected in neutrophils. Stimulation with trauma-related factors such as interleukin-6 and S. aureus induced lysozyme expression. Liver tissue samples of patients without trauma show little lysozyme expression compared to neutrophils. After stimulation with bacterial fragments, lysozyme expression of hepatocytes is upregulated significantly. Toll-like receptor 2, a classic receptor of Gram-positive bacterial protein, was detected as a possible target for lysozyme induction.

Complex coacervate core micelles with a lysozyme-modified corona.

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Danial, Maarten; Klok, Harm-Anton; Norde, Willem; Stuart, Martien A Cohen

2007-07-17

This paper describes the preparation, characterization, and enzymatic activity of complex coacervate core micelles (C3Ms) composed of poly(acrylic acid) (PAA) and poly(N-methyl-2-vinyl pyridinium iodide)-b-poly(ethylene oxide) (PQ2VP-PEO) to which the antibacterial enzyme lysozyme is end-attached. C3Ms were prepared by polyelectrolyte complex formation between PAA and mixtures containing different ratios of aldehyde and hydroxyl end-functionalized PQ2VP-PEO. This resulted in the formation of C3Ms containing 0-40% (w/w) of the aldehyde end-functionalized PQ2VP-PEO block copolymer (PQ2VP-PEO-CHO). Chemical conjugation of lysozyme was achieved via reductive amination of the aldehyde groups, which are exposed at the surface of the C3M, with the amine groups present in the side chains of the lysine residues of the protein. Dynamic and static light scattering indicated that the conjugation of lysozyme to C3Ms prepared using 10 and 20% (w/w) PQ2VP-PEO-CHO resulted in the formation of unimicellar particles. Multimicellar aggregates, in contrast, were obtained when lysozyme was conjugated to C3Ms prepared using 30 or 40% (w/w) PQ2VP-PEO-CHO. The enzymatic activity of the unimicellar lysozyme-C3M conjugates toward the hydrolysis of the bacterial substrate Micrococcus lysodeikticus was comparable to that of free lysozyme. For the multimicellar particles, in contrast, significantly reduced enzymatic rates of hydrolysis, altered circular dichroism, and red-shifted tryptophan fluorescence spectra were measured. These results are attributed to the occlusion of lysozyme in the interior of the multimicellar conjugates.

Poly lactic acid based injectable delivery systems for controlled release of a model protein, lysozyme.

Science.gov (United States)

Al-Tahami, Khaled; Meyer, Amanda; Singh, Jagdish

2006-02-01

The objective of this study was to evaluate the critical formulation parameters (i.e., polymer concentration, polymer molecular weight, and solvent nature) affecting the controlled delivery of a model protein, lysozyme, from injectable polymeric implants. The conformational stability and biological activity of the released lysozyme were also investigated. Three formulations containing 10%, 20%, and 30% (w/v) poly lactic acid (PLA) in triacetin were investigated. It was found that increasing polymer concentration in the formulations led to a lower burst effect and a slower release rate. Formulation with a high molecular weight polymer showed a greater burst effect as compared to those containing low molecular weight. Conformational stability and biological activity of released samples were studied by differential scanning calorimeter and enzyme activity assay, respectively. The released samples had significantly (P solution kept at same conditions). Increasing polymer concentration increased both the conformational stability and the biological activity of released lysozyme. In conclusion, phase sensitive polymer-based delivery systems were able to deliver a model protein, lysozyme, in a conformationally stable and biologically active form at a controlled rate over an extended period.

The Preventive Effect of L-Lysine on Lysozyme Glycation in Type 2 Diabetes

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Hossein Mirmiranpour

2016-01-01

Full Text Available Lysozyme is a bactericidal enzyme whose structure and functions change in diabetes. Chemical chaperones are small molecules including polyamines (e.g. spermine, amino acids (e.g. L-lysine and polyols (e.g. glycerol. They can improve protein conformation in several stressful conditions such as glycation. In this study, the authors aimed to observe the effect of L-lysine as a chemical chaperone on structure and function of glycated lysozyme. In this study, in vitro and in vivo effects of L-lysine on lysozyme glycation were investigated. Lysozyme was incubated with glucose and/or L-lysine, followed by an investigation of its structure by electrophoresis, fluorescence spectroscopy, and circular dichroism spectroscopy and also assessment of its bactericidal activity against M. lysodeikticus. In the clinical trial, patients with type 2 diabetes mellitus (T2DM were randomly divided into two groups of 25 (test and control. All patients received metformin and glibenclamide for a three months period. The test group was supplemented with 3 g/day of L-lysine. The quantity and activity of lysozyme and other parameters were then measured. Among the test group, L-lysine was found to reduce the advanced glycation end products (AGEs in the sera of patients with T2DM and in vitro condition. This chemical chaperone reversed the alteration in lysozyme structure and function due to glycation and resulted in increased lysozyme activity. Structure and function of glycated lysozyme are significantly improved by l-lysine; therefore it can be considered an effective therapeutic supplementation in T2DM, decreasing the risk of infection in these patients.

The antibacterial protein lysozyme identified as the termite egg recognition pheromone.

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Kenji Matsuura

Full Text Available Social insects rely heavily on pheromone communication to maintain their sociality. Egg protection is one of the most fundamental social behaviours in social insects. The recent discovery of the termite-egg mimicking fungus 'termite-ball' and subsequent studies on termite egg protection behaviour have shown that termites can be manipulated by using the termite egg recognition pheromone (TERP, which strongly evokes the egg-carrying and -grooming behaviours of workers. Despite the great scientific and economic importance, TERP has not been identified because of practical difficulties. Herein we identified the antibacterial protein lysozyme as the TERP. We isolated the target protein using ion-exchange and hydrophobic interaction chromatography, and the MALDI-TOF MS analysis showed a molecular size of 14.5 kDa. We found that the TERP provided antibacterial activity against a gram-positive bacterium. Among the currently known antimicrobial proteins, the molecular size of 14.5 kDa limits the target to lysozyme. Termite lysozymes obtained from eggs and salivary glands, and even hen egg lysozyme, showed a strong termite egg recognition activity. Besides eggs themselves, workers also supply lysozyme to eggs through frequent egg-grooming, by which egg surfaces are coated with saliva containing lysozyme. Reverse transcript PCR analysis showed that mRNA of termite lysozyme was expressed in both salivary glands and eggs. Western blot analysis confirmed that lysozyme production begins in immature eggs in queen ovaries. This is the first identification of proteinaceous pheromone in social insects. Researchers have focused almost exclusively on hydrocarbons when searching for recognition pheromones in social insects. The present finding of a proteinaceous pheromone represents a major step forward in, and result in the broadening of, the search for recognition pheromones. This novel function of lysozyme as a termite pheromone illuminates the profound influence

Production of Antimicrobial Films by Incorporation of Partially Purified Lysozyme into Biodegradable Films of Crude Exopolysaccharides Obtained from Aureobasidium pullulans Fermentation

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Nilay Kandemir

2005-01-01

Full Text Available Antimicrobial films were produced by incorporating partially purified lysozyme into films of crude exopolysaccharides (59 % pullulan obtained from Aureobasidium pullulans fermentation. After film making, the films containing lysozyme at 100, 260, 520 and 780 μg/cm2 showed 23 to 70 % of their expected enzyme activities. The highest recovery of enzyme activity (65–70 % after the film making was obtained in films prepared by incorporating lysozyme at 260 μg/cm2 (1409 U/cm2. The incorporation of disodium EDTA×2H2O and sucrose did not affect the initial lysozyme activity of the films significantly. With or without the presence of disodium EDTA×2H2O at 52 or 520 μg/cm2, lysozyme activity showed sufficient stability in the films during 21 days of cold storage. However, the presence of sucrose at 10 mg/cm2 in the films caused the destabilization of part of enzyme activity (almost 35 % at the end of storage. The combinational incorporation of lysozyme at 780 μg/cm2 (4227 U/cm2 and disodium EDTA×2H2O at 520 μg/cm2 gave antimicrobial films effective on Escherichia coli. However, in the studied lysozyme concentration range the films did not show any antimicrobial activity against Lactobacillus plantarum. This study clearly showed that the partially purified lysozyme and crude exopolysaccharides from Aureobasidium pullulans may be used to obtain antimicrobial films to increase the safety of foods.

New sub-family of lysozyme-like proteins shows no catalytic activity: crystallographic and biochemical study of STM3605 protein from Salmonella Typhimurium

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Michalska, Karolina; Brown, Roslyn N.; Li, Hui; Jedrzejczak, Robert; Niemann, George; Heffron, Fred; Cort, John R.; Adkins, Joshua N.; Babnigg, Gyorgy; Joachimiak, Andrzej

2013-03-01

Phage viruses that infect prokaryotes integrate their genome into the host chromosome; thus, microbial genomes typically contain genetic remnants of both recent and ancient phage infections. Often phage genes occur in clusters of atypical G+C content that reflect integration of the foreign DNA. However, some phage genes occur in isolation without other phage gene neighbors, probably resulting from horizontal gene transfer. In these cases, the phage gene product is unlikely to function as a component of a mature phage particle, and instead may have been co-opted by the host for its own benefit. The product of one such gene from Salmonella enterica serovar Typhimurium, STM3605, encodes a protein with modest sequence similarity to phage-like lysozyme (N-acetylmuramidase) but appears to lack essential catalytic residues that are strictly conserved in all lysozymes. Close homologs in other bacteria share this characteristic. The structure of the STM3605 protein was characterized by X-ray crystallography, and functional assays showed that it is a stable, folded protein whose structure closely resembles lysozyme. However, this protein is unlikely to hydrolyze peptidoglycan. Instead, STM3605 is presumed to have evolved an alternative function because it shows some lytic activity and partitions to micelles.

Isolation and partial purification of lysozyme from saliva of Bali cattle ...

African Journals Online (AJOL)

About 100 μg/ml lysozyme of 14.2 kDa, determined through sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), per 4800 μg/ml saliva was obtained. Based on turbidity assay of Staphylococcus aureus, it was revealed that inhibition activities of 40 μg/ml isolated lysozyme were comparable to 800 μg/ml ...

Fabrication of Sericin/Agrose Gel Loaded Lysozyme and Its Potential in Wound Dressing Application

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Meirong Yang

2018-04-01

Full Text Available Sericin is a biomaterial resource for its significant biodegradability, biocompatibility, hydrophilicity, and reactivity. Designing a material with superabsorbent, antiseptic, and non-cytotoxic wound dressing properties is advantageous to reduce wound infection and promote wound healing. Herein, we propose an environment-friendly strategy to obtain an interpenetrating polymer network gel through blending sericin and agarose and freeze-drying. The physicochemical characterizations of the sericin/agarose gel including morphology, porosity, swelling behavior, crystallinity, secondary structure, and thermal property were well characterized. Subsequently, the lysozyme loaded sericin/agarose composite gel was successfully prepared by the solution impregnation method. To evaluate the potential of the lysozyme loaded sericin/agarose gel in wound dressing application, we analyzed the lysozyme loading and release, antimicrobial activity, and cytocompatibility of the resulting gel. The results showed the lysozyme loaded composite gel had high porosity, excellent water absorption property, and good antimicrobial activities against Escherichia coli and Staphylococcus aureus. Also, the lysozyme loaded gel showed excellent cytocompatibility on NIH3T3 and HEK293 cells. So, the lysozyme loaded sericin/agarose gel is a potential alternative biomaterial for wound dressing.

Different Analytical Approaches in Assessing Antibacterial Activity and the Purity of Commercial Lysozyme Preparations for Dairy Application

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Luisa Pellegrino

2013-05-01

Full Text Available Hen egg-white lysozyme (LSZ is currently used in the food industry to limit the proliferation of lactic acid bacteria spoilage in the production of wine and beer, and to inhibit butyric acid fermentation in hard and extra hard cheeses (late blowing caused by the outgrowth of clostridial spores. The aim of this work was to evaluate how the enzyme activity in commercial preparations correlates to the enzyme concentration and can be affected by the presence of process-related impurities. Different analytical approaches, including turbidimetric assay, SDS-PAGE and HPLC were used to analyse 17 commercial preparations of LSZ marketed in different countries. The HPLC method adopted by ISO allowed the true LSZ concentration to be determined with accuracy. The turbidimetric assay was the most suitable method to evaluate LSZ activity, whereas SDS-PAGE allowed the presence of other egg proteins, which are potential allergens, to be detected. The analytical results showed that the purity of commercially available enzyme preparations can vary significantly, and evidenced the effectiveness of combining different analytical approaches in this type of control.

ABCC-JNIH adult health study: Hiroshima. Serum lysozyme determinations, April-June 1961

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Finch, S C; Lamphere, J P; Jablon, S

1961-01-01

Serum lysozyme levels were determined on 670 consecutive subjects seen for regularly scheduled clinic examinations of the Adult Health Study in Hiroshima. Serum lysozyme levels were found to vary significantly with the absolute peripheral granulocyte count, age, sex, and month of study. A high level of correlation also was noted between serum lysozyme and diabetes mellitus. This was at least in part attributable to greater average age in patients with diabetes. A suggestive relationship was established between serum lysozyme levels, respiratory diseases, and tuberculosis. These changes are believed to reflect active inflammation with excessive destruction of granulocytes and parenchymal tissues in those patients with the more acute processes. No relationship was found between serum lysozyme and previous exposure to ionizing radiation. These studies indicate that the serum lysozyme level may be useful in the study of the kinetics of leukopoiesis, the aging process, and in the detection of subtle inflammatory processes.

Analysis of two lysozyme genes and antimicrobial functions of their recombinant proteins in Asian seabass.

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Gui Hong Fu

Full Text Available Lysozymes are important proteins of the innate immune system for the defense against bacterial infection. We cloned and analyzed chicken-type (c-type and goose-type (g-type lysozymes from Asian seabass (Lates calcarifer. The deduced amino acid sequence of the c-type lysozyme contained 144 residues and possessed typical structure residues, conserved catalytic residues (Glu(50 and Asp(67 and a "GSTDYGIFQINS" motif. The deduced g-type lysozyme contained 187 residues and possessed a goose egg white lysozyme (GEWL domain containing three conserved catalytic residues (Glu(71, Asp(84, Asp(95 essential for catalytic activity. Real time quantitative PCR (qRT-PCR revealed that the two lysozyme genes were constitutively expressed in all the examined tissues. The c-type lysozyme was most abundant in liver, while the g-type lysozyme was predominantly expressed in intestine and weakly expressed in muscle. The c-type and g-type transcripts were up-regulated in the kidney, spleen and liver in response to a challenge with Vibrio harveyi. The up-regulation of the c-type lysozyme was much stronger than that of the g-type lysozyme in kidney and spleen. The recombinant proteins of the c-type and g-type lysozymes showed lytic activities against the bacterial pathogens Vibrio harveyi and Photobacterium damselae in a dosage-dependent manner. We identified single nucleotide polymorphisms (SNPs in the two lysozyme genes. There were significant associations of these polymorphisms with resistance to the big belly disease. These results suggest that the c- and g-type genes play an important role in resistance to bacterial pathogens in fish. The SNP markers in the two genes associated with the resistance to bacterial pathogens may facilitate the selection of Asian seabass resistant to bacterial diseases.

Effect of ethanol as a co-solvent on the aerosol performance and stability of spray-dried lysozyme

DEFF Research Database (Denmark)

Ji, Shuying; Thulstrup, Peter Waaben; Mu, Huiling

2016-01-01

In the spray drying process, organic solvents can be added to facilitate drying, accommodate certain functional excipients, and modify the final particle characteristics. In this study, lysozyme was used as a model pharmaceutical protein to study the effect of ethanol as a co...... the spray drying process. The enzymatic activities of the spray-dried lysozyme showed no significant impact of ethanol; however, the lysozyme enzymatic activity was ca. 25% lower compared to the starting material. In conclusion, the addition of ethanol as a co-solvent in the spray drying feed for lysozyme......-solvent on the stability and aerosol performance of spray-dried protein. Lysozyme was dissolved in solutions with various ratios of ethanol and water, and subsequently spray-dried. A change from spherical particles into wrinkled and folded particles was observed upon increasing the ratio of ethanol in the feed...

Covalent immobilization of lysozyme onto woven and knitted crimped polyethylene terephthalate grafts to minimize the adhesion of broad spectrum pathogens

International Nuclear Information System (INIS)

Al Meslmani, Bassam M.; Mahmoud, Gihan F.; Leichtweiß, Thomas; Strehlow, Boris; Sommer, Frank O.; Lohoff, Michael D.; Bakowsky, Udo

2016-01-01

Graft-associated infections entirely determine the short-term patency of polyethylene terephthalate PET cardiovascular graft. We attempted to enzymatically inhibit the initial bacterial adhesion to PET grafts using lysozyme. Lysozyme was covalently immobilized onto woven and knitted forms of crimped PET grafts by the end-point method. Our figures of merit revealed lysozyme immobilization yield of 15.7 μg/cm"2, as determined by the Bradford assay. The activity of immobilized lysozyme on woven and knitted PET manifested 58.4% and 55.87% using Micrococcus lysodeikticus cells, respectively. Noteworthy, the adhesion of vein catheter-isolated Staphylococcus epidermidis decreased by 6- to 8-folds and of Staphylococcus aureus by 11- to 12-folds, while the Gram-negative Escherichia coli showed only a decrease by 3- to 4-folds. The anti-adhesion efficiency was specific for bacterial cells and no significant effect was observed on adhesion and growth of L929 cells. In conclusion, immobilization of lysozyme onto PET grafts can inhibit the graft-associated infection. - Highlights: • Lysozyme was covalently immobilized on crimped polyethylene terephthalate (PET). • The activity of immobilized lysozyme was meaningfully reduced. • The maintained activity significantly declined the adhesion of Gram-positive stains. • The enzymatic anti-adhesion efficiency reported lesser extent against Gram-negative. • The anti-bacterial activity displayed no significant effect on cells compatibility.

Covalent immobilization of lysozyme onto woven and knitted crimped polyethylene terephthalate grafts to minimize the adhesion of broad spectrum pathogens

Energy Technology Data Exchange (ETDEWEB)

Al Meslmani, Bassam M., E-mail: almeslmanib@yahoo.com [Department of Pharmaceutical Technology and Biopharmaceutics, Marburg University, Ketzerbach 63, 35037 Marburg (Germany); Mahmoud, Gihan F., E-mail: mahmoudg@staff.uni-marburg.de [Department of Pharmaceutical Technology and Biopharmaceutics, Marburg University, Ketzerbach 63, 35037 Marburg (Germany); Department of Pharmaceutics and Industrial Pharmacy, Helwan University, Ain Helwan, 11795 Cairo (Egypt); Leichtweiß, Thomas, E-mail: Thomas.Leichtweiss@phys.Chemie.uni-giessen.de [Institute of Physical Chemistry, Justus-Liebig-University Giessen, Heinrich-Buff-Ring 58, 35392 Giessen (Germany); Strehlow, Boris, E-mail: strehlo4@staff.uni-marburg.de [Department of Pharmaceutical Technology and Biopharmaceutics, Marburg University, Ketzerbach 63, 35037 Marburg (Germany); Sommer, Frank O., E-mail: sommerf@med.uni-marburg.de [Institute for Medical Microbiology and Hospital Hygiene, Marburg University, Hans Meerwein Str 2, 35032 Marburg (Germany); Lohoff, Michael D., E-mail: lohoff@med.uni-marburg.de [Institute for Medical Microbiology and Hospital Hygiene, Marburg University, Hans Meerwein Str 2, 35032 Marburg (Germany); Bakowsky, Udo, E-mail: ubakowsky@aol.com [Department of Pharmaceutical Technology and Biopharmaceutics, Marburg University, Ketzerbach 63, 35037 Marburg (Germany)

2016-01-01

Graft-associated infections entirely determine the short-term patency of polyethylene terephthalate PET cardiovascular graft. We attempted to enzymatically inhibit the initial bacterial adhesion to PET grafts using lysozyme. Lysozyme was covalently immobilized onto woven and knitted forms of crimped PET grafts by the end-point method. Our figures of merit revealed lysozyme immobilization yield of 15.7 μg/cm{sup 2}, as determined by the Bradford assay. The activity of immobilized lysozyme on woven and knitted PET manifested 58.4% and 55.87% using Micrococcus lysodeikticus cells, respectively. Noteworthy, the adhesion of vein catheter-isolated Staphylococcus epidermidis decreased by 6- to 8-folds and of Staphylococcus aureus by 11- to 12-folds, while the Gram-negative Escherichia coli showed only a decrease by 3- to 4-folds. The anti-adhesion efficiency was specific for bacterial cells and no significant effect was observed on adhesion and growth of L929 cells. In conclusion, immobilization of lysozyme onto PET grafts can inhibit the graft-associated infection. - Highlights: • Lysozyme was covalently immobilized on crimped polyethylene terephthalate (PET). • The activity of immobilized lysozyme was meaningfully reduced. • The maintained activity significantly declined the adhesion of Gram-positive stains. • The enzymatic anti-adhesion efficiency reported lesser extent against Gram-negative. • The anti-bacterial activity displayed no significant effect on cells compatibility.

Prophenoloxidase system, lysozyme and protease inhibitor distribution in the common cuttlefish Sepia officinalis.

Science.gov (United States)

Le Pabic, Charles; Safi, Georges; Serpentini, Antoine; Lebel, Jean-Marc; Robin, Jean-Paul; Koueta, Noussithé

2014-01-01

The immune system of cephalopods remains poorly understood. The aim of this study was to determine the specific activity of immune enzymes in epithelial barriers, circulatory and digestive systems of the common cuttlefish Sepia officinalis. Three enzyme groups with putative functions in immunity were investigated: phenoloxidases (POs), lysozymes and protease inhibitors (PIs). Consistent with a role in immunity, highest PO activities were found in the integument as well as the respiratory and circulatory organs under zymogenic (proPO) and active form. Surprisingly, high PO activities were also found in the digestive gland and its appendages. Similarly, high lysozyme activities were detected in the integument and circulatory organs, but also in the posterior salivary glands, highlighting the implication of this antibacterial enzyme group in most tissues exposed to the environment but also within the circulatory system. Albeit highest in digestive organs, the ubiquitous detection of PI activity in assayed compartments suggests immune function(s) in a wide range of tissues. Our study reports proPO/PO, lysozyme and PI distributions in S. officinalis body compartments for the first time, and thus provides the fundamental basis for a better understanding of the humoral immune system in cephalopods as well as invertebrates. Copyright © 2014 Elsevier Inc. All rights reserved.

Renaturation of reduced hen egg white lysozyme containing two blocked sulfhydryl groups

Energy Technology Data Exchange (ETDEWEB)

Acharya, A.S.; Taniuchi, H.

1980-10-01

Formation of native lysozyme from the reduced form involves many pathways in two processes: incorrect pairing of half-cystine residues by oxidation and rearrangement of disulfide (SS) bonds. The energy barrier against suflhydryl (SH)-disulfide interchange of the native or nativelike species thus formed causes accumulation of these species. For example, the enzymatically active isomers containing three presumably native SS bonds and one open SS bond may be thermodynamically favorable over the nonnative isomers and can be formed from reduced lysozyme or lysozyme containing scrambled SS bonds by nonobligatory and flexible pathways. As an extension of these observations formation of nativelike species from reduced lysozyme containing the average of two carboxymethyl (CM)-cysteine was investigated.

Modified lysozymes as novel broad spectrum natural antimicrobial agents in foods.

Science.gov (United States)

Aminlari, Ladan; Hashemi, Marjan Mohammadi; Aminlari, Mahmoud

2014-06-01

In recent years much attention and interest have been directed toward application of natural antimicrobial agents in foods. Some naturally occurring proteins such as lactoperoxidase, lactoferrin, and lysozyme have received considerable attention and are being considered as potential antimicrobial agents in foods. Lysozyme kills bacteria by hydrolyzing the peptidoglycan layer of the cell wall of certain bacterial species, hence its application as a natural antimicrobial agent has been suggested. However, limitations in the action of lysozyme against only Gram-positive bacteria have prompted scientists to extend the antimicrobial effects of lysozyme by several types of chemical modifications. During the last 2 decades extensive research has been directed toward modification of lysozyme in order to improve its antimicrobial properties. This review will report on the latest information available on lysozyme modifications and examine the applicability of the modified lysozymes in controlling growth of Gram-positive and Gram-negative bacteria in foods. The results of modifications of lysozyme using its conjugation with different small molecule, polysaccharides, as well as modifications using proteolytic enzymes will be reviewed. These types of modifications have not only increased the functional properties of lysozyme (such as solubility and heat stability) but also extended the antimicrobial activity of lysozyme. Many examples will be given to show that modification can decrease the count of Gram-negative bacteria in bacterial culture and in foods by as much as 5 log CFU/mL and in some cases essentially eliminated Escherichia coli. In conclusion this review demonstrates that modified lysozymes are excellent natural food preservatives, which can be used in food industry. The subject described in this review article can lead to the development of methods to produce new broad-spectrum natural antimicrobial agents, based on modification of chicken egg white lysozyme, which

A zinc complex of heparan sulfate destabilises lysozyme and alters its conformation

International Nuclear Information System (INIS)

Hughes, Ashley J.; Hussain, Rohanah; Cosentino, Cesare; Guerrini, Marco; Siligardi, Giuliano; Yates, Edwin A.; Rudd, Timothy R.

2012-01-01

Highlights: ► Zinc–heparan sulfate complex destabilises lysozyme, a model amyloid protein. ► Addition of zinc, without heparan sulfate, stabilises lysozyme. ► Heparan sulfate cation complexes provide alternative protein folding routes. -- Abstract: The naturally occurring anionic cell surface polysaccharide heparan sulfate is involved in key biological activities and is implicated in amyloid formation. Following addition of Zn–heparan sulfate, hen lysozyme, a model amyloid forming protein, resembled β-rich amyloid by far UV circular dichroism (increased β-sheet: +25%), with a significantly reduced melting temperature (from 68 to 58 °C) by fluorescence shift assay. Secondary structure stability of the Zn–heparan sulfate complex with lysozyme was also distinct from that with heparan sulfate, under stronger denaturation conditions using synchrotron radiation circular dichroism. Changing the cation associated with heparan sulfate is sufficient to alter the conformation and stability of complexes formed between heparan sulfate and lysozyme, substantially reducing the stability of the protein. Complexes of heparan sulfate and cations, such as Zn, which are abundant in the brain, may provide alternative folding routes for proteins.

Covalent immobilization of lysozyme on ethylene vinyl alcohol films for nonmigrating antimicrobial packaging applications.

Science.gov (United States)

Muriel-Galet, V; Talbert, J N; Hernandez-Munoz, P; Gavara, R; Goddard, J M

2013-07-10

The objective of this study was to develop a new antimicrobial film, in which lysozyme was covalently attached onto two different ethylene vinyl alcohol copolymers (EVOH 29 and EVOH 44). The EVOH surface was modified with UV irradiation treatment to generate carboxylic acid groups, and lysozyme was covalently attached to the functionalized polymer surface. Surface characterization of control and modified films was performed using attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and dye assay. The value of protein loading after attachment on the surface was 8.49 μg protein/cm(2) and 5.74 μg protein/cm(2) for EVOH 29 and EVOH 44, respectively, after 10 min UV irradiation and bioconjugation. The efficacy of the EVOH-lysozyme films was assessed using Micrococcus lysodeikticus. The antimicrobial activity of the films was tested against Listeria monocytogenes and was similar to an equivalent amount of free enzyme. The reduction was 1.08 log for EVOH 29-lysozyme, 0.95 log for EVOH 44-lysozyme, and 1.34 log for free lysozyme. This work confirmed the successful use of lysozyme immobilization on the EVOH surface for antimicrobial packaging.

Production, optimization, characterization and antifungal activity of ...

African Journals Online (AJOL)

SAM

2014-04-02

Apr 2, 2014 ... the present study, the antifungal activity of crude A. terrus chitinase was investigated against Apergillus niger, Aspergillus oryzae .... Chitinase activity was determined spectrophotometrically by estimating the amount of ..... characterization of two. Bifunctional chitinases lysozyme extracellularly produced by.

Lysozymes in the animal kingdom.

Science.gov (United States)

Callewaert, Lien; Michiels, Chris W

2010-03-01

Lysozymes (EC 3.2.1.17) are hydrolytic enzymes, characterized by their ability to cleave the beta-(1,4)-glycosidic bond between N-acetylmuramic acid and N-acetylglucosamine in peptidoglycan, the major bacterial cell wall polymer. In the animal kingdom, three major distinct lysozyme types have been identified--the c-type (chicken or conventional type), the g-type (goose-type) and the i-type (invertebrate type) lysozyme. Examination of the phylogenetic distribution of these lysozymes reveals that c-type lysozymes are predominantly present in the phylum of the Chordata and in different classes of the Arthropoda. Moreover, g-type lysozymes (or at least their corresponding genes) are found in members of the Chordata, as well as in some bivalve mollusks belonging to the invertebrates. In general, the latter animals are known to produce i-type lysozymes. Although the homology in primary structure for representatives of these three lysozyme types is limited, their three-dimensional structures show striking similarities. Nevertheless, some variation exists in their catalytic mechanisms and the genomic organization of their genes. Regarding their biological role, the widely recognized function of lysozymes is their contribution to antibacterial defence but, additionally, some lysozymes (belonging to different types) are known to function as digestive enzymes.

Multiple I-Type Lysozymes in the Hydrothermal Vent Mussel Bathymodiolus azoricus and Their Role in Symbiotic Plasticity.

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Camille Detree

Full Text Available The aim of this study was first to identify lysozymes paralogs in the deep sea mussel Bathymodiolus azoricus then to measure their relative expression or activity in different tissue or conditions. B. azoricus is a bivalve that lives close to hydrothermal chimney in the Mid-Atlantic Ridge (MAR. They harbour in specialized gill cells two types of endosymbiont (gram-bacteria: sulphide oxidizing bacteria (SOX and methanotrophic bacteria (MOX. This association is thought to be ruled by specific mechanism or actors of regulation to deal with the presence of symbiont but these mechanisms are still poorly understood. Here, we focused on the implication of lysozyme, a bactericidal enzyme, in this endosymbiosis. The relative expression of Ba-lysozymes paralogs and the global anti-microbial activity, were measured in natural population (Lucky Strike--1700 m, Mid-Atlantic Ridge, and in in situ experimental conditions. B. azoricus individuals were moved away from the hydrothermal fluid to induce a loss of symbiont. Then after 6 days some mussels were brought back to the mussel bed to induce a re-acquisition of symbiotic bacteria. Results show the presence of 6 paralogs in B. azoricus. In absence of symbionts, 3 paralogs are up-regulated while others are not differentially expressed. Moreover the global activity of lysozyme is increasing with the loss of symbiont. All together these results suggest that lysozyme may play a crucial role in symbiont regulation.

Complex coacervate core micelles with a lysozyme-modified corona

NARCIS (Netherlands)

Danial, Maarten; Klok, Harm-Anton; Norde, Willem; Stuart, Martien A. Cohen

2007-01-01

This paper describes the preparation, characterization, and enzymatic activity of complex coacervate core micelles (C3Ms) composed of poly(acrylic acid) (PAA) and poly(N-methyl-2-vinyl pyridinium iodide)-b-poly(ethylene oxide) (PQ2VP-PEO) to which the antibacterial enzyme lysozyme is end-attached.

Positron annihilation studies in lysozyme and catalase

International Nuclear Information System (INIS)

Rohilla, Y.; Singh, K.P.; Roy Choudhury, S.; Jain, P.C.

1992-01-01

Positron annihilation studies have been carried out in two enzymes, lysozyme and catalase. Temperature dependence of the positron lifetimes in these two enzymes has been investigated. The results explained in terms of the free volume model and fluctuations between different conformational micro states of enzyme structures provide a new insight into the mechanism of bio-activity of these enzymes. (author). 15 refs., 4 figs

Purification and Characterization of Recombinant Human Lysozyme from Eggs of Transgenic Chickens.

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Hanyu Wu

Full Text Available Transgenic chickens as bioreactors have several advantages, such as the simple establishment procedure, correct glycosylation profile of expressed proteins, etc. Lysozyme is widely used in food industry, livestock farming, and medical field as a replacement of antibiotics because of its antibacterial and complement system-modulating activity. In this study, we used RT-PCR, Western blot, and immunofluorescence to detect the expression of recombinant human lysozyme (rhLY in the transgenic chicken. We demonstrated that the transgene of rhLY was genetically stable across different generations. We next optimized the purification procedure of rhLY from the transgenic eggs by utilizing two steps of cation-exchange chromatography and one gel-filtration chromatography. About 6 mg rhLY with the purity exceeding 90% was obtained from ten eggs, and the purification efficiency was about 75%. The purified rhLY had similar physicochemical and biological properties in molecular mass and antibacterial activity compared to the commercial human lysozyme. Additionally, both of them exhibited thermal stability at 60°C and tolerated an extensive pH range of 2 to 11. In conclusion, our study proved that the transgenic chickens we have previously generated were genetically stable and suitable for the production of active rhLY. We also provided a pipeline for purifying the recombinant proteins from transgenic eggs, which could be useful for other studies.

Purification of Egg White Lysozyme from Indonesian Kampung Chicken and Ducks

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Z. Wulandari

2015-04-01

Full Text Available Egg white lysozyme (EWL has considerably a wide functional protein exhibiting antibacterial activity mainly against Gram-positive bacteria. The EWL is widely applied in food industry and is considerably safe. Despite its high potency, EWL of Indonesian poultry has never been studied and exploited. This study was aimed to purify EWL from two Indonesian poultry: kampung chicken and Cihateup duck, and compared to egg of commercial laying hens. The eggs in this study were obtained from field laboratory of Faculty of Animal Science, Bogor Agricultural University (IPB and classified in AA quality based on the interior quality. First attempt to purify the EWL was performed by using ethanol precipitation yielding purified EWL which was still contaminated by other proteins, hence designated as partially purified EWL. Final concentrations of partially purified EWL of kampung chicken, commercial laying hens, and Cihateup duck were about 5800, 5400, and 5500 μg/mL, respectively. To confirm whether the use of ethanol in the purification affecting EWL antibacterial activities, the activities were examined against Staphylococcus aureus. It demonstrated that the partially purified EWL exhibited ability to inhibit S. aureus at 6 and 26 h suggesting that the method was feasible as it did not interfere EWL antibacterial activities. Yet, based on SDS-Page, purity was the issue in ethanol precipitation method. Further attempt using ion exchange chromatography at pH 10 successfully purified lysozyme as indicated by a single band corresponding to lysozyme size (~14 kD free from bands of other proteins. Altogether, a single step of ion exchange chromatography is sufficient and promising to isolate EWL from Indonesian poultry for various industrial purposes.

A novel C-type lysozyme from Mytilus galloprovincialis: insight into innate immunity and molecular evolution of invertebrate C-type lysozymes.

Directory of Open Access Journals (Sweden)

Qing Wang

Full Text Available A c-type lysozyme (named as MgCLYZ gene was cloned from the mussel Mytilus galloprovincialis. Blast analysis indicated that MgCLYZ was a salivary c-type lysozyme which was mainly found in insects. The nucleotide sequence of MgCLYZ was predicted to encode a polypeptide of 154 amino acid residues with the signal peptide comprising the first 24 residues. The deduced mature peptide of MgCLYZ was of a calculated molecular weight of 14.4 kD and a theoretical isoelectric point (pI of 8.08. Evolution analysis suggested that bivalve branch of the invertebrate c-type lysozymes phylogeny tree underwent positive selection during evolution. By quantitative real-time RT-PCR (qRT-PCR analysis, MgCLYZ transcript was widely detected in all examined tissues and responded sensitively to bacterial challenge in hemocytes and hepatopancreas. The optimal temperature and pH of recombinant MgCLYZ (rMgCLYZ were 20°C and 4, respectively. The rMgCLYZ displayed lytic activities against Gram-positive bacteria including Micrococcus luteus and Staphyloccocus aureus, and Gram-negative bacteria including Vibrio anguillarum, Enterobacter cloacae, Pseudomonas putida, Proteus mirabilis and Bacillus aquimaris. These results suggest that MgCLYZ perhaps play an important role in innate immunity of M. galloprovincialis, and invertebrate c-type lysozymes might be under positive selection in a species-specific manner during evolution for undergoing adaptation to different environment and diverse pathogens.

Immunological response in egg-sensitive adults challenged with cheese containing or not containing lysozyme.

Science.gov (United States)

Rossi, Filippo; Iaconelli, Amerigo; Fiorentini, Lucia; Zito, Francesco; Donati, Maria Benedett; De Cristofaro, Maria Laura; Piva, Gianfranco; Mingrone, Geltrude

2012-12-01

Lysozyme is an enzyme that hydrolyzes bacterial peptidoglicans. For this reason, it is used in cheese manufacturing in order to prevent a defect of long-ripened hard cheese called "late blowing" due to the outgrowth of spores of Clostridium tyrobutyricum and Clostridium butyricum. Moreover, germination of Listeria monocytogenes spores into vegetative cells is also sensitive to lysozyme. The enzyme can be an allergenic molecule, and for this reason there are concerns about its use in food industry. The immunological and clinical response of consumption of lysozyme-containing cheese has been evaluated in 25 egg-sensitive subjects with or without lysozyme sensitization. A total of 25 egg-sensitive subjects were enrolled in this study. All the subjects were already treated for egg-sensitization and presented a positive skin prick test. All the subjects had a body mass index ≤ 25 kg/m(2) and were in the age range of 20-50 years. Each subject was studied twice and received randomly 30 g of Grana Padano (containing lysozyme) or TrentinGrana cheese (lysozyme-free) of two different aging periods: 16 or 24 months. A washout period of 1 week between each cheese intake was adopted. Blood samples were taken in fasting conditions and 1 hour after cheese intake and IgA, total IgE, and lysozyme-, ovomucoid-, and ovalbumin-specific IgE were measured. No adverse reactions were observed in both groups of patients after cheese samples were given. Lysozyme did not determine any variation of specific IgE compared with basal level. In lysozyme-sensitive patients a significant relationship between IgA and lysozyme-specific IgE was observed when lysozyme-containing cheese was given, confirming that lysozyme can pass the gut barrier. Neither adverse events nor immunological responses were observed after ingestion of cheese containing lysozyme. However, the immunological properties of peptides deriving from cheese protein hydrolysis need to be clarified, as does the effect of lysozyme on

Expression of T4 Lysozyme Gene (gene e) in Streptococcus ...

African Journals Online (AJOL)

pL2 plasmid isolated from E. coli was introduced into S. salivarius subsp. thermophilus and Lactococcus lactis cells by electro-transformation. The lysozyme enzymes expressing by these bacteria were found to be active on Micrococcus luteus cells and thereby preventing their growth on assay plates. Thermostability of ...

Control of Electrostatic Interactions Between F-Actin And Genetically Modified Lysozyme in Aqueous Media

International Nuclear Information System (INIS)

Sanders, L.K.; Xian, W.; Guaqueta, C.; Strohman, M.; Vrasich, C.R.; Luijten, E.; Wong, G.C.L.

2009-01-01

The aim for deterministic control of the interactions between macroions in aqueous media has motivated widespread experimental and theoretical work. Although it has been well established that like-charged macromolecules can aggregate under the influence of oppositely charged condensing agents, the specific conditions for the stability of such aggregates can only be determined empirically. We examine these conditions, which involve an interplay of electrostatic and osmotic effects, by using a well defined model system composed of F-actin, an anionic rod-like polyelectrolyte, and lysozyme, a cationic globular protein with a charge that can be genetically modified. The structure and stability of actin-lysozyme complexes for different lysozyme charge mutants and salt concentrations are examined by using synchrotron x-ray scattering and molecular dynamics simulations. We provide evidence that supports a structural transition from columnar arrangements of F-actin held together by arrays of lysozyme at the threefold interstitial sites of the actin sublattice to marginally stable complexes in which lysozyme resides at twofold bridging sites between actin. The reduced stability arises from strongly reduced partitioning of salt between the complex and the surrounding solution. Changes in the stability of actin-lysozyme complexes are of biomedical interest because their formation has been reported to contribute to the persistence of airway infections in cystic fibrosis by sequestering antimicrobials such as lysozyme. We present x-ray microscopy results that argue for the existence of actin-lysozyme complexes in cystic fibrosis sputum and demonstrate that, for a wide range of salt conditions, charge-reduced lysozyme is not sequestered in ordered complexes while retaining its bacterial killing activity.

High-pressure protein crystallography of hen egg-white lysozyme

Energy Technology Data Exchange (ETDEWEB)

Yamada, Hiroyuki; Nagae, Takayuki [Nagoya University, Chikusa, Nagoya, Aichi 464-8603 (Japan); Watanabe, Nobuhisa, E-mail: nobuhisa@nagoya-u.jp [Nagoya University, Chikusa, Nagoya, Aichi 464-8603 (Japan); Nagoya University, Chikusa, Nagoya, Aichi 464-8603 (Japan)

2015-04-01

The crystal structure of hen egg-white lysozyme (HEWL) was analyzed under pressures of up to 950 MPa. The high pressure modified the conformation of the molecule and induced a novel phase transition in the tetragonal crystal of HEWL. Crystal structures of hen egg-white lysozyme (HEWL) determined under pressures ranging from ambient pressure to 950 MPa are presented. From 0.1 to 710 MPa, the molecular and internal cavity volumes are monotonically compressed. However, from 710 to 890 MPa the internal cavity volume remains almost constant. Moreover, as the pressure increases to 950 MPa, the tetragonal crystal of HEWL undergoes a phase transition from P4{sub 3}2{sub 1}2 to P4{sub 3}. Under high pressure, the crystal structure of the enzyme undergoes several local and global changes accompanied by changes in hydration structure. For example, water molecules penetrate into an internal cavity neighbouring the active site and induce an alternate conformation of one of the catalytic residues, Glu35. These phenomena have not been detected by conventional X-ray crystal structure analysis and might play an important role in the catalytic activity of HEWL.

Antimicrobial lysozyme-containing starch microgel to target and inhibit amylase-producing microorganisms

NARCIS (Netherlands)

Li, Y.; Kadam, S.; Abee, T.; Slaghek, T.M.; Timmermans, J.W.; Cohen Stuart, M.A.; Norde, W.; Kleijn, M.J.

2012-01-01

The aim of this study is to determine the release of lysozyme from oxidized starch microgels and subsequently test its antimicrobial activity. The gels are made of oxidized potato starch polymers, which are chemically cross-linked by sodium trimetaphosphate (STMP). The microgel is negatively charged

Electrostatic interactions in protein adsorption probed by comparing lysozyme and succinylated lysozyme

NARCIS (Netherlands)

Veen, van der M.; Norde, W.; Cohen Stuart, M.A.

2004-01-01

The influence of electrostatic interactions on protein adsorption was studied by comparing the adsorption of lysozyme and succinylated lysozyme at silica surfaces. The succinylation affects the charge of the protein, but also the stability. Although changes in stability can have an influence on

Molecular Cloning and Characterization of a New C-type Lysozyme Gene from Yak Mammary Tissue

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Ming Feng Jiang

2015-12-01

Full Text Available Milk lysozyme is the ubiquitous enzyme in milk of mammals. In this study, the cDNA sequence of a new chicken-type (c-type milk lysozyme gene (YML, was cloned from yak mammary gland tissue. A 444 bp open reading frames, which encodes 148 amino acids (16.54 kDa with a signal peptide of 18 amino acids, was sequenced. Further analysis indicated that the nucleic acid and amino acid sequences identities between yak and cow milk lysozyme were 89.04% and 80.41%, respectively. Recombinant yak milk lysozyme (rYML was produced by Escherichia coli BL21 and Pichia pastoris X33. The highest lysozyme activity was detected for heterologous protein rYML5 (M = 1,864.24 U/mg, SD = 25.75 which was expressed in P. pastoris with expression vector pPICZαA and it clearly inhibited growth of Staphylococcus aureus. Result of the YML gene expression using quantitative polymerase chain reaction showed that the YML gene was up-regulated to maximum at 30 day postpartum, that is, comparatively high YML can be found in initial milk production. The phylogenetic tree indicated that the amino acid sequence was similar to cow kidney lysozyme, which implied that the YML may have diverged from a different ancestor gene such as cow mammary glands. In our study, we suggest that YML be a new c-type lysozyme expressed in yak mammary glands that plays a role as host immunity.

Functionalization of multiwalled carbon nanotubes by microwave irradiation for lysozyme attachment: comparison of covalent and adsorption methods by kinetics of thermal inactivation

Science.gov (United States)

Puentes-Camacho, Daniel; Velázquez, Enrique F.; Rodríguez-Félix, Dora E.; Castillo-Ortega, Mónica; Sotelo-Mundo, Rogerio R.; del Castillo-Castro, Teresa

2017-12-01

Proteins suffer changes in their tertiary structure when they are immobilized, and enzymatic activity is affected due to the low biocompatibility of some supporting materials. In this work immobilization of lysozyme on carbon nanotubes previously functionalized by microwave irradiation was studied. The effectiveness of the microwave-assisted acid treatment of carbon nanotubes was evaluated by XPS, TEM, Raman and FTIR spectroscopy. The carboxylic modification of nanotube surfaces by this fast, simple and feasible method allowed the physical adsorption and covalent linking of active lysozyme onto the carbonaceous material. Thermal inactivation kinetics, thermodynamic parameters and storage stability were studied for adsorbed and covalent enzyme complexes. A major stability was found for lysozyme immobilized by the covalent method, the activation energy for inactivation of the enzyme was higher for the covalent method and it was stable after 50 d of storage at 4 °C. The current study highlights the effect of protein immobilization method on the biotechnological potential of nanostructured biocatalysts.

Molecular Characterization of a Lysozyme Gene and Its Altered Expression Profile in Crowded Beet Webworm (Loxostege sticticalis.

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Hailong Kong

Full Text Available There is growing evidence that insects living in high-density populations exhibit an increase in immune function to counter a higher risk of disease. This phenomenon, known as density-dependent prophylaxis, has been experimentally tested in a number of insect species. Although density-dependent prophylaxis is especially prevalent in insects exhibiting density-dependent phase polyphenism, the molecular mechanism remains unclear. Our previous study demonstrated that the antibacterial activity of lysozyme is important for this process in the beet webworm Loxostege sticticalis. In this study, a lysozyme cDNA from L. sticticalis was cloned and characterized. The full-length cDNA is 1078 bp long and contains an open reading frame of 426 bp that encodes 142 amino acids. The deduced protein possesses structural characteristics of a typical c-type lysozyme and clusters with c-type lysozymes from other Lepidoptera. LsLysozyme was found to be expressed throughout all developmental stages, showing the highest level in pupae. LsLysozyme was also highly expressed in the midgut and fat body. Elevated LsLysozyme expression was observed in L. sticticalis larvae infected by Beauveria bassiana and in larvae reared under crowding conditions. In addition, the expression level of LsLysozyme in infected larvae reared at a density of 10 larvae per jar was significantly higher compared to those reared at a density of l or 30 larvae per jar. These results suggest that larval crowding affects the gene expression profile of this lysozyme. This study provides additional insight into the expression of an immune-associated lysozyme gene and helps us to better understand the immune response of L. sticticalis under crowding conditions.

1H NMR studies of human lysozyme: Spectral assignment and comparison with hen lysozyme

International Nuclear Information System (INIS)

Redfield, C.; Dobson, C.M.

1990-01-01

Complete main-chain (NH and αCH) 1 H NMR assignments are reported for the 130 residues of human lysozyme, along with extensive assignments for side-chain protons. Analysis of 2-D NOESY experiments shows that the regions of secondary structure for human lysozyme in solution are essentially identical with those found previously in a similar study of hen lysozyme and are in close accord with the structure of the protein reported previously from x-ray diffraction studies in the crystalline state. Comparison of the chemical shifts, spin-spin coupling constants, and hydrogen exchange behavior are also consistent with closely similar structures for the two proteins in solution. In a number of cases specific differences in the NMR parameters between hen and human lysozymes can be correlated with specific differences observed in the crystal structures

Complex coacervates of hyaluronic acid and lysozyme

DEFF Research Database (Denmark)

Water, Jorrit J.; Schack, Malthe M.; Velazquez-Campoy, Adrian

2014-01-01

stoichiometry was determined using solution depletion and isothermal titration calorimetry. The binding stoichiometry of lysozyme to hyaluronic acid (870 kDa) determined by solution depletion was found to be 225.9 ± 6.6 mol, or 0.1 bound lysozyme molecules per hyaluronic acid monomer. This corresponded well...... with that obtained by isothermal titration calorimetry of 0.09 bound lysozyme molecules per hyaluronic acid monomer. The complexation did not alter the secondary structure of lysozyme measured by Fourier-transform infrared spectroscopy overlap analysis and had no significant impact on the Tm of lysozyme determined...

Lysozymes in the animal kingdom

Indian Academy of Sciences (India)

In the animal kingdom, three major distinct lysozyme types have been ... reveals that c-type lysozymes are predominantly present in the phylum of the Chordata and in different classes of the Arthropoda. ... Journal of Biosciences | News ...

Antibacterial activity of domestic Balkan donkey milk toward Listeria monocytogenes and Staphylococcus aureus

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Šarić Ljubiša Ć.

2014-01-01

Full Text Available The aim of this study was to investigate the antibacterial activity of raw milk from Domestic Balkan donkey breed toward Listeria monocytogenes and Staphylococcus aureus. Examination of antibacterial activity was performed in artificially contaminated milk samples by monitoring the changes of count of viable cells of tested bacteria during 8 hours of incubation at 38°C. Lysozyme and fatty acids contents were also determined in donkey milk. The obtained results indicated inhibitory effect of donkey milk toward both tested bacteria. The lysozyme content in the analyzed milk samples was ranged from 0.67 to 3.54 g/L. The most abundant fatty acids with known antibacterial activity toward Gram positive bacteria were linoleic, lauric and oleic acid.

Study of a photo-induced lysozyme-riboflavin bond

Energy Technology Data Exchange (ETDEWEB)

Ferrer, I; Silva, E

1985-01-01

Irradiation of lysozyme in the presence of riboflavin results in the formation of a lysozyme-riboflavin adduct. Reduction and carboxymethylation of the four disulfide bonds as well as the chemical modification of the Tyr residues and the photochemical alteration of the His residue in lysozyme, do not affect the formation of the photo-induced lysozyme-riboflavin bond. When the lysozyme-riboflavin adduct was subjected to mild acid hydrolysis and ion exchange chromatography, the retention of a compound containing /sup 14/C-riboflavin was observed. Free /sup 14/C-riboflavin, on the contrary is not retained by the column. The photo-oxidation of free Trp in the presence of /sup 14/C-riboflavin, gave a compound which bound to the ion exchange resin like the above-mentioned derivative. The photo-oxidation of the Trp residues in lysozyme and in peptides obtained from lysozyme showed very high quantum yields, and these values were directly related to the incorporation of /sup 14/C-riboflavin in these samples.

Study of a photo-induced lysozyme-riboflavin bond

International Nuclear Information System (INIS)

Ferrer, I.; Silva, E.

1985-01-01

Irradiation of lysozyme in the presence of riboflavin results in the formation of a lysozyme-riboflavin adduct. Reduction and carboxymethylation of the four disulfide bonds as well as the chemical modification of the Tyr residues and the photochemical alteration of the His residue in lysozyme, do not affect the formation of the photo-induced lysozyme-riboflavin bond. When the lysozyme-riboflavin adduct was subjected to mild acid hydrolysis and ion exchange chromatography, the retention of a compound containing 14 C-riboflavin was observed. Free 14 C-ribboflavin, on the contrary is not retained by the column. The photo-oxidation of free Trp in the presence of 14 C-riboflavin, gave a compound which bound to the ion exchange resin like the above-mentioned derivative. The photo-oxidation of the Trp residues in lysozyme and in peptides obtained from lysozyme showed very high quantum yields, and these values were directly related to the incorporation of 14 C-riboflavin in these samples. (orig.)

Reduced Position Effect in Mature Transgenic Plants Conferred by the Chicken Lysozyme Matrix-Associated Region

NARCIS (Netherlands)

Mlynárová, Ľudmila; Loonen, Annelies; Heldens, Jos; Jansen, Ritsert C.; Keizer, Paul; Stiekema, Willem J.; Nap, Jan-Peter

1994-01-01

Matrix-associated regions may be useful for studying the role of chromatin architecture in transgene activity of transformed plants. The chicken lysozyme A element was shown to have specific affinity for tobacco nuclear matrices, and its influence on the variability of transgene expression in

Spectroscopic determination of lysozyme conformational changes in the presence of trehalose and guanidine.

Science.gov (United States)

Barreca, Davide; Laganà, Giuseppina; Ficarra, Silvana; Gattuso, Giuseppe; Magazù, Salvatore; La Torre, Roberto; Tellone, Ester; Bellocco, Ersilia

2013-06-01

The bioprotective action of the disaccharide trehalose has been studied against the well-known denaturating agent, guanidine hydrochloride. The results indicated a direct influence of trehalose on both enzymatic activity and conformational changes of lysozyme, as shown by the decrease of the inactivation rate constant of about 1.48-fold and the loss of α-helix structure of lysozyme. In addition, ESI-MS hydrogen-deuterium (H/D) exchange experiments allowed us to correlate the structural and dynamic features of the protein in the presence of the two additives, highlighting as trehalose remarkably influenced this exchange by decreasing local protein environment changes and solvent accessibility to the amide peptide backbone, as further evidenced by circular dichroism and (1)H NMR measurements.

Interaction of magnetic nanoparticles with lysozyme amyloid fibrils

Energy Technology Data Exchange (ETDEWEB)

Gdovinová, Veronika [Institute of Experimental Physics SAS, Watsonova 47, 040 01 Košice (Slovakia); Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Joliot-Curie 6, 141980 Dubna, Moscow Region (Russian Federation); Tomašovičová, Natália, E-mail: nhudak@saske.sk [Institute of Experimental Physics SAS, Watsonova 47, 040 01 Košice (Slovakia); Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Joliot-Curie 6, 141980 Dubna, Moscow Region (Russian Federation); Batko, Ivan; Batková, Marianna; Balejčíková, Lucia [Institute of Experimental Physics SAS, Watsonova 47, 040 01 Košice (Slovakia); Garamus, Vasyl M. [Helmholtz-Zentrum Geesthacht: Zentrum fr Material, und Kstenforschung GmbH, Max-Plank-Strae 1, Geesthacht 216502 (Germany); Petrenko, Viktor I. [Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Joliot-Curie 6, 141980 Dubna, Moscow Region (Russian Federation); Physics Department, Taras Shevchenko Kyiv National University, Volodymyrska Street 64, 01601 Kyiv (Ukraine); Avdeev, Mikhail V. [Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Joliot-Curie 6, 141980 Dubna, Moscow Region (Russian Federation); Kopčanský, Peter [Institute of Experimental Physics SAS, Watsonova 47, 040 01 Košice (Slovakia)

2017-06-01

This work is devoted to the structural study of complex solutions of magnetic nanoparticles with lysozyme amyloid fibrils due to possible ordering of such system by applying the external magnetic field. The interaction of magnetic nanoparticles with amyloid fibrils has been followed by atomic force microscopy and small-angle X-ray scattering. It has been observed that magnetic nanoparticles (MNPs) adsorb to lysozyme amyloid fibrils. It was found that MNPs alter amyloids structures, namely the diameter of lysozyme amyloid fibrils is increased whereas the length of fibrils is decreased. In the same time MNPs do not change the helical pitch significantly. - Highlights: • Solution of MNPs with lysozyme amyloid fibrils was characterized by AFM and SAXS. • MNPs adsorb to lysozyme amyloid fibrils. • Diameter and size of lysozyme amyloid fibrils change due to doping with MNPs.

Recognition of lysozyme using surface imprinted bacterial cellulose nanofibers.

Science.gov (United States)

Saylan, Yeşeren; Tamahkar, Emel; Denizli, Adil

2017-11-01

Here, we developed the lysozyme imprinted bacterial cellulose (Lyz-MIP/BC) nanofibers via the surface imprinting strategy that was designed to recognize lysozyme. This study includes the molecular imprinting method onto the surface of bacterial cellulose nanofibers in the presence of lysozyme by metal ion coordination, as well as further characterizations methods FTIR, SEM and contact angle measurements. The maximum lysozyme adsorption capacity of Lyz-MIP/BC nanofibers was found to be 71 mg/g. The Lyz-MIP/BC nanofibers showed high selectivity for lysozyme towards bovine serum albumin and cytochrome c. Overall, the Lyz-MIP/BC nanofibers hold great potential for lysozyme recognition due to the high binding capacity, significant selectivity and excellent reusability.

Prevention of Bacterial Contamination of a Silica Matrix Containing Entrapped β-Galactosidase through the Action of Covalently Bound Lysozymes

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Heng Li

2017-02-01

Full Text Available β-galactosidase was successfully encapsulated within an amino-functionalised silica matrix using a “fish-in-net” approach and molecular imprinting technique followed by covalent binding of lysozyme via a glutaraldehyde-based method. Transmission electron microscopy (TEM, X-ray diffraction (XRD, scanning electron microscopy (SEM, and Fourier transform infrared (FTIR spectroscopy were used to characterise the silica matrix hosting the two enzymes. Both encapsulated β-galactosidase and bound lysozyme exhibited high enzymatic activities and outstanding operational stability in model reactions. Moreover, enzyme activities of the co-immobilised enzymes did not obviously change relative to enzymes immobilised separately. In antibacterial tests, bound lysozyme exhibited 95.5% and 89.6% growth inhibition of Staphylococcus aureus ATCC (American type culture collection 653 and Escherichia coli ATCC 1122, respectively. In milk treated with co-immobilised enzymes, favourable results were obtained regarding reduction of cell viability and high lactose hydrolysis rate. In addition, when both co-immobilised enzymes were employed to treat milk, high operational and storage stabilities were observed. The results demonstrate that the use of co-immobilised enzymes holds promise as an industrial strategy for producing low lactose milk to benefit people with lactose intolerance.

A more clear insight of the lysozyme crystal composition

Energy Technology Data Exchange (ETDEWEB)

Mueller, C.; Ulrich, J. [Martin-Luther-Universitaet Halle-Wittenberg, Zentrum fuer Ingenieurswissenschaften, Verfahrenstechnik/TVT, 06099 Halle Saale (Germany)

2011-07-15

Crystallization can be used as a purification method for proteins. Lysozyme was chosen as a model substance. Changing crystallization conditions will lead as shown to different lysozyme crystal morphologies with different properties. Beside others, lysozyme crystals can show a Tetragonal, High Temperature and Low Temperature Orthorhombic crystal morphology. Experiments such as conductivity measurements, pH tests, chloride detection tests, experiments using methylene blue as a dye and dissolution experiments were carried out to investigate the composition of the lysozyme crystals. It is proven that lysozyme crystals are made up of the initial buffer solution components: lysozyme (the protein), water which is part of the crystal lattice, salt ions which are attached to the protein molecule and voids filled with the buffer solution containing the crystallization agent (e.g. salt). Interesting dissolution behaviours of the lysozyme crystals were observed which are not described so far elsewhere (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

The association of lysozyme with casein

NARCIS (Netherlands)

Roos, de A.L.; Walstra, P.; Geurts, T.J.

1998-01-01

The association of hen eggs’ lysozyme with caseins was studied by using three casein substrates: (I) solutions of the various caseins, (II) artificially made casein micelles of various compositions and (III) caseins adsorbed onto soya-oil emulsion droplets. In solution, lysozyme associated most

Evaluation of lysozyme, complement C3, and total protein in different developmental stages of Caspian kutum (Rutilus frisii kutum K.

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Abdollahi Razieh

2016-03-01

Full Text Available In this study, non–specific immune parameters in fertilized eggs, eyed embryos, larvae 10, 25, 50, 60, and 70 days post hatch (DPH, and female broodstock of Caspian kutum, Rutilus frisii kutum (Kamensky, were evaluated. The lysozyme activity, complement C3, and total protein levels were measured with the turbidimetric, immunoturbidimetric, and Bradford methods, respectively. The results showed that lysozyme levels decreased from levels noted in the fertilized eggs until the larvae were 10 days old. Subsequently, significant increases in lysozyme levels were observed until 70 DPH. An increasing trend of complement component C3 was noted from the levels in fertilized eggs to 10 DPH, following which it decreased significantly. Total protein levels differed significantly in early developmental stages of Caspian kutum. The higher values of complement component C3 than of lysozyme in the early life stages could be indicative of the former’s more fundamental role.

Engineering Pichia pastoris for Efficient Production of a Novel Bifunctional Strongylocentrotus purpuratus Invertebrate-Type Lysozyme.

Science.gov (United States)

Huang, Peng; Shi, Jinlei; Sun, Qingwen; Dong, Xianping; Zhang, Ning

2018-04-13

Lysozymes are known as ubiquitously distributed immune effectors with hydrolytic activity against peptidoglycan, the major bacterial cell wall polymer, to trigger cell lysis. In the present study, the full-length cDNA sequence of a novel sea urchin Strongylocentrotus purpuratus invertebrate-type lysozyme (sp-iLys) was synthesized according to the codon usage bias of Pichia pastoris and was cloned into a constitutive expression plasmid pPIC9K. The resulting plasmid, pPIC9K-sp-iLys, was integrated into the genome of P. pastoris strain GS115. The bioactive recombinant sp-iLys was successfully secreted into the culture broth by positive transformants. The highest lytic activity of 960 U/mL of culture supernatant was reached in fed-batch fermentation. Using chitin affinity chromatography and gel-filtration chromatography, recombinant sp-iLys was produced with a yield of 94.5 mg/L and purity of > 99%. Recombinant sp-iLys reached its peak lytic activity of 8560 U/mg at pH 6.0 and 30 °C and showed antimicrobial activities against Gram-negative bacteria (Vibrio vulnificus, Vibrio parahemolyticus, and Aeromonas hydrophila) and Gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis). In addition, recombinant sp-iLys displayed isopeptidase activity which reached the peak at pH 7.5 and 37 °C with the presence of 0.05 M Na + . In conclusion, this report describes the heterologous expression of recombinant sp-iLys in P. pastoris on a preparative-scale, which possesses lytic activity and isopeptidase activity. This suggests that sp-iLys might play an important role in the innate immunity of S. purpuratus.

Technology Optimization of Lysozyme's Fresh Maintaining Effect on Apple.

Science.gov (United States)

Jun-Hong, Liu; Kun-Yu, Wang

2016-10-03

Lysozyme is a kind of alkaline globin, which functions well in the degradation of the cell wall of microbe. Currently, lysozyme is widely used in various fields, such as medicine, fruit, and vegetable industry, dairy industry, and so on. Therefore, the exploitation and utilization of lysozyme is of significant economic benefit. Taking apple as material, weight loss ratio and reducing sugar content as objectives, this paper studied the fresh-keeping effect of lysozyme. Influential factors, lysozyme concentration, soaking time, modified temperature, and reaction time were discussed in detail. The results showed that reducing sugar content was 2.043% and the weight loss ratio was the minimum in the presence of soaking time of 2 min, modified temperature of 65 °C, reaction time of 4 d, and lysozyme concentration of 0.5 g/L. © 2016 Institute of Food Technologists®.

Leukocytes respiratory burst and lysozyme level in pacu (Piaractus mesopotamicus Holmberg, 1887

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JS. Abreu

Full Text Available Innate immune responses are useful to determine the health status of fish and to evaluate the effect of immunomodulatory substances in fish farming. Leukocytes respiratory burst was measured in pacu (Piaractus mesopotamicus using chemiluminescence assay and nitroblue tetrazolium (NBT reduction assay. The nitroblue tetrazolium reduction seemed more adequate than chemiluminescence assay for leukocytes oxidative burst determination, since it was difficult to isolate the blood leucocytes for chemiluminescence assay. Plasma and serum lysozyme were measured using a turbidimetric assay. The heating of serum and plasma samples (56 ºC for 30 minutes for complement system inactivation darkened the plasma samples and interfered in the results. The lysozyme activity in serum was higher than in plasma, suggesting that serum samples are more appropriate for the analysis. This study established protocols that can be useful tools in the study of immune mechanisms of the tropical fish pacu.

Antimicrobial polycaprolactone/polyethylene glycol embedded lysozyme coatings of Ti implants for osteoblast functional properties in tissue engineering

Science.gov (United States)

Visan, A.; Cristescu, R.; Stefan, N.; Miroiu, M.; Nita, C.; Socol, M.; Florica, C.; Rasoga, O.; Zgura, I.; Sima, L. E.; Chiritoiu, M.; Chifiriuc, M. C.; Holban, A. M.; Mihailescu, I. N.; Socol, G.

2017-09-01

In this study, coatings based on lysozyme embedded into a matrix of polyethylene glycol (PEG) and polycaprolactone (PCL) were fabricated by two different methods (Matrix Assisted Pulsed Laser Evaporation - MAPLE and Dip Coating) for obtaining antimicrobial coatings envisaged for long term medical applications. Coatings with different PEG:PCL compositions (3:1; 1:1; 1:3) were synthesized in order to evaluate the antimicrobial activity of lysozyme embedded into the polymeric matrix. The main surface features, such as roughness and wettability, with impact on the microbial adhesion as well as on the eukaryote cell function were measured. The obtained composite coatings exhibited a significant antibacterial activity against Escherichia coli, Bacillus subtilis, Enterococcus faecalis and Staphylococcus aureus strains. As well, specific blended coatings showed appropriate viability, good spreading and normal cell morphology of SaOs2 human osteoblasts and mesenchymal stem cells (MSCs). These investigations highlight the suitability of biodegradable composites as implant coatings for decreasing the risk of bacterial contamination associated with prosthetic procedures.

A novel electrochemical aptamer-antibody sandwich assay for lysozyme detection.

Science.gov (United States)

Ocaña, Cristina; Hayat, Akhtar; Mishra, Rupesh; Vasilescu, Alina; del Valle, Manel; Marty, Jean-Louis

2015-06-21

In this paper, we have reported a novel electrochemical aptamer-antibody based sandwich biosensor for the detection of lysozyme. In the sensing strategy, an anti-lysozyme aptamer was immobilized onto the carbon electrode surface by covalent binding via diazonium salt chemistry. After incubating with a target protein (lysozyme), a biotinylated antibody was used to complete the sandwich format. The subsequent additions of avidin-alkaline phosphatase as an enzyme label, and a 1-naphthyl phosphate substrate (1-NPP) allowed us to determine the concentration of lysozyme (Lys) via Differential Pulse Voltammetry (DPV) of the generated enzyme reaction product, 1-naphthol. Using this strategy, a wide detection range from 5 fM to 5 nM was obtained for a target lysozyme, with a detection limit of 4.3 fM. The control experiments were carried out by using bovine serum albumin (BSA), cytochrome c and casein. The results showed that the proposed biosensor had good specificity, stability and reproducibility for lysozyme analysis. In addition, the biosensor was applied for detecting lysozyme in spiked wine samples, and very good recovery rates were obtained in the range from 95.2 to 102.0% for lysozyme detection. This implies that the proposed sandwich biosensor is a promising analytical tool for the analysis of lysozyme in real samples.

[Do lactoferrin, lysozyme and the lactoperoxidase-thiocyanate-hydrogen peroxide-system cause negative microbiological results in mastitis secretions?].

Science.gov (United States)

Schmedt Auf Der Günne, H; Tenhagen, B A; Kutzer, P; Forderung, D; Heuwieser, W

2002-07-01

Lactoferrin, lysozyme and the lactoperoxidase-thiocyanate-peroxide-system are naturally occurring antimicrobial components of milk. The objective of this study was to examine, whether these components were responsible for negative results, when mastitis milk is cultured microbiologically. Quarter milk samples from 75 cows with clinical mastitis on a dairy farm in Brandenburg were submitted for microbiological culture and analysed for the content and the activities of the three components. Animals from all stages of lactation with clinical mastitis were included in the study. Animals were examined clinically and milk samples were collected prior to first treatment. Secretions from quarters with clinical mastitis were compared to those of neighbouring quarters without clinical mastitis. Secretions with positive cultural results were compared to those with negative results. The concentrations or activities of the three factors were significantly higher in the diseased quarters than in the quarters without clinical signs of mastitis. The concentration of lysozyme increased with severity of the clinical signs (local swelling and changes in secretion). The concentration of lactoferrin was significantly higher in quarters with slight alterations of glandular tissue than in quarters with medium or severe alterations (P mastitis with positive and negative culture results. The concentration of lysozyme was even higher in culturally positive samples than in negative samples (P culture of milk samples from quarters with clinical mastitis.

The state of immunological reactivity and nonspecific protection factor (lysozyme in children with reactive arthritis

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Vladimir Savvo

2016-03-01

Full Text Available Aim. An improvement of diagnostics and prognostication of ReA clinical course in children on the base of studying the immunological reactivity and non-specific protection factor (lysozyme.Materials and methods. Examination of children took place in the municipal children’s cardiorheumatologic department of MHPI “Kharkov municipal children’s clinical hospital № 24" and municipal children’s polyclinic of the Kharkov city (№ 1, 2, 7, 12, 13, 14, 23.40 children with ReA underwent immunological examinations, detection of sIgA in the saliva and lysozyme in the blood serum in acute period and in 9–12 months after the beginning of disease. 19 children (47,5 % – 2–6 years old, 21 children (52,5 %. – 7–14 years old. Boys – 22 (55,0 %, girls – 18 (45,0 %. The mean age of children in group was 7,2±0,32. The control group included 32 healthy children. The mean age of children in group was 7,4±0,54.The ReA diagnosis was set according to the order of Ukrainian MHP of 19.07.2005 № 362 “Protocol of diagnostics and treatment of disease of musculoskeletal system and connective tissue in children ICD-D М00-М25 arthropathies”.Immunological examinations included the study of indices of cellular, humoral, monocytic-phagocytic links of immunity, content of cytokines (IL-1β, IL-6, detection of sIgA and index of nonspecific protection factor (lysozyme.Assessment of results of researches was carried out using STATISTICА program for Windows (version 10.0, Microsoft Excel 2012, MATLAB 2015a.Results. In the ReA acute period in children was observed depression of T-system on the background of activation of immunity B-system as the reliable decrease of СD8, СD25 and increase of СD21. There was revealed an increase of IL-6, increase of phagocytic number, spontaneous NBT-test and spontaneous neutrophils activity index.The sIgA level reliably exceeded the standard. At determination of lysozyme the blood serum of patients with ReA in acute

Study of ethanol-lysozyme interactions using neutron diffraction

International Nuclear Information System (INIS)

Lehmann, M.S.; Mason, S.A.; McIntyre, G.J.

1985-01-01

Single-crystal neutron diffraction has been used to observe the interactions between deuterated ethanol (CD3CD2OH) and lysozyme in triclinic crystals of hen egg white lysozyme soaked in 25% (v/v) ethanol solutions. A total of 6047 observed reflections to a resolution of 2 A were used, and 13 possible ethanol sites were identified. The three highest occupied sites are close to locations for bromoethanol found in an earlier study by Yonath et al. [Yonath, A., Podjarny, A., Honig, B., Traub, W., Sielecki, A., Herzberg, O., and Moult, J. (1978) Biophys. Struct. Mech. 4, 27-36]. Structure refinements including a model for the flat solvent lead to a final crystallographic agreement factor of 0.097. Comparison with earlier neutron studies on triclinic lysozyme showed that neither the molecular structure nor the thermal motions were affected significantly by the ethanol. A detailed analysis of the ethanol-lysozyme contacts showed 61% of these to be with hydrophobic sites, in agreement with the dominant hydrophobic nature of ethanol. This, together with the fact that the molecular structure of lysozyme is not perturbed, suggests a model for denaturation of lysozyme by alcohol, which proceeds via a dehydration of the protein at high alcohol concentration

The interaction of lysozyme with caffeine, theophylline and theobromine in solution.

Science.gov (United States)

Zhang, Hong-Mei; Tang, Bo-Ping; Wang, Yan-Qing

2010-10-01

The interactions of lysozyme with caffeine (Caf), theophylline (Tph) and theobromine (Tbr) were investigated using UV-Vis absorption, fluorescence, synchronous fluorescence, and three-dimensional fluorescence spectra techniques. The results revealed that Caf (Tph or Tbr) caused the fluorescence quenching of lysozyme by the formation of Caf (Tph or Tbr)-lysozyme complex. The binding constants (K(A)) and thermodynamic parameters (ΔG°, ΔH°, ΔS°) at two different temperatures, the binding locality, and the binding power were obtained. The results showed that the process of binding Caf (Tph or Tbr) to lysozyme was a spontaneous molecular interaction procedure and the hydrophobic and electrostatic interactions play a major role in stabilizing the complex; The distance r between donor (lysozyme) and acceptor (Caf, Tph or Tbr) was obtained according to fluorescence resonance energy transfer. The effect of Caf (Tph or Tbr) on the conformation of lysozyme was analyzed using synchronous fluorescence and three-dimensional fluorescence spectra techniques. The results showed that the binding of Caf (Tph or Tbr) to lysozyme induced some micro-environmental and conformational changes in lysozyme and disturbed the environment of the polypeptide of lysozyme.

THE BACTERICIDAL ACTIVITY OF NORMAL GUINEA PIG SERUM AGAINST LISTERIA MONOCYTOGENES AND ITS INHIBITION BY A LISTERIAL CELL EXTRACT,

Science.gov (United States)

Normal guinea pig serum contains bactericidins active against Listeria monocytogenes. The listeriocidal activity of the serum did not increase after...factor. Lysozyme was not implicated in the bactericidal system. It was suggested that the bactericidal activity of guinea pig serum might be due either to

Phase behavior of mixtures of oppositely charged nanoparticles: Heterogeneous Poisson-Boltzmann cell model applied to lysozyme and succinylated lysozyme

NARCIS (Netherlands)

Biesheuvel, P.M.; Lindhoud, S.; Vries, de R.J.; Stuart, M.A.C.

2006-01-01

We study the phase behavior of mixtures of oppositely charged nanoparticles, both theoretically and experimentally. As an experimental model system we consider mixtures of lysozyme and lysozyme that has been chemically modified in such a way that its charge is nearly equal in magnitude but opposite

Expression and prognostic significance of lysozyme in male breast cancer

International Nuclear Information System (INIS)

Serra, Carlos; Baltasar, Aniceto; Medrano, Justo; Vizoso, Francisco; Alonso, Lorena; Rodríguez, Juan C; González, Luis O; Fernández, María; Lamelas, María L; Sánchez, Luis M; García-Muñiz, José L

2002-01-01

Lysozyme, one of the major protein components of human milk that is also synthesized by a significant percentage of breast carcinomas, is associated with lesions that have a favorable outcome in female breast cancer. Here we evaluate the expression and prognostic value of lysozyme in male breast cancer (MBC). Lysozyme expression was examined by immunohistochemical methods in a series of 60 MBC tissue sections and in 15 patients with gynecomastia. Staining was quantified using the HSCORE (histological score) system, which considers both the intensity and the percentage of cells staining at each intensity. Prognostic value of lysozyme was retrospectively evaluated by multivariate analysis taking into account conventional prognostic factors. Lysozyme immunostaining was negative in all cases of gynecomastia. A total of 27 of 60 MBC sections (45%) stained positively for this protein, but there were clear differences among them with regard to the intensity and percentage of stained cells. Statistical analysis showed that lysozyme HSCORE values in relation to age, tumor size, nodal status, histological grade, estrogen receptor status, metastasis and histological type did not increase the statistical significance. Univariate analysis confirmed that both nodal involvement and lysozyme values were significant predictors of short-term relapse-free survival. Multivariate analysis, according to Cox's regression model, also showed that nodal status and lysozyme levels were significant independent indicators of short-term relapse-free survival. Tumor expression of lysozyme is associated with lesions that have an unfavorable outcome in male breast cancer. This milk protein may be a new prognostic factor in patients with breast cancer

Biomimetic mineralization of calcium carbonate/carboxymethylcellulose microspheres for lysozyme immobilization

International Nuclear Information System (INIS)

Lu Zheng; Zhang Juan; Ma Yunzi; Song Siyue; Gu Wei

2012-01-01

Porous calcium carbonate/carboxymethylcellulose (CaCO 3 /CMC) microspheres were prepared by the biomimetic mineralization method for lysozyme immobilization via adsorption. The size and morphology of CaCO 3 /CMC microspheres were characterized by transmitted electron microscopy (TEM) and zeta potential measurement. The lysozyme immobilization was verified by Fourier transform infrared (FTIR) spectroscopy. The effects of pHs and temperatures on lysozyme adsorption were investigated as well. It was revealed that CaCO 3 /CMC microspheres could immobilize lysozyme efficiently via electrostatic interactions and a maximum adsorption capacity of 450 mg/g was achieved at pH 9.2 and 25 °C. Moreover, it was found that the adsorption process fitted well with the Langmuir isothermal model. In addition, UV, fluorescence, and circular dichroism (CD) spectroscopic studies showed that lysozyme maintained its original secondary structure during the adsorption/desorption process. Our study therefore demonstrated that CaCO 3 /CMC microsphere can be used as a cost-effective and efficient support for lysozyme immobilization. - Graphical abstract: CaCO 3 /CMC microsphere was prepared by a facile biomimetic mineralization method and can be used as an efficient and cost-effective support for lysozyme immobilization. Highlights: ► CaCO 3 /CMC microspheres were prepared by the biomimetic mineralization method. ► Lysozyme was efficiently immobilized to CaCO 3 /CMC microspheres via adsorption. ► A maximum adsorption capacity of 450 mg/g was obtained at pH 9.2 and 25 °C. ► The original secondary structure of lysozyme was maintained upon immobilization.

Two duplicated chicken-type lysozyme genes in disc abalone Haliotis discus discus: molecular aspects in relevance to structure, genomic organization, mRNA expression and bacteriolytic function.

Science.gov (United States)

Umasuthan, Navaneethaiyer; Bathige, S D N K; Kasthuri, Saranya Revathy; Wan, Qiang; Whang, Ilson; Lee, Jehee

2013-08-01

Lysozymes are crucial antibacterial proteins that are associated with catalytic cleavage of peptidoglycan and subsequent bacteriolysis. The present study describes the identification of two lysozyme genes from disc abalone Haliotis discus discus and their characterization at sequence-, genomic-, transcriptional- and functional-levels. Two cDNAs and BAC clones bearing lysozyme genes were isolated from abalone transcriptome and BAC genomic libraries, respectively and sequences were determined. Corresponding deduced amino acid sequences harbored a chicken-type lysozyme (LysC) family profile and exhibited conserved characteristics of LysC family members including active residues (Glu and Asp) and GS(S/T)DYGIFQINS motif suggested that they are LysC counterparts in disc abalone and designated as abLysC1 and abLysC2. While abLysC1 represented the homolog recently reported in Ezo abalone [1], abLysC2 shared significant identity with LysC homologs. Unlike other vertebrate LysCs, coding sequence of abLysCs were distributed within five exons interrupted by four introns. Both abLysCs revealed a broader mRNA distribution with highest levels in mantle (abLysC1) and hepatopancreas (abLysC2) suggesting their likely main role in defense and digestion, respectively. Investigation of temporal transcriptional profiles post-LPS and -pathogen challenges revealed induced-responses of abLysCs in gills and hemocytes. The in vitro muramidase activity of purified recombinant (r) abLysCs proteins was evaluated, and findings indicated that they are active in acidic pH range (3.5-6.5) and over a broad temperature range (20-60 °C) and influenced by ionic strength. When the antibacterial spectra of (r)abLysCs were examined, they displayed differential activities against both Gram positive and Gram negative strains providing evidence for their involvement in bacteriolytic function in abalone physiology. Copyright © 2013 Elsevier Ltd. All rights reserved.

Penetration and fusion of phospholipid vesicles by lysozyme

International Nuclear Information System (INIS)

Kim, J.; Kim, H.

1989-01-01

The lysozyme-induced fusion of phosphatidylserine/phosphatidylethanolamine vesicles as studied at a wide range of pH is found to correlate well with the binding of this protein to the vesicles. An identical 6000 molecular weight segment of lysozyme at the N-terminal region is found to be protected from tryptic digestion when initially incubated with vesicles at several pH values. Only this segment is labeled by dansyl chloride, which is partitioned into the bilayer. These results suggest the penetration of one segment of lysozyme into the bilayer. Photoactivated labeling of the membrane-penetrating segment of lysozyme with 3-(trifluoromethyl)-3-([ 125 I]iodophenyl)diazirine ([ 125 I]TID) and subsequent identification of the labeled residues by Edman degradation and gamma-ray counting indicate that four amino acids from the N-terminal are located outside the hydrophobic core of the bilayer. Although treatment of the membrane-embedded segment with aminopeptidase failed to cleave any amino acids from the N-terminal, it appears that a loop of lysozyme segment near the N-terminal penetrates into the bilayer at acidic pH. A helical wheel diagram shows that the labeling is done mainly on one surface of the alpha-helix. The penetration kinetics as studied by time-dependent [ 125 I]TID labeling coincide with the fusion kinetics, strongly suggesting that the penetration of the lysozyme segment into the vesicles is the cause of the fusion

Penetration and fusion of phospholipid vesicles by lysozyme

Energy Technology Data Exchange (ETDEWEB)

Kim, J.; Kim, H. (Korea Advanced Institute of Science and Technology, Seoul)

1989-10-01

The lysozyme-induced fusion of phosphatidylserine/phosphatidylethanolamine vesicles as studied at a wide range of pH is found to correlate well with the binding of this protein to the vesicles. An identical 6000 molecular weight segment of lysozyme at the N-terminal region is found to be protected from tryptic digestion when initially incubated with vesicles at several pH values. Only this segment is labeled by dansyl chloride, which is partitioned into the bilayer. These results suggest the penetration of one segment of lysozyme into the bilayer. Photoactivated labeling of the membrane-penetrating segment of lysozyme with 3-(trifluoromethyl)-3-(({sup 125}I)iodophenyl)diazirine (({sup 125}I)TID) and subsequent identification of the labeled residues by Edman degradation and gamma-ray counting indicate that four amino acids from the N-terminal are located outside the hydrophobic core of the bilayer. Although treatment of the membrane-embedded segment with aminopeptidase failed to cleave any amino acids from the N-terminal, it appears that a loop of lysozyme segment near the N-terminal penetrates into the bilayer at acidic pH. A helical wheel diagram shows that the labeling is done mainly on one surface of the alpha-helix. The penetration kinetics as studied by time-dependent ({sup 125}I)TID labeling coincide with the fusion kinetics, strongly suggesting that the penetration of the lysozyme segment into the vesicles is the cause of the fusion.

Antibiotic and fermentative activity of bacteria found in water and digestive tract of fish from Lake Drukshiai at Ignalina Nuclear Power Plant

International Nuclear Information System (INIS)

Lubianskiene, V.; Jastiuginiene, R.

1996-01-01

The composition and antagonistic activity of microflora found in water and digestive tract of roaches - fish, which prevail in Lake Drukshiai, were investigated. The investigations revealed that unfavourable environmental conditions first of all gave rise to the changes in bacteria composition. It has been found that the bacteria of g. Vibrio, prevailed, their virulentic properties became more intense, antibiotical properties weakened, the prevailing microflora lost its ability to fight with pathogenic microorganisms. An increased lysozymic activity of g. Vibrio bacteria in the intestinal tract of fishes shows their resistance to phagocytosis and ability to stay for a long time in the digestive tract. The high antilysozymic activity of g. Vibrio bacteria in fishes digestive tract shows their ability to inactivate the lysozyme secreted by cells of organism reaction to pathogenic microflora. Antilysozymic and lysozymic activity of g. Vibrio bacteria is supposed to be one of the causes predetermining the predominance of this genus in biocenosis. The predominance of g. Vibrio bacteria in biocenosis of water and fish digestive tract bacteria, the strengthening of their virulentic properties speak for poor microecological conditions in the lake and lower immunological state of fish. 15 refs., 7 figs

Lysozyme and bilirubin bind to ACE and regulate its conformation and shedding

Science.gov (United States)

Danilov, Sergei M.; Lünsdorf, Heinrich; Akinbi, Henry T.; Nesterovitch, Andrew B.; Epshtein, Yuliya; Letsiou, Eleftheria; Kryukova, Olga V.; Piegeler, Tobias; Golukhova, Elena Z.; Schwartz, David E.; Dull, Randal O.; Minshall, Richard D.; Kost, Olga A.; Garcia, Joe G. N.

2016-01-01

Angiotensin I-converting enzyme (ACE) hydrolyzes numerous peptides and is a critical participant in blood pressure regulation and vascular remodeling. Elevated tissue ACE levels are associated with increased risk for cardiovascular and respiratory disorders. Blood ACE concentrations are determined by proteolytic cleavage of ACE from the endothelial cell surface, a process that remains incompletely understood. In this study, we identified a novel ACE gene mutation (Arg532Trp substitution in the N domain of somatic ACE) that increases blood ACE activity 7-fold and interrogated the mechanism by which this mutation significantly increases blood ACE levels. We hypothesized that this ACE mutation disrupts the binding site for blood components which may stabilize ACE conformation and diminish ACE shedding. We identified the ACE-binding protein in the blood as lysozyme and also a Low Molecular Weight (LMW) ACE effector, bilirubin, which act in concert to regulate ACE conformation and thereby influence ACE shedding. These results provide mechanistic insight into the elevated blood level of ACE observed in patients on ACE inhibitor therapy and elevated blood lysozyme and ACE levels in sarcoidosis patients. PMID:27734897

Effects of Purification on the Crystallization of Lysozyme

Science.gov (United States)

Ewing, Felecia L.; Forsythe, Elizabeth L.; Van Der Woerd, Mark; Pusey, Marc L.

1996-01-01

We have additionally purified a commercial lysozyme preparation by cation exchange chromatography, followed by recrystallization. This material is 99.96% pure with respect to macromolecular impurities. At basic pH, the purified lysozyme gave only tetragonal crystals at 20 C. Protein used directly from the bottle, prepared by dialysis against distilled water, or which did not bind to the cation exchange column had considerably altered crystallization behavior. Lysozyme which did not bind to the cation exchange column was subsequently purified by size exclusion chromatography. This material gave predominately bundles of rod-shaped crystals with some small tetragonal crystals at lower pHs. The origin of the bundled rod habit was postulated to be a thermally dependent tetragonal- orthorhombic change in the protein structure. This was subsequently ruled out on the basis of crystallization behavior and growth rate experiments. This suggests that heterogeneous forms of lysozyme may be responsible. These results demonstrate three classes of impurities: (1) small molecules, which may be removed by dialysis; (2) macromolecules, which are removable by chromatographic techniques; and (3) heterogeneous forms of the protein, which can be removed in this case by cation exchange chromatography. Of these, heterogeneous forms of the lysozyme apparently have the greatest affect on its crystallization behavior.

Use of Lysozyme as a Feed Additive on Rumen Fermentation and Methane Emission

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Ashraf A. Biswas

2016-11-01

Full Text Available This study was conducted to determine the effect of lysozyme addition on in vitro rumen fermentation and to identify the lysozyme inclusion rate for abating methane (CH4 production. An in vitro ruminal fermentation technique was done using a commercial concentrate to rice straw ratio of 8:2 as substrate. The following treatments were applied wherein lysozyme was added into 1 mg dry matter substrate at different levels of inclusion: Without lysozyme, 2,000, 4,000, and 8,000 U lysozyme. Results revealed that, lysozyme addition had a significant effect on pH after 24 h of incubation, with the highest pH (p<0.01 observed in 8,000 U lysozyme, followed by the 4,000 U, 2,000 U, and without lysozyme. The highest amounts of acetic acid, propionic acid (p<0.01 and total volatile fatty acid (TVFA (p<0.05 were found in 8,000 U after 24 h of incubation. The CH4 concentration was the lowest in the 8,000 U and the highest in the without lysozyme addition after 24 h of incubation. There was no significant differences in general bacteria, methanogen, or protozoan DNA copy number. So far, addition of lysozyme increased the acetate, propionate, TVFA, and decreased CH4 concentration. These results suggest that lysozyme supplementation may improve in vitro rumen fermentation and reduce CH4 emission.

Potential toxicity and affinity of triphenylmethane dye malachite green to lysozyme.

Science.gov (United States)

Ding, Fei; Li, Xiu-Nan; Diao, Jian-Xiong; Sun, Ye; Zhang, Li; Ma, Lin; Yang, Xin-Ling; Zhang, Li; Sun, Ying

2012-04-01

Malachite green is a triphenylmethane dye that is used extensively in many industrial and aquacultural processes, generating environmental concerns and health problems to human being. In this contribution, the complexation between lysozyme and malachite green was verified by means of computer-aided molecular modeling, steady state and time-resolved fluorescence, and circular dichroism (CD) approaches. The precise binding patch of malachite green in lysozyme has been identified from molecular modeling and ANS displacement, Trp-62, Trp-63, and Trp-108 residues of lysozyme were earmarked to possess high-affinity for this dye, the principal forces in the lysozyme-malachite green adduct are hydrophobic and π-π interactions. Steady state fluorescence proclaimed the complex of malachite green with lysozyme yields quenching through static type, which substantiates time-resolved fluorescence measurements that lysozyme-malachite green conjugation formation has an affinity of 10(3)M(-1). Moreover, via molecular modeling and also CD data, we can safely arrive at a conclusion that the polypeptide chain of lysozyme partially destabilized upon complexation with malachite green. The data emerged here will help to further understand the toxicological action of malachite green in human body. Copyright © 2012 Elsevier Inc. All rights reserved.

The Timing of cotE Expression Affects Bacillus subtilis Spore Coat Morphology but Not Lysozyme Resistance▿

Science.gov (United States)

Costa, Teresa; Serrano, Mónica; Steil, Leif; Völker, Uwe; Moran, Charles P.; Henriques, Adriano O.

2007-01-01

The synthesis of structural components and morphogenetic factors required for the assembly of the Bacillus subtilis spore coat is governed by a mother cell-specific transcriptional cascade. The first two temporal classes of gene expression, which involve RNA polymerase sigma σE factor and the ancillary regulators GerR and SpoIIID, are deployed prior to engulfment of the prespore by the mother cell. The two last classes rely on σK, whose activation follows engulfment completion, and GerE. The cotE gene codes for a morphogenetic protein essential for the assembly of the outer coat layer and spore resistance to lysozyme. cotE is expressed first from a σE-dependent promoter and, in a second stage, from a promoter that additionally requires SpoIIID and that remains active under σK control. CotE localizes prior to engulfment completion close to the surface of the developing spore, but formation of the outer coat is a late, σK-controlled event. We have transplanted cotE to progressively later classes of mother cell gene expression. This created an early class of mutants in which cotE is expressed prior to engulfment completion and a late class in which expression of cotE follows the complete engulfment of the prespore. Mutants of the early class assemble a nearly normal outer coat structure, whereas mutants of the late class do not. Hence, the early expression of CotE is essential for outer coat assembly. Surprisingly, however, all mutants were fully resistant to lysozyme. The results suggest that CotE has genetically separable functions in spore resistance to lysozyme and spore outer coat assembly. PMID:17172339

Cross-linked lysozyme crystal templated synthesis of Au nanoparticles as high-performance recyclable catalysts

International Nuclear Information System (INIS)

Liang Miao; Liu Xia; Qi Wei; Su Rongxin; Huang Renliang; Yu Yanjun; He Zhimin; Wang Libing

2013-01-01

Bio-nanomaterials fabricated using a bioinspired templating technique represent a novel class of composite materials with diverse applications in biomedical, electronic devices, drug delivery, and catalysis. In this study, Au nanoparticles (NPs) are synthesized within the solvent channels of cross-linked lysozyme crystals (CLLCs) in situ without the introduction of extra chemical reagents or physical treatments. The as-prepared AuNPs-in-protein crystal hybrid materials are characterized by light microscopy, transmission electron microscopy, x-ray diffraction, and Fourier-transform infrared spectroscopy analyses. Small AuNPs with narrow size distribution reveal the restriction effects of the porous structure in the lysozyme crystals. These composite materials are proven to be active heterogeneous catalysts for the reduction of 4-nitrophenol to 4-aminophenol. These catalysts can be easily recovered and reused at least 20 times because of the physical stability and macro-dimension of CLLCs. This work is the first to use CLLCs as a solid biotemplate for the preparation of recyclable high-performance catalysts. (paper)

Use of lysozyme from chicken egg white as a nitrite replacer in an Italian-type chicken sausage

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Nalaka Sandun Abeyrathne

2015-09-01

Full Text Available Background: Sodium or potassium nitrite is widely used as a curing agent in sausages and other cured meat products. Nitrite has strong antimicrobial and antioxidant effects and generates cured meat color. Nitrite, however, can react with secondary or tertiary amines in meat to form carcinogenic, teratogenic and mutagenic N-nitroso compounds. Several findings have been suggested that high consumption of processed meat may increase the risk of cancer, and emphasized that dietary nitrosamines are positively associated with cancer. Lysozyme is one of the major egg proteins that have antimicrobial and antioxidant characteristics. Therefore, lysozyme can be used in meat processing to prevent microbial growth and oxidative degradation in meat products during storage. This study is focused on evaluating the antimicrobial and antioxidant effects of lysozyme extracted from egg white as a replacer of nitrite in a cooked Italian-type chicken sausage. Methods: Four curing treatments including 100% nitrite (control, 100% lysozyme (treatment 1, 25% nitrite + 75% lysozyme (treatment 2 and 50% nitrite + 50% lysozyme (treatment 3 were used to prepare Italian-type chicken sausage samples. Recipe was developed with 64% (w/w meat, 17% (w/w binder (bread crumble, 12% (w/w ice, 4% (w/w vegetable oil, 2% (w/w salt, 1% (w/w spices (chili, black pepper, cardamom. Prepared samples were cooked in an 80 °C smoke house to a core temperature of 65 °C and cooled in cold water to 20-25 °C subsequently packed in polyethylene and stored in a freezer (-18 °C. The antimicrobial effect lysozyme was tested using Escherichia coli and Salmonella. The growth of these pathogens at 0, 3 and 5 days of storage of spore inoculation was determined. The antioxidant activity of lysozyme was determined using the TBARS value during the 25 d storage period. The redness (a*, lightness (L*, and yellowness (b* of sausages were analyzed using a Minolta color meter (CR 410, Konica Minolta Inc

Antimicrobial activity of innate immune molecules against Streptococcus pneumoniae, Moraxella catarrhalis and nontypeable Haemophilus influenzae

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Teufert Karen

2004-05-01

Full Text Available Abstract Background Despite its direct connection to the nasopharynx which harbors otitis media pathogens as part of its normal flora, the middle ear cavity is kept free of these bacteria by as yet unknown mechanisms. Respiratory mucosal epithelia, including those of the middle ear and eustachian tube, secrete antimicrobial effectors including lysozyme, lactoferrin and β defensins-1 and -2. To elucidate the role of these innate immune molecules in the normal defense and maintenance of sterility of respiratory mucosa such as that of the middle ear, we assessed their effect on the respiratory pathogens nontypeable Haemophilus influenzae (NTHi 12, Moraxella catarrhalis 035E, and Streptococcus pneumoniae 3, and 6B. Methods Two assay methods, the radial assay and the liquid broth assay, were employed for testing the antimicrobial activity of the molecules. This was done in order to minimize the possibility that the observed effects were artifacts of any single assay system employed. Also, transmission electron microscopy (TEM was employed to evaluate the effect of antimicrobial innate immune molecules on OM pathogens. For the statistical analysis of the data, Student's t-test was performed. Results Results of the radial diffusion assay showed that β defensin-2 was active against all four OM pathogens tested, while treatment with β defensin-1 appeared to only affect M. catarrhalis. The radial assay results also showed that lysozyme was quite effective against S. pneumoniae 3 and 6B and was partially bacteriostatic/bactericidal against M. catarrhalis. Lysozyme however, appeared not to affect the growth of NTHi. Thus, lysozyme seems to have a more pronounced impact on the growth of the Gram-positive S. pneumoniae as compared to that of Gram-negative pathogens. Lactoferrin on the other hand, enhanced the growth of the bacteria tested. The results of the radial assays were confirmed using liquid broth assays for antimicrobial activity, and showed that

A population-based study of salivary lysozyme concentrations and candidal counts.

Science.gov (United States)

Yeh, C K; Dodds, M W; Zuo, P; Johnson, D A

1997-01-01

The relationship between salivary lysozyme concentration and oral candida load was examined in 595 adults. Unstimulated whole saliva, and citrate-stimulated parotid and submandibular/sublingual saliva were collected from each participant. Candida colony-forming units (c.f.u.) in unstimulated whole saliva were determined. An enzyme-linked immunosorbent assay for lysozyme using commercially available antibodies was developed. This assay showed a linear relation of salivary lysozyme concentrations from 0.5 to 4.0 ng/ml. Significant negative relations were observed between lysozyme concentration and flow rate: r = -0.16 (p candida counts (r = 0.18: p candida in whole saliva revealed that lysozyme concentrations were higher in the high candida (> or = 1000 c.f.u./ml) group than in the zero and moderate candida categories in stimulated parotid saliva (p candida load increases.

Molecular dynamics simulations of lysozyme in water/sugar solutions

Energy Technology Data Exchange (ETDEWEB)

Lerbret, A. [Department of Food Science, Cornell University, 101 Stocking Hall, Ithaca, NY 14853 (United States); Affouard, F. [Laboratoire de Dynamique et Structure des Materiaux Moleculaires, UMR CNRS 8024, Universite Lille I, 59655 Villeneuve d' Ascq Cedex (France)], E-mail: frederic.affouard@univ-lille1.fr; Bordat, P. [Laboratoire de Chimie Theorique et de Physico-Chimie Moleculaire, UMR 5624, Universite de Pau et des Pays de l' Adour, 64000 Pau (France); Hedoux, A.; Guinet, Y.; Descamps, M. [Laboratoire de Dynamique et Structure des Materiaux Moleculaires, UMR CNRS 8024, Universite Lille I, 59655 Villeneuve d' Ascq Cedex (France)

2008-04-18

Structural and dynamical properties of the solvent at the protein/solvent interface have been investigated by molecular dynamics simulations of lysozyme in trehalose, maltose and sucrose solutions. Results are discussed in the framework of the bioprotection phenomena. The analysis of the relative concentration of water oxygen atoms around lysozyme suggests that lysozyme is preferentially hydrated. When comparing the three sugars, trehalose is seen more excluded than maltose and sucrose. The preferential exclusion of sugars from the protein surface induces some differences in the behavior of trehalose and maltose, particularly at 50 and 60 wt% concentrations, that are not observed experimentally in binary sugar/mixtures. The dynamical slowing down of the solvent is suggested to mainly arise from the homogeneity of the water/sugar matrices controlled by the percolation of the sugar hydrogen bonds networks. Furthermore, lysozyme strongly increases relaxation times of solvent molecules at the protein/solvent interface.

Interaction of anthraquinone dyes with lysozyme: Evidences from spectroscopic and docking studies

International Nuclear Information System (INIS)

Paramaguru, G.; Kathiravan, A.; Selvaraj, S.; Venuvanalingam, P.; Renganathan, R.

2010-01-01

The interaction between lysozyme and anthraquinone dyes such as Alizarin Red S, Acid blue 129 and Uniblue was studied using steady state, time resolved fluorescence measurements and docking studies. Addition of anthraquinone dyes effectively quenched the intrinsic fluorescence of lysozyme. Fluorescence quenching of lysozyme by dyes has revealed the formation of complex. The number of binding sites (n) and binding constant (K) for all the three dyes was calculated by relevant fluorescence quenching data. Based on Foerster's non-radiative energy transfer theory, distance (r 0 ) between the donor (lysozyme) and acceptor (dyes) as well as the critical energy transfer distance (R 0 ) has also been calculated. The interaction between dyes and lysozyme occurs through static quenching mechanism as confirmed by time resolved spectroscopy. The conformational change of lysozyme has been analyzed using synchronous fluorescence measurement. Finally, docking studies revealed that specific interactions were observed with the residue of Trp 62.

Growth and optical microscopy observation of the lysozyme crystals

OpenAIRE

R.Vlokh; L.Marsel; I.Teslyuk; O.G.Vlokh

2001-01-01

The little single lysozyme crystals in the capillary after 15 days of growth process with average size 0.1´0.1´0.16mm3 were obtained. It was shown that lysozyme crystals are optically anisotropical and birefringence along a axis is Dn=(2.2±0.5)´10-3 in visible spectrum region. From the measurements of crystallographic angles follows that on the {001} faces angles equal a=81o, b=99o. On the sexangle faces angles equal e=100o, f=140o and g=120o. On the base of obtained results the lysozyme crys...

Computational study of aggregation mechanism in human lysozyme[D67H].

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Dharmeshkumar Patel

Full Text Available Aggregation of proteins is an undesired phenomena that affects both human health and bioengineered products such as therapeutic proteins. Finding preventative measures could be facilitated by a molecular-level understanding of dimer formation, which is the first step in aggregation. Here we present a molecular dynamics (MD study of dimer formation propensity in human lysozyme and its D67H variant. Because the latter protein aggregates while the former does not, they offer an ideal system for testing the feasibility of the proposed MD approach which comprises three stages: i partially unfolded conformers involved in dimer formation are generated via high-temperature MD simulations, ii potential dimer structures are searched using docking and refined with MD, iii free energy calculations are performed to find the most stable dimer structure. Our results provide a detailed explanation for how a single mutation (D67H turns human lysozyme from non-aggregating to an aggregating protein. Conversely, the proposed method can be used to identify the residues causing aggregation in a protein, which can be mutated to prevent it.

Nanocomposites Based on PCL and Halloysite Nanotubes Filled with Lysozyme: Effect of Draw Ratio on the Physical Properties and Release Analysis

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Valeria Bugatti

2017-08-01

Full Text Available Halloysite nanotubes (HNTs were loaded with lsozyme, as antimicrobial molecule, at a HNTs/lysozyme ratio of 1:1. Such a nano-hybrid was incorporated into a poly (ε-caprolactone (PCL matrix at 10 wt % and films were obtained. The nano-composites were submitted to a cold drawn process at three different draw ratios, λ = 3, 4, and 5, where λ is l(final length/l0(initial length. Morphology, physical, and barrier properties of the starting nanocomposite and drawn samples were studied, and correlated to the release of the lysozyme molecule. It was demonstrated that with a simple mechanical treatment it is possible to obtain controlled release systems for specific active packaging requirements.

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

Interaction of anthraquinone dyes with lysozyme: Evidences from spectroscopic and docking studies

Energy Technology Data Exchange (ETDEWEB)

Paramaguru, G.; Kathiravan, A.; Selvaraj, S.; Venuvanalingam, P. [School of Chemistry, Bharathidasan University, Tiruchirappalli 620024, Tamil Nadu (India); Renganathan, R., E-mail: rrengas@gmail.com [School of Chemistry, Bharathidasan University, Tiruchirappalli 620024, Tamil Nadu (India)

2010-03-15

The interaction between lysozyme and anthraquinone dyes such as Alizarin Red S, Acid blue 129 and Uniblue was studied using steady state, time resolved fluorescence measurements and docking studies. Addition of anthraquinone dyes effectively quenched the intrinsic fluorescence of lysozyme. Fluorescence quenching of lysozyme by dyes has revealed the formation of complex. The number of binding sites (n) and binding constant (K) for all the three dyes was calculated by relevant fluorescence quenching data. Based on Foerster's non-radiative energy transfer theory, distance (r{sub 0}) between the donor (lysozyme) and acceptor (dyes) as well as the critical energy transfer distance (R{sub 0}) has also been calculated. The interaction between dyes and lysozyme occurs through static quenching mechanism as confirmed by time resolved spectroscopy. The conformational change of lysozyme has been analyzed using synchronous fluorescence measurement. Finally, docking studies revealed that specific interactions were observed with the residue of Trp 62.

Adsorption of lysozyme unto silica and polystyrene surfaces in ...

African Journals Online (AJOL)

The adsorption capacity of lysozyme (chicken egg white) from aqueous solutions unto silica and polystyrene interfaces was studied at varying lysozyme concentrations and ionic strength. The studies revealed an increase in adsorption capacity with increase in concentration and with maximum adsorption densities of 1.34 ...

The direct piezoelectric effect in the globular protein lysozyme

Science.gov (United States)

Stapleton, A.; Noor, M. R.; Sweeney, J.; Casey, V.; Kholkin, A. L.; Silien, C.; Gandhi, A. A.; Soulimane, T.; Tofail, S. A. M.

2017-10-01

Here, we present experimental evidence of the direct piezoelectric effect in the globular protein, lysozyme. Piezoelectric materials are employed in many actuating and sensing applications because they can convert mechanical energy into electrical energy and vice versa. Although originally studied in inorganic materials, several biological materials including amino acids and bone, also exhibit piezoelectricity. The exact mechanisms supporting biological piezoelectricity are not known, nor is it known whether biological piezoelectricity conforms strictly to the criteria of classical piezoelectricity. The observation of piezoelectricity in protein crystals presented here links biological piezoelectricity with the classical theory of piezoelectricity. We quantify the direct piezoelectric effect in monoclinic and tetragonal aggregate films of lysozyme using conventional techniques based on the Berlincourt Method. The largest piezoelectric effect measured in a crystalline aggregate film of lysozyme was approximately 6.5 pC N-1. These findings raise fundamental questions as to the possible physiological significance of piezoelectricity in lysozyme and the potential for technical applications.

Dielectric and gravimetric studies of water binding to lysozyme

International Nuclear Information System (INIS)

Bone, S.

1996-01-01

Time domain dielectric spectroscopy and hydration isotherm measurements as a function of temperature have been applied to hydrated lysozyme powder. Two dielectric dispersions were identified, the first centred at approximately 8 MHz and a second above 1 GHz. The higher dispersion is considered to be the result of rotational relaxation of water molecules bound to the enzyme. In this case the results indicate the existence of a population of 32 water molecules per lysozyme molecule which are irrotationally bound to the lysozyme structure. A larger population of water molecules is relatively free to respond to the electric field and exhibits a dipole moment close to that of vapour phase water molecules. Multi-temperature hydration isotherm measurements are used to calculate enthalpies and entropies associated with the binding of water to lysozyme. Discontinuities both in dielectric and in thermodynamic characteristics in the range 10-14% hydration are interpreted as a re-ordering of the water structure on the enzyme surface

A study of the interaction between malachite green and lysozyme by steady-state fluorescence.

Science.gov (United States)

Ding, Fei; Liu, Wei; Liu, Feng; Li, Zhi-Yuan; Sun, Ying

2009-09-01

The interaction of a N-methylated diaminotriphenylmethane dye, malachite green, with lysozyme was investigated by fluorescence spectroscopic techniques under physiological conditions. The binding parameters have been evaluated by fluorescence quenching methods. The results revealed that malachite green caused the fluorescence quenching of lysozyme through a static quenching procedure. The thermodynamic parameters like DeltaH and DeltaS were calculated to be -15.33 kJ mol(-1) and 19.47 J mol(-1) K(-1) according to van't Hoff equation, respectively, which proves main interaction between malachite green and lysozyme is hydrophobic forces and hydrogen bond contact. The distance r between donor (lysozyme) and acceptor (malachite green) was obtained to be 3.82 nm according to Frster's theory. The results of synchronous fluorescence, UV/vis and three-dimensional fluorescence spectra showed that binding of malachite green with lysozyme can induce conformational changes in lysozyme. In addition, the effects of common ions on the constants of lysozyme-malachite green complex were also discussed.

Genetic control of the humoral immune response to avian egg white lysozymes in the chicken

International Nuclear Information System (INIS)

Flanagan, M.P.

1987-01-01

Chickens from two closely related sublines, GHs-B6 and GHs-B13, differing serologically at the major histocompatibility complex, were significantly different in their humoral response to three avian egg white lysozymes. Specific antisera levels were measured by radioimmunoassay using 125 I-labeled lysozymes. Antibodies elicited in response to these lysozymes are assumed to be directed against sites on these lysozymes where their amino acid sequence differs from that of the recipient G. domesticus egg white lysozyme (HEL). GHs-B6 birds produced a high level of antibody in response to immunization of turkey (TEL), pheasant (PhL) and guinea hen (GHL) lysozymes. GHs-B13 birds produced no detectable antibody to TEL, were intermediate in their response to PhL and equaled the antibody production of GHs-B6 birds in response to GHL. Antisera to each lysozyme were examined for crossreactivity with all other lysozymes by use of a competitive binding assay

A complex of equine lysozyme and oleic acid with bactericidal activity against Streptococcus pneumoniae.

Directory of Open Access Journals (Sweden)

Emily A Clementi

Full Text Available HAMLET and ELOA are complexes consisting of oleic acid and two homologous, yet functionally different, proteins with cytotoxic activities against mammalian cells, with HAMLET showing higher tumor cells specificity, possibly due to the difference in propensity for oleic acid binding, as HAMLET binds 5-8 oleic acid molecules per protein molecule and ELOA binds 11-48 oleic acids. HAMLET has been shown to possess bactericidal activity against a number of bacterial species, particularly those with a respiratory tropism, with Streptococcus pneumoniae displaying the greatest degree of sensitivity. We show here that ELOA also displays bactericidal activity against pneumococci, which at lower concentrations shows mechanistic similarities to HAMLET's bactericidal activity. ELOA binds to S. pneumoniae and causes perturbations of the plasma membrane, including depolarization and subsequent rupture, and activates an influx of calcium into the cells. Selective inhibition of calcium channels and sodium/calcium exchange activity significantly diminished ELOA's bactericidal activity, similar to what we have observed with HAMLET. Finally, ELOA-induced death was also accompanied by DNA fragmentation into high molecular weight fragments - an apoptosis-like morphological phenotype that is seen during HAMLET-induced death. Thus, in contrast to different mechanisms of eukaryote cell death induced by ELOA and HAMLET, these complexes are characterized by rather similar activities towards bacteria. Although the majority of these events could be mimicked using oleic acid alone, the concentrations of oleic acid required were significantly higher than those present in the ELOA complex, and for some assays, the results were not identical between oleic acid alone and the ELOA complex. This indicates that the lipid, as a common denominator in both complexes, is an important component for the complexes' bactericidal activities, while the proteins are required both to solubilize

Probabilistic approach to lysozyme crystal nucleation kinetics.

Science.gov (United States)

Dimitrov, Ivaylo L; Hodzhaoglu, Feyzim V; Koleva, Dobryana P

2015-09-01

Nucleation of lysozyme crystals in quiescent solutions at a regime of progressive nucleation is investigated under an optical microscope at conditions of constant supersaturation. A method based on the stochastic nature of crystal nucleation and using discrete time sampling of small solution volumes for the presence or absence of detectable crystals is developed. It allows probabilities for crystal detection to be experimentally estimated. One hundred single samplings were used for each probability determination for 18 time intervals and six lysozyme concentrations. Fitting of a particular probability function to experimentally obtained data made possible the direct evaluation of stationary rates for lysozyme crystal nucleation, the time for growth of supernuclei to a detectable size and probability distribution of nucleation times. Obtained stationary nucleation rates were then used for the calculation of other nucleation parameters, such as the kinetic nucleation factor, nucleus size, work for nucleus formation and effective specific surface energy of the nucleus. The experimental method itself is simple and adaptable and can be used for crystal nucleation studies of arbitrary soluble substances with known solubility at particular solution conditions.

Binding of Lysozyme to Spherical Poly(styrenesulfonate Gels

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Martin Andersson

2018-01-01

Full Text Available Polyelectrolyte gels are useful as carriers of proteins and other biomacromolecules in, e.g., drug delivery. The rational design of such systems requires knowledge about how the binding and release are affected by electrostatic and hydrophobic interactions between the components. To this end we have investigated the uptake of lysozyme by weakly crosslinked spherical poly(styrenesulfonate (PSS microgels and macrogels by means of micromanipulator assisted light microscopy and small angle X-ray scattering (SAXS in an aqueous environment. The results show that the binding process is an order of magnitude slower than for cytochrome c and for lysozyme binding to sodium polyacrylate gels under the same conditions. This is attributed to the formation of very dense protein-rich shells in the outer layers of the microgels with low permeability to the protein. The shells in macrogels contain 60 wt % water and nearly charge stoichiometric amounts of lysozyme and PSS in the form of dense complexes of radius 8 nm comprising 30–60 lysozyme molecules. With support from kinetic modelling results we propose that the rate of protein binding and the relaxation rate of the microgel are controlled by the protein mass transport through the shell, which is strongly affected by hydrophobic and electrostatic interactions. The mechanism explains, in turn, an observed dependence of the diffusion rate on the apparent degree of crosslinking of the networks.

Polymorphism of Lysozyme Condensates.

Science.gov (United States)

Safari, Mohammad S; Byington, Michael C; Conrad, Jacinta C; Vekilov, Peter G

2017-10-05

Protein condensates play essential roles in physiological processes and pathological conditions. Recently discovered mesoscopic protein-rich clusters may act as crucial precursors for the nucleation of ordered protein solids, such as crystals, sickle hemoglobin polymers, and amyloid fibrils. These clusters challenge settled paradigms of protein condensation as the constituent protein molecules present features characteristic of both partially misfolded and native proteins. Here we employ the antimicrobial enzyme lysozyme and examine the similarities between mesoscopic clusters, amyloid structures, and disordered aggregates consisting of chemically modified protein. We show that the mesoscopic clusters are distinct from the other two classes of aggregates. Whereas cluster formation and amyloid oligomerization are both reversible, aggregation triggered by reduction of the intramolecular S-S bonds is permanent. In contrast to the amyloid structures, protein molecules in the clusters retain their enzymatic activity. Furthermore, an essential feature of the mesoscopic clusters is their constant radius of less than 50 nm. The amyloid and disordered aggregates are significantly larger and rapidly grow. These findings demonstrate that the clusters are a product of limited protein structural flexibility. In view of the role of the clusters in the nucleation of ordered protein solids, our results suggest that fine-tuning the degree of protein conformational stability is a powerful tool to control and direct the pathways of protein condensation.

Rapid tryptic mapping using enzymatically active mass spectrometer probe tips

Energy Technology Data Exchange (ETDEWEB)

Dogruel, D.; Williams, P.; Nelson, R.W. [Arizona State Univ., Tempe, AZ (United States)

1995-12-01

A method has been developed for rapid, sensitive, and accurate tryptic mapping of polypeptides using matrix-assisted laser desorption/ionization time-of-flight mass analysis. The technique utilizes mass spectrometer probe tips which have been activated through the covalent immobilization of trypsin. The enzymatically active probe tips were used for the tryptic mapping of chicken egg lysozyme and the results compared with those obtained using either free trypsin or agarose-immobilized trypsin. A significant increase in the overall sensitivity of the process was observed using the active probe tips, as well as the production of more characteristic proteolytic fragments and the elimination of background signals due to the autolysis of the trypsin. Further, probe tip digestions were found to be rapid and convenient. 19 refs., 6 figs., 2 tabs.

Production and Application of Lysozyme-Gum Arabic Conjugate in Mayonnaise as a Natural Preservative and Emulsifier

DEFF Research Database (Denmark)

Hashemi, Marjan M.; Aminlari, Mahmoud; Forouzan, Mehdi M.

2018-01-01

Nowadays demand for food products made by natural sources is rising so fast. In this work Lysozyme (Lyz) was conjugated with gum Arabic (GA) in order to be applied in mayonnaise, at which the presence of both preservative and emulsifier is essential. Interestingly, the Lyz-GA conjugate exhibited...... possible the application of a natural preservative and emulsifier in food and pharmaceutical industries, whereas Lyz alone does not have a broad-spectrum antibacterial activity or emulsifying properties....... improved functional properties and antibacterial activity. In order to approve the results of this study, the Lyz-GA conjugate was applied to mayonnaise as a natural preservative and emulsifier. Application of the Lzy-GA conjugate in mayonnaise expedited the death rate of both S. aureus and E. coli K-12...

Adsorption of lysozyme to phospholipid and meibomian lipid monolayer films.

Science.gov (United States)

Mudgil, Poonam; Torres, Margaux; Millar, Thomas J

2006-03-15

It is believed that a lipid layer forms the outer layer of the pre-ocular tear film and this layer helps maintain tear film stability by lowering its surface tension. Proteins of the aqueous layer of the tear film (beneath the lipid layer) may also contribute to reducing surface tension by adsorbing to, or penetrating the lipid layer. The purpose of this study was to compare the penetration of lysozyme, a tear protein, into films of meibomian lipids and phospholipids held at different surface pressures to determine if lysozyme were part of the surface layer of the tear film. Films of meibomian lipids or phospholipids were spread onto the surface of a buffered aqueous subphase. Films were compressed to particular pressures and lysozyme was injected into the subphase. Changes in surface pressure were monitored to determine adsorption or penetration of lysozyme into the surface film. Lysozyme penetrated a meibomian lipid film at all pressures tested (max=20 mN/m). It also penetrated phosphatidylglycerol, phosphatidylserine or phosphatidylethanolamine lipid films up to a pressure of 20 mN/m. It was not able to penetrate a phosphatidylcholine film at pressures >or=10 mN/m irrespective of the temperature being at 20 or 37 degrees C. However, it was able to penetrate it at very low pressures (<10 mN/m). Epifluorescence microscopy showed that the protein either adsorbs to or penetrates the lipid layer and the pattern of mixing depended upon the lipid at the surface. These results indicate that lysozyme is present at the surface of the tear film where it contributes to decreasing the surface tension by adsorbing and penetrating the meibomian lipids. Thus it helps to stabilize the tear film.

Coassembly of Lysozyme and Amphiphilic Biomolecules Driven by Unimer-Aggregate Equilibrium.

Science.gov (United States)

Tao, Yuanyuan; Ma, Xiaoteng; Cai, Yaqian; Liu, Li; Zhao, Hanying

2018-04-12

Synthesis and self-assembly of bioconjugates composed of proteins and synthetic molecules have been widely studied because of the potential applications in medicine, biotechnology, and nanotechnology. One of the challenging research studies in this area is to develop organic solvent-free approaches to the synthesis and self-assembly of amphiphilic bioconjugates. In this research, dialysis-assisted approach, a method based on unimer-aggregate equilibrium, was applied in the coassembly of lysozyme and conjugate of cholesterol and glutathione (Ch-GSH). In phosphate buffer solution, amphiphilic Ch-GSH conjugate self-assembles into vesicles, and the vesicle solution is dialyzed against lysozyme solution. Negatively charged Ch-GSH unimers produced in the unimer-vesicle exchange equilibrium, diffuse across the dialysis membrane and have electrostatic interaction with positively charged lysozyme, resulting in the formation of Ch-GSH-lysozyme bioconjugate. Above a critical concentration, the three-component bioconjugate molecules self-assemble into bioactive vesicles.

Increased autoimmune activity against 5-HT: a key component of depression that is associated with inflammation and activation of cell-mediated immunity, and with severity and staging of depression.

Science.gov (United States)

Maes, Michael; Ringel, Karl; Kubera, Marta; Berk, Michael; Rybakowski, Janusz

2012-02-01

Depression is characterized by inflammation and cell-mediated immune (CMI) activation and autoimmune reactions directed against a multitude of self-epitopes. There is evidence that the inflammatory response in depression causes dysfunctions in the metabolism of 5-HT, e.g. lowering the 5-HT precursor tryptophan, and upregulating 5-HT receptor mRNA. This study has been undertaken to examine autoimmune activity directed against 5-HT in relation to CMI activation and inflammation. 5-HT antibodies were examined in major depressed patients (n=109) versus normal controls (n=35) in relation to serum neopterin and lysozyme, and plasma pro-inflammatory cytokines (PIC), i.e. interleukin-1 (IL-1) and tumor necrosis factor-α (TNFα). Severity of depression was assessed with the Hamilton Depression Rating Scale (HDRS) and severity of fatigue and somatic symptoms with the Fibromyalgia and Chronic Fatigue Syndrome (FF) Rating Scale. The incidence of anti-5-HT antibody activity was significantly higher in depressed patients (54.1%), and in particular in those with melancholia (82.9%), than in controls (5.7%). Patients with positive 5-HT antibodies showed increased serum neopterin and lysozyme, and plasma TNFα and IL-1; higher scores on the HDRS and FF scales, and more somatic symptoms, including malaise and neurocognitive dysfunctions. There was a significant association between autoimmune activity to 5-HT and the number of previous depressive episodes. The autoimmune reactions directed against 5-HT might play a role in the pathophysiology of depression and the onset of severe depression. The strong association between autoimmune activity against 5-HT and inflammation/CMI activation is explained by multiple, reciprocal pathways between these factors. Exposure to previous depressive episodes increases the incidence of autoimmune activity directed against 5-HT, which in turn may increase the likelihood to develop new depressive episodes. These findings suggest that sensitization

Effect of histatin-5 and lysozyme on the ability of Streptococcus mutans to form biofilms in in vitro conditions.

Science.gov (United States)

Krzyściak, Wirginia; Jurczak, Anna; Piątkowski, Jakub; Kościelniak, Dorota; Gregorczyk-Maga, Iwona; Kołodziej, Iwona; Papież, Monika A; Olczak-Kowalczyk, Dorota

2015-09-20

The mechanisms of adhesion to solid surfaces enable S. mutans to colonize oral cavities and form biofilms, which play an important role in caries development. Additional properties enabling the survival of S. mutans in the oral cavity include its ability to survive in acidic environments and specific interactions with other microorganisms inhabiting this ecosystem. The aim of this study was to determine the antibacterial activity of saliva histatin-5 (peptide) and lysozyme (protein) against S. mutans and L. rhamnosus, as representatives of physiological flora. The study involved strains of physiological (L. rhamnosus) and cariogenic (S. mutans) flora isolated from one patient with diagnosed early caries of the deciduous teeth. It was proved that the presence of probiotic L. rhamnosus bacteria in the environment had a negative impact on the ability of S. mutans to produce biofilm. Moreover, the antibacterial activity of histatin-5 was confirmed, and it inhibited S. mutans growth at concentrations of 27.2 μg/ml and 54.4 μg/ml, both individually and in a mixture with lysozyme (in a total concentration of 54.4 μg/ml). The data obtained constitute a promising result due to their potential future application in the prevention and early diagnosis of caries.

Effect of histatin-5 and lysozyme on the ability of Streptococcus mutans to form biofilms in in vitro conditions

Directory of Open Access Journals (Sweden)

Wirginia Krzyściak

2015-09-01

Full Text Available The mechanisms of adhesion to solid surfaces enable S. mutans to colonize oral cavities and form biofilms, which play an important role in caries development. Additional properties enabling the survival of S. mutans in the oral cavity include its ability to survive in acidic environments and specific interactions with other microorganisms inhabiting this ecosystem.The aim of this study was to determine the antibacterial activity of saliva histatin-5 (peptide and lysozyme (protein against S. mutans and L. rhamnosus, as representatives of physiological flora.The study involved strains of physiological (L. rhamnosus and cariogenic (S. mutans flora isolated from one patient with diagnosed early caries of the deciduous teeth.It was proved that the presence of probiotic L. rhamnosus bacteria in the environment had a negative impact on the ability of S. mutans to produce biofilm. Moreover, the antibacterial activity of histatin-5 was confirmed, and it inhibited S. mutans growth at concentrations of 27.2 μg/ml and 54.4 μg/ml, both individually and in a mixture with lysozyme (in a total concentration of 54.4 μg/ml.The data obtained constitute a promising result due to their potential future application in the prevention and early diagnosis of caries.

Crystallization, data collection and phasing of two digestive lysozymes from Musca domestica

Energy Technology Data Exchange (ETDEWEB)

Marana, S. R.; Cançado, F. C. [Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo (Brazil); Valério, A. A. [Centro de Biologia Molecular e Estrutural (CeBiMe), Laboratório Nacional de Luz Síncrotron (LNLS), CP 6192, Campinas, SP 13084-971 (Brazil); Departamento de Bioquímica, Universidade Estadual de Campinas, Campinas (Brazil); Ferreira, C.; Terra, W. R. [Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo (Brazil); Barbosa, J. A. R. G., E-mail: joao@lnls.br [Centro de Biologia Molecular e Estrutural (CeBiMe), Laboratório Nacional de Luz Síncrotron (LNLS), CP 6192, Campinas, SP 13084-971 (Brazil); Departamento de Bioquímica, Universidade Estadual de Campinas, Campinas (Brazil); Departamento de Genética e Evolução, Universidade Estadual de Campinas, Campinas (Brazil); Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo (Brazil)

2006-08-01

The digestive lysozymes 1 and 2 from M. domestica were crystallized by vapour diffusion. The crystallographic data were processed to a maximum resolution of 1.9 Å in both cases. Lysozymes are mostly known for their defensive role against bacteria, but in several animals lysozymes have a digestive function. Here, the initial crystallographic characterization of two digestive lysozymes from Musca domestica are presented. The proteins were crystallized using the sitting-drop vapour-diffusion method in the presence of ammonium sulfate or PEG/2-propanol as the precipitant. X-ray diffraction data were collected to a maximum resolution of 1.9 Å using synchrotron radiation. The lysozyme 1 and 2 crystals belong to the monoclinic space group P2{sub 1} (unit-cell parameters a = 36.52, b = 79.44, c = 45.20 Å, β = 102.97°) and the orthorhombic space group P2{sub 1}2{sub 1}2 (unit-cell parameters a = 73.90, b = 96.40, c = 33.27 Å), respectively. The crystal structures were solved by molecular replacement and structure refinement is in progress.

Surface Plasmon Resonance based sensing of lysozyme in serum on Micrococcus lysodeikticus-modified graphene oxide surfaces.

Science.gov (United States)

Vasilescu, Alina; Gáspár, Szilveszter; Gheorghiu, Mihaela; David, Sorin; Dinca, Valentina; Peteu, Serban; Wang, Qian; Li, Musen; Boukherroub, Rabah; Szunerits, Sabine

2017-03-15

Lysozyme is an enzyme found in biological fluids, which is upregulated in leukemia, renal diseases as well as in a number of inflammatory gastrointestinal diseases. We present here the development of a novel lysozyme sensing concept based on the use of Micrococcus lysodeikticus whole cells adsorbed on graphene oxide (GO)-coated Surface Plasmon Resonance (SPR) interfaces. M. lysodeikticus is a typical enzymatic substrate for lysozyme. Unlike previously reported sensors which are based on the detection of lysozyme through bioaffinity interactions, the bioactivity of lysozyme will be used here for sensing purposes. Upon exposure to lysozyme containing serum, the integrity of the bacterial cell wall is affected and the cells detach from the GO based interfaces, causing a characteristic decrease in the SPR signal. This allows sensing the presence of clinically relevant concentrations of lysozyme in undiluted serum samples. Copyright © 2016 Elsevier B.V. All rights reserved.

Interaction of Lysozyme with Rhodamine B: A combined analysis of spectroscopic & molecular docking.

Science.gov (United States)

Millan, Sabera; Satish, Lakkoji; Kesh, Sandeep; Chaudhary, Yatendra S; Sahoo, Harekrushna

2016-09-01

The interaction of Rhodamine B (RB) with Lysozyme (Lys) was investigated by different optical spectroscopic techniques such as absorption, fluorescence, and circular-dichroism (CD), along with molecular docking studies. The fluorescence results (including steady-state and time-resolved mode) revealed that the addition of RB effectively causes strong quenching of intrinsic fluorescence in Lysozyme and mostly, by the static quenching mechanism. Different binding and thermodynamic parameters were calculated at different temperatures and the binding constant value was found to be 2963.54Lmol(-1) at 25°C. The average distance (r0) was found to be 3.31nm according to Förster's theory of non-radiative energy transfer between Lysozyme and RB. The conformational change in Lysozyme during interaction with RB was confirmed from absorbance, synchronous fluorescence, and circular dichroism measurements. Finally, molecular docking studies were done to confirm that the dye binds with Lysozyme. Copyright © 2016 Elsevier B.V. All rights reserved.

Variable Lysozyme Transport Dynamics on Oxidatively Functionalized Polystyrene Films.

Science.gov (United States)

Moringo, Nicholas A; Shen, Hao; Tauzin, Lawrence J; Wang, Wenxiao; Bishop, Logan D C; Landes, Christy F

2017-10-17

Tuning protein adsorption dynamics at polymeric interfaces is of great interest to many biomedical and material applications. Functionalization of polymer surfaces is a common method to introduce application-specific surface chemistries to a polymer interface. In this work, single-molecule fluorescence microscopy is utilized to determine the adsorption dynamics of lysozyme, a well-studied antibacterial protein, at the interface of polystyrene oxidized via UV exposure and oxygen plasma and functionalized by ligand grafting to produce varying degrees of surface hydrophilicity, surface roughness, and induced oxygen content. Single-molecule tracking indicates lysozyme loading capacities, and surface mobility at the polymer interface is hindered as a result of all functionalization techniques. Adsorption dynamics of lysozyme depend on the extent and the specificity of the oxygen functionalities introduced to the polystyrene surface. Hindered adsorption and mobility are dominated by hydrophobic effects attributed to water hydration layer formation at the functionalized polystyrene surfaces.

Mechanical, physico-chemical, and antimicrobial properties of gelatin-based film incorporated with catechin-lysozyme

Directory of Open Access Journals (Sweden)

Rawdkuen Saroat

2012-11-01

Full Text Available Abstract Background Microbial activity is a primary cause of deterioration in many foods and is often responsible for reduced quality and safety. Food-borne illnesses associated with E. coli O157:H7, S. aureus, S. enteritidis and L. monocytogenes are a major public health concern throughout the world. A number of methods have been employed to control or prevent the growth of these microorganisms in food. Antimicrobial packaging is one of the most promising active packaging systems for effectively retarding the growth of food spoilage and pathogenic microorganisms. The aim of this study was to determine the mechanical, physico-chemical properties and inhibitory effects of the fish gelatin films against selected food spoilage microorganisms when incorporated with catechin-lysozyme. Results The effect of the catechin-lysozyme combination addition (CLC: 0, 0.125, 0.25, and 0.5%, w/v on fish gelatin film properties was monitored. At the level of 0.5% addition, the CLC showed the greatest elongation at break (EAB at 143.17% with 0.039 mm thickness, and the lowest water vapor permeability (WVP at 6.5 x 10−8 g·mm·h-1·cm-2·Pa-1, whereas the control showed high tensile strength (TS and the highest WVP. Regarding color attributes, the gelatin film without CLC addition gave the highest lightness (L* 91.95 but lowest in redness (a*-1.29 and yellowness (b* 2.25 values. The light transmission of the film did not significantly decrease and nor did film transparency (p>0.05 with increased CLC. Incorporating CLC could not affect the film microstructure. The solubility of the gelatin based film incorporated with CLC was not affected, especially at a high level of addition (p>0.05. Inhibitory activity of the fish gelatin film against E.coli, S.aureus, L. innocua and S. cerevisiae was concentration dependent. Conclusions These findings suggested that CLC incorporation can improve mechanical, physico-chemical, and antimicrobial properties of the resulting films

Impact of lysozyme on stability mechanism of nanozirconia aqueous suspension

Energy Technology Data Exchange (ETDEWEB)

Szewczuk-Karpisz, Katarzyna, E-mail: k.szewczuk-karpisz@wp.pl; Wiśniewska, Małgorzata

2016-08-30

Highlights: • Adsorption and stabilization-destabilization properties of lysozyme (LSZ) in the nanozirconia-biopolymer solution system were determined. • The stability measurements were performed using turbidimetric method. • Lysozyme macromolecules undergo adsorption on the ZrO{sub 2} surface under electrostatic adsorbent-adsorbate attraction, i.e. at pH 6 and 9. • The biopolymer adsorption impact on the zirconia stability varies at different pH values. - Abstract: The effect of lysozyme (LSZ) presence on the zirconium(IV) oxide (ZrO{sub 2}) aqueous suspension stability was examined. The applied zirconia contains mesopores (with a diameter about 30 nm) and its mean particle size is about 100 nm. To determine the stability mechanism of ZrO{sub 2} suspension in the biopolymer presence, the adsorption and electrokinetic (surface charge density and zeta potential) measurements were performed in the pH range 3–10. The lysozyme adsorption on the nanozirconia surface proceeds mainly through electrostatic forces. Under solid-polymer repulsion conditions, there is no adsorption of lysozyme (pH < 6, C{sub NaCl} 0.01 mol/dm{sup 3}). The increase of solution ionic strength to 0.2 mol/dm{sup 3} causes screening of unfavourable forces and biopolymer adsorption becomes possible. The LSZ addition to the ZrO{sub 2} suspension influences its stability. At pH 3, 4.6 and 7.6, slight improvement of the system stability was obtained. In turn, at pH 9 considerable destabilization of nanozirconia particles covered by polymeric layers occurs.

The dissolution phenomenon of lysozyme crystals

Energy Technology Data Exchange (ETDEWEB)

Mueller, C.; Ulrich, J. [Martin Luther University Halle-Wittenberg, Department of Thermal Separation Processes, Centre of Engineering Science, Halle/Saale (Germany)

2012-02-15

Dissolution studies on lysozyme crystals were carried out since the observed dissolution pattern look different from non-protein dissolved crystals. The Tetragonal, High Temperature and Low Temperature Orthorhombic morphologies, crystallized using sodium chloride, were chosen and the influence of different pH, salt and protein concentration on their dissolution was investigated. An increase in pH and/or salt concentration can modify the dissolution behaviour. The pattern of the crystals during the dissolution process will, therefore, develop differently. Frequently a skeleton like crystal pattern followed by a falling apart of the crystals is observed. The multi-component character of the lysozyme crystal (protein, water, buffer, salt) as well as ''solvatomorphism'' gives first insights in the phenomena happening in the dissolution process. (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Hydrophobic nano-carrier for lysozyme adsorption

Indian Academy of Sciences (India)

1 polymer in pH 7.0 phosphate buffer at ... lysozyme concentration, temperature and ionic strength are varied and .... tions at initial and final adsorption medium were measured ... ties such as very high specific surface area, low mass transfer.

Influence of lysozyme on the precipitation of calcium carbonate: a kinetic and morphologic study

Science.gov (United States)

Jimenez-Lopez, Concepcion; Rodriguez-Navarro, Alejandro; Dominguez-Vera, Jose M.; Garcia-Ruiz, Juan M.

2003-05-01

Several mechanisms have been proposed to explain the interactions between proteins and mineral surfaces, among them a combination of electrostatic, stereochemical interactions and molecular recognition between the protein and the crystal surface. To identify the mechanisms of interaction in the lysozyme-calcium carbonate model system, the effect of this protein on the precipitation kinetics and morphology of calcite crystals was examined. The solution chemistry and morphology of the solid were monitored over time in a set of time-series free-drift experiments in which CaCO 3 was precipitated from solution in a closed system at 25°C and 1 atm total pressure, in the presence and absence of lysozyme. The precipitation of calcite was preceded by the precipitation of a metastable phase that later dissolved and gave rise to calcite as the sole phase. With increasing lysozyme concentration, the nucleation of both the metastable phase and calcite occurred at lower Ω calcite, indicating that lysozyme favored the nucleation of both phases. Calcite growth rate was not affected by the presence of lysozyme, at least at protein concentrations ranging from 0 mg/mL to 10 mg/mL. Lysozyme modified the habit of calcite crystals. The degree of habit modification changed with protein concentration. At lower concentrations of lysozyme, the typical rhombohedral habit of calcite crystals was modified by the expression of {110} faces, which resulted from the preferential adsorption of protein on these faces. With increasing lysozyme concentration, the growth of {110}, {100}, and finally {001} faces was sequentially inhibited. This adsorption sequence may be explained by an electrostatic interaction between lysozyme and calcite, in which the inhibition of the growth of {110}, {100}, and {001} faces could be explained by a combined effect of the density of carbonate groups in the calcite face and the specific orientation (perpendicular) of these carbonate groups with respect to the calcite

[Lysozyme in the treatment of juvenile laryngeal papillomatosis. A new concept in its etiopathogenesis].

Science.gov (United States)

Altamar-Ríos, J

1990-01-01

The A. inform about the results achieved with lysozyme chlorhydrate in the treatment of 15 patients with juvenile laryngeal papillomatosis. The lysozyme is an electropositive enzyme which synthesis is related to the degree of proteins and vitamin B complex ingestion. Lysozyme is a component of the immunitary inespecific system, serving to prevent against HPV-DNA at the level of the secretory film of the mucociliary apparatus of the respiratory mucous membrane. Furthermore, lysozyme hydrolyzes the mucopolysaccharide of the connective tissue and inhibits the virus-DNA replication. 100-300 mgr daily during 30-60 days simultaneously with hyperproteic diet and vitamin B complex (after correction of the nutrimental deficiencies) brought about the evanishment of papillomatosis. The A. suggest that the predisposition to infection by virus DNA is primarily of immunitary origin, because of lysozyme deficiency, and secondary due to a low intake of proteins and vitamin B complex.

Pulsed laser deposition of lysozyme: the dependence on shot numbers and the angular distribution

DEFF Research Database (Denmark)

Constantinescu, C.; Matei, A.; Schou, Jørgen

2013-01-01

The ejection of molecules from a pressed solid target of lysozyme induced by laser ablation in the UV-regime at a wavelength of 355 nm was investigated. The ablation studies were carried out in vacuum at a laser fluence of 2 J/cm2 for which a significant fraction of proteins remains intact....... This was verified by matrix-assisted laser desorption ionization (MALDI) spectrometry of thin films deposited on silicon substrates. The deposition rate of lysozyme was found to decrease with the number of shots and was correlated with increasing thermal damage of the lysozyme. This was monitored by measurements...... of the optical reflectivity of dry lysozyme. The angular distribution of the mass deposition can be fitted well by Anisimov’s hydrodynamic model. The total deposited yield over the entire hemisphere from direct laser ablation of lysozyme was estimated from this model and found to be three orders of magnitude...

Surface morphology of thin lysozyme films produced by matrix-assisted pulsed laser evaporation (MAPLE)

DEFF Research Database (Denmark)

Purice, Andreea; Schou, Jørgen; Pryds, Nini

2007-01-01

Thin films of the protein, lysozyme, have been deposited by the matrix-assisted pulsed laser evaporation (MAPLE) technique. Frozen targets of 0.3-1.0 wt.% lysozyme dissolved in ultrapure water were irradiated by laser light at 355 mn with a fluence of 2 J/cm(2). The surface quality of the thin....... The concentration of lysozyme in the ice matrix apparently does not play any significant role for the morphology of the film. The morphology obtained with MAPLE has been compared with results for direct laser irradiation of a pressed lysozyme sample (i.e. pulsed laser deposition (PLD)). (C) 2007 Elsevier B.V. All...

Modified denatured lysozyme effectively solubilizes fullerene c60 nanoparticles in water

Science.gov (United States)

Siepi, Marialuisa; Politi, Jane; Dardano, Principia; Amoresano, Angela; De Stefano, Luca; Monti, Daria Maria; Notomista, Eugenio

2017-08-01

Fullerenes, allotropic forms of carbon, have very interesting pharmacological effects and engineering applications. However, a very low solubility both in organic solvents and water hinders their use. Fullerene C60, the most studied among fullerenes, can be dissolved in water only in the form of nanoparticles of variable dimensions and limited stability. Here the effect on the production of C60 nanoparticles by a native and denatured hen egg white lysozyme, a highly basic protein, has been systematically studied. In order to obtain a denatured, yet soluble, lysozyme derivative, the four disulfides of the native protein were reduced and exposed cysteines were alkylated by 3-bromopropylamine, thus introducing eight additional positive charges. The C60 solubilizing properties of the modified denatured lysozyme proved to be superior to those of the native protein, allowing the preparation of biocompatible highly homogeneous and stable C60 nanoparticles using lower amounts of protein, as demonstrated by dynamic light scattering, transmission electron microscopy and atomic force microscopy studies. This lysozyme derivative could represent an effective tool for the solubilization of other carbon allotropes.

Raman mapping of mannitol/lysozyme particles produced via spray drying and single droplet drying.

Science.gov (United States)

Pajander, Jari Pekka; Matero, Sanni; Sloth, Jakob; Wan, Feng; Rantanen, Jukka; Yang, Mingshi

2015-06-01

This study aimed to investigate the effect of a model protein on the solid state of a commonly used bulk agent in spray-dried formulations. A series of lysozyme/mannitol formulations were spray-dried using a lab-scale spray dryer. Further, the surface temperature of drying droplet/particles was monitored using the DRYING KINETICS ANALYZER™ (DKA) with controllable drying conditions mimicking the spray-drying process to estimate the drying kinetics of the lysozyme/mannitol formulations. The mannitol polymorphism and the spatial distribution of lysozyme in the particles were examined using X-ray powder diffractometry (XRPD) and Raman microscopy. Partial Least Squares Discriminant Analysis was used for analyzing the Raman microscopy data. XRPD results indicated that a mixture of β-mannitol and α-mannitol was produced in the spray-drying process which was supported by the Raman analysis, whereas Raman analysis indicated that a mixture of α-mannitol and δ-mannitol was detected in the single particles from DKA. In addition Raman mapping indicated that the presence of lysozyme seemed to favor the appearance of α-mannitol in the particles from DKA evidenced by close proximity of lysozyme and mannitol in the particles. It suggested that the presence of lysozyme tend to induce metastable solid state forms upon the drying process.

Characterization of lysozyme films produced by matrix assisted pulsed laser evaporation (MAPLE)

DEFF Research Database (Denmark)

Purice, Andreea; Schou, Jørgen; Kingshott, Peter

2007-01-01

Thin lysozyme films of thickness up to more than 100 nm have been produced in a dry environment by MAPLE (matrix assisted pulsed laser evaporation) from a water ice matrix. Analysis of the films demonstrates that a significant part of the lysozyme molecules is transferred to the substrate without...

Formation of Silica-Lysozyme Composites Through Co-Precipitation and Adsorption

Directory of Open Access Journals (Sweden)

Daniela B. van den Heuvel

2018-04-01

Full Text Available Interactions between silica and proteins are crucial for the formation of biosilica and the production of novel functional hybrid materials for a range of industrial applications. The proteins control both precipitation pathway and the properties of the resulting silica–organic composites. Here, we present data on the formation of silica–lysozyme composites through two different synthesis approaches (co-precipitation vs. adsorption and show that the chemical and structural properties of these composites, when analyzed using a combination of synchrotron-based scattering (total scattering and small-angle X-ray scattering, spectroscopic, electron microscopy, and potentiometric methods vary dramatically. We document that while lysozyme was not incorporated into nor did its presence alter the molecular structure of silica, it strongly enhanced the aggregation of silica particles due to electrostatic and potentially hydrophobic interactions, leading to the formation of composites with characteristics differing from pure silica. The differences increased with increasing lysozyme content for both synthesis approaches. Yet, the absolute changes differ substantially between the two sets of composites, as lysozyme did not just affect aggregation during co-precipitation but also particle growth and likely polymerization during co-precipitation. Our results improve the fundamental understanding of how organic macromolecules interact with dissolved and nanoparticulate silica and how these interactions control the formation pathway of silica–organic composites from sodium silicate solutions, a widely available and cheap starting material.

Formation of Silica-Lysozyme Composites Through Co-Precipitation and Adsorption

Science.gov (United States)

van den Heuvel, Daniela B.; Stawski, Tomasz M.; Tobler, Dominique J.; Wirth, Richard; Peacock, Caroline L.; Benning, Liane G.

2018-04-01

Interactions between silica and proteins are crucial for the formation of biosilica and the production of novel functional hybrid materials for a range of industrial applications. The proteins control both precipitation pathway and the properties of the resulting silica-organic composites. Here we present data on the formation of silica-lysozyme composites through two different synthesis approaches (co-precipitation vs. adsorption) and show that the chemical and structural properties of these composites, when analyzed using a combination of synchrotron-based scattering (total scattering and SAXS), spectroscopic, electron microscopy and potentiometric methods vary dramatically. We document that while lysozyme was not incorporated into nor did its presence alter the molecular structure of silica, it strongly enhanced the aggregation of silica particles due to electrostatic and potentially hydrophobic interactions, leading to the formation of composites with characteristics differing from pure silica. The differences increased with increasing lysozyme content for both synthesis approaches. Yet, the absolute changes differ substantially between the two sets of composites, as lysozyme did not just affect aggregation during co-precipitation but also particle growth and likely polymerization during co-precipitation. Our results improve the fundamental understanding of how organic macromolecules interact with dissolved and nanoparticulate silica and how these interactions control the formation pathway of silica-organic composites from sodium silicate solutions, a widely available and cheap starting material.

Effects of modified β-cyclodextrin on thermal stability and conformation of lysozyme

International Nuclear Information System (INIS)

Kamiyama, Tadashi; Satoh, Megumi; Tateishi, Takahiro; Nojiri, Tomoaki; Takeuchi, Daisuke; Kimura, Takayoshi

2012-01-01

Highlights: ► Effects of cyclodextrin on stability and conformation of lysozyme were clarified. ► The CD influences the hydrophobic interaction of lysozyme by the inclusion. ► The CD relatively destabilized the folded state by stabilizing the unfolded state. ► The destabilization depends on the concentration and the substituent of CD. ► The conformation of lysozyme was more spread at unfolded state by inclusion of CD. - Abstract: Effects of cyclic oligosaccharide cyclodextrin (CD) on stability and conformation of lysozyme were clarified thermodynamically and rheologically by DSC, viscosity, and circular dichroism measurements. The modified β-CD relatively destabilized the folded state of lysozyme by stabilizing the unfolded state due to inclusion of hydrophobic part into the hydrophobic interior of CD. The order of higher destabilization effect was acetyl-β-CD > methyl-β-CD > hydroxypropyl-β-CD. Apparent number of bound CD to unfolded state for methyl-, hydroxypropyl-, and acetyl-β-CD is 6.7 ± 0.7, 4.2 ± 1.1, and 18.6 ± 4.3 and the binding constant is 5.5 ± 0.8, 6.7 ± 2.4, and 4.4 ± 1.2 L mol −1 , respectively. The viscosity for unfolded state was increased with an increase in the each modified β-CD concentration, suggesting that the inclusion of CD on a part of hydrophobic core at unfolded state leads to break the hydrophobic core, then lysozyme would be more spread structure. The substituent of CD can accelerate instability by directly breaking hydrogen bond and/or can restrain instability by increase in hydrophobic interaction. The fact that the each modified CDs has different destabilization effect shows a possibility to control the stability of protein by the substitution of CD.

First evidence of the possible implication of the 11-deoxycorticosterone (DOC) in immune activity of Eurasian perch (Perca fluviatilis, L.): comparison with cortisol.

Science.gov (United States)

Mathieu, Cédric; Milla, Sylvain; Mandiki, S N M; Douxfils, Jessica; Douny, Caroline; Scippo, Marie-Louise; De Pauw, Edwin; Kestemont, Patrick

2013-06-01

Cortisol, the main corticosteroid in fish, is frequently described as a modulator of fish immune system. Moreover, 11-deoxycorticosterone (DOC) was shown to bind and transcriptionally activate the mineralocorticoid receptor and may act as a mineralocorticoid in fish. Immune modulations induced by intraperitoneal injections of these two corticosteroids were assessed in Eurasian perch juveniles. Cortisol and DOC were injected at 0.8 mg kg(-1) and 0.08 mg kg(-1) body weight respectively. Cortisol increased plasma lysozyme activity 72 h post-injection, C-type lysozyme expression in spleen from 1 to 72 h post-injection, and favoured blood neutrophils at the expense of a mixture of lymphocytes and thrombocytes. Moreover, 6 h after injection, cortisol reduced expression levels of the pro-inflammatory cytokine TNF-α in spleen. DOC had no effects on the immune variables measured in plasma, but increased expression levels of C-type lysozyme and apolipoprotein A1 mRNA in both gills and spleen. Meanwhile, DOC stimulated its putative signalling pathway by increasing expression of mineralocorticoid receptor and 11β-hydroxysteroid dehydrogenase-2 in spleen. These results confirmed the role of cortisol as an innate, short term immune stimulator. For the first time, DOC is described as a possible immune stimulator in fish. Copyright © 2013 Elsevier Inc. All rights reserved.

Regular arrangement of periodates bound to lysozyme

Czech Academy of Sciences Publication Activity Database

Ondráček, Jan; Weiss, M.S.; Brynda, Jiří; Fiala, J.; Jursík, F.; Řezáčová, Pavlína; Jenner, L.B.; Sedláček, Juraj

2005-01-01

Roč. 61, Pt9 (2005), s. 1181-1189 ISSN 0907-4449 Institutional research plan: CEZ:AV0Z50520514 Keywords : hen egg white lysozyme * periodate * epitaxy Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.401, year: 2005

Macromolecular complexes of lysozyme with kappa carrageenan

NARCIS (Netherlands)

Antonov, Y.A.; Zhuravleva, I.L.; Cardinaels, R.; Moldenaers, P.

2018-01-01

We present a structural study of the complexation and binding of lysozyme (Lys) with kappa carrageenan (kCG) by means of turbidity measurements, phase analysis, dynamic and electrophoretic light scattering, differential scanning microcalorimetry (DSMC), confocal laser scanning (CLSM) microscopy,

Interaction of lysozyme protein with different sized silica nanoparticles and their resultant structures

Energy Technology Data Exchange (ETDEWEB)

Yadav, Indresh, E-mail: iykumarindresh288@gmail.com; Aswal, V. K. [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Kohlbrecher, J. [Laboratory for Neutron Scattering, Paul Scherrer Institut, CH-5232 PSI Villigen (Switzerland)

2016-05-23

The interaction of model protein-lysozyme with three different sized anionic silica nanoparticles has been studied by UV-vis spectroscopy, dynamic light scattering (DLS) and small-angle neutron scattering (SANS). The surface area and curvature of the nanoparticles change with size, which significantly influence their interaction with protein. The lysozyme adsorbs on the surface of the nanoparticles due to electrostatic attraction and leads to the phase transformation from one phase (clear) to two-phase (turbid) of the nanoparticle-protein system. The dominance of lysozyme induced short-range attraction over long-range electrostatic repulsion between nanoparticles is responsible for phase transformation and modeled by the two-Yukawa potential. The magnitude of the attractive interaction increases with the size of the nanoparticles as a result the phase transformation commences relatively at lower concentration of lysozyme. The structure of the nanoparticle-protein system in two-phase is characterized by the diffusion limited aggregate type of mass fractal morphology.

Molecular cloning, sequence analysis and phylogeny of first caudata g-type lysozyme in axolotl (Ambystoma mexicanum).

Science.gov (United States)

Yu, Haining; Gao, Jiuxiang; Lu, Yiling; Guang, Huijuan; Cai, Shasha; Zhang, Songyan; Wang, Yipeng

2013-11-01

Lysozymes are key proteins that play important roles in innate immune defense in many animal phyla by breaking down the bacterial cell-walls. In this study, we report the molecular cloning, sequence analysis and phylogeny of the first caudate amphibian g-lysozyme: a full-length spleen cDNA library from axolotl (Ambystoma mexicanum). A goose-type (g-lysozyme) EST was identified and the full-length cDNA was obtained using RACE-PCR. The axolotl g-lysozyme sequence represents an open reading frame for a putative signal peptide and the mature protein composed of 184 amino acids. The calculated molecular mass and the theoretical isoelectric point (pl) of this mature protein are 21523.0 Da and 4.37, respectively. Expression of g-lysozyme mRNA is predominantly found in skin, with lower levels in spleen, liver, muscle, and lung. Phylogenetic analysis revealed that caudate amphibian g-lysozyme had distinct evolution pattern for being juxtaposed with not only anura amphibian, but also with the fish, bird and mammal. Although the first complete cDNA sequence for caudate amphibian g-lysozyme is reported in the present study, clones encoding axolotl's other functional immune molecules in the full-length cDNA library will have to be further sequenced to gain insight into the fundamental aspects of antibacterial mechanisms in caudate.

Receptor-mediated endocytosis of lysozyme in renal proximal tubules of the frog Rana temporaria

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E.V. Seliverstova

2015-04-01

Full Text Available The mechanism of protein reabsorption in the kidney of lower vertebrates remains insufficiently investigated in spite of raising interest to the amphibian and fish kidneys as a useful model for physiological and pathophysiological examinations. In the present study, we examined the renal tubular uptake and the internalization rote of lysozyme after its intravenous injection in the wintering frog Rana temporaria using immunohisto- and immunocytochemistry and specific markers for some endocytic compartments. The distinct expression of megalin and cubilin in the proximal tubule cells of lysozyme-injected frogs was revealed whereas kidney tissue of control animals showed no positive immunoreactivity. Lysozyme was detected in the apical endocytic compartment of the tubular cells and colocalized with clathrin 10 min after injection. After 20 min, lysozyme was located in the subapical compartment negative to clathrin (endosomes, and intracellular trafficking of lysozyme was coincided with the distribution of megalin and cubilin. However, internalized protein was retained in the endosomes and did not reach lysosomes within 30 min after treatment that may indicate the inhibition of intracellular trafficking in hibernating frogs. For the first time, we provided the evidence that lysozyme is filtered through the glomeruli and absorbed by receptor-mediated clathrin-dependent endocytosis in the frog proximal tubule cells. Thus, the protein uptake in the amphibian mesonephros is mediated by megalin and cubilin that confirms a critical role of endocytic receptors in the renal reabsorption of proteins in amphibians as in mammals.

Oxidized epigallocatechin gallate inhibited lysozyme fibrillation more strongly than the native form

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Ting-Ting An

2017-04-01

Full Text Available Epigallocatechin gallate (EGCG, the most abundant flavanoid in green tea, is currently being evaluated in the clinic due to its benefits in the treatment of amyloid disorders. Its anti-amyloidogenic effect has been attributed to direct interaction of the intact molecule with misfolded polypeptides. In addition, antioxidant activity is also involved in the anti-amyloidogenic role. The detailed molecular mechanism is still unclear and requires further investigation. In the present study, the kinetics of EGCG oxidation and the anti-amyloidogenic effect of the resultant oxidation substances have been examined. The results indicate that EGCG degrades in a medium at pH 8.0 with a half-life less than 2 h. By utilizing lysozyme as an in vitro model, the oxidized EGCG demonstrates a more potent anti-amyloidogenic capacity than the intact molecule, as shown by ThT and ANS fluorescence, TEM determination, and hemolytic assay. The oxidized EGCG also has a stronger disruptive effect on preformed fibrils than the native form. Ascorbic acid eliminates the disruptive role of native EGCG on the fibrils, suggesting that oxidation is a prerequisite in fibril disruption. The results of this work demonstrate that oxidized EGCG plays a more important role than the intact molecule in anti-amyloidogenic activity. These insights into the action of EGCG may provide a novel route to understand the anti-amyloidogenic activity of natural polyphenols.

21 CFR 862.1490 - Lysozyme (muramidase) test system.

Science.gov (United States)

2010-04-01

... serum, plasma, leukocytes, and urine. Lysozyme measurements are used in the diagnosis and treatment of monocytic leukemia and kidney disease. (b) Classification. Class I (general controls). The device is exempt...

Synthesis of Ag{sub 2}S nanorods by biomimetic method in the lysozyme matrix

Energy Technology Data Exchange (ETDEWEB)

Qin, Dezhi, E-mail: dezhiqin@163.com; Zhang, Li; He, Guoxu; Zhang, Qiuxia

2013-09-01

Graphical abstract: - Highlights: • Firstly, Ag{sub 2}S nanorods were synthesized by biomimetic method in the lysozyme solutions. • The study of the interaction between Ag{sup +} and the lysozyme. • Discussion of possible formation mechanism of Ag{sub 2}S nanorods. • The synthesis process of lyso-conjugated Ag{sub 2}S nanocrystals is facile, effective and environment friendly. - Abstract: Ag{sub 2}S nanorods were successfully synthesized by biomimetic route in the lysozyme solution at physiological temperature and atmospheric pressure. The transmission electron microscopy (TEM) images revealed that the prepared nanorods are uniform and monodisperse with homogeneous size about 50 nm in diameter and 150 nm in length. The optical property of Ag{sub 2}S nanocrystals was studied by the ultraviolet–visible (UV–vis) and photoluminescence (PL) spectroscopy, the results show that the products exhibit well-defined emission at 471 nm and 496 nm excited by 292 nm. The interaction of Ag{sup +}/Ag{sub 2}S with the lysozyme was investigated through Fourier transform infrared (FT-IR) spectroscopy, which shows that the cooperation effect of the lysozyme and Ag{sup +} could be responsible for the formation of as obtained Ag{sub 2}S nanorods.

Influence of Prolonged Storage Process, Pasteurization, and Heat Treatment on Biologically-active Human Milk Proteins

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Jih-Chin Chang

2013-12-01

Conclusion: Various freezing/heating/pasteurization processes applied to human milk prior to delivery to neonates could affect the concentration of immunomodulatory proteins, especially lactoferrin, secretory immunoglobulin A, and lysozyme. Leptin was unaffected by the various handling processes tested. Fresh milk was found to be the best food for neonates. Further studies are warranted to evaluate the functional activity of these proteins and their effects on infants' immunological status.

Effects of the aromatase inhibitor Letrozole on serum immunoglobulin and lysozyme levels in immunized rainbow trout (Oncorhynchus mykiss Walbaum females

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Paria Akbary

2013-12-01

Full Text Available Letrozole is a synthetic aromatase inhibitor and interfere in the committed step in the synthesis of endogenous estrogens from androgens. Also estrogens regulate the immune system in teleost. Changes of 17- β- esrtradiol (E2, serum immunoglobulin and lysozyme levels were measured using a method based on the ability of lysozyme to lyse the bacterium Micrococcus lysodeikticus, enzyme-linked immunosorbent assay (ELISA and ELISA respectively. Twelve broodstocks were injected weekly with 2.5 mg kg-1 letrozole (an endocrine disrupter component two months before spawning season and vaccinated intraperitoneally (i.p with a bacterin (inactivated L. garviae one month before spawning. Twelve broodstocks for vaccination and twelve female rainbow trout as control group were also immiunised (i.p with the bacterin and injected (i.p with PBS, respectively. In the group received 2.5 mg AI kg-1 per week, serum E2 levels were significantly lower than that of other groups. Total immunoglobulin level and lysozyme activity were significantly higher in the parents received 2.5 mg kg-1 per week and were immunized with 10-9 cells ml-1 Lactococcus garvieae  compared to the group which immunized with L. garvieae and the control (non- immunized. The present study, suggests that aromatase inhibitors such as letrozole may be a potential tool to regulate the synthesis of E2, is involved in the hormone- immune system interaction in rainbow trout.

[Inactivating Effect of Heat-Denatured Lysozyme on Murine Norovirus in Bread Fillings].

Science.gov (United States)

Takahashi, Michiko; Yasuda, Yuka; Takahashi, Hajime; Takeuchi, Akira; Kuda, Takashi; Kimura, Bon

2018-01-01

In this study, we investigated the viability of murine norovirus strain 1 (MNV-1), a surrogate for human norovirus, in bread fillings used for making stuffed buns and pastries. The inactivating effect of heat-denatured lysozyme, which was recently reported to have an antiviral effect, on MNV-1 contaminating the bread fillings was also examined. MNV-1 was inoculated into two types of fillings (chocolate cream, marmalade jam) at 4.5 log PFU/g, and the bread fillings were stored at 4℃ for 5 days. MNV-1 remained viable in the bread fillings during storage. However, addition of 1% heat-denatured lysozyme to the fillings resulted in a decrease of MNV-1 infectivity immediately after inoculation, in both fillings. On the fifth day of storage, MNV-1 infectivity was decreased by 1.2 log PFU/g in chocolate cream and by 0.9 log PFU/g in marmalade jam. Although the mechanism underlying the anti-norovirus effect of heat-denatured lysozyme has not been clarified, our results suggest that heat-denatured lysozyme can be used as an inactivating agent against norovirus in bread fillings.

An electron microscopy study of the diversity of Streptococcus sanguinis cells induced by lysozyme in vitro.

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Hao, Yuqing; Li, Li; Li, Wei; Zhou, Xuedong; Lu, Junjun

2010-01-01

Bacterial virulence could be altered by the antimicrobial agents of the host. Our aim was to identify the damage and survival of Streptococcus sanguinis induced by lysozymes in vitro and to analyse the potential of oral microorganisms to shirk host defences, which cause infective endocarditis. S. sanguinis ATCC 10556 received lysozyme at concentrations of 12.5, 25, 50 and 100 microg/ml. Cells were examined by electron microscopy. The survival was assessed by colony counting and construction of a growth curve. Challenged by lysozymes, cells mainly exhibited cell wall damage, which seemed to increase with increasing lysozyme concentration and longer incubation period in the presence of ions. Cells with little as well as apparent lesion were observed under the same treatment set, and anomalous stick and huge rotund bodies were occasionally observed. After the removal of the lysozyme, some damaged cells could be reverted to its original form with brain heart infusion (BHI), and their growth curve was similar to the control cells. After further incubation in BHI containing lysozyme, S. sanguinis cell damage stopped progressing, and their growth curve was also similar to the control cells. The results suggested that the S. sanguinis lesions caused by the lysozyme in the oral cavity may be nonhomogeneous and that some damaged cells could self-repair and survive. It also indicated that S. sanguinis with damaged cell walls may survive and be transmitted in the bloodstream.

Thermodynamic Exploration of Eosin-Lysozyme Binding: A Physical Chemistry and Biochemistry Laboratory Experiment

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Huisman, Andrew J.; Hartsell, Lydia R.; Krueger, Brent P.; Pikaart, Michael J.

2010-01-01

We developed a modular pair of experiments for use in the undergraduate physical chemistry and biochemistry laboratories. Both experiments examine the thermodynamics of the binding of a small molecule, eosin Y, to the protein lysozyme. The assay for binding is the quenching of lysozyme fluorescence by eosin through resonant energy transfer. In…

Synergistic cytotoxicity and mechanism of caffeine and lysozyme on hepatoma cell line HepG2

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Yang, Hongchao; Li, Jingjuan; Cui, Lin; Ren, Yanqing; Niu, Liying; Wang, Xinguo; Huang, Yun; Cui, Lijian

2018-03-01

The influences of caffeine, lysozyme and the joint application of them on the hepatoma cell line HepG2 proliferation inhibition and cell apoptosis were observed by 3-(4, 5-dimethyl-2-thiazyl)-2, 5-diphenyl-2H-tetrazolium bromide assay and Hoechst 33342, which showed the proliferation inhibition rate of the joint application on HepG2 cells was 47.21%, significantly higher than caffeine or lysozyme, and the joint application promoted the apoptosis of HepG2 cells obviously. Van't Hoff classical thermodynamics formula, the Föster theory of non-radiation energy transfer and fluorescence phase diagram were used to manifest that the process of lysozyme binding to caffeine followed a two-state model, which was spontaneous at low temperature driven by enthalpy change, and the predominant intermolecular force was hydrogen bonding or Van der Waals force to stabilize caffeine-lysozyme complex with the distance 5.86 nm. The attenuated total reflection-Fourier transform infrared spectra indicated that caffeine decreased the relative contents of α-helix and β-turn, which inferred the structure of lysozyme tended to be "loose". Synchronous fluorescence spectra and ultraviolet spectra supported the above conclusion. The amino acid residues in the cleft of lysozyme were exposed and electropositivity was increased attributing to the loose structure, which were conducive to increasing caffeine concentration on the HepG2 cell surface by electrostatic interaction to show synergistic effect. The great quantities of microvilli on the liver cancer cell membrane surface, is beneficial for the lysozyme-caffeine compound to aggregate on cell surface to increase the concentration of caffeine to play stronger physiological role by electrostatic effect.

In Vitro Effect of Lysozyme on Albumin Deposition to Hydrogel Contact Lens Materials.

Science.gov (United States)

Babaei Omali, Negar; Subbaraman, Lakshman N; Heynen, Miriam; Fadli, Zohra; Coles-Brennan, Chantal; Jones, Lyndon W

2017-11-01

Albumin deposition on contact lenses could be detrimental to contact lens (CL) wear because this may increase the risk of bacterial binding and reduce comfort. Lysozyme deposition on selected lens materials would reduce albumin deposition on lenses. This study aims to determine if lysozyme deposition on CLs could act as a barrier against subsequent albumin adsorption, using an in vitro model. Six hydrogel CL materials (etafilcon A, polymacon, nelfilcon A, omafilcon A, ocufilcon B, and nesofilcon A) were evaluated. Four CLs of each type were soaked in lysozyme solution for 16 hours at 37°C. Lysozyme-coated lenses were then placed in vials with 1.5 mL of artificial tear solution containing I-labeled albumin for 16 hours at 37°C with shaking. Four uncoated lenses of each type were used as controls. Lenses soaked in radiolabeled albumin were rinsed in a phosphate-buffered saline solution, and radioactive counts were measured directly on lenses using a gamma counter. Albumin uptake on lenses was measured using a calibration curve by plotting radioactive counts versus protein concentration. Results are reported as mean ± SD. Lysozyme-coated etafilcon A lenses exhibited lower levels of deposited albumin than uncoated etafilcon A lenses (58 ± 12 vs. 84 ± 5 ng/lens; P albumin adsorption between control (uncoated) and lysozyme-coated polymacon (105 ± 10 vs. 110 ± 34 ng/lens), nelfilcon A (51 ± 7 vs. 42 ± 20 ng/lens), omafilcon A (90 ± 20 vs. 80 ± 38 ng/lens), ocufilcon B (87 ± 20 vs. 115 ± 50 ng/lens), and nesofilcon A (170 ± 29 vs. 161 ± 10 ng/lens) lens materials (P > .05). Uncoated nesofilcon A lenses deposited the highest amount of albumin when compared with other uncoated lenses (P albumin, which may potentially be beneficial to CL wearers.

Mechanisms of hydrogen exchange in proteins from nuclear magnetic resonance studies of individual tryptophan indole NH hydrogens in lysozyme

International Nuclear Information System (INIS)

Wedin, R.E.; Delepierre, M.; Dobson, C.M.; Poulsen, F.M.

1982-01-01

The individual rates of solvent exchange of the six tryptophan indole NH hydrogens of lysozyme in 2 H 2 O have been measured over a wide range of temperatures by using 1 H NMR. Two distinct mechanisms for exchange have been identified, one characterized by a high activation energy and the other by a much lower activation energy. The high-energy process has been shown to be associated directly with the cooperative thermal unfolding of the protein and is the dominant mechanism for exchange of the most slowly exchanging hydrogen even 15 0 C below the denaturation temperature. Rate constants and activation energies for the folding and unfolding reactions were obtained from the experimental exchange rates. At low temperatures, a lower activation energy mechanism is dominant for all hydrogens, and this can be associated with local fluctuations in the protein structure which allow access of solvent. The relative exchange rates and activation energies can only qualitatively be related to the different environments of the residues in the crystal structure. There is provisional evidence that a mechanism intermediate between these two extremes may be significant for some hydrogens under restricted conditions

Cloning the human lysozyme cDNA: Inverted Alu repeat in the mRNA and in situ hybridization for macrophages and Paneth cells

International Nuclear Information System (INIS)

Chung, L.P.; Keshav, S.; Gordon, S.

1988-01-01

Lysozyme is a major secretory product of human and rodent macrophages and a useful marker for myelomonocytic cells. Based on the known human lysozyme amino acid sequence, oligonucleotides were synthesized and used as probes to screen a phorbol 12-myristate 13-acetate-treated U937 cDNA library. A full-length human lysozyme cDNA clone, pHL-2, was obtained and characterized. Sequence analysis shows that human lysozyme, like chicken lysozyme, has in 18-amino-acid-long signal peptide, but unlike the chicken lysozyme cDNA, the human lysozyme cDNA has a >1-kilobase-long 3' nontranslated sequence. Interestingly, within this 3' region, an inverted repeat of the Alu family of repetitive sequences was discovered. In RNA blot analyses, DNA probes prepared from pHL-2 can be used to detect lysozyme mRNA not only from human but also from mouse and rat. Moreover, by in situ hybridization, complementary RNA transcripts have been used as probes to detect lysozyme mRNA in mouse macrophages and Paneth cells. This human lysozyme cDNA clone is therefore likely to be a useful molecular probe for studying macrophage distribution and gene expression

Controlled Release of Lysozyme from Double-Walled Poly(Lactide-Co-Glycolide (PLGA Microspheres

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Rezaul H. Ansary

2017-10-01

Full Text Available Double-walled microspheres based on poly(lactide-co-glycolide (PLGA are potential delivery systems for reducing a very high initial burst release of encapsulated protein and peptide drugs. In this study, double-walled microspheres made of glucose core, hydroxyl-terminated poly(lactide-co-glycolide (Glu-PLGA, and carboxyl-terminated PLGA were fabricated using a modified water-in-oil-in-oil-in-water (w1/o/o/w2 emulsion solvent evaporation technique for the controlled release of a model protein, lysozyme. Microspheres size, morphology, encapsulation efficiency, lysozyme in vitro release profiles, bioactivity, and structural integrity, were evaluated. Scanning electron microscopy (SEM images revealed that double-walled microspheres comprising of Glu-PLGA and PLGA with a mass ratio of 1:1 have a spherical shape and smooth surfaces. A statistically significant increase in the encapsulation efficiency (82.52% ± 3.28% was achieved when 1% (w/v polyvinyl alcohol (PVA and 2.5% (w/v trehalose were incorporated in the internal and external aqueous phase, respectively, during emulsification. Double-walled microspheres prepared together with excipients (PVA and trehalose showed a better control release of lysozyme. The released lysozyme was fully bioactive, and its structural integrity was slightly affected during microspheres fabrication and in vitro release studies. Therefore, double-walled microspheres made of Glu-PLGA and PLGA together with excipients (PVA and trehalose provide a controlled and sustained release for lysozyme.

Biofilm formation and transcriptome analysis of Streptococcus gallolyticus subsp. gallolyticus in response to lysozyme.

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Imke Grimm

Full Text Available Streptococcus gallolyticus subsp. gallolyticus is a commensal bacterium of the human gastrointestinal tract, and a pathogen causing infective endocarditis and other biofilm-associated infections via exposed collagen. This study focuses on the characterization of the biofilm formation and collagen adhesion of S. gallolyticus subsp. gallolyticus under different conditions. In this study, it has been observed that the isolate UCN 34 is resistant to 20 mg/ml lysozyme in BHI medium, whereas the strain BAA-2069 builds more biofilm in the presence of lysozyme compared to in a control of BHI without lysozyme. A transcriptome analysis with whole genome microarrays of these two isolates in BHI medium with lysozyme compared to control without lysozyme revealed changes in gene expression levels. In the isolate BAA-2069, 67 genes showed increased expression in the presence of lysozyme, while in the isolate UCN 34, 165 genes showed increased expression and 30 genes showed decreased expression through lysozyme treatment. Products of genes which were higher expressed are in involved in transcription and translation, in cell-wall modification, in hydrogen peroxide resistance and in bacterial immunity. Furthermore, the adhesion ability of different strains of S. gallolyticus subsp. gallolyticus to collagen type I and IV was analyzed. Thereby, we compared the adhesion of 46 human isolates with 23 isolates from animals. It was shown that the adhesion ability depends significantly on whether the isolate was isolated from human or animal. For example, high adhesion ability was observed for strain UCN 34 isolated from an infective endocarditis patient, whereas strain DSM 16831 isolated from koala feces adhered only marginally to collagen. Full genome microarray analysis of these two strains revealed strain-dependent gene expression due to adhesion. The expression of 25 genes of a transposon and 15 genes of a phage region in strain DSM 16831 were increased, which

Binding and Inhibitory Effect of the Dyes Amaranth and Tartrazine on Amyloid Fibrillation in Lysozyme.

Science.gov (United States)

Basu, Anirban; Suresh Kumar, Gopinatha

2017-02-16

Interaction of two food colorant dyes, amaranth and tartrazine, with lysozyme was studied employing multiple biophysical techniques. The dyes exhibited hypochromic changes in the presence of lysozyme. The intrinsic fluorescence of lysozyme was quenched by both dyes; amaranth was a more efficient quencher than tartrazine. The equilibrium constant of amaranth was higher than that of tartarzine. From FRET analysis, the binding distances for amaranth and tartrazine were calculated to be 4.51 and 3.93 nm, respectively. The binding was found to be dominated by non-polyelectrolytic forces. Both dyes induced alterations in the microenvironment surrounding the tryptophan and tyrosine residues of the protein, with the alterations being comparatively higher for the tryptophans than the tyrosines. The interaction caused significant loss in the helicity of lysozyme, the change being higher with amaranth. The binding of both dyes was exothermic. The binding of amaranth was enthalpy driven, while that of tartrazine was predominantly entropy driven. Amaranth delayed lysozyme fibrillation at 25 μM, while tartrazine had no effect even at 100 μM. Nevertheless, both dyes had a significant inhibitory effect on fibrillogenesis. The present study explores the potential antiamyloidogenic property of these azo dyes used as food colorants.

Isothermal Titration Calorimetry and Macromolecular Visualization for the Interaction of Lysozyme and Its Inhibitors

Science.gov (United States)

Wei, Chin-Chuan; Jensen, Drake; Boyle, Tiffany; O'Brien, Leah C.; De Meo, Cristina; Shabestary, Nahid; Eder, Douglas J.

2015-01-01

To provide a research-like experience to upper-division undergraduate students in a biochemistry teaching laboratory, isothermal titration calorimetry (ITC) is employed to determine the binding constants of lysozyme and its inhibitors, N-acetyl glucosamine trimer (NAG[subscript 3]) and monomer (NAG). The extremely weak binding of lysozyme/NAG is…

Influence of Soil Humic and Fulvic Acid on the Activity and Stability of Lysozyme and Urease

NARCIS (Netherlands)

Li, Yan; Tan, WenFeng; Koopal, Luuk K.; Wang, MingXia; Liu, Fan; Norde, Willem

2013-01-01

Humic substances (HS), including humic acids (HA) and fulvic acids (FA), are important components of soil systems. HS form strong complexes with oppositely charged proteins, which will lead to changes in the enzyme activity. The effect of soil HS on the activity and stability of two enzymes was

Inheritance of the lysozyme inhibitor Ivy was an important evolutionary step by Yersinia pestis to avoid the host innate immune response.

Science.gov (United States)

Derbise, Anne; Pierre, François; Merchez, Maud; Pradel, Elizabeth; Laouami, Sabrina; Ricard, Isabelle; Sirard, Jean-Claude; Fritz, Jill; Lemaître, Nadine; Akinbi, Henry; Boneca, Ivo G; Sebbane, Florent

2013-05-15

Yersinia pestis (the plague bacillus) and its ancestor, Yersinia pseudotuberculosis (which causes self-limited bowel disease), encode putative homologues of the periplasmic lysozyme inhibitor Ivy and the membrane-bound lysozyme inhibitor MliC. The involvement of both inhibitors in virulence remains subject to debate. Mutants lacking ivy and/or mliC were generated. We evaluated the mutants' ability to counter lysozyme, grow in serum, and/or counter leukocytes; to produce disease in wild-type, neutropenic, or lysozyme-deficient rodents; and to induce host inflammation. MliC was not required for lysozyme resistance and the development of plague. Deletion of ivy decreased Y. pestis' ability to counter lysozyme and polymorphonuclear neutrophils, but it did not affect the bacterium's ability to grow in serum or resist macrophages. Y. pestis lacking Ivy had attenuated virulence, unless animals were neutropenic or lysozyme deficient. The Ivy mutant induced inflammation to a degree similar to that of the parental strain. Last, Y. pseudotuberculosis did not require Ivy to counter lysozyme and for virulence. Ivy is required to counter lysozyme during infection, but its role as a virulence factor is species dependent. Our study also shows that a gene that is not necessary for the virulence of an ancestral bacterium may become essential in the emergence of a new pathogen.

Size-dependent interaction of silica nanoparticles with lysozyme and bovine serum albumin proteins

Science.gov (United States)

Yadav, Indresh; Aswal, Vinod K.; Kohlbrecher, Joachim

2016-05-01

The interaction of three different sized (diameter 10, 18, and 28 nm) anionic silica nanoparticles with two model proteins—cationic lysozyme [molecular weight (MW) 14.7 kDa)] and anionic bovine serum albumin (BSA) (MW 66.4 kDa) has been studied by UV-vis spectroscopy, dynamic light scattering (DLS), and small-angle neutron scattering (SANS). The adsorption behavior of proteins on the nanoparticles, measured by UV-vis spectroscopy, is found to be very different for lysozyme and BSA. Lysozyme adsorbs strongly on the nanoparticles and shows exponential behavior as a function of lysozyme concentration irrespective of the nanoparticle size. The total amount of adsorbed lysozyme, as governed by the surface-to-volume ratio, increases on lowering the size of the nanoparticles for a fixed volume fraction of the nanoparticles. On the other hand, BSA does not show any adsorption for all the different sizes of the nanoparticles. Despite having different interactions, both proteins induce similar phase behavior where the nanoparticle-protein system transforms from one phase (clear) to two phase (turbid) as a function of protein concentration. The phase behavior is modified towards the lower concentrations for both proteins with increasing the nanoparticle size. DLS suggests that the phase behavior arises as a result of the nanoparticles' aggregation on the addition of proteins. The size-dependent modifications in the interaction potential, responsible for the phase behavior, have been determined by SANS data as modeled using the two-Yukawa potential accounting for the repulsive and attractive interactions in the systems. The protein-induced interaction between the nanoparticles is found to be short-range attraction for lysozyme and long-range attraction for BSA. The magnitude of attractive interaction irrespective of protein type is enhanced with increase in the size of the nanoparticles. The total (attractive+repulsive) potential leading to two-phase formation is found to be

The Natural Antimicrobial Enzyme Lysozyme is Up-Regulated in Gastrointestinal Inflammatory Conditions

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Carlos A. Rubio

2014-01-01

Full Text Available The cells that line the mucosa of the human gastrointestinal tract (GI, that is, oral cavity, oesophagus, stomach, small intestine, large intestine, and rectum are constantly challenged by adverse micro-environmental factors, such as different pH, enzymes, and bacterial flora. With exception of the oral cavity, these microenvironments also contain remnant cocktails of secreted enzymes and bacteria from upper organs along the tract. The density of the GI bacteria varies, from 103/mL near the gastric outlet, to 1010/mL at the ileocecal valve, to 1011 to 1012/mL in the colon. The total microbial population (ca. 1014 exceeds the total number of cells in the tract. It is, therefore, remarkable that despite the prima facie inauspicious mixture of harmful secretions and bacteria, the normal GI mucosa retains a healthy state of cell renewal. To counteract the hostile microenvironment, the GI epithelia react by speeding cell exfoliation (the GI mucosa has a turnover time of two to three days, by increasing peristalsis, by eliminating bacteria through secretion of plasma cell-immunoglobulins and by increasing production of natural antibacterial compounds, such as defensin-5 and lysozyme. Only recently, lysozyme was found up-regulated in Barrett’s oesophagitis, chronic gastritis, gluten-induced atrophic duodenitis (coeliac disease, collagenous colitis, lymphocytic colitis, and Crohn’s colitis. This up-regulation is a response directed to the special types of bacteria recently detected in these diseases. The aim of lysozyme up-regulation is to protect individual mucosal segments to chronic inflammation. The molecular mechanisms connected to the crosstalk between the intraluminal bacterial flora and the production of lysozyme released by the GI mucosae, are discussed. Bacterial resistance continues to exhaust our supply of commercial antibiotics. The potential use of lysozyme to treat infectious diseases is receiving much attention.

A comparative study on the aggregating effects of guanidine thiocyanate, guanidine hydrochloride and urea on lysozyme aggregation

Energy Technology Data Exchange (ETDEWEB)

Emadi, Saeed, E-mail: emadi@iasbs.ac.ir; Behzadi, Maliheh

2014-08-08

Highlights: • Lysozyme aggregated in guanidine thiocyanate (1.0 and 2.0 M). • Lysozyme aggregated in guanidine hydrochloride (4 and 5 M). • Lysozyme did not aggregated at any concentration (0.5–5 M) of urea. • Unfolding pathway is more important than unfolding per se in aggregation. - Abstract: Protein aggregation and its subsequent deposition in different tissues culminate in a diverse range of diseases collectively known as amyloidoses. Aggregation of hen or human lysozyme depends on certain conditions, namely acidic pH or the presence of additives. In the present study, the effects on the aggregation of hen egg-white lysozyme via incubation in concentrated solutions of three different chaotropic agents namely guanidine thiocyanate, guanidine hydrochloride and urea were investigated. Here we used three different methods for the detection of the aggregates, thioflavin T fluorescence, circular dichroism spectroscopy and atomic force microscopy. Our results showed that upon incubation with different concentrations (0.5, 1.0, 2.0, 3.0, 4.0, 5.0 M) of the chemical denaturants, lysozyme was aggregated at low concentrations of guanidine thiocyanate (1.0 and 2.0 M) and at high concentrations of guanidine hydrochloride (4 and 5 M), although no fibril formation was detected. In the case of urea, no aggregation was observed at any concentration.

Human Lysozyme Synergistically Enhances Bactericidal Dynamics and Lowers the Resistant Mutant Prevention Concentration for Metronidazole to Helicobacter pylori by Increasing Cell Permeability

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Xiaolin Zhang

2016-10-01

Full Text Available Metronidazole (MNZ is an effective agent that has been employed to eradicate Helicobacter pylori (H. pylori. The emergence of broad MNZ resistance in H. pylori has affected the efficacy of this therapeutic agent. The concentration of MNZ, especially the mutant prevention concentration (MPC, plays an important role in selecting or enriching resistant mutants and regulating therapeutic effects. A strategy to reduce the MPC that can not only effectively treat H. pylori but also prevent resistance mutations is needed. H. pylori is highly resistant to lysozyme. Lysozyme possesses a hydrolytic bacterial cell wall peptidoglycan and a cationic dependent mode. These effects can increase the permeability of bacterial cells and promote antibiotic absorption into bacterial cells. In this study, human lysozyme (hLYS was used to probe its effects on the integrity of the H. pylori outer and inner membranes using as fluorescent probe hydrophobic 1-N-phenyl-naphthylamine (NPN and the release of aspartate aminotransferase. Further studies using a propidium iodide staining method assessed whether hLYS could increase cell permeability and promote cell absorption. Finally, we determined the effects of hLYS on the bactericidal dynamics and MPC of MNZ in H. pylori. Our findings indicate that hLYS could dramatically increase cell permeability, reduce the MPC of MNZ for H. pylori, and enhance its bactericidal dynamic activity, demonstrating that hLYS could reduce the probability of MNZ inducing resistance mutations.

Obtaining of lysozyme spherulitic forms at ambient temperature using pyrrolidinium octanoat as ionic liquid additive

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Claudia Simona ŞTEFAN

2012-12-01

Full Text Available Pyrrolidinium octanoate carboxylate (Py+CnH2n+1COO-; PyO in abbreviation was used as additive for advanced crystallization of Lysozyme protein, to investigate the impact of protic ionic liquid on the protein crystal morphology. The ionic liquid was synthesized by acidic-base Brönsted neutralization, and its purity was checked by HPLC. The protein crystallization was made through the method of vapour diffusion with hanging drops. Crystallization experiments of Lysozyme with the addition of PyO were performed at 0.4 M PyO and respectively 1.6 M. The morphological of spherulitic forms of Lysozyme in aqueous solutions of PyO protic ionic liquid was investigated by optical microscopy after trials were incubated at ambient temperature (18-20°C, in various growth periods (3 days and 1 week. Hanging-drop vapour diffusion crystallization experiments with the addition of 0.4 M of PyO show that Lysozyme crystallized in type I spherulitic form. This is assumed to be a result of heterogeneous nucleation, with thin needles radially growing outwardfrom a more or less spherical particle. Hanging-drop vapour diffusioncrystallization experiments revealed that the addition of 1.6 M of PyO led to a second type of spherulitic form of the Lysozyme.

The disruptive effect of lysozyme on the bacterial cell wall explored by an in-silico structural outlook.

Science.gov (United States)

Primo, Emiliano D; Otero, Lisandro H; Ruiz, Francisco; Klinke, Sebastián; Giordano, Walter

2018-01-01

The bacterial cell wall, a structural unit of peptidoglycan polymer comprised of glycan strands consisting of a repeating disaccharide motif [N-acetylglucosamine (NAG) and N-acetylmuramylpentapeptide (NAM pentapeptide)], encases bacteria and provides structural integrity and protection. Lysozymes are enzymes that break down the bacterial cell wall and disrupt the bacterial life cycle by cleaving the linkage between the NAG and NAM carbohydrates. Lab exercises focused on the effects of lysozyme on the bacterial cell wall are frequently incorporated in biochemistry classes designed for undergraduate students in diverse fields as biology, microbiology, chemistry, agronomy, medicine, and veterinary medicine. Such exercises typically do not include structural data. We describe here a sequence of computer tasks designed to illustrate and reinforce both physiological and structural concepts involved in lysozyme effects on the bacterial cell-wall structure. This lab class usually lasts 3.5 hours. First, the instructor presents introductory concepts of the bacterial cell wall and the effect of lysozyme on its structure. Then, students are taught to use computer modeling to visualize the three-dimensional structure of a lysozyme in complex with bacterial cell-wall fragments. Finally, the lysozyme inhibitory effect on a bacterial culture is optionally proposed as a simple microbiological assay. The computer lab exercises described here give students a realistic understanding of the disruptive effect of lysozymes on the bacterial cell wall, a crucial component in bacterial survival. © 2017 by The International Union of Biochemistry and Molecular Biology, 46(1):83-90, 2018. © 2017 The International Union of Biochemistry and Molecular Biology.

Activation of immunity, immune response, antioxidant ability, and resistance against Vibrio alginolyticus in white shrimp Litopenaeus vannamei decrease under long-term culture at low pH.

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Chen, Yu-Yuan; Chen, Jiann-Chu; Tseng, Kuei-Chi; Lin, Yong-Chin; Huang, Chien-Lun

2015-10-01

The growth, activation of immunity, immune parameters, and transcript levels of cytMnSOD, mtMnSOD, ecCuZnSOD, glutathione peroxidase (GPx), catalase, lysozyme, and penaeidin 3a were examined in white shrimp Litopenaeus vannamei reared at pH 6.8 and 8.1 after 24 weeks. No significant difference in growth was observed between the two groups. An in vitro study indicated that phenoloxidase activity and respiratory bursts (RB, release of the superoxide anion) were significantly higher in the haemocytes of pH 8.1 shrimp (shrimp reared at pH 8.1) than in pH 6.8 shrimp (shrimp reared at pH 6.8). An in vivo study indicated that the levels of immune parameters of pH 8.1 shrimp were significantly higher than in pH 6.8 shrimp, and the transcript levels of cytMnSOD, ecCuZnSOD, glutathione peroxidase, lysozyme, and penaeidin 3a were down-regulated in pH 6.8 shrimp. In another experiment, shrimp reared at pH 6.8 and 8.1 for 24 weeks were challenged with Vibrio alginolyticus. The mortality rate of pH 6.8 shrimp was significantly higher than in pH 8.1 shrimp over 12-168 h. Phagocytic activity, phagocytic index, and clearance efficiency to V. alginolyticus were significantly lower in pH 6.8 shrimp. We concluded that shrimp under long-term culture at pH 6.8 exhibited decreased resistance against V. alginolyticus as evidenced by reductions in the activation of immunity and immune parameters together with decreased transcript levels of cytMnSOD, ecCuZnSOD, GPx, lysozyme, and penaeidin 3a. Copyright © 2015 Elsevier Ltd. All rights reserved.

Pulsed electric field (PEF)-induced aggregation between lysozyme, ovalbumin and ovotransferrin in multi-protein system.

Science.gov (United States)

Wu, Li; Zhao, Wei; Yang, Ruijin; Yan, Wenxu

2015-05-15

The aggregation of multi-proteins is of great interest in food processing and a good understanding of the formation of aggregates during PEF processing is needed for the application of the process to pasteurize protein-based foods. The aggregates formation of a multi-protein system (containing ovalbumin, ovotransferrin and lysozyme) was studied through turbidity, size exclusion chromatography and SDS-PAGE patterns for interaction studies and binding forces. Results from size exclusion chromatography indicated that there was no soluble aggregates formed during PEF processing. The existence of lysozyme was important to form insoluble aggregates in the chosen ovalbumin solution. The results of SDS-PAGE patterns indicated that lysozyme was prone to precipitate, and was relatively the higher component of aggregates. Citric acid could be effective in inhibiting lysozyme from interacting with other proteins during PEF processing. Blocking the free sulphydryl by N-ethylmaleimide (NEM) did not affect aggregation inhibition. Copyright © 2014 Elsevier Ltd. All rights reserved.

Associations between microsatellite polymorphism within the macrophage expressed lysozyme (mLys gene and milk Indices Properties in Polish Black-and-White Cows

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Małgorzata Walczak-Wójciak

2005-01-01

Full Text Available The experiment was performed in the years 1998–2000 on two farms located near to Vistula Lowlands. The experimental materials were comprised of 52 daughters of bull Paran, among which 21 possessed the mLys-mic 7 allele and 31 – the mLys-mic 3 allele. The serum and whey bacteriolytic activity of the lysozyme, concentrations of selected mineral elements, technological properties of milk at successive the first lactation stages (30, 100, 150 and 200 days, somatic cell count and bacterial count were investigated in this study. The results obtained indicate that Lys-mic polymorphism has low suitability as a marker for milk production capacity in cows. The lysozyme gene, treated as a mastitis resistance factor, showed no effects on somatic cell count and bacterial count. Further investigations, conducted not only during the first lactation, but also during the next lactation in a herd threatened by a variety of pathogenic factors, would be carried to validate this Lys-mic gene polymorphism on mastitis resistance.

Dye-Affinity Nanofibrous Membrane for Adsorption of Lysozyme: Preparation and Performance Evaluation

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Steven Sheng-Shih Wang

2018-01-01

Full Text Available Polyacrylonitrile (PAN nanofibrous membrane was prepared by an electrospinning technique. After heat treatment and alkaline hydrolysis, the weak ion exchange membrane was grafted with chitosan molecule and then covalently immobilized with a Cibacron Blue F3GA (CB. Fibre diameter, porosity and pore size of the membrane and immobilized dye density were characterized. Furthermore, the membrane was applied to evaluate the binding performance of lysozyme under various operating parameters (pH, chitosan mass per volume ratio, dye concentration, ionic strength and temperature in batch mode. The experimental results were directly applied to purify lysozyme from chicken egg white by membrane chromatography. The results showed that the capture efficiency, recovery yield and purification factor were 90 and 87 %, and 47-fold, respectively, in a single step. The binding capacity remained consistent after five repeated cycles of adsorption-desorption operations. This work demonstrates that the dye-affinity nanofibrous membrane holds great potential for purification of lysozyme from real feedstock.

Ultra-sensitive quantification of lysozyme based on element chelate labeling and capillary electrophoresis–inductively coupled plasma mass spectrometry

International Nuclear Information System (INIS)

Yang, MingWei; Wu, WeiHua; Ruan, YaJuan; Huang, LiMei; Wu, Zujian; Cai, Yong; Fu, FengFu

2014-01-01

Graphical abstract: An ultra-sensitive method for the determination of lysozyme was developed based on the Gd 3+ chelate labeling and CE–ICP–MS. The proposed method has an extremely low detection limit of 3.89 attomole and has been successfully used to detect lysozyme in saliva sample, showing excellent reliability. The success of the present method provides a new possibility for biological assays and clinical diagnoses. -- Highlights: •An ultra-sensitive method for detecting lysozyme based on CE–ICP–MS was described. •The proposed method has an extremely low detection limit of 3.89 attomole. •It can be used to detect trace lysozyme in saliva sample with a satisfied recovery. •The method provides a new potential for sensitive detection of low-abundant proteins. -- Abstract: In this study, an ultra-sensitive method for the quantification of lysozyme based on the Gd 3+ diethylenetriamine-N,N,N′,N″,N″-pentaacetic acid labeling and capillary electrophoresis–inductively coupled plasma mass spectrometry (CE–ICP–MS) was described. The Gd 3+ -tagged lysozyme was effectively separated by capillary electrophoresis (CE) and sensitively determined by inductively coupled plasma mass spectrometry (ICP–MS). Based on the gadolinium-tagging and CE–ICP–MS, the lysozyme was determined within 12 min with an extremely low detection limit of 3.89 attomole (3.89 × 10 −11 mol L −1 for 100 nL of sample injection) and a RSD < 6% (n = 5). The proposed method has been successfully used to detect lysozyme in saliva samples with a recovery of 91–106%, suggesting that our method is sensitive and reliable. The success of the present method provides a new potential for the biological assays and sensitive detection of low-abundant proteins

Adsorption of lysozyme unto silica and polystyrene surfaces in ...

African Journals Online (AJOL)

user

2011-04-11

Apr 11, 2011 ... surfaces were well fitted by the Langmuir adsorption isotherm model with maximum adsorption .... following reasons: (1) Lysozyme is a globular protein with ... vigorously for 1 h to attain equilibrium adsorption and allowed to.

Preparation and preliminary characterization of crystallizing fluorescent derivatives of chicken egg white lysozyme

Science.gov (United States)

Sumida, John P.; Forsythe, Elizabeth L.; Pusey, Marc L.

2001-11-01

Fluorescence is one of the most versatile and powerful tools for the study of macromolecules. While most proteins are intrinsically fluorescent, working at crystallization concentrations require the use of covalently prepared derivatives added as tracers. This approach requires derivatives that do not markedly affect the crystal packing. We have prepared fluorescent derivatives of chicken egg white lysozyme with probes bound to one of two different sites on the protein molecule. Lucifer yellow and 5-(2-aminoethyl)aminonapthalene-1-sulfonic acid (EDANS) have been attached to the side chain carboxyl of Asp 101 using a carbodiimide coupling procedure. Asp 101 lies within the active site cleft, and it is believed that the probes are "buried" within that cleft. Lucifer yellow and EDANS probes with iodoacetamide reactive groups have been bound to His 15, located on the "back side" of the molecule relative to the active site. All the derivatives fluoresce in the solution and the crystalline states. Fluorescence characterization has focused on determination of binding effects on the probe quantum yield, lifetime, absorption and emission spectra, and quenching by added solutes. Quenching studies show that, as postulated, the Asp 101-bound probes are partially sheltered from the bulk solution by their location within the active site cleft. Probes bound to His 15 have quenching constants about equal to those for the free probes, indicating that this site is highly exposed to the bulk solution.

Functional Micrococcus lysodeikticus layers deposited by laser technique for the optical sensing of lysozyme.

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Dinca, Valentina; Zaharie-Butucel, Diana; Stanica, Luciana; Brajnicov, Simona; Marascu, Valentina; Bonciu, Anca; Cristocea, Andra; Gaman, Laura; Gheorghiu, Mihaela; Astilean, Simion; Vasilescu, Alina

2018-02-01

Whole cell optical biosensors, made by immobilizing whole algal, bacterial or mammalian cells on various supports have found applications in several fields, from ecology and ecotoxicity testing to biopharmaceutical production or medical diagnostics. We hereby report the deposition of functional bacterial layers of Micrococcus lysodeikticus (ML) via Matrix-Assisted Pulsed Laser Evaporation (MAPLE) on poly(diallyldimethylamonium) (PDDA)-coated-glass slides and their application as an optical biosensor for the detection of lysozyme in serum. Lysozyme is an enzyme upregulated in inflammatory diseases and ML is an enzymatic substrate for this enzyme. The MAPLE-deposited bacterial interfaces were characterised by Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), Fourier-Transformed Infrared Spectroscopy (FTIR), Raman and optical microscopy and were compared with control interfaces deposited via layer-by-layer on the same substrate. After MAPLE deposition and coating with graphene oxide (GO), ML-modified interfaces retained their functionality and sensitivity to lysozyme's lytic action. The optical biosensor detected lysozyme in undiluted serum in the clinically relevant range up to 10μgmL -1 , in a fast and simple manner. Copyright © 2017 Elsevier B.V. All rights reserved.

In vitro study of proteins surface activity by tritium probe

International Nuclear Information System (INIS)

Chernysheva, M.G.; Badun, G.A.

2010-01-01

A new technique for in vitro studies of biomacromolecules interactions, their adsorption at aqueous/organic liquid interfaces and distribution in the bulk of liquid/liquid systems was developed. The method includes (1) tritium labeling of biomolecules by tritium thermal activation method and (2) scintillation phase step with organic phase, which can be concerned as a model of cellular membrane. Two globular proteins lysozyme and human serum albumin tested. We have determined the conditions of tritium labeling when labeled by-products can be easy separated by means of dialysis and size-exclusion chromatography. Scintillation phase experiments were conducted for three types of organic liquids. Thus, the influences of the nature of organic phase on proteins adsorption and its distribution in the bulk of aqueous/organic liquid system were determined. It was found that proteins possess high surface activity at aqueous/organic liquid interface. Furthermore, values of hydrophobicity of globular proteins were found by the experiment. (author)

Pyroelectricity in globular protein lysozyme films

Science.gov (United States)

Stapleton, A.; Noor, M. R.; Haq, E. U.; Silien, C.; Soulimane, T.; Tofail, S. A. M.

2018-03-01

Pyroelectricity is the ability of certain non-centrosymmetric materials to generate an electric charge in response to a change in temperature and finds use in a range of applications from burglar alarms to thermal imaging. Some biological materials also exhibit pyroelectricity but the examples of the effect are limited to fibrous proteins, polypeptides, and tissues and organs of animals and plants. Here, we report pyroelectricity in polycrystalline aggregate films of lysozyme, a globular protein.

Pseudomonas aeruginosa outer membrane vesicles triggered by human mucosal fluid and lysozyme can prime host tissue surfaces for bacterial adhesion

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Matteo Maria Emiliano Metruccio

2016-06-01

Full Text Available Pseudomonas aeruginosa is a leading cause of human morbidity and mortality that often targets epithelial surfaces. Host immunocompromise, or the presence of indwelling medical devices, including contact lenses, can predispose to infection. While medical devices are known to accumulate bacterial biofilms, it is not well understood why resistant epithelial surfaces become susceptible to P. aeruginosa. Many bacteria, including P. aeruginosa, release Outer Membrane Vesicles (OMVs in response to stress that can fuse with host cells to alter their function. Here, we tested the hypothesis that mucosal fluid can trigger OMV release to compromise an epithelial barrier. This was tested using tear fluid and corneal epithelial cells in vitro and in vivo. After 1 h both human tear fluid, and the tear component lysozyme, greatly enhanced OMV release from P. aeruginosa strain PAO1 compared to PBS controls (~100 fold. TEM and SDS-PAGE showed tear fluid and lysozyme-induced OMVs were similar in size and protein composition, but differed from biofilm-harvested OMVs, the latter smaller with fewer proteins. Lysozyme-induced OMVs were cytotoxic to human corneal epithelial cells in vitro and murine corneal epithelium in vivo. OMV exposure in vivo enhanced Ly6G/C expression at the corneal surface, suggesting myeloid cell recruitment, and primed the cornea for bacterial adhesion (~4-fold, P < 0.01. Sonication disrupted OMVs retained cytotoxic activity, but did not promote adhesion, suggesting the latter required OMV-mediated events beyond cell killing. These data suggest that mucosal fluid induced P. aeruginosa OMVs could contribute to loss of epithelial barrier function during medical device-related infections.

Urediospores of rust fungi are ice nucleation active at > -10 °C and harbor ice nucleation active bacteria

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Morris, C. E.; Sands, D. C.; Glaux, C.; Samsatly, J.; Asaad, S.; Moukahel, A. R.; Gonçalves, F. L. T.; Bigg, E. K.

2013-04-01

Various features of the biology of the rust fungi and of the epidemiology of the plant diseases they cause illustrate the important role of rainfall in their life history. Based on this insight we have characterized the ice nucleation activity (INA) of the aerially disseminated spores (urediospores) of this group of fungi. Urediospores of this obligate plant parasite were collected from natural infections of 7 species of weeds in France, from coffee in Brazil and from field and greenhouse-grown wheat in France, the USA, Turkey and Syria. Immersion freezing was used to determine freezing onset temperatures and the abundance of ice nuclei in suspensions of washed spores. Microbiological analyses of spores from France, the USA and Brazil, and subsequent tests of the ice nucleation activity of the bacteria associated with spores were deployed to quantify the contribution of bacteria to the ice nucleation activity of the spores. All samples of spores were ice nucleation active, having freezing onset temperatures as high as -4 °C. Spores in most of the samples carried cells of ice nucleation-active strains of the bacterium Pseudomonas syringae (at rates of less than 1 bacterial cell per 100 urediospores), but bacterial INA accounted for only a small fraction of the INA observed in spore suspensions. Changes in the INA of spore suspensions after treatment with lysozyme suggest that the INA of urediospores involves a polysaccharide. Based on data from the literature, we have estimated the concentrations of urediospores in air at cloud height and in rainfall. These quantities are very similar to those reported for other biological ice nucleators in these same substrates. However, at cloud level convective activity leads to widely varying concentrations of particles of surface origin, so that mean concentrations can underestimate their possible effects on clouds. We propose that spatial and temporal concentrations of biological ice nucleators active at temperatures > -10 �

Laser ablation of lysozyme with UV, visible and infrared femto- and nanosecond pulses

DEFF Research Database (Denmark)

Schou, Jørgen; Canulescu, Stela; Matei, Andreea

Lysozyme is an interesting molecule for laser ablation of organic materials, because the ablation has been comprehensively studied, it is a medium heavy molecule with a mass of 14305 Da, which can be detected by standard techniques, and because it is used as a bactericidal protein in the food...... industry. Lysozyme molecules do not absorb energy for wavelengths above 310 nm, but nevertheless there is a strong mass loss by ablation for laser irradiation in the visible regime. The total ablation yield of lysozyme at 355 nm and at 2 J/cm2 is about 155 µg/pulse, possibly one of the highest ablation...... the ablation process for different wavelengths and time duration. Measurements for 6-7-ns laser ablation were carried out at DTU on Risø Campus, while measurements with pulses of 300 fs were carried out at the University of Naples in a similar setup. For all wavelengths except at nanosecond laser pulses at 355...

Raman mapping of mannitol/lysozyme particles produced via spray drying and single droplet drying

DEFF Research Database (Denmark)

Pekka Pajander, Jari; Matero, Sanni Elina; Sloth, Jakob

2015-01-01

PURPOSE: This study aimed to investigate the effect of a model protein on the solid state of a commonly used bulk agent in spray-dried formulations. METHODS: A series of lysozyme/mannitol formulations were spray-dried using a lab-scale spray dryer. Further, the surface temperature of drying droplet....../particles was monitored using the DRYING KINETICS ANALYZER™ (DKA) with controllable drying conditions mimicking the spray-drying process to estimate the drying kinetics of the lysozyme/mannitol formulations. The mannitol polymorphism and the spatial distribution of lysozyme in the particles were examined using X......-ray powder diffractometry (XRPD) and Raman microscopy. Partial Least Squares Discriminant Analysis was used for analyzing the Raman microscopy data. RESULTS: XRPD results indicated that a mixture of β-mannitol and α-mannitol was produced in the spray-drying process which was supported by the Raman analysis...

Effects of lead administration at low doses by different routes on rat spleens. Study of response of splenic lymphocytes and tissue lysozyme

International Nuclear Information System (INIS)

Teijon, Cesar; Olmo, Rosa; Dolores Blanco, Maria; Romero, Arturo; Maria Teijon, Jose

2003-01-01

The aim of this study was to evaluate the effects of low doses of lead (200 ppm of PbAc 2 for 4 weeks) on rat spleens using different routes of administration. The study has been carried out at different levels: a histological evaluation has been made, and alterations of cell proliferation, B and T lymphocyte subpopulations, and CD4 + and CD8 + T cell subpopulations have been evaluated. Apoptosis and necrosis of lymphoid cells were also analysed. Furthermore, lysozyme activity was measured. Results indicate a large increase in spleen size when lead is administered by intraperitoneal injection, being this route in which lead causes larger modifications in all of the parameters measured. Lead administered orally causes histological modifications, such as an increase in the number of lymphocytes as well as edema. However, significant alterations in other parameters studied have not been detected. Lead administration by intraperitoneal route causes more evident histological modifications as well as an increase in the number of lymphocytes, and also induces a decrease in the percentage of B + , T + and CD4 + cells, and an increase in CD8 + cells. Cell death of splenic lymphocytes is not altered by lead. With regard to the immune innate response, lead behaves as an immunomodulator as can be deduced from data on lysozyme activity in tissue. Therefore, it is possible to affirm that the effect of low doses of lead depends on the route of administration. Thus, the intraperitoneal route, through which lead goes directly to the bloodstream, causes drastic effects, generating important immunological alterations

Structural basis of protein oxidation resistance: a lysozyme study.

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Marion Girod

Full Text Available Accumulation of oxidative damage in proteins correlates with aging since it can cause irreversible and progressive degeneration of almost all cellular functions. Apparently, native protein structures have evolved intrinsic resistance to oxidation since perfectly folded proteins are, by large most robust. Here we explore the structural basis of protein resistance to radiation-induced oxidation using chicken egg white lysozyme in the native and misfolded form. We study the differential resistance to oxidative damage of six different parts of native and misfolded lysozyme by a targeted tandem/mass spectrometry approach of its tryptic fragments. The decay of the amount of each lysozyme fragment with increasing radiation dose is found to be a two steps process, characterized by a double exponential evolution of their amounts: the first one can be largely attributed to oxidation of specific amino acids, while the second one corresponds to further degradation of the protein. By correlating these results to the structural parameters computed from molecular dynamics (MD simulations, we find the protein parts with increased root-mean-square deviation (RMSD to be more susceptible to modifications. In addition, involvement of amino acid side-chains in hydrogen bonds has a protective effect against oxidation Increased exposure to solvent of individual amino acid side chains correlates with high susceptibility to oxidative and other modifications like side chain fragmentation. Generally, while none of the structural parameters alone can account for the fate of peptides during radiation, together they provide an insight into the relationship between protein structure and susceptibility to oxidation.

Effects of prolonged running in the heat and cool environments on selected physiological parameters and salivary lysozyme responses

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Nur S. Ibrahim

2017-12-01

Conclusion: This study found similar lysozyme responses between both hot and cool trials. Thus, room/ambient temperature did not affect lysozyme responses among recreational athletes. Nevertheless, the selected physiological parameters were significantly affected by room temperature.

Dynamics of hydration in hen egg white lysozyme.

Science.gov (United States)

Sterpone, F; Ceccarelli, M; Marchi, M

2001-08-10

We investigate the hydration dynamics of a small globular protein, hen egg-white lysozyme. Extensive simulations (two trajectories of 9 ns each) were carried out to identify the time-scales and mechanism of water attachment to this protein. The location of the surface and integral water molecules in lysozyme was also investigated. Three peculiar temporal scales of the hydration dynamics can be discerned: two among these, with sub-nanosecond mean residence time, tau(w), are characteristic of surface hydration water; the slower time-scale (tau(w) approximately 2/3 ns) is associated with buried water molecules in hydrophilic pores and in superficial clefts. The computed tau(w) values in the two independent runs fall in a similar range and are consistent with each other, thus adding extra weight to our result. The tau(w) of surface water obtained from the two independent trajectories is 20 and 24 ps. In both simulations only three water molecules are bound to lysozyme for the entire length of the trajectories, in agreement with nuclear magnetic relaxation dispersion estimates. Locations other than those identified in the protein crystal are found to be possible for these long-residing water molecules. The dynamics of the hydration water molecules observed in our simulations implies that each water molecule visits a multitude of residues during the lifetime of its bound with the protein. The number of residues seen by a single water molecule increases with the time-scale of its residence time and, on average, is equal to one only for the water molecules with shorter residence time. Thus, tau(w) values obtained from inelastic neutron scattering and based on jump-diffusion models are likely not to account for the contribution of water molecules with longer residence time. Copyright 2001 Academic Press.

Fluorinated ionic liquids for protein drug delivery systems: Investigating their impact on the structure and function of lysozyme.

Science.gov (United States)

Alves, Márcia; Vieira, Nicole S M; Rebelo, Luís Paulo N; Araújo, João M M; Pereiro, Ana B; Archer, Margarida

2017-06-30

Since the approval of recombinant human insulin by FDA in 1982, more than 200 proteins are currently available for pharmaceutical use to treat a wide range of diseases. However, innovation is still required to develop effective approaches for drug delivery. Our aim is to investigate the potential use of fluorinated ionic liquids (FILs) as drug delivery systems (DDS) for therapeutic proteins. Some initial parameters need to be assessed before further studies can proceed. This work evaluates the impact of FILs on the stability, function, structure and aggregation state of lysozyme. Different techniques were used for this purpose, which included differential scanning fluorimetry (DSF), spectrophotometric assays, circular dichroism (CD), dynamic light scattering (DLS), and scanning and transmission electron microscopy (SEM/TEM). Ionic liquids composed of cholinium-, imidazolium- or pyridinium- derivatives were combined with different anions and analysed at different concentrations in aqueous solutions (below and above the critical aggregation concentration, CAC). The results herein presented show that the addition of ionic liquids had no significant effect on the stability and hydrolytic activity of lysozyme. Moreover, a distinct behaviour was observed in DLS experiments for non-surfactant and surfactant ionic liquids, with the latter encapsulating the protein at concentrations above the CAC. These results encourage us to further study ionic liquids as promising tools for DDS of protein drugs. Copyright © 2017 Elsevier B.V. All rights reserved.

Lysozyme as an alternative to antibiotics improves growth performance and small intestinal morphology in nursery pigs.

Science.gov (United States)

Oliver, W T; Wells, J E

2013-07-01

Lysozyme is a 1,4-β-N-acetylmuramidase that has antimicrobial properties. The objective of this experiment was to determine if lysozyme in nursery diets improved growth performance and gastrointestinal health of pigs weaned from the sow at 24 d of age. Two replicates of 96 pigs (192 total; 96 males, 96 females) were weaned from the sow at 24 d of age, blocked by BW and gender, and then assigned to 1 of 24 pens (4 pigs/pen). Each block was randomly assigned 1 of 3 dietary treatments for 28 d: control (two 14-d phases), control + antibiotics (carbadox/copper sulfate), or control + lysozyme (100 mg/kg diet). Pigs were weighed and blood sampled on d 0, 14, and 28 of treatment. Blood was analyzed for plasma urea nitrogen (PUN) and IgA. At 28 d, pigs were killed, and samples of jejunum and ileum were collected and fixed for intestinal morphology measurements. An additional jejunum sample was taken from the 12 pigs with the median BW per treatment to determine transepithelial electrical resistance (TER). Pigs consuming antibiotics or lysozyme grew at a faster rate than control pigs (0.433 ± 0.009 and 0.421 ± 0.008 vs. 0.398 ± 0.008 kg/d, respectively; P 0.48), but G:F was improved in pigs consuming antibiotics or lysozyme (0.756 ± 0.014, 0.750 ± 0.021, and 0.695 ± 0.019 kg/kg; P 0.48). Dietary treatment did not affect TER (P > 0.37), but gilts had lower TER compared with barrows (P 0.53). However, jejunum villi height was increased and crypt depth was decreased in pigs consuming antibiotics or lysozyme (P pigs weaned from the sow at 24 d of age.

Antimicrobial Membranes of Bio-Based PA 11 and HNTs Filled with Lysozyme Obtained by an Electrospinning Process

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Valeria Bugatti

2018-03-01

Full Text Available Bio-based membranes were obtained using Polyamide 11 (PA11 from renewable sources and a nano-hybrid composed of halloysite nanotubes (HNTs filled with lysozyme (50 wt % of lysozyme, as a natural antimicrobial molecule. Composites were prepared using an electrospinning process, varying the nano-hybrid loading (i.e., 1.0, 2.5, 5.0 wt %. The morphology of the membranes was investigated through SEM analysis and there was found to be a narrow average fiber diameter (0.3–0.5 μm. The mechanical properties were analyzed and correlated to the nano-hybrid content. Controlled release of lysozyme was followed using UV spectrophotometry and the release kinetics were found to be dependent on HNTs–lysozyme loading. The experimental results were analyzed by a modified Gallagher–Corrigan model. The application of the produced membranes, as bio-based pads, for extending the shelf life of chicken slices has been tested and evaluated.

Combined pulmonary involvement in hereditary lysozyme amyloidosis with associated pulmonary sarcoidosis: a case report.

Science.gov (United States)

McCarthy, Cormac; Deegan, Alexander P; Garvey, John F; McDonnell, Timothy J

2013-12-17

Sarcoidosis is a multisystem inflammatory disorder of unknown cause which can affect any organ system. Autosomal dominant lysozyme amyloidosis is a very rare form of hereditary amyloidosis. The Arg64 variant is extraordinarily rare with each family showing a particular pattern of organ involvement, however while Sicca syndrome, gastrointestinal involvement and renal failure are common, lymph node involvement is very rare. In this case report we describe the first reported case of sarcoidosis in association with hereditary lysozyme amyloidosis.

Lysozyme's lectin-like characteristics facilitates its immune defense function

KAUST Repository

Zhang, Ruiyan

2017-06-06

Interactions between human lysozyme (HL) and the lipopolysaccharide (LPS) of Klebsiella pneumoniae O1, a causative agent of lung infection, were identified by surface plasmon resonance. To characterize the molecular mechanism of this interaction, HL binding to synthetic disaccharides and tetrasaccharides representing one and two repeating units, respectively, of the O-chain of this LPS were studied. pH-dependent structural rearrangements of HL after interaction with the disaccharide were observed through nuclear magnetic resonance. The crystal structure of the HL-tetrasaccharide complex revealed carbohydrate chain packing into the A, B, C, and D binding sites of HL, which primarily occurred through residue-specific, direct or water-mediated hydrogen bonds and hydrophobic contacts. Overall, these results support a crucial role of the Glu35/Asp53/Trp63/Asp102 residues in HL binding to the tetrasaccharide. These observations suggest an unknown glycan-guided mechanism that underlies recognition of the bacterial cell wall by lysozyme and may complement the HL immune defense function.

Lysozyme's lectin-like characteristics facilitates its immune defense function

KAUST Repository

Zhang, Ruiyan; Wu, Lisha; Eckert, Thomas; Burg-Roderfeld, Monika; Rojas-Macias, Miguel A.; Lü tteke, Thomas; Krylov, Vadim B.; Argunov, Dmitry A.; Datta, Aritreyee; Markart, Philipp; Guenther, Andreas; Norden, Bengt; Schauer, Roland; Bhunia, Anirban; Enani, Mushira Abdelaziz; Billeter, Martin; Scheidig, Axel J.; Nifantiev, Nikolay E.; Siebert, Hans-Christian

2017-01-01

Interactions between human lysozyme (HL) and the lipopolysaccharide (LPS) of Klebsiella pneumoniae O1, a causative agent of lung infection, were identified by surface plasmon resonance. To characterize the molecular mechanism of this interaction, HL binding to synthetic disaccharides and tetrasaccharides representing one and two repeating units, respectively, of the O-chain of this LPS were studied. pH-dependent structural rearrangements of HL after interaction with the disaccharide were observed through nuclear magnetic resonance. The crystal structure of the HL-tetrasaccharide complex revealed carbohydrate chain packing into the A, B, C, and D binding sites of HL, which primarily occurred through residue-specific, direct or water-mediated hydrogen bonds and hydrophobic contacts. Overall, these results support a crucial role of the Glu35/Asp53/Trp63/Asp102 residues in HL binding to the tetrasaccharide. These observations suggest an unknown glycan-guided mechanism that underlies recognition of the bacterial cell wall by lysozyme and may complement the HL immune defense function.

Modeling growth of Alicyclobacillus acidoterrestris DSM 3922 type strain vegetative cells in the apple juice with nisin and lysozyme

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Celenk Molva

2017-05-01

Full Text Available In the present study, the effect of storage temperature on A. acidoterrestris DSM 3922 cells (105 CFU/mL was examined during growth in reconstituted apple juice (pH 3.8, °Brix 11.3 containing nisin (0–100 IU/mL and lysozyme (0–100 mg/L. The growth curves were obtained at three temperatures of 27, 35 and 43 °C using absorbance data (OD600 nm. Based on the results, the minimal inhibitory concentrations (MICs of nisin were found as 10 IU/mL at all tested temperatures. On the other hand, increasing the temperature decreased the amount of lysozyme for growth inhibition. The MICs of lysozyme were found as 10, 2.5 and 1.25 mg/L at 27, 35 and 43 °C, respectively. At selected non-inhibitory doses, nisin (1.25–5 IU/mL and lysozyme (0.3–2.5 mg/L prolonged the lag time compared to the controls at the corresponding temperatures. In addition, there was a strong linear relationship between the lag time and lysozyme concentrations at 27 and 35 °C (R2 > 0.98. The results of this study demonstrated that both nisin and lysozyme could be used to inhibit the growth of A. acidoterrestris cells in the apple juice. The results also indicated that the growth parameters were variable depending on the storage temperature and the type of the antimicrobial agent used in the apple juice.

Pulsed laser deposition of the lysozyme protein: an unexpected “Inverse MAPLE” process

DEFF Research Database (Denmark)

Schou, Jørgen; Matei, Andreea; Constantinescu, Catalin

2012-01-01

Films of organic materials are commonly deposited by laser assisted methods, such as MAPLE (matrix-assisted pulsed laser evaporation), where a few percent of the film material in the target is protected by a light-absorbing volatile matrix. Another possibility is to irradiate the dry organic...... the ejection and deposition of lysozyme. This can be called an “inverse MAPLE” process, since the ratio of “matrix” to film material in the target is 10:90, which is inverse of the typical MAPLE process where the film material is dissolved in the matrix down to several wt.%. Lysozyme is a well-known protein...

Discovery of Cryoprotective Activity in Human Genome-Derived Intrinsically Disordered Proteins

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Naoki Matsuo

2018-01-01

Full Text Available Intrinsically disordered proteins (IDPs are an emerging phenomenon. They may have a high degree of flexibility in their polypeptide chains, which lack a stable 3D structure. Although several biological functions of IDPs have been proposed, their general function is not known. The only finding related to their function is the genetically conserved YSK2 motif present in plant dehydrins. These proteins were shown to be IDPs with the YSK2 motif serving as a core region for the dehydrins’ cryoprotective activity. Here we examined the cryoprotective activity of randomly selected IDPs toward the model enzyme lactate dehydrogenase (LDH. All five IDPs that were examined were in the range of 35–45 amino acid residues in length and were equally potent at a concentration of 50 μg/mL, whereas folded proteins, the PSD-95/Dlg/ZO-1 (PDZ domain, and lysozymes had no potency. We further examined their cryoprotective activity toward glutathione S-transferase as an example of the other enzyme, and toward enhanced green fluorescent protein as a non-enzyme protein example. We further examined the lyophilization protective activity of the peptides toward LDH, which revealed that some IDPs showed a higher activity than that of bovine serum albumin (BSA. Based on these observations, we propose that cryoprotection is a general feature of IDPs. Our findings may become a clue to various industrial applications of IDPs in the future.

Effects of lead administration at low doses by different routes on rat spleens. Study of response of splenic lymphocytes and tissue lysozyme

Energy Technology Data Exchange (ETDEWEB)

Teijon, Cesar; Olmo, Rosa; Dolores Blanco, Maria; Romero, Arturo; Maria Teijon, Jose

2003-09-30

The aim of this study was to evaluate the effects of low doses of lead (200 ppm of PbAc{sub 2} for 4 weeks) on rat spleens using different routes of administration. The study has been carried out at different levels: a histological evaluation has been made, and alterations of cell proliferation, B and T lymphocyte subpopulations, and CD4{sup +} and CD8{sup +} T cell subpopulations have been evaluated. Apoptosis and necrosis of lymphoid cells were also analysed. Furthermore, lysozyme activity was measured. Results indicate a large increase in spleen size when lead is administered by intraperitoneal injection, being this route in which lead causes larger modifications in all of the parameters measured. Lead administered orally causes histological modifications, such as an increase in the number of lymphocytes as well as edema. However, significant alterations in other parameters studied have not been detected. Lead administration by intraperitoneal route causes more evident histological modifications as well as an increase in the number of lymphocytes, and also induces a decrease in the percentage of B{sup +}, T{sup +} and CD4{sup +} cells, and an increase in CD8{sup +} cells. Cell death of splenic lymphocytes is not altered by lead. With regard to the immune innate response, lead behaves as an immunomodulator as can be deduced from data on lysozyme activity in tissue. Therefore, it is possible to affirm that the effect of low doses of lead depends on the route of administration. Thus, the intraperitoneal route, through which lead goes directly to the bloodstream, causes drastic effects, generating important immunological alterations.

[Partially unfolded state of lysozyme with a developed secondary structure in dimethylsulfoxide].

Science.gov (United States)

Timchenko, A A; Kirkitadze, M D; Prokhorov, D A; Potekhin, S A; Serdiuk, I N

1996-06-01

The conformation of a chicken egg lysozyme molecule (dimensions, stoichiometry of its associates, and the degree of helicity) in DMSO was studied by small-angle neutron scattering, dynamic light scattering, and optical rotatory dispersion in the visible region of the spectrum. At high DMSO concentrations (70%), the protein was shown to exist as a dimer. The monomer molecules in the dimer adopt a partially unfolded conformation, with dimensions substantially greater than those in the native state and a high content of secondary structure (the degree of helicity is close to that of native lysozyme). This approach provides a unique possibility to assess the compactness of molecules in associates, which may be very useful in studying protein self-organization.

Electromagnetic Fields Effects on the Secondary Structure of Lysozyme and Bioprotective Effectiveness of Trehalose

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Emanuele Calabrò

2012-01-01

Full Text Available FTIR spectroscopy was used to investigate the effects of extremely low frequency (50 Hz electromagnetic field and of microwaves at 900 MHz on the secondary structure of a typical protein, the lysozyme, evaluating the bioprotective effectiveness of trehalose. Lysozyme in D2O solution (60 mg/ml was exposed to 50 Hz frequency electromagnetic field at 180 μT. The FTIR spectra indicated an increase of CH2 group at 1921 and 1853 cm−1 after 3 h of exposure. Such effect was not observed after the addition of trehalose (150 mg/mL at the same exposure conditions. Lysozyme dissolved in D2O at the concentration of 100 mg/mL was exposed up to 4 h to 900 MHz mobile phone microwaves at 25 mA/m. A significant increase in intensity of the amide I vibration band in the secondary structure of the protein was observed after 4 h exposure to microwaves. This effect was inhibited by the presence of trehalose at the concentration of 150 mg/mL. Fourier self-deconvolution spectral analysis of lysozyme in D2O solution after exposure to microwaves revealed an increase in intensity of the conformational components of amide I mode, particularly of β-sheet and turn that can be attributed to disorder and unfolding processes of the protein.

Fibrous polymer grafted magnetic chitosan beads with strong poly(cation-exchange) groups for single step purification of lysozyme.

Science.gov (United States)

Bayramoglu, Gulay; Tekinay, Turgay; Ozalp, V Cengiz; Arica, M Yakup

2015-05-15

Lysozyme is an important polypetide used in medical and food applications. We report a novel magnetic strong cation exchange beads for efficient purification of lysozyme from chicken egg white. Magnetic chitosan (MCHT) beads were synthesized via phase inversion method, and then grafted with poly(glycidyl methacrylate) (p(GMA)) via the surface-initiated atom transfer radical polymerization (SI-ATRP). Epoxy groups of the grafted polymer, were modified into strong cation-exchange groups (i.e., sulfonate groups) in the presence of sodium sulfite. The MCTH and MCTH-g-p(GMA)-SO3H beads were characterized by ATR-FTIR, SEM, and VSM. The sulphonate groups content of the modified MCTH-g-p(GMA)-4 beads was found to be 0.53mmolg(-1) of beads by the potentiometric titration method. The MCTH-g-p(GMA)-SO3H beads were first used as an ion-exchange support for adsorption of lysozyme from aqueous solution. The influence of different experimental parameters such as pH, contact time, and temperature on the adsorption process was evaluated. The maximum adsorption capacity was found to be 208.7mgg(-1) beads. Adsorption of lysozyme on the MCTH-g-p(GMA)-SO3H beads fitted to Langmuir isotherm model and followed the pseudo second-order kinetic. More than 93% of the adsorbed lysozyme was desorbed using Na2CO3 solution (pH 11.0). The purity of the lysozyme was checked by HPLC and SDS gel electrophoresis. In addition, the MCTH-g-p(GMA)-SO3H beads prepared in this work showed promising potential for separation of various anionic molecules. Copyright © 2015 Elsevier B.V. All rights reserved.

Isolation and partial purification of lysozyme from saliva of Bali Cattle ...

African Journals Online (AJOL)

SND

2012-01-26

Jan 26, 2012 ... 2Faculty of Mathematics and Life Sciences, Mataram University, Jl. Majapahit No. ... The method adopted for isolation of the lysozyme was from Su and ... Vis spectrophotometer (Shimadzu UV-160, Japan) using a BSA.

Chitosan and Cystatin/Lysozyme Preparation as Protective Edible Films Components

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Anna Zimoch-Korzycka

2015-01-01

Full Text Available This work characterizes biological, physical, and chemical properties of films formed from an aqueous solution of hydroxypropyl methylcellulose (HPMC, with different concentrations of chitosan (CH and bioactive cystatin/lysozyme preparation (C/L. The properties of biocomposites were examined by Dynamic Mechanical Analysis (DMA, Fourier’s transfer infrared spectroscopy (FTIR, water vapour permeability (WVP, and tensile testing. Antimicrobial activity against Micrococcus flavus, Bacillus cereus, Escherichia coli, Pseudomonas fluorescens, and Candida famata was conducted. Films glass transition and storage modulus were dependent on the C/L and CH concentration. Modulus values decreased during the temperature scan and with higher reagents levels. An increase of CH and C/L concentrations in the films resulted in a decrease in tensile strength from 2.62 to 1.08 MPa. It suggests the hydrolyzing influence of C/L, also observed in smaller peak size of α relaxation. C/L addition caused shifting Tg to higher temperature. DMA and FTIR analysis proved that HPMC and CH are compatible polymers. Water resistance was improved with rising CH concentration from 1.08E-09 to 7.71E−10 g/m∗s∗Pa. The highest inhibition zone in M. flavus and C. famata was recorded at the highest concentration of CH and C/L.

Plant flavones enhance antimicrobial activity of respiratory epithelial cell secretions against Pseudomonas aeruginosa.

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Benjamin M Hariri

Full Text Available Flavones are a class of natural plant secondary metabolites that have anti-inflammatory and anti-bacterial effects. Some flavones also activate the T2R14 bitter taste receptor, which is expressed in motile cilia of the sinonasal epithelium and activates innate immune nitric oxide (NO production. Flavones may thus be potential therapeutics for respiratory infections. Our objective was to examine the anti-microbial effects of flavones on the common sinonasal pathogens Candida albicans, Staphylococcus aureus, and Pseudomonas aeruginosa, evaluating both planktonic and biofilm growth. Flavones had only very low-level antibacterial activity alone. They did not reduce biofilm formation, but did reduce production of the important P. aeruginosa inflammatory mediator and ciliotoxin pyocyanin. However, flavones exhibited synergy against P. aeruginosa in the presence of antibiotics or recombinant human lysozyme. They also enhanced the efficacy of antimicrobials secreted by cultured and primary human airway cells grown at air-liquid interface. This suggests that flavones may have anti-gram-negative potential as topical therapeutics when combined with antibiotics or in the context of innate antimicrobials secreted by the respiratory or other epithelia. This may have an additive effect when combined with T2R14-activated NO production. Additional studies are necessary to understand which flavone compounds or mixtures are the most efficacious.

[Proteolytic activity of IgG-antibodies of mice, immunized by calf thymus histones].

Science.gov (United States)

Kit, Iu Ia; Korniĭ, N; Kril', I Ĭ; Mahorivs'ka, I B; Tkachenko, V; Bilyĭ, R O; Stoĭka, R S

2014-01-01

The main goal of the study was to determine the ability of histones to induce production of the proteolytically active IgG-antibodies in BALB/c mice. In order to perform this study 8 mice were immunized with the fraction of total calf thymus histones. IgGs were isolated from the serum of the immunized and not immunized animals by means of precipitation with 33% ammonium sulfate, followed by affinity chromatography on protein G-Sepharose column. Histones, myelin basic protein (MBP), lysozyme, BSA, ovalbumin, macroglobulin, casein and cytochrome c served as substrates for determining the proteolytic activity. It was found that IgGs from the blood serum of immunized mice are capable of hydrolyzing histone H1, core histone and MBP. On the contrary, the proteolytic activity of IgGs from the blood serum of not immunized mice was not detected. The absence of proteolytical enzymes in the fraction of IgGs was proven by HPLC chromatography. High levels of proteolytic activity toward histones have been also detected in affinity purified IgGs from blood serum of patients with rheumatoid arthritis, but not in healthy donors. These data indicate that eukaryotic histones may induce production of protabzymes in mammals. The possible origin of these protabzymes and their potential biological role in mammalians is discussed.

Label-Free Aptasensor for Lysozyme Detection Using Electrochemical Impedance Spectroscopy

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Dionisia Ortiz-Aguayo

2018-01-01

Full Text Available This research develops a label-free aptamer biosensor (aptasensor based on graphite-epoxy composite electrodes (GECs for the detection of lysozyme protein using Electrochemical Impedance Spectroscopy (EIS technique. The chosen immobilization technique was based on covalent bonding using carbodiimide chemistry; for this purpose, carboxylic moieties were first generated on the graphite by electrochemical grafting. The detection was performed using [Fe(CN6]3−/[Fe(CN6]4− as redox probe. After recording the frequency response, values were fitted to its electric model using the principle of equivalent circuits. The aptasensor showed a linear response up to 5 µM for lysozyme and a limit of detection of 1.67 µM. The sensitivity of the established method was 0.090 µM−1 in relative charge transfer resistance values. The interference response by main proteins, such as bovine serum albumin and cytochrome c, has been also characterized. To finally verify the performance of the developed aptasensor, it was applied to wine analysis.

Label-Free Aptasensor for Lysozyme Detection Using Electrochemical Impedance Spectroscopy.

Science.gov (United States)

Ortiz-Aguayo, Dionisia; Del Valle, Manel

2018-01-26

This research develops a label-free aptamer biosensor (aptasensor) based on graphite-epoxy composite electrodes (GECs) for the detection of lysozyme protein using Electrochemical Impedance Spectroscopy (EIS) technique. The chosen immobilization technique was based on covalent bonding using carbodiimide chemistry; for this purpose, carboxylic moieties were first generated on the graphite by electrochemical grafting. The detection was performed using [Fe(CN)₆] 3- /[Fe(CN)₆] 4- as redox probe. After recording the frequency response, values were fitted to its electric model using the principle of equivalent circuits. The aptasensor showed a linear response up to 5 µM for lysozyme and a limit of detection of 1.67 µM. The sensitivity of the established method was 0.090 µM -1 in relative charge transfer resistance values. The interference response by main proteins, such as bovine serum albumin and cytochrome c, has been also characterized. To finally verify the performance of the developed aptasensor, it was applied to wine analysis.

Entrapment of active ion-permeable cyanobacteria (Anacystis nidulans) in calcium alginate

Energy Technology Data Exchange (ETDEWEB)

Papageorgiou, G.C.; Kalosaka, K.; Sotiropoulou, G.; Barbotin, J.N.; Thomasset, B.; Thomas, T.

1988-12-01

Cells of the unicellular cyanobacterium Anacystis nidulans were made permeable to ions by treating them with lysozyme and EDTA in a way that leaves the photosynthetic water-splitting function, the photoreduction of exogenous oxidants and the peptidoglycan exoskeleton of the cell virtually intact. The permeabilized cells (permeaplasts) were subsequently immobilized by entrapment in calcium alginate beads. The immobilized preparation exhibits remarkable stability both on storage and in action. On prolonged storage at room temperature in darkness, its photosynthetic activity deteriorates one-third as fast as the activity of immobilized intact cells. Illumination accelerates deactivation. Tested in prolonged runs, however, performed in an illuminated open reactor, alginate-immobilized Anacystis permeaplasts were capable of photoreducing ionic oxidants (ferricyanide) and of exporting ionic reductants (ferrocyanide) to the suspension medium continuously for more than 5 h before being totally inactivated. It is also shown that the major impediment to the photoreduction performance of immobilized permeaplasts arises from diffusion limitations, while the photonic limitation due to light reflection and scattering is approx. 7%.

Complexation of lysozyme with adsorbed PtBS-b-SCPI block polyelectrolyte micelles on silver surface.

Science.gov (United States)

Papagiannopoulos, Aristeidis; Christoulaki, Anastasia; Spiliopoulos, Nikolaos; Vradis, Alexandros; Toprakcioglu, Chris; Pispas, Stergios

2015-01-20

We present a study of the interaction of the positively charged model protein lysozyme with the negatively charged amphiphilic diblock polyelectrolyte micelles of poly(tert-butylstyrene-b-sodium (sulfamate/carboxylate)isoprene) (PtBS-b-SCPI) on the silver/water interface. The adsorption kinetics are monitored by surface plasmon resonance, and the surface morphology is probed by atomic force microscopy. The micellar adsorption is described by stretched-exponential kinetics, and the micellar layer morphology shows that the micelles do not lose their integrity upon adsorption. The complexation of lysozyme with the adsorbed micellar layers depends on the micelles arrangement and density in the underlying layer, and lysozyme follows the local morphology of the underlying roughness. When the micellar adsorbed amount is small, the layers show low capacity in protein complexation and low resistance in loading. When the micellar adsorbed amount is high, the situation is reversed. The adsorbed layers both with or without added protein are found to be irreversibly adsorbed on the Ag surface.

Interaction of lysozyme with a tear film lipid layer model: A molecular dynamics simulation study.

Science.gov (United States)

Wizert, Alicja; Iskander, D Robert; Cwiklik, Lukasz

2017-12-01

The tear film is a thin multilayered structure covering the cornea. Its outermost layer is a lipid film underneath of which resides on an aqueous layer. This tear film lipid layer (TFLL) is itself a complex structure, formed by both polar and nonpolar lipids. It was recently suggested that due to tear film dynamics, TFLL contains inhomogeneities in the form of polar lipid aggregates. The aqueous phase of tear film contains lachrymal-origin proteins, whereby lysozyme is the most abundant. These proteins can alter TFLL properties, mainly by reducing its surface tension. However, a detailed nature of protein-lipid interactions in tear film is not known. We investigate the interactions of lysozyme with TFLL in molecular details by employing coarse-grained molecular dynamics simulations. We demonstrate that lysozyme, due to lateral restructuring of TFLL, is able to penetrate the tear lipid film embedded in inverse micellar aggregates. Copyright © 2017 Elsevier B.V. All rights reserved.

Influence of prolonged storage process, pasteurization, and heat treatment on biologically-active human milk proteins.

Science.gov (United States)

Chang, Jih-Chin; Chen, Chao-Huei; Fang, Li-Jung; Tsai, Chi-Ren; Chang, Yu-Chuan; Wang, Teh-Ming

2013-12-01

The bioactive proteins in human milk may be influenced by prolonged storage process, pasteurization, and heat treatment. This study was conducted to evaluate the effects of these procedures. Three forms of human milk - freshly expressed, frozen at -20°C for a prolonged duration, and pasteurized milk - were collected from 14 healthy lactating mothers and a milk bank. The concentrations of major bioactive proteins (secretory immunoglobulin A, lactoferrin, lysozyme, and leptin) were quantified using enzyme-linked immunosorbent assay kits. Changes in these proteins by heat treatment at 40°C or 60°C for 30 minutes were further evaluated. The mean concentrations of lactoferrin and secretory immunoglobulin A were significantly reduced by 66% and 25.9%, respectively, in pasteurized milk compared with those in freshly-expressed milk. Heat treatment at 40°C or 60°C did not cause significant changes in lactoferrin and secretory immunoglobulin A, but there was an apparent increase in lysozyme (p = 0.016). There were no significant differences in leptin level among these three forms of milk prior to (p = 0.153) or after heat treatment (p = 0.053). Various freezing/heating/pasteurization processes applied to human milk prior to delivery to neonates could affect the concentration of immunomodulatory proteins, especially lactoferrin, secretory immunoglobulin A, and lysozyme. Leptin was unaffected by the various handling processes tested. Fresh milk was found to be the best food for neonates. Further studies are warranted to evaluate the functional activity of these proteins and their effects on infants' immunological status. Copyright © 2013. Published by Elsevier B.V.

Identification and biological activity of potential probiotic bacterium isolated from the stomach mucus of breast-fed lamb

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H. Kiňová Sepov��

2011-09-01

Full Text Available The lactic acid bacterium E isolated from the stomach mucus of breast-fed lamb was identified by sequencing of 16S rDNA fragment and species-specific PCR as Lactobacillus reuteri. Its potential antimicrobial activity and ability to modulate immune system in vitro and in vivo was determined. The growth inhibition of potential pathogens decreased from Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella enterica ser. Minnesota to Escherichia coli. The lowest inhibition activity was observed in the case of Candida albicans. The ability of L. reuteri E to modulate biological activities of human and mouse mononuclear cells was estimated in vitro and in vivo, respectively. The production of IL-1β by monocytes in vitro was significantly induced by L. reuteri E (relative activity 2.47. The ability to modulate biological activities of mononuclear cells by living L. reuteri E cells in vitro in comparison to disintegrated L. reuteri E cells in vivo differed. For example lysozyme activity in vitro was inhibited while in vivo was stimulated (relative activities 0.30 and 1.83, respectively. The peroxidase activity in vitro was stimulated while in vivo was inhibited (relative activities 1.53 and 0.17, respectively. Obtained results indicate that L. reuteri E is potential candidate to be used in probiotic preparations for animals and/or human.

Electron loss from multiply protonated lysozyme ions in high energy collisions with molecular oxygen

DEFF Research Database (Denmark)

Hvelplund, P; Nielsen, SB; Sørensen, M

2001-01-01

We report on the electron loss from multiply protonated lysozyme ions Lys-Hn(n)+ (n = 7 - 17) and the concomitant formation of Lys-Hn(n+1)+. in high-energy collisions with molecular oxygen (laboratory kinetic energy = 50 x n keV). The cross section for electron loss increases with the charge state...... of the precursor from n = 7 to n = 11 and then remains constant when n increases further. The absolute size of the cross section ranges from 100 to 200 A2. The electron loss is modeled as an electron transfer process between lysozyme cations and molecular oxygen....

Behavior of lysozyme adsorbed onto biological liquid crystal lipid monolayer at the air/water interface

Science.gov (United States)

Lu, Xiaolong; Shi, Ruixin; Hao, Changchun; Chen, Huan; Zhang, Lei; Li, Junhua; Xu, Guoqing; Sun, Runguang

2016-09-01

The interaction between proteins and lipids is one of the basic problems of modern biochemistry and biophysics. The purpose of this study is to compare the penetration degree of lysozyme into 1,2-diapalmitoyl-sn-glycero-3-phosphocholine (DPPC) and 1,2-dipalmitoyl-sn-glycero-3-phosphoethano-lamine (DPPE) by analyzing the data of surface pressure-area (π-A) isotherms and surface pressure-time (π-T) curves. Lysozyme can penetrate into both DPPC and DPPE monolayers because of the increase of surface pressure at an initial pressure of 15 mN/m. However, the changes of DPPE are larger than DPPC, indicating stronger interaction of lysozyme with DPPE than DPPC. The reason may be due to the different head groups and phase state of DPPC and DPPE monolayers at the surface pressure of 15 mN/m. Atomic force microscopy reveals that lysozyme was absorbed by DPPC and DPPE monolayers, which leads to self-aggregation and self-assembly, forming irregular multimers and conical multimeric. Through analysis, we think that the process of polymer formation is similar to the aggregation mechanism of amyloid fibers. Project supported by the National Natural Science Foundation of China (Grant Nos. 21402114 and 11544009), the Natural Science Basic Research Plan in Shaanxi Province of China (Grant No. 2016JM2010), the Fundamental Research Funds for the Central Universities of China (Grant No. GK201603026), and the National University Science and Technology Innovation Project of China (Grant No. 201610718013).

Studies on isolation and partial purification of lysozyme from egg ...

African Journals Online (AJOL)

STORAGESEVER

2009-01-05

Jan 5, 2009 ... nine species of lovebirds, and many different colour var- ieties. Their scientific name Agapornis comes from the. Greek Agapa meaning, “Love” and ornis meaning “bird”. This paper describes the isolation, partial purification and determination of molecular weight of lysozyme of Agapor- nis sp. egg white.

Molecular Insight into Human Lysozyme and Its Ability to Form Amyloid Fibrils in High Concentrations of Sodium Dodecyl Sulfate: A View from Molecular Dynamics Simulations.

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Majid Jafari

Full Text Available Changes in the tertiary structure of proteins and the resultant fibrillary aggregation could result in fatal heredity diseases, such as lysozyme systemic amyloidosis. Human lysozyme is a globular protein with antimicrobial properties with tendencies to fibrillate and hence is known as a fibril-forming protein. Therefore, its behavior under different ambient conditions is of great importance. In this study, we conducted two 500000 ps molecular dynamics (MD simulations of human lysozyme in sodium dodecyl sulfate (SDS at two ambient temperatures. To achieve comparative results, we also performed two 500000 ps human lysozyme MD simulations in pure water as controls. The aim of this study was to provide further molecular insight into all interactions in the lysozyme-SDS complexes and to provide a perspective on the ability of human lysozyme to form amyloid fibrils in the presence of SDS surfactant molecules. SDS, which is an anionic detergent, contains a hydrophobic tail with 12 carbon atoms and a negatively charged head group. The SDS surfactant is known to be a stabilizer for helical structures above the critical micelle concentration (CMC [1]. During the 500000 ps MD simulations, the helical structures were maintained by the SDS surfactant above its CMC at 300 K, while at 370 K, human lysozyme lost most of its helices and gained β-sheets. Therefore, we suggest that future studies investigate the β-amyloid formation of human lysozyme at SDS concentrations above the CMC and at high temperatures.

Molecular characterization, transcriptional profiling, and antibacterial potential of G-type lysozyme from seahorse (Hippocampus abdominalis).

Science.gov (United States)

Ko, Jiyeon; Wan, Qiang; Bathige, S D N K; Lee, Jehee

2016-11-01

Lysozymes are a family of enzymes that catalyze the hydrolysis of bacterial cell wall, acting as antimicrobial effectors of the innate immune system. In the present study, an ortholog of goose-type lysozyme (ShLysG) from the big-belly seahorse (Hippocampus abdominalis) was identified and characterized structurally and functionally. The full-length cDNA sequence (1213 bp) of ShLysG is comprised of an open reading frame made up of 552 bp, encoding a polypeptide of 184 amino acid (aa) with a predicted molecular mass of 20 kDa. In silico analysis of ShLysG revealed the absence of signal peptide and the presence of a characteristic bacterial soluble lytic transglycosylase (SLT) domain bearing three catalytic residues (Glu 71 , Asp 84 , and Asp 95 ) and seven N-acetyl-d-glucosamine binding sites (Glu 71 , Asp 95 , Tyr 98 , His 99 , Ile 117 , Tyr 145 , and Asn 146 ). Homology analysis demonstrated that the aa sequence of ShLysG shared 60.7-67.4% identity and 72.6-79.3% similarity with the orthologs of other teleosts. Phylogenetic analysis of ShLysG indicated a closest relationship with the ortholog from Gadus morhua. In healthy seahorse, ShLysG mRNA showed a constitutive expression in all the tissues examined, with the highest expression in kidney and the least expression in liver. The ShLysG mRNA levels were also shown significant elevation upon the bacterial and pathogen-associated molecular pattern (PAMPs) challenges. Furthermore, lytic activities of ShLysG recombinant protein were detected against several Gram-negative and Gram-positive bacterial species. Taken together, these results suggest that ShLysG might possess a potential immune defensive role against invading microbial pathogens in seahorse. Copyright © 2016 Elsevier Ltd. All rights reserved.

Generation of bi-transgenic pigs overexpressing human lactoferrin and lysozyme in milk.

Science.gov (United States)

Cui, Dan; Li, Jia; Zhang, Linlin; Liu, Shen; Wen, Xiao; Li, Qiuyan; Zhao, Yaofeng; Hu, Xiaoxiang; Zhang, Ran; Li, Ning

2015-04-01

Intensive swine production industry uses antibiotics to treat diseases and improve pig growth. This can not only cause antibiotic resistance, but can also pollute the environment or eventually affect human public health. To date, human lactoferrin (hLF) and human lysozyme (hLZ) have been known as non-adaptive but interactive antimicrobial members and could act in concert against bacteria, which contribute to host defense. Therefore, their expression in pigs might be an alternative strategy for replacing antibiotics in the pig production industry. In our study, we produced hLF and hLZ bi-transgenic pigs and assessed the milk's antibacterial ability. Integration of both transgenes was confirmed by PCR and southern blot. Both the hLF and hLZ were expressed in the mammary gland of bi-transgenic pigs, as detected by western blotting. The expression amounts were 6.5 g/L for hLF and 1.1 mg/L for hLZ using ELISA. Interestingly, pig milk containing hLF and hLZ had synergistic antimicrobial activity. Our results suggest an alternative approach for avoiding the use of antibiotics in the pig industry, which would be of great benefit to the commercial swine production.

The extracytoplasmic function sigma factor SigV plays a key role in the original model of lysozyme resistance and virulence of Enterococcus faecalis.

Directory of Open Access Journals (Sweden)

André Le Jeune

Full Text Available BACKGROUND: Enterococcus faecalis is one of the leading agents of nosocomial infections. To cause diseases, pathogens or opportunistic bacteria have to adapt and survive to the defense systems encountered in the host. One of the most important compounds of the host innate defense response against invading microorganisms is lysozyme. It is found in a wide variety of body fluids, as well as in cells of the innate immune system. Lysozyme could act either as a muramidase and/or as a cationic antimicrobial peptide. Like Staphylococcus aureus, E. faecalis is one of the few bacteria that are completely lysozyme resistant. RESULTS: This study revealed that oatA (O-acetyl transferase and dlt (D-Alanylation of lipoteicoic acids genes contribute only partly to the lysozyme resistance of E. faecalis and that a specific transcriptional regulator, the extracytoplasmic function SigV sigma factor plays a key role in this event. Indeed, the sigV single mutant is as sensitive as the oatA/dltA double mutant, and the sigV/oatA/dltA triple mutant displays the highest level of lysozyme sensitivity suggesting synergistic effects of these genes. In S. aureus, mutation of both oatA and dlt genes abolishes completely the lysozyme resistance, whereas this is not the case in E. faecalis. Interestingly SigV does not control neither oatA nor dlt genes. Moreover, the sigV mutants clearly showed a reduced capacity to colonize host tissues, as they are significantly less recovered than the parental JH2-2 strain from organs of mice subjected to intravenous or urinary tract infections. CONCLUSIONS: This work led to the discovery of an original model of lysozyme resistance mechanism which is obviously more complex than those described for other Gram positive pathogens. Moreover, our data provide evidences for a direct link between lysozyme resistance and virulence of E. faecalis.

Crystallization and preliminary x-ray structure analysis of the egg-white lysozyme from a Taiwanese Soft-Shelled Turtle (Tri onyx Sinensis Wiegmann)

International Nuclear Information System (INIS)

Siritapetawee, Jaruwan; Thammasirirak, Sompong; Yuvaniyama, Jirudon

2005-10-01

Lysozyme has been purified from the egg-white of a Taiwanese soft-shelled turtle. This soft-shelled turtle ' s egg-white lysozyme migrated on 12.5% SDS-PAGE at about 14.8 kDa. The lysozyme has been crystallized using the sitting drop vapor diffusion technique and 30% (w/v) polyethylene glycol 8000 in 0.1 M sodium cacodylate, p H 6.5 containing 0.2 M ammonium sulfate as a precipitant. One of the crystals diffracted X rays beyond 2 angstrom unit resolution and belonged to the orthorhombic, space group P212121, with unit cell dimensions of a = 37.8 angstrom unit, b = 55.6 angstrom unit, and c 72.2 angstrom unit and one molecule of the enzyme per asymmetric unit. The data were collected to 1.9 angstrom resolution with an R merge of 4.6%, suitable for high resolution structure analysis. The single-crystal X-ray structure of lysozyme has been initially phased with the Molecular Replacement technique using pheasant egg-white lysozyme (PDB ID 1GHL) as a search template. Model rebuilding and refinement are in progress

Lysozyme as an alternative to antibiotics improves growth performance and tumor necrosis factor-a levels during an indirect immune challenge

Science.gov (United States)

Lysozyme is a 1,4-ß-N-acetylmuramidase that has antimicrobial properties. The objective of this study was to determine the effect of lysozyme and antibiotics on growth performance and immune response during an indirect disease challenge. Two replicates of 720 pigs each were weaned from the sow at ...

Production, crystallization and X-ray characterization of chemically glycosylated hen egg-white lysozyme

International Nuclear Information System (INIS)

López-Jaramillo, F. J.; Pérez-Banderas, F.; Hernández-Mateo, F.; Santoyo-González, F.

2005-01-01

The feasibility of glycosylation post-purification has been demonstrated by introducing glucose into the model protein lysozyme via a novel reaction that is compatible with biological samples. The crystallization of glycoproteins is one of the challenges to be confronted by the crystallographic community in the frame of what is known as glycobiology. The state of the art for the crystallization of glycoproteins is not promising and removal of the carbohydrate chains is generally suggested since they are flexible and a source of heterogeneity. In this paper, the feasibility of introducing glucose into the model protein hen egg-white lysozyme via a post-purification glycosylation reaction that may turn any protein into a model glycoprotein whose carbohydrate fraction can be manipulated is demonstrated

Lysozyme-magnesium aluminum silicate microparticles: Molecular interaction, bioactivity and release studies

DEFF Research Database (Denmark)

Kanjanakawinkul, Watchara; Medlicott, Natalie J.; Rades, Thomas

2015-01-01

The objectives of this study were to investigate the adsorption behavior of lysozyme (LSZ) onto magnesium aluminum silicate (MAS) at various pHs and to characterize the LSZ–MAS microparticles obtained from the molecular interaction between LSZ and MAS. The results showed that LSZ could be bound...

Interactions of cisplatin analogues with lysozyme: a comparative analysis.

Science.gov (United States)

Ferraro, Giarita; De Benedictis, Ilaria; Malfitano, Annamaria; Morelli, Giancarlo; Novellino, Ettore; Marasco, Daniela

2017-10-01

The biophysical characterization of drug binding to proteins plays a key role in structural biology and in the discovery and optimization of drug discovery processes. The search for optimal combinations of biophysical techniques that can correctly and efficiently identify and quantify binding of metal-based drugs to their final target is challenging, due to the physicochemical properties of these agents. Different cisplatin derivatives have shown different citotoxicities in most common cancer lines, suggesting that they exert their biological activity via different mechanisms of action. Here we carried out a comparative analysis, by studying the behaviours of three Pt-compounds under the same experimental conditions and binding assays to properly deepen the determinants of the different MAOs. Indeed we compared the results obtained using surface plasmon resonance, isothermal titration calorimetry, fluorescence spectroscopy and thermal shift assays based on circular dichroism experiments in the characterization of the formation of adducts obtained upon reaction of cisplatin, carboplatin and iodinated analogue of cisplatin, cis-Pt (NH 3 ) 2 I 2 , with the model protein hen egg white lysozyme, both at neutral and acid pHs. Further we reasoned on the applicability of employed techniques for the study the thermodynamics and kinetics of the reaction of a metallodrug with a protein and to reveal which information can be obtained using a combination of these analyses. Data were discussed on the light of the existing structural data collected on the platinated protein.

Inactivation of gram-negative bacteria in milk and banana juice by hen egg white and lambda lysozyme under high hydrostatic pressure.

Science.gov (United States)

Nakimbugwe, Dorothy; Masschalck, Barbara; Anim, Grace; Michiels, Chris W

2006-10-15

The effect of hen egg white lysozyme (HEWL) and bacteriophage lambda lysozyme (LaL) in combination with high pressure (HP) treatment on the inactivation of four gram-negative bacteria (Escherichia coli O157:H7, Shigella flexneri, Yersinia enterocolitica and Salmonella typhimurium), was studied in skim milk (pH 6.8; a(w) 0.997) and in banana juice (pH 3.8; a(w) 0.971). In the absence of lysozymes, S. flexneri was more sensitive to HP in milk than in banana juice, while the opposite was observed for the other three bacteria. In combination with HP treatment, LaL was more effective than HEWL on all bacteria in both milk and banana juice. Depending on the bacteria, inactivation levels in banana juice were increased from 0.4-2.7 log units by HP treatment alone to 3.6-6.5 log units in the presence of 224 U/ml LaL. Bacterial inactivation in milk was also enhanced by LaL but only by 0.5-2.1 log units. Under the experimental conditions used, LaL was more effective in banana juice than in milk, while the effectiveness of HEWL under the same conditions was not significantly affected by the food matrix. This effect could be ascribed to the low pH of the banana juice since LaL was also more effective on E. coli in buffer at pH 3.8 than at pH 6.8. Since neither LaL nor HEWL are enzymatically active at pH 3.8, we analysed bacterial lysis after HP treatment in the presence of these enzymes, and found that inactivation proceeds through a non-lytic mechanism at pH 3.8 and a lytic mechanism at pH 6.8. Based on these results, LaL may offer interesting perspectives for use as an extra hurdle in high pressure food preservation.

Clearing of suspensions of Micrococcus lysodeikticus catalysed by lysozymes from hen, goose, and turkey egg whites, human milk, and phage T4. Assessment of potential as signal generators for homogeneous enzyme immunoassays for urinary steroids.

Science.gov (United States)

Cooke, Delwyn G; Blackwell, Leonard F

2007-01-01

Lysozymes (3.2.1.17) from goose (Anser anser) egg white, turkey (Melagris gallopavo) egg white, phage T4 and human milk were compared with hen egg white lysozyme in their ability to clear a suspension of Micrococcus lysodeikticus. All of the lysozymes, except hen egg white lysozyme, catalysed the clearing of the Micrococcus lysodeikticus suspension in a biphasic fashion. Compared to hen egg white lysozyme, the total absorbance or transmission change over 5 and 20 minutes was less in all cases, except for human lysozyme. Human lysozyme was, therefore, a potential alternative, more rapid signal generator for the measurement of urinary estrone glucuronide excretion rates because of its structural similarity to hen egg white lysozyme. The apparent K(M) values for hen egg white lysozyme increased with the enzyme concentration.

Chronopotentiometric sensing of specific interactions between lysozyme and the DNA aptamer

Czech Academy of Sciences Publication Activity Database

Ostatná, Veronika; Vargová, Veronika; Kekedy-Nagy, L.; Černocká, Hana; Ferapontova, E.E.

2017-01-01

Roč. 114, APR2017 (2017), s. 42-47 ISSN 1567-5394 R&D Projects: GA ČR GA13-00956S Institutional support: RVO:68081707 Keywords : self-assembled monolayers * protein interactions * lysozyme Subject RIV: CE - Biochemistry OBOR OECD: Biochemistry and molecular biology Impact factor: 3.346, year: 2016

Magnetic cation exchange isolation of lysozyme from native hen egg white

Czech Academy of Sciences Publication Activity Database

Šafařík, Ivo; Maděrová, Zdeňka; Tokar, O.; Šafaříková, Miroslava

2007-01-01

Roč. 45, - (2007), s. 355-359 ISSN 1330-9862 R&D Projects: GA MŠk(CZ) 1P05OC053 Institutional research plan: CEZ:AV0Z60870520 Keywords : magnetic separation * lysozyme * hen egg white Subject RIV: EI - Biotechnology ; Bionics Impact factor: 0.906, year: 2007

Lysozyme complexes with thermo- and pH-responsive PNIPAM-b-PAA block copolymer

Energy Technology Data Exchange (ETDEWEB)

Pippa, Natassa [National and Kapodistrian University of Athens, Department of Pharmaceutical Technology, Faculty of Pharmacy (Greece); Meristoudi, Anastasia; Pispas, Stergios, E-mail: pispas@eie.gr [National Hellenic Research Foundation, Theoretical and Physical Chemistry Institute (Greece); Demetzos, Costas [National and Kapodistrian University of Athens, Department of Pharmaceutical Technology, Faculty of Pharmacy (Greece)

2017-02-15

Lysozyme is an enzyme responsible for the damage of bacterial cell walls and is abundant in a number of secretions such as tears and human milk. In the present study, we investigated the structure, the physicochemical characteristics, and the temperature-responsiveness of lysozyme complexes with poly(N-isopropylacrylamide)-b-poly(acrylic acid) block polyelectrolyte in aqueous media. A gamut of light-scattering techniques and fluorescence spectroscopy were used in order to examine the complexation process, as well as the structure, solution behavior, and temperature response of the nanosized complexes. The concentration of copolymer polyelectrolyte was kept constant. The values of the scattering intensity, I{sub 90}, which is proportional to the mass of the species in solution, increased gradually as a function of C{sub LYS,} providing proof of the occurring complexation, while the size of the nanostructures decreased. The structure of the complexes became more open as the C{sub LYS} increased. The increase of the salinity did not affect the structural characteristics of the supramolecular nanoparticulate aggregates. On the other hand, the physicochemical and structural characteristics of the complexes changed upon increasing temperature, and the changes depended on the initial ratio block polyelectrolyte/lysozyme. The knowledge on developing block polyelectrolyte/protein complexes through electrostatic interactions, obtained from this investigation, may be applied to the design of nutraceuticals.

Effects of tributyltin and benzo[a]pyrene on the immune-associated activities of hemocytes and recovery responses in the gastropod abalone, Haliotis diversicolor.

Science.gov (United States)

Gopalakrishnan, Singaram; Huang, Wei-Bin; Wang, Qiang-Wei; Wu, Man-Li; Liu, Jie; Wang, Ke-Jian

2011-08-01

Our previous study reports that short-term exposure to sublethal concentrations of benzo[a]pyrene (BaP) induces immunomodulation in the gastropod abalone, Haliotis diversicolor. In the present study, it was further observed that long-term chronic exposure to sublethal concentrations of BaP modulated the immunocompetence of abalones in terms of the change in activity of the antioxidant and immune associated parameters tested. In addition, the effect of tributyltin (TBT), another important genotoxicant in the aquatic environment, was investigated. Exposure of abalones to sublethal concentrations of TBT and BaP for 21 days resulted in significant decrease of total hemocyte count, phagocytosis, membrane stability and lysozyme activity. Conversely induction of extra and intra cellular superoxide generation, nitric oxide, nitric oxide synthase and myeloperoxidase activity was present when the abalones were exposed to TBT and BaP. Most of the immune associated parameters tested showed clear time dependent response to both toxicants. Within 14 days after the 21 day exposure to BaP, recovery was observed as evidenced by most of the parameters returning to their normal level. However, no recovery was observed within 14 days after the 21 day exposure to TBT as evidenced by continued elevation of intra cellular superoxide and nitrite production and decrease in THC, membrane stability and lysozyme activity. This suggested a prolonged TBT-induced impact on the immune reaction and possibly more damage than that caused by BaP. Overall the results suggest that chronic exposure to sublethal concentrations of TBT or BaP causes modulations in the immunocompetence of abalones with most of the immune associated parameters tested being stimulated, and this might be harmful to the host. Copyright © 2011 Elsevier Inc. All rights reserved.

Anisotropy of the Coulomb Interaction between Folded Proteins: Consequences for Mesoscopic Aggregation of Lysozyme

Science.gov (United States)

Chan, Ho Yin; Lankevich, Vladimir; Vekilov, Peter G.; Lubchenko, Vassiliy

2012-01-01

Toward quantitative description of protein aggregation, we develop a computationally efficient method to evaluate the potential of mean force between two folded protein molecules that allows for complete sampling of their mutual orientation. Our model is valid at moderate ionic strengths and accounts for the actual charge distribution on the surface of the molecules, the dielectric discontinuity at the protein-solvent interface, and the possibility of protonation or deprotonation of surface residues induced by the electric field due to the other protein molecule. We apply the model to the protein lysozyme, whose solutions exhibit both mesoscopic clusters of protein-rich liquid and liquid-liquid separation; the former requires that protein form complexes with typical lifetimes of approximately milliseconds. We find the electrostatic repulsion is typically lower than the prediction of the Derjaguin-Landau-Verwey-Overbeek theory. The Coulomb interaction in the lowest-energy docking configuration is nonrepulsive, despite the high positive charge on the molecules. Typical docking configurations barely involve protonation or deprotonation of surface residues. The obtained potential of mean force between folded lysozyme molecules is consistent with the location of the liquid-liquid coexistence, but produces dimers that are too short-lived for clusters to exist, suggesting lysozyme undergoes conformational changes during cluster formation. PMID:22768950

Complex formation in mixtures of lysozyme-stabilized emulsions and human saliva

NARCIS (Netherlands)

Silletti, E.; Vingerhoeds, M.H.; Norde, W.; Aken, van G.A.

2007-01-01

In this paper, we studied the interaction between human unstimulated saliva and lysozyme-stabilized oil-in-water emulsions (10 wt/wt% oil phase, 10 mM NaCl, pH 6.7), to reveal the driving force for flocculation of these emulsions. Confocal scanning laser microscopy (CSLM) showed formation of

Improvement of wine aromatic quality using mixtures of lysozyme and dimethyl dicarbonate, with low SO2 concentration.

Science.gov (United States)

Nieto-Rojo, Rodrigo; Luquin, Asuncion; Ancín-Azpilicueta, Carmen

2015-01-01

The use of sulphur dioxide (SO2) in the treatment of foodstuffs presents some problems as it could lead to pseudo-allergies in some people. The aim of this research work was to study the addition of different preservative mixtures and their influence on the concentration of volatile compounds and sensorial quality in wine. To do so, vinifications were carried out using Garnacha must to which lysozyme, dimethyl dicarbonate (DMDC) and mixtures of these with SO2 were added at different doses (25 and 50 mg l(-1)). The results were compared with a control sample to which only SO2 had been added (50 mg l(-1)). In general, mixtures of SO2 with lysozyme and DMDC favoured the formation of volatile compounds in the wines. Wines obtained from the mixtures of lysozyme and DMDC with 25 mg l(-1) of SO2 had better sensorial quality than the wines obtained with 50 mg l(-1) as the only preservative used.

Effects of mannose, fructose, and fucose on the structure, stability, and hydration of lysozyme in aqueous solution

DEFF Research Database (Denmark)

Rahim, Abdoul; Peters, Günther H.J.; Jalkanen, Karl J.

2013-01-01

The bio-protective properties of monosaccharaides, namely mannose, fructose and fucose, on the stability and dynamical properties of the NMR determined hen egg-white lysozyme structure have been investigated by means of molecular dynamics simulations at room temperature in aqueous solution and in...... of the solvent and sugar distributions around lysozyme was used to investigate the interfacial solvent and sugar structure near the protein surface.......The bio-protective properties of monosaccharaides, namely mannose, fructose and fucose, on the stability and dynamical properties of the NMR determined hen egg-white lysozyme structure have been investigated by means of molecular dynamics simulations at room temperature in aqueous solution and in 7...... and 13 wt % concentrations of the three sugars. Results are discussed in the framework of the bio-protective phenomena. The three sugars show similar bio-protective behaviours at room temperature (300 K) in the concentration range studied as shown by the small RMSDs of the resulting MD structures from...

Relationship between salivary immunoglobulin a, lactoferrin and lysozyme flow rates and lifestyle factors in Japanese children: a cross-sectional study.

Science.gov (United States)

Ide, Momo; Saruta, Juri; To, Masahiro; Yamamoto, Yuko; Sugimoto, Masahiro; Fuchida, Shinya; Yokoyama, Mina; Kimoto, Shigenari; Tsukinoki, Keiichi

2016-10-01

The antimicrobial substances in saliva contribute to the maintenance of both oral health and overall health of the body. Therefore, the associations among immunoglobulin A (IgA), lactoferrin and lysozyme flow rates in the saliva of children, and their relationships with the physical attributes and lifestyle factors of children, were examined. Saliva was collected from 90 children who visited the Kanagawa Dental University Hospital Pediatric Dentistry, and questionnaires were completed by guardians. IgA, lactoferrin and lysozyme concentrations were measured in the saliva samples using enzyme-linked immunosorbent assays (ELISAs). The IgA flow rate in saliva increased as age, height and weight increased. A correlation was found between lactoferrin and lysozyme flow rates. When the antimicrobial substance flow rates in the saliva were divided into two groups of 22 children each based on the highest and lowest quartiles, children with either a low or high IgA flow rate also had a high or low lactoferrin flow rate, respectively. The same pattern was observed for lactoferrin and lysozyme flow rates. There is a high probability that the IgA flow rate in the saliva of children reflects and corresponds to the developmental status of immune function as the child ages and increases in height and weight. The flow rates of lactoferrin and lysozyme were correlated in children. In addition, regarding lifestyle factors, the duration of sleep and lactoferrin flow rate were also related.

Specific delivery of captopril to the kidney with the prodrug captopril-lysozyme

NARCIS (Netherlands)

Kok, R.J; Moolenaar, Frits; de Zeeuw, D; Meijer, D.K F

Low-molecular-weight proteins (LMWPs) accumulate in the proximal tubular cells of the kidney, which makes these proteins interesting tools for renal drug targeting. We studied this approach using the LMWP lysozyme as a carrier for the angiotensin-converting enzyme inhibitor captopril. Captopril was

Binding of naringin and naringenin with hen egg white lysozyme: A spectroscopic investigation and molecular docking study

Science.gov (United States)

Das, Sourav; Ghosh, Pooja; Koley, Sudipta; Singha Roy, Atanu

2018-03-01

The interactions of naringenin (NG) and naringin (NR) with Hen Egg White Lysozyme (HEWL) in aqueous medium have been investigated using UV-vis spectroscopy, steady-state fluorescence, circular dichroism (CD), Fourier Transform infrared spectroscopy (FT-IR) and molecular docking analyses. Both NG and NR can quench the intrinsic fluorescence of HEWL via static quenching mechanism. At 300 K, the value of binding constant (Kb) of HEWL-NG complex (5.596 ± 0.063 × 104 M- 1) was found to be greater than that of HEWL-NR complex (3.404 ± 0.407 × 104 M- 1). The negative ΔG° values in cases of both the complexes specify the spontaneous binding. The binding distance between the donor (HEWL) and acceptor (NG/NR) was estimated using the Försters theory and the possibility of non-radiative energy transfer from HEWL to NG/NR was observed. The presence of metal ions (Ca2 +, Cu2 + and Fe2 +) decreased the binding affinity of NG/NR towards HEWL. Synchronous fluorescence studies indicate the change in Trp micro-environment due to the incorporation of NG/NR into HEWL. CD and FT-IR studies indicated that the α-helicity of the HEWL was slightly enhanced due to ligand binding. NG and NR inhibited the enzymatic activity of HEWL and exhibited their affinity for the active site of HEWL. Molecular docking studies revealed that both NG and NR bind in the close vicinity of Trp 62 and Trp 63 residues which is vital for the catalytic activity.

Use of europium ions for SAD phasing of lysozyme at the Cu Kα wavelength

International Nuclear Information System (INIS)

Vijayakumar, Balakrishnan; Velmurugan, Devadasan

2012-01-01

Europium(III) ions bound to the surface of hen egg-white lysozyme were found to exhibit good anomalous signal facilitating SAD phasing using laboratory-source data and automated model building. The europium ion-binding sites were observed up to the 15σ level. Europium is shown to be a good anomalous scatterer in SAD phasing for solving the structure of biological macromolecules. The large value of the anomalous contribution of europium, f′′ = 11.17 e − , at the Cu Kα wavelength is an advantage in de novo phasing and automated model building. Tetragonal crystals of hen egg-white lysozyme (HEWL) incorporating europium(III) chloride (50 mM) were obtained which diffracted to a resolution of 2.3 Å at a wavelength of 1.54 Å (Cu Kα). The master data set (360° frames) was split and analyzed for anomalous signal-to-noise ratio, multiplicity, completeness, SAD phasing and automated building. The structure solution and model building of the split data sets were carried out using phenix.autosol and phenix.autobuild. The contributions of the Eu ions to SAD phasing using in-house data collection are discussed. This study revealed successful lysozyme phasing by SAD using laboratory-source data involving Eu ions, which are mainly coordinated by the side chains of Asn46, Asp52 and Asp101 together with some water molecules

Complexation of lysozyme with sodium caseinate and micellar casein in aqueous buffered solutions

NARCIS (Netherlands)

Antonov, Y.A.; Moldenaers, P.; Cardinaels, R.M.

We present an extended structural and morphological study of the complexation of lysozyme (Lys) with sodium caseinate (SC) and micellar casein (MC) by means of turbidity measurements, phase analysis, dynamic, static and electrophoretic light scattering, bright-field and confocal laser scanning

Zero-order release of lysozyme from (poly)ethylene glycol)/poly(butylene terephthalate) matrices

NARCIS (Netherlands)

Bezemer, J.M.; Radersma, R.; Grijpma, Dirk W.; Dijkstra, Pieter J.; Feijen, Jan; van Blitterswijk, Clemens

2000-01-01

Protein release from a series of biodegradable poly(ether ester) multiblock copolymers, based on poly(ethylene glycol) (PEG) and poly(butylene terephthalate) (PBT) was investigated. Lysozyme-containing PEG/PBT films and microspheres were prepared using an emulsion technique. Proteins were

A Marine Actinomycete Rescues Caenorhabditis elegans from Pseudomonas aeruginosa Infection through Restitution of Lysozyme 7

Directory of Open Access Journals (Sweden)

Siti N. Fatin

2017-11-01

Full Text Available The resistance of Pseudomonas aeruginosa to conventional antimicrobial treatment is a major scourge in healthcare. Therefore, it is crucial that novel potent anti-infectives are discovered. The aim of the present study is to screen marine actinomycetes for chemical entities capable of overcoming P. aeruginosa infection through mechanisms involving anti-virulence or host immunity activities. A total of 18 actinomycetes isolates were sampled from marine sediment of Songsong Island, Kedah, Malaysia. Upon confirming that the methanolic crude extract of these isolates do not display direct bactericidal activities, they were tested for capacity to rescue Caenorhabditis elegans infected with P. aeruginosa strain PA14. A hexane partition of the extract from one isolate, designated as Streptomyces sp. CCB-PSK207, could promote the survival of PA14 infected worms by more than 60%. Partial 16S sequence analysis on this isolate showed identity of 99.79% with Streptomyces sundarbansensis. This partition did not impair feeding behavior of C. elegans worms. Tested on PA14, the partition also did not affect bacterial growth or its ability to colonize host gut. The production of biofilm, protease, and pyocyanin in PA14 were uninterrupted, although there was an increase in elastase production. In lys-7::GFP worms, this partition was shown to induce the expression of lysozyme 7, an important innate immunity defense molecule that was repressed during PA14 infection. GC-MS analysis of the bioactive fraction of Streptomyces sp. CCB-PSK207 revealed the presence of methyl esters of branched saturated fatty acids. In conclusion, this is the first report of a marine actinomycete producing metabolites capable of rescuing C. elegans from PA14 through a lys-7 mediated activity.

Pluronic-lysozyme conjugates as anti-adhesive and antibacterial bifunctional polymers for surface coating

NARCIS (Netherlands)

Muszanska, A.K.; Busscher, H.J.; Herrmann, A.; Mei, van der H.C.; Norde, W.

2011-01-01

This paper describes the preparation and characterization of polymer protein conjugates composed of a synthetic triblock copolymer with a central polypropylene oxide (PPO) block and two terminal polyethylene oxide (PEO) segments, Pluronic F-127, and the antibacterial enzyme lysozyme attached to the

Influence of the ionic liquid 1-butyl-3-methylimidazolium bromide on amyloid fibrillogenesis in lysozyme: Evidence from photophysical and imaging studies.

Science.gov (United States)

Basu, Anirban; Bhattacharya, Subhash Chandra; Kumar, Gopinatha Suresh

2018-02-01

Many proteins can abnormally fold to form pathological amyloid deposits/aggregates that are responsible for various degenerative disorders called amyloidosis. Here we have examined the anti-amyloidogenic potency of an ionic liquid, 1-butyl-3-methylimidazolium bromide, using lysozyme as a model system. Thioflavin T fluorescence assay demonstrated that the ionic liquid suppressed the formation of lysozyme fibrils significantly. This observation was further confirmed by the Congo red assay. Fluorescence microscopy, intrinsic fluorescence studies, nile red fluorescence assay, ANS binding assay and circular dichroism studies also testified diminishing of the fibrillogenesis in the presence of ionic liquid. Formation of amyloid fibrils was also characterized by α to β conformational transition. From far-UV circular dichroism studies it was observed that the β-sheet content of the lysozyme samples decreased in the presence of the ionic liquid which in turn implied that fibrillogenesis was supressed by the ionic liquid. Atomic force microscopy imaging unequivocally established that the ionic liquid attenuated fibrillogenesis in lysozyme. These results may be useful for the development of more effective therapeutics for amyloidosis. Copyright © 2017 Elsevier B.V. All rights reserved.

Structural basis for the appearance of a molten globule state in chimeric molecules derived from lysozyme and alpha-lactalbumin.

Science.gov (United States)

Joniau, M; Haezebrouck, P; Noyelle, K; Van Dael, H

2001-07-01

The problem as to why alpha-lactalbumin, in the absence of Ca(2+), forms a molten globule intermediate, in contrast to its structural homologue lysozyme, has been addressed by the construction of chimeras of human lysozyme in which either the Ca(2+)-binding loop or a part of helix C of bovine alpha-lactalbumin were transplanted. Previously, we have shown that the introduction of both structural elements together in the lysozyme matrix causes the apo form of the resulting chimera to display molten globule behavior during the course of thermal denaturation. In this article, we demonstrate that this molten globule character is not correlated with the Ca(2+)-binding loop. Also, the Del 101 mutant in which Arg101 was deleted to simulate the alpha-lactalbumin conformation of the connecting loop between helix C and helix D, does not show a stable equilibrium intermediate. Rather, the molten globule character of the chimeras has to be related with a specific part of helix C. More particularly, attention is drawn to the four hydrophobic side-chains I93, V96, I99, and L100, the lysozyme counterparts of which are constituted of less bulky valines and alanine. Our observations are discussed in terms of decreased stability of the native form and increased stability of the intermediate molten globule. Copyright 2001 Wiley-Liss, Inc.

Targeting the human lysozyme gene on bovine αs1- casein gene ...

African Journals Online (AJOL)

Targeting an exogenous gene into a favorable gene locus and for expression under endogenous regulators is an ideal method in mammary gland bioreactor research. For this purpose, a gene targeting vector was constructed to targeting the human lysozyme gene on bovine αs1-casein gene locus. In this case, the ...

Targeting the human lysozyme gene on bovine αs1- casein gene ...

African Journals Online (AJOL)

ajl yemi

2011-11-28

Nov 28, 2011 ... Targeting an exogenous gene into a favorable gene locus and for expression under endogenous regulators is ... case, the expression of human lysozyme could be regulated by the endogenous cis-element of αs1- casein gene in .... Mouse mammary epithelial C127 cells (Cell Bank, Chinese. Academy of ...

Label-Free Aptasensor for Lysozyme Detection Using Electrochemical Impedance Spectroscopy

OpenAIRE

Dionisia Ortiz-Aguayo; Manel del Valle

2018-01-01

This research develops a label-free aptamer biosensor (aptasensor) based on graphite-epoxy composite electrodes (GECs) for the detection of lysozyme protein using Electrochemical Impedance Spectroscopy (EIS) technique. The chosen immobilization technique was based on covalent bonding using carbodiimide chemistry; for this purpose, carboxylic moieties were first generated on the graphite by electrochemical grafting. The detection was performed using [Fe(CN)6]3−/[Fe(CN)6]4− as redox probe. Afte...

Can lactoferrin modulate the immunostimulant activity of levamisole in rats

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Wafaa Abdou Mohamed Mohamed

2014-03-01

Full Text Available Objective: The aim of this study was to study the immunomodulatory activity improvement of levamisole by using lactoferrin when applied to immunosuppressed rat model. Methods: The study was designed as follows, 140 male albino rats (250-280 g 14 weeks old were used in our work. Rats were randomly divided into seven groups, 20 in each. The group I was kept as a control, group II was given cyclophosphamide (CYP at a single intraperitoneal dose of (250 mg/kg body weight, group III CYP and lactoferrin (Lac treated group, group IV orally administrated Lac only (0.5% in drinking water, group V treated with CYP and levamisole, group VI administrated levamisole orally at a dose of (2.5 mg/kg body weight and group VII was given CYP, Lac and levamisole. Animals were sacrificed and two separate blood samples were collected after 21 days from the beginning of the experiment for measuring the total and differential leukocyte count, serum total proteins, albumin, alpha globulin, beta globulin and gamma globulin, Nitric oxide (NO production and lysozyme activity. Results: CYP group showed significant decrease in the above mentioned parameters, which were improved after administration of both lactoferrin and levamisole. Conclusion: Our study concluded that lactoferrin improve the immunostimulant effect of levamisole in CYP- immunosuppressed rats. J Clin Exp Invest 2014; 5 (1: 48-53

A comparative study for adsorption of lysozyme from aqueous samples onto Fe3O4 magnetic nanoparticles using different ionic liquids as modifier.

Science.gov (United States)

Kamran, Sedigheh; Absalan, Ghodratollah; Asadi, Mozaffar

2015-12-01

In this paper, nanoparticles of Fe3O4 as well as their modified forms with different ionic liquids (IL-Fe3O4) were prepared and used for adsorption of lysozyme. The mean size and the surface morphology of the nanoparticles were characterized by TEM, XRD and FTIR techniques. Adsorption studies of lysozyme were performed under different experimental conditions in batch system on different modified magnetic nanoparticles such as, lysozyme concentration, pH of the solution, and contact time. Experimental results were obtained under the optimum operational conditions of pH 9.0 and a contact time of 10 min when initial protein concentrations of 0.05-2.0 mg mL(-1) were used. The isotherm evaluations revealed that the Langmuir model attained better fits to the equilibrium data than the Freundlich model. The maximum obtained adsorption capacities were 370.4, 400.0 500.0 and 526.3 mg of lysozyme for adsorption onto Fe3O4 and modified magnetic nanoparticles by [C4MIM][Br], [C6MIM][Br] and [C8MIM][Br] per gram of adsorbent, respectively. The Langmuir adsorption constants were 0.004, 0.019, 0.024 and 0.012 L mg(-1) for adsorptions of lysozyme onto Fe3O4 and modified magnetic nanoparticles by [C4MIM][Br], [C6MIM][Br] and [C8MIM][Br], respectively. The adsorption capacity of lysozyme was found to be dependent on its chemical structure, pH of the solution, temperature and type of ionic liquid as modifier. The applicability of two kinetic models including pseudo-first order and pseudo-second order model was estimated. Furthermore, the thermodynamic parameters were calculated. Protein could desorb from IL-Fe3O4 nanoparticles by using NaCl solution at pH 9.5 and was reused.

[Purification of human goose-type lysozyme 2 (HLysG2) from human seminal plasma and analysis of its enzymatic properties].

Science.gov (United States)

Huang, Peng; Yang, Zhifang; Bao, Jianying; Zhang, Ning; Li, Wenshu

2017-03-01

Objective To purify human goose-type lysozyme 2 (HLysG2) from human seminal plasma by chromatography and analyze its enzymatic properties. Methods The distribution of HLysG2 in semen was analyzed by Western blot analysis. Seminal plasma was subjected to the separation of target protein using cation-exchange chromatography, chitin affinity chromatography and size-exclusion chromatography. The purified product was identified by Western blot analysis and mass spectrometry (MS).The purity was analyzed by high performance liquid chromatography (HPLC). Then, the optimum pH, ion concentration and temperature of HLysG2 and its standard activity were determined by the turbidimetric assay. The bactericidal activity of HLysG2 was assessed by the colony-forming assay. Results The existence of HLysG2 in seminal plasma was confirmed by Western blot analysis. A protein of about 21.5 kDa was purified from seminal plasma by the three kinds of chromatography and identified as HLysG2 by Western blot analysis and MS. The final purity of the purified product was above 99.0% and the peak enzymatic activity reached 13 800 U/mg under the condition of pH 6.4, 0.09 mol/L Na + , 30DegreesCelsius. In vitro assay indicated that HLysG2 had a significant killing effect on Micrococcus lysodeikticus, Bacillus subtilis and Staphylococcus aureus, but not on Pseudomonas aeruginosa and Escherichia coli. Conclusion Native HLysG2 can be obtained from seminal plasma by chromatography. It has in vitro bactericidal activity against Gram-positive bacteria, suggesting that it might play a role in innate immunity of the male reproductive system.

Tetragonal Lysozyme Interactions Studied by Site Directed Mutagenesis

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Crawford, Lisa; Karr, Laurel J.; Nadarajah, Arunan; Pusey, Marc

1999-01-01

A number of recent experimental and theoretical studies have indicated that tetragonal lysozyme crystal growth proceeds by the addition of aggregates, formed by reversible self association of the solute molecules in the bulk solution. Periodic bond chain and atomic force microscopy studies have indicated that the probable growth unit is at minimum a 43 tetramer, and most likely an octamer composed of two complete turns about the 43 axis. If these results are correct, then there are intermolecular interactions which are only formed in the solution and others only formed at the joining of the growth unit to the crystal surface. We have set out to study these interactions, and the correctness of this hypothesis, using site directed mutagenesis of specific amino acid residues involved in the different bonds. We had initially expressed wild type lysozyme in S. cervasiae with yields of approximately 5 mg/L, which were eventually raised to approximately 40 mg/L. We are now moving the expression to the Pichia system, with anticipated yields of 300 to (3)500 mg/L, comparable to what can be obtained from egg whites. An additional advantage of using recombinant protein is the greater genetic homogeneity of the material obtained and the absence of any other contaminating egg proteins. The first mutation experiments are TYR 23 (Registered) PHE or ALA and ASN 113 (Registered) ALA or ASP. Both TYR 23 and ASN 113 form part of the postulated dimerization intermolecular binding site which lead to the formation of the 43 helix. Tyrosine also participates in an intermolecular hydrogen bond with ARG 114. The results of these and subsequent experiments will be discussed.

Investigation of factors affecting the stability of lysozyme spray dried from ethanol-water solutions

DEFF Research Database (Denmark)

Ji, Shuying; Thulstrup, Peter Waaben; Mu, Huiling

2017-01-01

-ethanol mixtures. The effect of formulation additives (trehalose, Tween 20 and phosphate-buffered saline) and processing conditions (inlet temperature and storage time of lysozyme in the feed solution before the spray drying process) on the protein bioactivity was investigated. The results showed...

Isolation of Lactococcus lactis Mutants Simultaneously Resistant to the Cell Wall-Active Bacteriocin Lcn972, Lysozyme, Nisin, and Bacteriophage c2

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Roces, Clara; Courtin, Pascal; Kulakauskas, Saulius; Rodríguez, Ana; Chapot-Chartier, Marie-Pierre

2012-01-01

Lactococcin 972 (Lcn972) is a nonlantibiotic bacteriocin that inhibits cell wall biosynthesis by binding to lipid II. In this work, two mutants resistant to Lcn972, Lactococcus lactis D1 and D1-20, with high (>320 arbitrary units [AU]/ml) and low (80 AU/ml) susceptibilities, respectively, have been isolated. Resistance to Lcn972 did not impose a burden to growth under laboratory conditions, nor did it substantially alter the physicochemical properties of the cell surface. However, the peptidoglycan of the mutants featured a higher content of muropeptides with tripeptide side chains than the wild-type strain, linking for the first time peptidoglycan remodelling to bacteriocin resistance. Moreover, L. lactis lacking a functional d,d-carboxypeptidase DacA (i.e., with a high content of pentapeptide side chain muropeptides) was shown to be more susceptible to Lcn972. Cross-resistance to lysozyme and nisin and enhanced susceptibility to penicillin G and bacitracin was also observed. Intriguingly, the Lcn972-resistant mutants were not infected by the lytic phage c2 and less efficiently infected by phage sk1. Lack of c2 infectivity was linked to a 22.6-kbp chromosomal deletion encompassing the phage receptor protein gene pip. The deletion also included maltose metabolic genes and the two-component system (TCS) F. However, a clear correlation between these genes and resistance to Lcn972 could not be clearly established, pointing to the presence of as-yet-unidentified mutations that account for Lcn972 resistance. PMID:22504807

Production of human lactoferrin and lysozyme in the milk of transgenic dairy animals: past, present, and future.

Science.gov (United States)

Cooper, Caitlin A; Maga, Elizabeth A; Murray, James D

2015-08-01

Genetic engineering, which was first developed in the 1980s, allows for specific additions to animals' genomes that are not possible through conventional breeding. Using genetic engineering to improve agricultural animals was first suggested when the technology was in the early stages of development by Palmiter et al. (Nature 300:611-615, 1982). One of the first agricultural applications identified was generating transgenic dairy animals that could produce altered or novel proteins in their milk. Human milk contains high levels of antimicrobial proteins that are found in low concentrations in the milk of ruminants, including the antimicrobial proteins lactoferrin and lysozyme. Lactoferrin and lysozyme are both part of the innate immune system and are secreted in tears, mucus, and throughout the gastrointestinal (GI) tract. Due to their antimicrobial properties and abundance in human milk, multiple lines of transgenic dairy animals that produce either human lactoferrin or human lysozyme have been developed. The focus of this review is to catalogue the different lines of genetically engineered dairy animals that produce either recombinant lactoferrin or lysozyme that have been generated over the years as well as compare the wealth of research that has been done on the in vitro and in vivo effects of the milk they produce. While recent advances including the development of CRISPRs and TALENs have removed many of the technical barriers to predictable and efficient genetic engineering in agricultural species, there are still many political and regulatory hurdles before genetic engineering can be used in agriculture. It is important to consider the substantial amount of work that has been done thus far on well established lines of genetically engineered animals evaluating both the animals themselves and the products they yield to identify the most effective path forward for future research and acceptance of this technology.

SERS activity of silver and gold nanostructured thin films deposited by pulsed laser ablation

Science.gov (United States)

Agarwal, N. R.; Tommasini, M.; Fazio, E.; Neri, F.; Ponterio, R. C.; Trusso, S.; Ossi, P. M.

2014-10-01

Nanostructured Au and Ag thin films were obtained by nanosecond pulsed laser ablation in presence of a controlled Ar atmosphere. Keeping constant other deposition parameters such as target-to-substrate distance, incidence angle, laser wavelength and laser fluence, the film morphology, revealed by SEM, ranges from isolated NPs to island structures and sensibly depends on gas pressure (10-100 Pa) and on the laser pulse number (500-3 × 10). The control of these two parameters allows tailoring the morphology and correspondingly the optical properties of the films. The position and width of the surface plasmon resonance peak, in fact, can be varied with continuity. The films showed remarkable surface-enhanced Raman activity (SERS) that depends on the adopted deposition conditions. Raman maps were acquired on micrometer-sized areas of both silver and gold substrates selected among those with the strongest SERS activity. Organic dyes of interest in cultural heritage studies (alizarin, purpurin) have been also considered for bench marking the substrates produced in this work. Also the ability to detect the presence of biomolecules was tested using lysozyme in a label free configuration.

The Effect of Ethylene Glycol, Glycine Betaine, and Urea on Lysozyme Thermal Stability

Science.gov (United States)

Schwinefus, Jeffrey J.; Leslie, Elizabeth J.; Nordstrom, Anna R.

2010-01-01

The four-week student project described in this article is an extension of protein thermal denaturation experiments to include effects of added cosolutes ethylene glycol, glycine betaine, and urea on the unfolding of lysozyme. The transition temperatures and van't Hoff enthalpies for unfolding are evaluated for six concentrations of each cosolute,…

Pathological changes in the retina of eyes rats with experimental 2 type diabetes mellitus and their correction by oral gels with biologically active substances

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V. V. Vit

2014-07-01

Full Text Available Purpose: To study of therapeutic and prophylactic action on the retina of rats with experimental diabetes mellitus type 2 (DM2 oral mucosal gels containing biologically active substances (BAS.Methods: DM2 was induced by protamine method Ulyanov and Tarasova [2000]. As BAS used lysozyme, flour of grape leaves, the water extract of blueberries and quercetin. Mucosal gels containing active substances, applied to the mucous lining of the mouth for 2 weeks. The serum glucose concentration was performed and histological studies of the retina.Results: Application mucosal gels reduces BAS 8‑22 % glucose (most with blueberry extract and significantly improves retinal histology (vacuolar degeneration less pronounced ganglion cells, there are no structural changes in photoreceptor layer. Gels revealed more effective with containing extract of bilberry, grape flour and quercetin.Conclusion: Oral mucosal application of gels containing active substances, have protection of retina in diabetes mellitus type 2.

Transposon mutagenesis of probiotic Lactobacillus casei identifies asnH, an asparagine synthetase gene involved in its immune-activating capacity.

Science.gov (United States)

Ito, Masahiro; Kim, Yun-Gi; Tsuji, Hirokazu; Takahashi, Takuya; Kiwaki, Mayumi; Nomoto, Koji; Danbara, Hirofumi; Okada, Nobuhiko

2014-01-01

Lactobacillus casei ATCC 27139 enhances host innate immunity, and the J1 phage-resistant mutants of this strain lose the activity. A transposon insertion mutant library of L. casei ATCC 27139 was constructed, and nine J1 phage-resistant mutants out of them were obtained. Cloning and sequencing analyses identified three independent genes that were disrupted by insertion of the transposon element: asnH, encoding asparagine synthetase, and dnaJ and dnaK, encoding the molecular chaperones DnaJ and DnaK, respectively. Using an in vivo mouse model of Listeria infection, only asnH mutant showed deficiency in their ability to enhance host innate immunity, and complementation of the mutation by introduction of the wild-type asnH in the mutant strain recovered the immuno-augmenting activity. AsnH protein exhibited asparagine synthetase activity when the lysozyme-treated cell wall extracts of L. casei ATCC 27139 was added as substrate. The asnH mutants lost the thick and rigid peptidoglycan features that are characteristic to the wild-type cells, indicating that AsnH of L. casei is involved in peptidoglycan biosynthesis. These results indicate that asnH is required for the construction of the peptidoglycan composition involved in the immune-activating capacity of L. casei ATCC 27139.

Transposon mutagenesis of probiotic Lactobacillus casei identifies asnH, an asparagine synthetase gene involved in its immune-activating capacity.

Directory of Open Access Journals (Sweden)

Masahiro Ito

Full Text Available Lactobacillus casei ATCC 27139 enhances host innate immunity, and the J1 phage-resistant mutants of this strain lose the activity. A transposon insertion mutant library of L. casei ATCC 27139 was constructed, and nine J1 phage-resistant mutants out of them were obtained. Cloning and sequencing analyses identified three independent genes that were disrupted by insertion of the transposon element: asnH, encoding asparagine synthetase, and dnaJ and dnaK, encoding the molecular chaperones DnaJ and DnaK, respectively. Using an in vivo mouse model of Listeria infection, only asnH mutant showed deficiency in their ability to enhance host innate immunity, and complementation of the mutation by introduction of the wild-type asnH in the mutant strain recovered the immuno-augmenting activity. AsnH protein exhibited asparagine synthetase activity when the lysozyme-treated cell wall extracts of L. casei ATCC 27139 was added as substrate. The asnH mutants lost the thick and rigid peptidoglycan features that are characteristic to the wild-type cells, indicating that AsnH of L. casei is involved in peptidoglycan biosynthesis. These results indicate that asnH is required for the construction of the peptidoglycan composition involved in the immune-activating capacity of L. casei ATCC 27139.

Susceptibility of bifidobacteria to lysozyme as a possible selection criterion for probiotic bifidobacterial strains

Czech Academy of Sciences Publication Activity Database

Rada, V.; Šplíchal, Igor; Rocková, S.; Grmanová, M.; Vlková, E.

2010-01-01

Roč. 32, č. 3 (2010), s. 451-455 ISSN 0141-5492 R&D Projects: GA ČR GA523/07/0572 Institutional research plan: CEZ:AV0Z50200510 Keywords : Bifidobacteria * human milk * Lysozyme Subject RIV: EE - Microbiology, Virology Impact factor: 1.768, year: 2010

Fourier transform infrared studies in solid egg white lysozyme

International Nuclear Information System (INIS)

Rivzi, T.Z.

1994-12-01

Fourier Transform Infrared (FTIR) Spectroscopy is the most recent addition to the arsenal of bioanalytical techniques capable of providing information about the secondary structure of proteins in a variety of environments. FTIR spectra have been obtained in solid egg white lysozyme. The spectra display the usual amide I, II and III bands. Secondary structural information obtained from the spectra after applying resolution enhancement techniques to the amide I band has been found consistent with the x-ray crystallographic data of the protein and also to the spectroscopic data of the protein in aqueous solution. (author). 17 refs, 6 figs, 2 tabs

Electrophoretic Approach for the Simultaneous Deposition and Functionalization of Reduced Graphene Oxide Nanosheets with Diazonium Compounds: Application for Lysozyme Sensing in Serum.

Science.gov (United States)

Wang, Qian; Vasilescu, Alina; Wang, Qi; Coffinier, Yannick; Li, Musen; Boukherroub, Rabah; Szunerits, Sabine

2017-04-12

Electrophoretic deposition (EPD) of reduced graphene oxide nanosheets (rGO) offers several advantages over other surface coating approaches, including process simplicity, uniformity of the deposited films, and good control of the film thickness. The EPD conditions might also be of interest for the reduction of diazonium salts, which upon the release of N 2 molecules and generation of radicals, can form covalent bonds with the sp 2 hybridized carbon lattice atoms of rGO films. In this work, we report on the coating of gold electrodes in one step with rGO/polyethylenimine (PEI) thin films and their simultaneous modification using different phenyl (Ph) diazonium salt precursors bearing various functionalities such as -B(OH) 2 , -COOH, and -C≡CH. We show further the interest of such interfaces for designing highly sensitive sensing platforms. Azide-terminated lysozyme aptamers were clicked onto the rGO/PEI/Ph-alkynyl matrix and used for the sensing of lysozyme levels in patients suffering from inflammatory bowel disease (IBD), where lysozyme levels are up-regulated. The approach attained the required demand for the determination of lysozyme level in patients suffering from IBD with a 200 fM detection limit and a linear range up to 20 pM without signal amplification.

Size Exclusion Chromatography Studies of the Initial Self-Association Steps of Chicken Egg White Lysozyme Nucleation

Science.gov (United States)

Ewing, Felecia; Donovan, David; Pusey, Marc

2000-01-01

Nucleation is one of the least understood aspects of crystallogenesis. In the case of macromolecule nucleation, this understanding is further hampered by uncertainty over what precisely is being discussed. We define the process of solute self-association (aggregation, oligomerization, interaction, clustering, etc.) whereby n-mers (n > or = 2) having a crystallographic or nascent crystallographic arrangement leading to the critical nucleus reversibly form in the solution, to be part of the nucleation process. This reversible self-association process is a fundamental part of the nucleation process, and occurs as a function of the solute concentration. In the case of chicken egg white lysozyme, a considerable body of experimental evidence leads us to the conclusion that it also forms the crystal growth units. Size exclusion chromatography is a simple and direct method for determining the equilibrium constants for the self-association process. A Pharmacia FPLC system was used to provide accurate solution flow rates. The column, injection valve, and sample loop were all mounted within a temperature-controlled chamber. Chromatographically re-purified lysozyme was first dialyzed against the column equilibration buffer, with injection onto the column after several hours pre-incubation at the running temperature. Preliminary experiments, were carried out using a Toyopearl HW-50F column (1 x 50cm), equilibrated with 0.1 M sodium acetate, 5% sodium chloride, pH 4.6, at 15C. Protein concentrations from 0.1 to 4 mg/ml were employed (C(sub sat) = 1.2 mg/ml). The data from several different protein preparations consistently shows a progressively decreasing elution volume with increasing protein concentration, indicating that reversible self-association is occurring. The dotted line indicates the monomeric lysozyme elution volume. However, lysozyme interacts with the column matrix in these experiments, which complicates data analysis.Accordingly, we are testing silica-based HPLC

Relationship between β-relaxation and structural stability of lysozyme: Microscopic insight on thermostabilization mechanism by trehalose from Raman spectroscopy experiments

Energy Technology Data Exchange (ETDEWEB)

Hédoux, Alain, E-mail: alain.hedoux@univ-lille1.fr; Paccou, Laurent; Guinet, Yannick [Université Lille Nord de France, F-59000 Lille France, USTL UMET UMR 8207 F-59655 Villeneuve d’Ascq (France)

2014-06-14

Raman investigations were carried out in the low-frequency and amide I regions on lysozyme aqueous solutions in absence and presence of trehalose. Raman spectroscopy gives the unique opportunity to analyze the protein and solvent dynamics in the low-frequency range while monitoring the unfolding process by capturing the spectrum of the amide I band. From the analysis of the quasielastic intensity, a dynamic change is firstly observed in a highly hydrated protein, around 70 °C, and interpreted in relation with the denaturation mechanism of the protein. The use of heavy water and partly deuterated trehalose gives clear information on protein–trehalose interactions in the native state of lysozyme (at room temperature) and during the thermal denaturation process of lysozyme. At room temperature, it was found that trehalose is preferentially excluded from the protein surface, and has a main effect on the tetrahedral local order of water molecules corresponding to a stiffening of the H-bond network in the solvent. The consequence is a significant reduction of the amplitude of fast relaxational motions, inducing a less marked dynamic transition shifted toward the high temperatures. Upon heating, interaction between trehalose and lysozyme is detected during the solvent penetration within the protein, i.e., while the native globular state softens into a molten globule (MG) state. Addition of trehalose reduces the protein flexibility in the MG state, improving the structural stability of the protein, and inhibiting the protein aggregation.

Is activation analysis still active?

International Nuclear Information System (INIS)

Chai Zhifang

2001-01-01

This paper reviews some aspects of neutron activation analysis (NAA), covering instrumental neutron activation analysis (INAA), k 0 method, prompt gamma-ray neutron activation analysis (PGNAA), radiochemical neutron activation analysis (RNAA) and molecular activation analysis (MAA). The comparison of neutron activation analysis with other analytical techniques are also made. (author)

Effect of intracrystalline water on micro-Vickers hardness in tetragonal hen egg-white lysozyme single crystals

International Nuclear Information System (INIS)

Koizumi, H; Kawamoto, H; Tachibana, M; Kojima, K

2008-01-01

Mechanical properties of high quality tetragonal hen egg-white lysozyme single crystals which are one type of protein crystal were investigated by the indentation method. The indentation marks were clearly observed on the crystal surface and no elastic recovery of them occurred. The value of the micro-Vickers hardness in the wet condition was estimated to be about 20 MPa at room temperature. The hardness greatly depended on the amount of intracrystalline water (mobile water) contained in the crystals. The hardness increased with increasing evaporation time to air at room temperature. It reached the maximum at about 260 MPa, which is 13 times as much as that in the wet condition. The origin of such a change in hardness was explained in terms of the dislocation mechanisms in lysozyme single crystals

Laser ablation of the protein lysozyme

DEFF Research Database (Denmark)

Schou, Jørgen; Canulescu, Stela; Amoruso, Salvatore

produced thin films of average thickness up to 300 nm, which not only contained a significant amount of intact molecules, but also maintained the bioactivity. These films were produced by a nanosecond laser in the UV regime at 355 nm with 2 J/cm2. The surprising fact that these molecules can be transferred......Lysozyme is a well-known protein, which is used in food processing because of its bactericidal properties. The mass (14307 amu) is in the range in which it easily can be monitored by mass spectrometric methods, for example by MALDI (Matrix assisted laser desorption ionization). We have recently...... to a substrate as intact molecules by the violent laser impact ( up to 50 mJ/pulse) has not yet been understood. One issue is that up to 150 ng/pulse is removed by the laser, and much of the material is ejected from the target in relatively large chunks. We have explored as well the excitation mechanics by laser...

Immobilization of lysozyme-cellulose amide-linked conjugates on cellulose i and ii cotton nanocrystalline preparations

Science.gov (United States)

Lysozyme was attached through an amide linkage between some of the protein’s aspartate and glutamate residues to amino-glycine-cellulose (AGC), which was prepared by esterification of glycine to preparations of cotton nanocrystals (CNC). The nanocrystalline preparations were produced through acid h...

A calorimetric study of the interactions in the aqueous solutions of lysozyme in the presence of denaturing cosolvents

Energy Technology Data Exchange (ETDEWEB)

Castronuovo, Giuseppina, E-mail: giuseppina.castronuovo@unina.it [Department of Chemistry, University Federico II of Naples, Complesso Universitario Monte S. Angelo, via Cintia, 80126 Naples (Italy); Niccoli, Marcella [Department of Chemistry, University Federico II of Naples, Complesso Universitario Monte S. Angelo, via Cintia, 80126 Naples (Italy)

2012-09-10

Highlights: Black-Right-Pointing-Pointer A thermodynamic method is reported to monitor the chemical denaturation of lysozyme. Black-Right-Pointing-Pointer The enthalpic interaction coefficients are very useful parameters to gain information about the mechanism through which two hydrated molecules interact in solution. Black-Right-Pointing-Pointer Hypotheses are proposed about the mechanism underlying the denaturation of lysozyme induced by high concentrations of urea or ethanol. - Abstract: A thermodynamic method is reported to monitor the chemical denaturation of lysozyme. Heats of dilution of the protein in concentrated aqueous solutions of urea or ethanol have been determined at 298.15 K by flow microcalorimetry. The pairwise enthalpic interaction coefficients of the protein in the different solvent media are derived. These parameters allow to gain information about the influence of the cosolvents on the interactions acting between two interacting hydrated molecules of lysozyme, hence on the denaturation process. At increasing urea concentration, up to about 6 mol kg{sup -1}, the values of the interaction coefficients are large and negative and remain almost unaltered. The invariance of the coefficients underlines that, even in highly concentrated urea, the hydration shell of the protein is such to maintain essentially unaltered the native conformation. At higher urea concentrations, a sudden change in the sign of the coefficients monitors the variation in the interactions between two hydrated denatured protein molecules. The same trend is found when ethanol is the cosolvent. At increasing concentration of the cosolvent, coefficients are, at first, almost invariant. After that, denaturation occurs, detected as a jump toward much more negative values. The results obtained are rationalized on the basis of those previously found for small model molecules in concentrated solutions of urea or ethanol. The thermodynamic framework allows useful comments to be made on

A calorimetric study of the interactions in the aqueous solutions of lysozyme in the presence of denaturing cosolvents

International Nuclear Information System (INIS)

Castronuovo, Giuseppina; Niccoli, Marcella

2012-01-01

Highlights: ► A thermodynamic method is reported to monitor the chemical denaturation of lysozyme. ► The enthalpic interaction coefficients are very useful parameters to gain information about the mechanism through which two hydrated molecules interact in solution. ► Hypotheses are proposed about the mechanism underlying the denaturation of lysozyme induced by high concentrations of urea or ethanol. - Abstract: A thermodynamic method is reported to monitor the chemical denaturation of lysozyme. Heats of dilution of the protein in concentrated aqueous solutions of urea or ethanol have been determined at 298.15 K by flow microcalorimetry. The pairwise enthalpic interaction coefficients of the protein in the different solvent media are derived. These parameters allow to gain information about the influence of the cosolvents on the interactions acting between two interacting hydrated molecules of lysozyme, hence on the denaturation process. At increasing urea concentration, up to about 6 mol kg −1 , the values of the interaction coefficients are large and negative and remain almost unaltered. The invariance of the coefficients underlines that, even in highly concentrated urea, the hydration shell of the protein is such to maintain essentially unaltered the native conformation. At higher urea concentrations, a sudden change in the sign of the coefficients monitors the variation in the interactions between two hydrated denatured protein molecules. The same trend is found when ethanol is the cosolvent. At increasing concentration of the cosolvent, coefficients are, at first, almost invariant. After that, denaturation occurs, detected as a jump toward much more negative values. The results obtained are rationalized on the basis of those previously found for small model molecules in concentrated solutions of urea or ethanol. The thermodynamic framework allows useful comments to be made on the possible mode of action of the two cosolvents on the stability of proteins

Investigation on Secondary Structure Perturbations of Proteins Embedded in Solid Lipid Matrices as a Novel Indicator of their Biological Activity upon In Vitro Release

DEFF Research Database (Denmark)

Zeeshan, Farrukh; Tabbassum, Misbah; Jorgensen, Lene

2018-01-01

encased in solid lipid matrices as a novel indicator of their stability upon in vitro release. Model proteins namely catalase and lysozyme were incorporated into lipid namely Precirol® AT05 (glycerol palmitostearate, melting point 58°C) at 30% w/w loading using melting and mixing and wet granulation...... aggregation for catalase which was increased using wet granulation. The biological activity of catalase was statistically different from that of control and was affected by the incorporation method and was found to be in alignment with ATR spectral changes and extent of aggregation. In conclusion, ATR...

Production of biofunctionalized MoS2 flakes with rationally modified lysozyme: a biocompatible 2D hybrid material

Science.gov (United States)

Siepi, Marialuisa; Morales-Narváez, Eden; Domingo, Neus; Monti, Daria Maria; Notomista, Eugenio; Merkoçi, Arben

2017-09-01

Bioapplications of 2D materials embrace demanding features in terms of environmental impact, toxicity and biocompatibility. Here we report on the use of a rationally modified lysozyme to assist the exfoliation of MoS2 bulk crystals suspended in water through ultrasonic exfoliation. The design of the proposed lysozyme derivative provides this exfoliated 2D-materail with both, hydrophobic groups that interact with the surface of MoS2 and hydrophilic groups exposed to the aqueous medium, which hinders its re-aggregation. This approach, clarified also by molecular docking studies, leads to a stable material (ζ-potential, 27  ±  1 mV) with a yield of up to 430 µg ml-1. The bio-hybrid material was characterized in terms of number of layers and optical properties according to different slots separated by diverse centrifugal forces. Furthermore the obtained material was proved to be biocompatible using human normal keratinocytes and human cancer epithelial cells, whereas the method was demonstrated to be applicable to produce other 2D materials such as graphene. This approach is appealing for the advantageous production of high quality MoS2 flakes and their application in biomedicine and biosensing. Moreover, this method can be applied to different starting materials, making the denatured lysozyme a promising bio-tool for surface functionalization of 2D materials.

Crystallization and evaluation of hen egg-white lysozyme crystals for protein pH titration in the crystalline state

International Nuclear Information System (INIS)

Iwai, Wakari; Yagi, Daichi; Ishikawa, Takuya; Ohnishi, Yuki; Tanaka, Ichiro; Niimura, Nobuo

2008-01-01

Hen egg-white lysozyme was crystallized over a wide pH range (2.5–8.0) and the quality of the crystals was characterized. Crystallization phase diagrams at pH 2.5, 6.0 and 7.5 were determined To observe the ionized status of the amino acid residues in proteins at different pH (protein pH titration in the crystalline state) by neutron diffraction, hen egg-white lysozyme was crystallized over a wide pH range (2.5–8.0). Crystallization phase diagrams at pH 2.5, 6.0 and 7.5 were determined. At pH < 4.5 the border between the metastable region and the nucleation region shifted to the left (lower precipitant concentration) in the phase diagram, and at pH > 4.5 the border shifted to the right (higher precipitant concentration). The qualities of these crystals were characterized using the Wilson plot method. The qualities of all crystals at different pH were more or less equivalent (B-factor values within 25–40). It is expected that neutron diffraction analysis of these crystals of different pH provides equivalent data in quality for discussions of protein pH titration in the crystalline state of hen egg-white lysozyme

Dietary Immunogen® modulated digestive enzyme activity and immune gene expression in Litopenaeus vannamei post larvae.

Science.gov (United States)

Miandare, Hamed Kolangi; Mirghaed, Ali Taheri; Hosseini, Marjan; Mazloumi, Nastaran; Zargar, Ashkan; Nazari, Sajad

2017-11-01

Pacific white shrimp Litopenaeus vannamei (Boone, 1931) is an important economical shrimp species worldwide, especially in the Middle East region, and farming activities of this species have been largely affected by diseases, mostly viral and bacterial diseases. Scientists have started to use prebiotics for bolstering the immune status of the animal. This study aimed to investigate the influence of Immunogen ® on growth, digestive enzyme activity and immune related gene expression of Litopenaeus vannamei post-larvae. All post-larvae were acclimated to the laboratory condition for 14 days. Upon acclimation, shrimps were fed on different levels of Immunogen ® (0, 0.5, 1 and 1.5 g kg -1 ) for 60 days. No significant differences were detected in weight gain, specific growth rate (SGR) and food conversion ratio (FCR) in shrimp post-larvae in which fed with different levels of Immunogen ® and control diet. The results showed that digestive enzymes activity including protease and lipase increased with different amounts of Immunogen ® in the shrimp diet. Protease activity increased with 1.5 g kg -1 Immunogen ® after 60 days and lipase activity increased with 1 and 1.5 g kg -1 Immunogen ® after 30 and 60 days of the trial respectively (P  0.05). The expression of immune related genes including, prophenoloxidase, crustin and g-type lysozyme increased with diet 1.5 g kg -1 Immunogen ® (P < 0.05) while expression of penaeidin gene increased only with experimental diet 1 g kg -1 of Immunogen ® . These results indicated that increase in digestive enzymes activity and expression of immune related genes could modulate the Immunogen ® in the innate immune system in L. vannamei in this study. Copyright © 2017. Published by Elsevier Ltd.

The Effect of Simulated Flash-Heat Pasteurization on Immune Components of Human Milk.

Science.gov (United States)

Daniels, Brodie; Schmidt, Stefan; King, Tracy; Israel-Ballard, Kiersten; Amundson Mansen, Kimberly; Coutsoudis, Anna

2017-02-22

A pasteurization temperature monitoring system has been designed using FoneAstra, a cellphone-based networked sensing system, to monitor simulated flash-heat (FH) pasteurization. This study compared the effect of the FoneAstra FH (F-FH) method with the Sterifeed Holder method currently used by human milk banks on human milk immune components (immunoglobulin A (IgA), lactoferrin activity, lysozyme activity, interleukin (IL)-8 and IL-10). Donor milk samples ( N = 50) were obtained from a human milk bank, and pasteurized. Concentrations of IgA, IL-8, IL-10, lysozyme activity and lactoferrin activity were compared to their controls using the Student's t -test. Both methods demonstrated no destruction of interleukins. While the Holder method retained all lysozyme activity, the F-FH method only retained 78.4% activity ( p pasteurization, the benefits of F-FH in terms of its low cost, feasibility, safety and retention of immune components make it a valuable resource in low-income countries for pasteurizing human milk, potentially saving infants' lives.

Isolation, biosynthesis and biological activity of alkaloids of Tylophora asthmatica, a versatile medicinal plant

International Nuclear Information System (INIS)

Mulchandani, N.B.

1987-01-01

Tylophorine and related new alkaloids have been isolated from Tylophora asthmatics, Pergularia pallida and Ficus hispida plants. Biosynthesis of this group of alkaloids has been carried out using various labelled precursors for the first time and from the systematic degradation of the isolated radiolabelled tylophorine, it has been concluded that these alkaloids arise from one molecule each of tyrosine, phenylalanine and ornithine. The interactions of Tylophora alkaloids particularly tylophorinidine with biomolecules such as lysozyme and bovine serum albumin have also been studied and binding characteristics determined. It was found that Tylophora alkaloid extract possesses antianaphylactic activity as observed in passive peritoneal anaphylaxis in rats. The drug also possessed mild antihistaminic and anticholinergic activities. Studies of the extract on the bronchial smooth muscle both in vivo and in vitro did not reveal bronchiodilator potential of the drug. In addition, the distribution and metabolism of the drug was studied in vivo using 14 C radiolabelled alkaloids prepared by biosynthetic method. This study further revealed its usefulness since the drug is absorbed by vital organs and also it is not metabolised into fragments which could cause some other damage. Tylophora alkaloids have also been found to be anti-mutagenic. 10 tables, 5 figures, 24 refs. (author)

Slow aggregation of lysozyme in alkaline pH monitored in real time employing the fluorescence anisotropy of covalently labelled dansyl probe.

Science.gov (United States)

Homchaudhuri, Lopamudra; Kumar, Satish; Swaminathan, Rajaram

2006-04-03

The onset of hen egg white lysozyme aggregation on exposure to alkaline pH of 12.2 and subsequent slow growth of soluble lysozyme aggregates (at 298 K) was directly monitored by steady-state and time-resolved fluorescence anisotropy of covalently attached dansyl probe over a period of 24 h. The rotational correlation time accounting for tumbling of lysozyme in solution (40 microM) increased from approximately 3.6 ns (in pH 7) to approximately 40ns on exposure to pH 12.2 over a period of 6 h and remained stable thereafter. The growth of aggregates was strongly concentration dependent, irreversible after 60 min and inhibited by the presence of 0.9 M l-arginine in the medium. The day old aggregates were resistant to denaturation by 6 M guanidine.HCl. Our results reveal slow segmental motion of the dansyl probe in day old aggregates in the absence of L-arginine (0.9 M), but a much faster motion in its presence, when growth of aggregates is halted.

[Microbiological and biochemical characteristics of inflammatory tissues in the periodontium].

Science.gov (United States)

Surna, Algimantas; Sakalauskiene, Jurgina; Vitkauskiene, Astra; Saferis, Viktoras

2008-01-01

To investigate bacterial populations in subgingival and supragingival plaque samples of patients with inflammatory periodontal diseases and activities of the lysosomal enzymes--lysozyme, alkaline phosphatase, and beta-glucuronidase--in peripheral venous blood, in gingival crevicular fluid, and mixed nonstimulated saliva. The study included 60 patients with inflammatory periodontal diseases without any internal pathology and 24 periodontally healthy subjects. Molecular genetic assay (Micro-IDent plus, Germany) for complex identification of additional six periodontopathic bacteria was applied. The activity of lysozyme was determined turbidimetrically, the activity of alkaline phosphatase--spectrophotometrically with a "Monarch" biochemical analyzer, the activity beta-glucuronidase--according to the method described by Mead et al. and modified by Strachunskii. A statistically significant association between clinical and bacteriological data was found in the following cases: gingival bleeding in the presence of Eubacterium nodatum, Eikenella corrodens, Capnocytophaga spp. (Pspp. (P<0.05); and satisfactory oral hygiene in the presence of all microorganisms investigated (P<0.05). The activity of lysozyme in gingival crevicular fluid and mixed nonstimulated saliva indicates the severity of periodontal inflammation. Based on clinical data, in assessing the amount of lysozyme in mixed nonstimulated saliva, sensitivity and specificity of 100% was found. Increased activities of lysozyme, alkaline phosphatase, and beta-glucuronidase were found in peripheral venous blood of patients with inflammatory periodontal disease as compared to control group. The main principles of the treatment of periodontal inflammatory diseases should be based on microorganism elimination, creation of individual treatment means affecting microflora in the mouth and immune system of macroorganisms.

Modulation of plasma antioxidant activity in weaned piglets by plant polyphenols

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Hai J. Zhang

2014-06-01

Full Text Available This study was conducted to evaluate the effect of plant polyphenols (PP on antioxidant activity in weaned piglets. First, a uniform design, one optimising an experimental technique that can rationally arrange the concentrations of mixture components, was used to obtain the best PP mixture of apple, grape seed, green tea and olive leaf polyphenols based on in vitro antioxidant capacity and inhibitory action on bacterial growth. Second, the optimised PP mixture was tested in vivo with an efficacy trial on piglets. The optimal effects of the mix were observed in vitro when apple, grape seed, green tea, olive leaf polyphenols and a carrier (silicon dioxide accounted for 16.5, 27.5, 30, 2.5 and 23.5%, respectively, of the mixture. Forty-eight weaned piglets were randomly allocated to two dietary treatments (6 replicates of 4 piglets each per treatment and fed a control diet (CTR or CTR supplemented with 0.1% of the optimised PP mixture. Dietary PP did not affect growth performance compared to the CTR group. Plasma total protein, urea nitrogen and lysozyme content were not affected by dietary treatment. No differences of E. coli or Clostridia counts in the faeces and caecum content between the CTR and PP groups were observed. A reduced malondialdehyde concentration in the PP group was observed on day 21 compared to the CTR group (P=0.02. In conclusion, the prepared PP mixture has the potential to improve plasma antioxidant activity.

Salt-specific effects in lysozyme solutions

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T. Janc

2016-03-01

Full Text Available The effects of additions of low-molecular-mass salts on the properties of aqueous lysozyme solutions are examined by using the cloud-point temperature, T_{cloud}, measurements. Mixtures of protein, buffer, and simple salt in water are studied at pH=6.8 (phosphate buffer and pH=4.6 (acetate buffer. We show that an addition of buffer in the amount above I_{buffer} = 0.6 mol dm^{-3} does not affect the T_{cloud} values. However, by replacing a certain amount of the buffer electrolyte by another salt, keeping the total ionic strength constant, we can significantly change the cloud-point temperature. All the salts de-stabilize the solution and the magnitude of the effect depends on the nature of the salt. Experimental results are analyzed within the framework of the one-component model, which treats the protein-protein interaction as highly directional and of short-range. We use this approach to predict the second virial coefficients, and liquid-liquid phase diagrams under conditions, where T_{cloud} is determined experimentally.

Graphene immobilized enzyme/polyethersulfone mixed matrix membrane: Enhanced antibacterial, permeable and mechanical properties

International Nuclear Information System (INIS)

Duan, Linlin; Wang, Yuanming; Zhang, Yatao; Liu, Jindun

2015-01-01

Graphical abstract: - Highlights: • Lysozyme was immobilized on the surface of graphene oxide (GO) and reduced GO (RGO). • The novel hybrid membranes based on lysozyme and graphene were fabricated firstly. • These membranes showed good antibacterial and mechanical performance. - Abstract: Enzyme immobilization has been developed to address lots of issues of free enzyme, such as instability, low activity and difficult to retain. In this study, graphene was used as an ideal carrier for lysozyme immobilization, including graphene oxide (GO) immobilized lysozyme (GO-Ly) and chemically reduced graphene oxide (CRGO) immobilized lysozyme (CRGO-Ly). Herein, lysozyme as a bio-antibacterial agent has excellent antibacterial performance and the products of its catalysis are safety and nontoxic. Then the immobilized lysozyme materials were blended into polyethersulfone (PES) casting solution to prepare PES ultrafiltration membrane via phase inversion method. GO and CRGO were characterized by Fourier transform infrared spectroscopy (FTIR), Ultraviolet–visible spectrum (UV), X-ray diffraction (XRD), and transmission electron microscopy (TEM) and the immobilized lysozyme composites were observed by fluorescent microscopy. The results revealed that GO and CRGO were successfully synthesized and lysozyme was immobilized on their surfaces. The morphology, hydrophilicity, mechanical properties, separation properties and antibacterial activity of the hybrid membranes were characterized in detail. The hydrophilicity, water flux and mechanical strength of the hybrid membranes were significantly enhanced after adding the immobilized lysozyme. In the antibacterial experiment, the hybrid membranes exhibited an effective antibacterial performance against Escherichia coli (E. coli).

EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA); Scientific Opinion related to a notification from the Oenological Products and Practices International Association (OENOPPIA) on lysozyme from hen‟s egg to be used in the manufacture of wine as an anti-microbial stabilizer

DEFF Research Database (Denmark)

Tetens, Inge

Following a request from the European Commission, the Panel on Dietetic Products, Nutrition and Allergies (NDA) was asked to deliver a scientific opinion related to a notification from the Oenological Products and Practices International Association (OENOPPIA) on lysozyme from hen‟s egg used in t...... reactions in susceptible individuals under the conditions of use proposed by the applicant. © European Food Safety Authority, 2011...... in the manufacture of wine as an anti-microbial stabilizer/additive pursuant to Article 6, paragraph 11 of Directive 2000/13/EC – for permanent exemption from labelling. Allergic sensitisation against lysozyme is common among egg allergic individuals. In winemaking, lysozyme is used for the control of lactic acid...... individuals have been demonstrated in wines treated with lysozyme, and a number of clinical reports (including one double-blind placebo-controlled food challenge with lysozyme) described clinical allergic reactions to lysozyme. The Panel concludes that wines treated with lysozyme may trigger adverse allergic...

Combining the Physical Adsorption Approach and the Covalent Attachment Method to Prepare a Bifunctional Bioreactor

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Zhi Wang

2012-09-01

Full Text Available Aminopropyl-functionalized SBA-15 mesoporous silica was used as a support to adsorb myoglobin. Then, in order to avoid the leakage of adsorbed myoglobin, lysozyme was covalently tethered to the internal and external surface of the mesoporous silica with glutaraldehyde as the coupling agent. The property of amino-functionalized mesoporous silica was characterized by N2 adsorption-desorption and thermogravimetric (TG analysis. The feature of the silica-based matrix before and after myoglobin adsorption was identified by fourier transform infrared (FTIR and UV/VIS measurement. With o-dianisidine and H2O2 as the substrate, the peroxidase activity of adsorbed myoglobin was determined. With Micrococus lysodeilicus as the substrate, the antibacterial activity of covalently tethered lysozyme was measured. Results demonstrated that the final product not only presented peroxidase activity of the myoglobin but yielded antibacterial activity of the lysozyme.

Re-refinement of 4xan: hen egg-white lysozyme with carboplatin in sodium bromide solution

NARCIS (Netherlands)

Tanley, Simon W. M.; Schreurs, Antoine M. M.; Kroon - Batenburg, Louise; Helliwell, John R.

2016-01-01

A re-refinement of 4xan, hen egg white lysozyme (HEWL) with carboplatin crystallised in NaBr solution, has been made (Tanley et al 2016). This follows our Response article (Tanley et al 2015) to the Critique article of Shabalin et al 2015, suggesting the need for corrections to some solute molecule

[Potentialization of antibiotics by lytic enzymes].

Science.gov (United States)

Brisou, J; Babin, P; Babin, R

1975-01-01

Few lytic enzymes, specially papaine and lysozyme, acting on the membrane and cell wall structures facilitate effects of bacitracine, streptomycine and other antibiotics. Streptomycino resistant strains became sensibles to this antibiotic after contact with papaine and lysozyme. The results of tests in physiological suspensions concern only the lytic activity of enzymes. The results on nutrient medium concern together lytic, and antibiotic activities.

[Markers of dental children`s health in the application of therapeutic orthodontic equipment].

Science.gov (United States)

Пачевська, Аліса В; Білошицька, Аліна В

Treatment of teeth anomalies using removable and non-removable orthodontic devices in children leads to complications such as caries, gingivitis, periodontitis, oral mucosa hyperplasia. Etiopathogenetical of these diseases can be associated with biochemical changes in the composition of saliva. To determine the activity of lysozyme and amylase in oral fluid in children when using a fixed and removable orthodontic devices. Amylase and lysozyme were studied in oral fluid. Analyzed the biochemical composition of the freshly samples of oral fluid that was obtained in the control, experimental group 1 and 2 (children ages 7-18 years, which were used medical non-removable and removable orthodontic devices). Saliva was collected at the beginning of the therapeutic use of orthodontic devices (the first day of treatment), on 3 and 6 months of treatment. Assessment of lysozyme activity was carried nephelometric method on the ability of lysozyme to dissolve indicator organism Micrococcus lysodeicticus. To construct a calibration graph using dry lysozyme company Sigma. Salivary amylase activity was determined by hydrolysis of starch. The results were subjected to statistical analysis by standard methods. Data processed using software packages applied statistical analysis Statistica 6.0, Microsoft Excel, 2003. The use of a fixed and removable orthodontic equipment led to a decrease in saliva amylase, major changes are observed on the 6th month of treatment. The activity of lysozyme in saliva decreased the mostin patients with a permanent equipment. Major changes were also recorded on the 6th month of treatment. Complications of orthodontic treatment teeth anomalies in children (caries, gingivitis, periodontitis) caused by changes in the biochemical composition of saliva. For the prevention of the emergence and development of these complications is necessary to control the level of amylase and lysozyme in the mouth.

Characteristics of Factors of Protozoa Blastocystis hominis Persistence.

Science.gov (United States)

Potaturkina-Nesterova, N I; Il'ina, N A; Bugero, N V; Nesterov, A S

2016-10-01

Persistence activity manifested in the expression of anti-lysozyme, anti-lactoferrin, and antihistone factors promoting inactivation of natural anti-infection resistance factors in the body was revealed in Blastocystis hominis protozoa. Activities of these factors were ranged. The frequency of these factors in clinical isolates of blastocyst decreased in the following order: anti-lactoferrin activity (84.5±3.7%)→anti-lysozyme activity (64.8±5.7%)→anti-histone activity (48.1±2.3%). In healthy humans, the corresponding parameters were 7.3±1.3, 5.3±0.9, and 3.3±0.4%, respectively (pprotozoa.

Natural stimulus responsive scaffolds/cells for bone tissue engineering: influence of lysozyme upon scaffold degradation and osteogenic differentiation of cultured marrow stromal cells induced by CaP coatings.

Science.gov (United States)

Martins, Ana M; Pham, Quynh P; Malafaya, Patrícia B; Raphael, Robert M; Kasper, F Kurtis; Reis, Rui L; Mikos, Antonios G

2009-08-01

This work proposes the use of nonporous, smart, and stimulus responsive chitosan-based scaffolds for bone tissue engineering applications. The overall vision is to use biodegradable scaffolds based on chitosan and starch that present properties that will be regulated by bone regeneration, with the capability of gradual in situ pore formation. Biomimetic calcium phosphate (CaP) coatings were used as a strategy to incorporate lysozyme at the surface of chitosan-based materials with the main objective of controlling and tailoring their degradation profile as a function of immersion time. To confirm the concept, degradation tests with a lysozyme concentration similar to that incorporated into CaP chitosan-based scaffolds were used to study the degradation of the scaffolds and the formation of pores as a function of immersion time. Degradation studies with lysozyme (1.5 g/L) showed the formation of pores, indicating an increase of porosity ( approximately 5-55% up to 21 days) resulting in porous three-dimensional structures with interconnected pores. Additional studies investigated the influence of a CaP biomimetic coating on osteogenic differentiation of rat marrow stromal cells (MSCs) and showed enhanced differentiation of rat MSCs seeded on the CaP-coated chitosan-based scaffolds with lysozyme incorporated. At all culture times, CaP-coated chitosan-based scaffolds with incorporated lysozyme demonstrated greater osteogenic differentiation of MSCs, bone matrix production, and mineralization as demonstrated by calcium deposition measurements, compared with controls (uncoated scaffolds). The ability of these CaP-coated chitosan-based scaffolds with incorporated lysozyme to create an interconnected pore network in situ coupled with the demonstrated positive effect of these scaffolds upon osteogenic differentiation of MSCs and mineralized matrix production illustrates the strong potential of these scaffolds for application in bone tissue engineering strategies.

Effects of experimentally increased in ovo lysozyme on egg hatchability, chicks complement activity, and phenotype in a precocial bird

Czech Academy of Sciences Publication Activity Database

Javůrková, Veronika; Krkavcová, E.; Kreisinger, J.; Hyršl, P.; Hyánková, L.

2015-01-01

Roč. 323, č. 8 (2015), s. 497-505 ISSN 1932-5223 R&D Projects: GA ČR(CZ) GAP506/12/2472; GA MŠk EE2.3.20.0303 Institutional support: RVO:68081766 Keywords : gram-negative bacteria * barn swallow nestlings * white proteins * embryonic development * divergent selection * albumin removal * japanese-quail * avian egg * antimicrobial proteins * antibacterial activity Subject RIV: EG - Zoology Impact factor: 1.226, year: 2015

Staying Active: Physical Activity and Exercise

Science.gov (United States)

... Events Advocacy For Patients About ACOG Staying Active: Physical Activity and Exercise Home For Patients Search FAQs Staying ... Exercise FAQ045, November 2016 PDF Format Staying Active: Physical Activity and Exercise Women's Health What are the benefits ...

The arginine of the DRY motif in transmembrane segment III functions as a balancing micro-switch in the activation of the β2-adrenergic receptor

DEFF Research Database (Denmark)

Hansen, Louise Valentin; Groenen, Marleen; Nygaard, Rie

2012-01-01

(s) signaling, arrestin mobilization, and internalization upon alanine substitutions. Conversely, TyrV:24 appears to play a role in stabilizing the active receptor conformation as loss of function of G(s) signaling, arrestin mobilization, and receptor internalization was observed upon alanine substitution......VI:-06 (Glu6.30) in the inactive conformation nor the interaction with TyrV:24 (Tyr5.58) in the active conformation were observed in the x-ray structures. Here we find through molecular dynamics simulations, after removal of the stabilizing T4 lysozyme, that the expected salt bridge between ArgIII:26...... and GluVI:-06 does form relatively easily in the inactive receptor conformation. Moreover, mutational analysis of GluVI:-06 in TM-VI and the neighboring AspIII:25 in TM-III demonstrated that these two residues do function as locks for the inactive receptor conformation as we observed increased G...

Rapid localized crystallization of lysozyme by laser trapping.

Science.gov (United States)

Yuyama, Ken-Ichi; Chang, Kai-Di; Tu, Jing-Ru; Masuhara, Hiroshi; Sugiyama, Teruki

2018-02-28

Confining protein crystallization to a millimetre size was achieved within 0.5 h after stopping 1 h intense trapping laser irradiation, which shows excellent performance in spatial and temporal controllability compared to spontaneous nucleation. A continuous-wave near-infrared laser beam is tightly focused into a glass/solution interfacial layer of a supersaturated buffer solution of hen egg-white lysozyme (HEWL). The crystallization is not observed during laser trapping, but initiated by stopping the laser irradiation. The generated crystals are localized densely in a circular area with a diameter of a few millimetres around the focal spot and show specific directions of the optical axes of the HEWL crystals. To interpret this unique crystallization, we propose a mechanism that nucleation and the subsequent growth take place in a highly concentrated domain consisting of HEWL liquid-like clusters after turning off laser trapping.

Active knee joint flexibility and sports activity

DEFF Research Database (Denmark)

Hahn, Thomas; Foldspang, Anders; Vestergaard, E

1999-01-01

was significantly higher in women than in men and significantly positively associated with weekly hours of swimming and weekly hours of competitive gymnastics. Active knee flexion was significantly positively associated with participation in basketball, and significantly negatively associated with age and weekly......The aim of the study was to estimate active knee flexion and active knee extension in athletes and to investigate the potential association of each to different types of sports activity. Active knee extension and active knee flexion was measured in 339 athletes. Active knee extension...... hours of soccer, European team handball and swimming. The results point to sport-specific adaptation of active knee flexion and active knee extension. Udgivelsesdato: 1999-Apr...

The interaction of equine lysozyme:oleic acid complexes with lipid membranes suggests a cargo off-loading mechanism

DEFF Research Database (Denmark)

Nielsen, Søren Bang; Wilhelm, Kristina; Vad, Brian

2010-01-01

The normal function of equine lysozyme (EL) is the hydrolysis of peptidoglycan residues of bacterial cell walls. EL is closely related to alpha-lactalbumins with respect to sequence and structure and further possesses the calcium binding site of alpha-lactalbumins. Recently, EL multimeric complexes...

The inhibition of the Human Immunodeficiency Virus type 1 activity by crude and purified human pregnancy plug mucus and mucins in an inhibition assay

Directory of Open Access Journals (Sweden)

Schoeman Leann

2008-05-01

Full Text Available Abstract Background The female reproductive tract is amongst the main routes for Human Immunodeficiency Virus (HIV transmission. Cervical mucus however is known to protect the female reproductive tract from bacterial invasion and fluid loss and regulates and facilitates sperm transport to the upper reproductive tract. The purpose of this study was to purify and characterize pregnancy plug mucins and determine their anti-HIV-1 activity in an HIV inhibition assay. Methods Pregnancy plug mucins were purified by caesium chloride density-gradient ultra-centrifugation and characterized by Western blotting analysis. The anti-HIV-1 activities of the crude pregnancy plug mucus and purified pregnancy plug mucins was determined by incubating them with HIV-1 prior to infection of the human T lymphoblastoid cell line (CEM SS cells. Results The pregnancy plug mucus had MUC1, MUC2, MUC5AC and MUC5B. The HIV inhibition assay revealed that while the purified pregnancy plug mucins inhibit HIV-1 activity by approximately 97.5%, the crude pregnancy plug mucus failed to inhibit HIV-1 activity. Conclusion Although it is not clear why the crude sample did not inhibit HIV-1 activity, it may be that the amount of mucins in the crude pregnancy plug mucus (which contains water, mucins, lipids, nucleic acids, lactoferrin, lysozyme, immunoglobulins and ions, is insufficient to cause viral inhibition or aggregation.

The Disruptive Effect of Lysozyme on the Bacterial Cell Wall Explored by an "In-Silico" Structural Outlook

Science.gov (United States)

Primo, Emiliano D.; Otero, Lisandro H.; Ruiz, Francisco; Klinke, Sebastián; Giordano, Walter

2018-01-01

The bacterial cell wall, a structural unit of peptidoglycan polymer comprised of glycan strands consisting of a repeating disaccharide motif [N-acetylglucosamine (NAG) and N-acetylmuramylpentapeptide (NAM pentapeptide)], encases bacteria and provides structural integrity and protection. Lysozymes are enzymes that break down the bacterial cell wall…

Correlates between Models of Virulence for Mycobacterium tuberculosis among Isolates of the Central Asian Lineage: a Case for Lysozyme Resistance Testing?

Science.gov (United States)

Casali, Nicola; Clark, Simon O.; Hooper, Richard; Williams, Ann; Velji, Preya; Gonzalo, Ximena

2015-01-01

Virulence factors (VFs) contribute to the emergence of new human Mycobacterium tuberculosis strains, are lineage dependent, and are relevant to the development of M. tuberculosis drugs/vaccines. VFs were sought within M. tuberculosis lineage 3, which has the Central Asian (CAS) spoligotype. Three isolates were selected from clusters previously identified as dominant in London, United Kingdom. Strain-associated virulence was studied in guinea pig, monocyte-derived macrophage, and lysozyme resistance assays. Whole-genome sequencing, single nucleotide polymorphism (SNP) analysis, and a literature review contributed to the identification of SNPs of interest. The animal model revealed borderline differences in strain-associated pathogenicity. Ex vivo, isolate C72 exhibited statistically significant differences in intracellular growth relative to C6 and C14. SNP candidates inducing lower fitness levels included 123 unique nonsynonymous SNPs, including three located in genes (lysX, caeA, and ponA2) previously identified as VFs in the laboratory-adapted reference strain H37Rv and shown to confer lysozyme resistance. C72 growth was most affected by lysozyme in vitro. A BLAST search revealed that all three SNPs of interest (C35F, P76Q, and P780R) also occurred in Tiruvallur, India, and in Uganda. Unlike C72, however, no single isolate identified through BLAST carried all three SNPs simultaneously. CAS isolates representative of three medium-sized human clusters demonstrated differential outcomes in models commonly used to estimate strain-associated virulence, supporting the idea that virulence varies within, not just across, M. tuberculosis lineages. Three VF SNPs of interest were identified in two additional locations worldwide, which suggested independent selection and supported a role for these SNPs in virulence. The relevance of lysozyme resistance to strain virulence remains to be established. PMID:25776753

Amino acids and glycine ethyl ester as new crystallization reagents for lysozyme

International Nuclear Information System (INIS)

Ito, Len; Shiraki, Kentaro; Yamaguchi, Hiroshi

2010-01-01

During the past two decades, amino acids and amino-acid derivatives have been applied in various fields of protein chemistry. The potential use of amino acids and their derivatives as new precipitating agents is described. Several amino acids and their derivatives are prominent additives in the field of protein chemistry. This study reports the use of charged amino acids and glycine ethyl ester as precipitants in protein crystallization, using hen egg-white lysozyme (HEWL) as a model. A discussion of the crystallization of HEWL using these reagents as precipitating agents is given

Laser ablation of the lysozyme protein: a model system for soft materials

DEFF Research Database (Denmark)

Schou, Jørgen; Matei, Andreea; Constantinescu, Catalin

.3 1015 molecules per pulse. This is perhaps one of the highest ablation yields ever measured. Films with a significant number of intact lysozyme molecules have been produced by PLD (pulsed laser deposition) and MAPLE (Matrix-assisted pulsed laser evaporation). The deposition of intact molecules...... is expected in MAPLE, but is surprising in PLD, where a high degree of thermal fragmentation is typically required for generation of a sufficient amount of volatile decomposition products that drive the transfer of molecules to the film substrate. The experimental results will be discussed based...

Crystallization and evaluation of hen egg-white lysozyme crystals for protein pH titration in the crystalline state.

Science.gov (United States)

Iwai, Wakari; Yagi, Daichi; Ishikawa, Takuya; Ohnishi, Yuki; Tanaka, Ichiro; Niimura, Nobuo

2008-05-01

To observe the ionized status of the amino acid residues in proteins at different pH (protein pH titration in the crystalline state) by neutron diffraction, hen egg-white lysozyme was crystallized over a wide pH range (2.5-8.0). Crystallization phase diagrams at pH 2.5, 6.0 and 7.5 were determined. At pH diagram, and at pH > 4.5 the border shifted to the right (higher precipitant concentration). The qualities of these crystals were characterized using the Wilson plot method. The qualities of all crystals at different pH were more or less equivalent (B-factor values within 25-40). It is expected that neutron diffraction analysis of these crystals of different pH provides equivalent data in quality for discussions of protein pH titration in the crystalline state of hen egg-white lysozyme.

Local pH at the surface of hen egg white lysozyme

Science.gov (United States)

Otosu, Takuhiro; Kobayashi, Kaito; Yamaguchi, Shoichi

2018-02-01

The microenvironment at the surface of hen-egg-white lysozyme (HEWL) was examined by analyzing the change in pKa of fluorescein isothiocyanate (FITC) upon binding to the N-terminus of HEWL. The result showed that the local pH at the HEWL surface is higher than the bulk pH. Furthermore, the data showed that the difference between the local and bulk pH becomes larger with decreasing pH, suggesting HEWL repels more protons at lower pH. Because the local pH affects the protonation states of functional amino-acids at the protein surface, the results provide the fundamental insight into the microenvironment at the protein surface.

High-level soluble expression of the functional peptide derived from the C-terminal domain of the sea cucumber lysozyme and analysis of its antimicrobial activity

Directory of Open Access Journals (Sweden)

Lina Cong

2014-11-01

Conclusion: These results indicate that the expressed rSjLys-C is a highly soluble product and has a strong antimicrobial activity. Therefore, gaining a large quantity of biologically active rSjLys-C will be used for further biochemical and structural studies and provide a potential use in aquaculture and medicine.

Lysozyme from the gut of the soft tick Ornithodoros moubata: the sequence, phylogeny and post-feeding regulation

Czech Academy of Sciences Publication Activity Database

Grunclová, L.; Fouquier, H.; Hypša, Václav; Kopáček, Petr

2003-01-01

Roč. 27, č. 8 (2003), s. 651-660 ISSN 0145-305X R&D Projects: GA ČR GA206/00/0266 Institutional research plan: CEZ:AV0Z6022909; CEZ:MSM 123100003 Keywords : Ornithodoros moubata * lysozyme * innate immunity Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.390, year: 2003

Preferential interactions and the effect of protein PEGylation

DEFF Research Database (Denmark)

Holm, Louise Stenstrup; Thulstrup, Peter Waaben; Kasimova, Marina Robertovna

2015-01-01

enthalpy was decreased to half the value for PEGylated lysozyme. The ratio between calorimetric and van't Hoff enthalpy suggests that our PEGylated lysozyme is a dimer. CONCLUSION/SIGNIFICANCE: The PEGylated model protein displayed similar stability responses to the addition of preferentially active...

Enzyme Activities in Waste Water and Activated Sludge

DEFF Research Database (Denmark)

Nybroe, Ole; Jørgensen, Per Elberg; Henze, Mogens

1992-01-01

The purpose of the present study was to evaluate the potential of selected enzyme activity assays to determine microbial abundance and heterotrophic activity in waste water and activated sludge. In waste water, esterase and dehydrogenase activities were found to correlate with microbial abundance...... measured as colony forming units of heterotrophic bacteria. A panel of four enzyme activity assays, α-glucosidase, alanine-aminopeptidase, esterase and dehydrogenase were used to characterize activated sludge and anaerobic hydrolysis sludge from a pilot scale plant. The enzymatic activity profiles were...... distinctly different, suggesting that microbial populations were different, or had different physiological properties, in the two types of sludge. Enzyme activity profiles in activated sludge from four full-scale plants seemed to be highly influenced by the composition of the inlet. Addition of hydrolysed...

Negotiating active ageing at a Danish activity centre

DEFF Research Database (Denmark)

Lassen, Aske Juul

Question: With the ‘Year of active aging and solidarity between generations’ in the EU, active aging is staged as a key policy area in an aging Europe. This paper follows the discourse of active aging from the EU to a Danish municipality to an activity centre and its users, and asks what active...... aging means in the everyday live of the elderly. Active aging is formed in many arenas and takes a variety of forms with different actors focusing on physical, occupational, social and mental activity. This paper focuses on how the elderly takes part in this forming, by asking how the elderly negotiates...... and practices active ageing. The paper uses an activity centre in Copenhagen as its site of negotiation. Methods: These questions have been explored with the use of ethnographic fieldwork and through a documentary study. The ethnographic fieldwork has been conducted at an activity centre with 4 months...

Effect of mobile phone use on salivary concentrations of protein, amylase, lipase, immunoglobulin A, lysozyme, lactoferrin, peroxidase and C-reactive protein of the parotid gland.

Science.gov (United States)

Hashemipour, M S; Yarbakht, M; Gholamhosseinian, A; Famori, H

2014-05-01

The possibility of side effects associated with the electromagnetic waves emitted from mobile phones is a controversial issue. The present study aimed to evaluate the effect of mobile phone use on parotid gland salivary concentrations of protein, amylase, lipase, immunoglobulin A, lysozyme, lactoferrin, peroxidase and C-reactive protein. Stimulated salivary samples were collected simultaneously from both parotid glands of 86 healthy volunteers. Salivary flow rate and salivary concentrations of proteins, amylase, lipase, lysozyme, lactoferrin, peroxidase, C-reactive protein and immunoglobulin A, were measured. Data were analysed using t-tests and one-way analyses of variance. Salivary flow rate and parotid gland salivary concentrations of protein were significantly higher on the right side compared to the left in those that predominantly held mobile phones on the right side. In addition, there was a decrease in concentrations of amylase, lipase, lysozyme, lactoferrin and peroxidase. The side of dominant mobile phone use was associated with differences in salivary flow rate and parotid gland salivary concentrations, in right-dominant users. Although mobile phone use influenced salivary composition, the relationship was not significant.

Destruction of Salmonellae on poultry meat with lysozyme, EDTA, x ray, microwave, and chlorine

International Nuclear Information System (INIS)

Teotia, J.S.; Miller, B.F.

1975-01-01

Lysozyme, ethylenediaminetetracetic acid, chlorine, x-irradiation and microwaves were used in experimental attempts to eliminate Salmonella senftenberg 775W or Salmonella typhimurium from turkey drumsticks and whole carcasses. Turkey drumsticks or whole carcasses were artificially contaminated with S. senfenberg 775W or S. typhimurium in concentrations ranging between 5 x 10 5 to 8 x 10 5 viable cells per ml. of contaminating fluid. After each treatment, samples were cultured, plated, and tested according to standard methods to determine the susceptibility of Salmonella organisms to the particular treatment. A 0.1 percent solution of lysozyme eliminated the S. senftenberg 775W at 22 0 C within three hours. A 0.5 percent solution of ethylenediaminetetracetic acid failed to destroy the test organism under the same conditions. Eighty thousand rads of X-ray eliminated the test organism on turkey drumsticks but failed to remove it from whole turkey carcasses. Microwaves eliminated the S. senftenberg 775W in 150 seconds from turkey drumsticks and ten minutes from broiler chicken carcasses. Aqueous solutions containing 3400 and 2125 ppM chlorine failed to destroy the test organism on turkey drumsticks at 21 0 C. in 9 and 24 hours. None of the treatments changed the appearance of the skin or meat, except microwaves produced a partially-cooked appearance. Chlorine produced off-color drumsticks

Small-angle neutron scattering study of differences in phase behavior of silica nanoparticles in the presence of lysozyme and bovine serum albumin proteins

Science.gov (United States)

Yadav, Indresh; Kumar, Sugam; Aswal, V. K.; Kohlbrecher, J.

2014-03-01

The differences in phase behavior of anionic silica nanoparticles (88 Å) in the presence of two globular proteins [cationic lysozyme (molecular weight (MW) 14.7 kD) and anionic bovine serum albumin (BSA) (MW 66.4 kD)] have been studied by small-angle neutron scattering. The measurements were carried out on a fixed concentration (1 wt %) of Ludox silica nanoparticles with varying concentrations of proteins (0-5 wt %) at pH = 7. It is found that, despite having different natures (opposite charges), both proteins can render to the same kind of aggregation of silica nanoparticles. However, the concentration regions over which the aggregation is observed are widely different for the two proteins. Lysozyme with very small amounts (e.g., 0.01 wt %) leads to the aggregation of silica nanoparticles. On the other hand, silica nanoparticles coexist with BSA as independent entities at low protein concentrations and turn to aggregates at high protein concentrations (>1 wt %). In the case of lysozyme, the charge neutralization by the protein on the nanoparticles gives rise to the protein-mediated aggregation of the nanoparticles. The nanoparticle aggregates coexist with unaggregated nanoparticles at low protein concentrations, whereas, they coexist with a free protein at higher protein concentrations. For BSA, the nonadsorbing nature of the protein produces the depletion force that causes the aggregation of the nanoparticles at higher protein concentrations. The evolution of the interaction is modeled by the two Yukawa potential, taking account of both attractive and repulsive terms of the interaction in these systems. The nanoparticle aggregation is found to be governed by the short-range attraction for lysozyme and the long-range attraction for BSA. The aggregates are characterized by the diffusion limited aggregate type of mass fractal morphology.

Interaction between lysozyme and humic acid in layer-by-layer assemblies: Effects of pH and ionic strength

NARCIS (Netherlands)

Tan, W.F.; Norde, W.; Koopal, L.K.

2014-01-01

The interaction between protein and soluble organic matter is studied through layer-by-layer assembly of lysozyme (LSZ) and purified Aldrich humic acid (PAHA) at a solid surface (2-D) and in solution (3-D). By bringing a silica surface in alternating contact with solutions of LSZ and PAHA a

Interaction between lysozyme and humic acid in layer-by-layer assemblies : Effects of pH and ionic strength

NARCIS (Netherlands)

Tan, Wenfeng; Norde, Willem; Koopal, Luuk K.

2014-01-01

The interaction between protein and soluble organic matter is studied through layer-by-layer assembly of lysozyme (LSZ) and purified Aldrich humic acid (PAHA) at a solid surface (2-D) and in solution (3-D). By bringing a silica surface in alternating contact with solutions of LSZ and PAHA a

In situ study of the growth and degradation processes in tetragonal lysozyme crystals on a silicon substrate by high-resolution X-ray diffractometry

Science.gov (United States)

Kovalchuk, M. V.; Prosekov, P. A.; Marchenkova, M. A.; Blagov, A. E.; D'yakova, Yu. A.; Tereshchenko, E. Yu.; Pisarevskii, Yu. V.; Kondratev, O. A.

2014-09-01

The results of an in situ study of the growth of tetragonal lysozyme crystals by high-resolution X-ray diffractometry are considered. The crystals are grown by the sitting-drop method on crystalline silicon substrates of different types: both on smooth substrates and substrates with artificial surface-relief structures using graphoepitaxy. The crystals are grown in a special hermetically closed crystallization cell, which enables one to obtain images with an optical microscope and perform in situ X-ray diffraction studies in the course of crystal growth. Measurements for lysozyme crystals were carried out in different stages of the crystallization process, including crystal nucleation and growth, developed crystals, the degradation of the crystal structure, and complete destruction.

Potential probiotic attributes and antagonistic activity of an indigenous isolate Lactobacillus plantarum DM5 from an ethnic fermented beverage "Marcha" of north eastern Himalayas.

Science.gov (United States)

Das, Deeplina; Goyal, Arun

2014-05-01

A novel isolate DM5 identified as Lactobacillus plantarum displayed in vitro probiotic properties as well as antimicrobial activity. It showed adequate level of survival to the harsh conditions of the gastrointestinal tract and survived low acidic pH 2.5 for 5 h. Artificial gastric juice and intestinal fluidic environment decreased the initial viable cell population of isolate DM5 only by 7% and 13%, respectively, while lysozyme (200 µg/ml) and bile salt (0.5%) enhanced its growth. It was found to deconjugate taurodeoxycholic acid, indicating its potential to reduce hypercholesterolemia. Isolate DM5 demonstrated cell surface hydrophobicity of 53% and autoaggregation of 54% which are the prerequisite for adhesion to epithelial cells and colonization to host. Bacteriocin activity of isolate was found to be 6400 AU/ml as it inhibited the growth of food borne pathogens Escherichia coli, Staphylococcus aureus, and Alcaligenes faecalis. The bactericidal action of bacteriocin from isolate was analyzed by flow cytometry, rendering its use as prospective probiotic and starter culture in food industry.

Is Enhanced Physical Activity Possible Using Active Videogames?

Science.gov (United States)

Baranowski, Tom; Baranowski, Janice; O'Connor, Teresia; Lu, Amy Shirong; Thompson, Debbe

2012-06-01

Our research indicated that 10-12-year-old children receiving two active Wii ™ (Nintendo ® ; Nintendo of America, Inc., Redmond, WA) console videogames were no more physically active than children receiving two inactive videogames. Research is needed on how active videogames may increase physical activity.

Is Enhanced Physical Activity Possible Using Active Videogames?

OpenAIRE

Baranowski, Tom; Baranowski, Janice; O'Connor, Teresia; Lu, Amy Shirong; Thompson, Debbe

2012-01-01

Our research indicated that 10–12-year-old children receiving two active Wii™ (Nintendo®; Nintendo of America, Inc., Redmond, WA) console videogames were no more physically active than children receiving two inactive videogames. Research is needed on how active videogames may increase physical activity.

Lysozyme-loaded lipid-polymer hybrid nanoparticles: preparation, characterization and colloidal stability evaluation.

Science.gov (United States)

Devrim, Burcu; Kara, Aslı; Vural, İmran; Bozkır, Asuman

2016-11-01

Lipid-polymer hybrid nanoparticles (LPNPs) are polymeric nanoparticles enveloped by lipid layers, which have emerged as a potent therapeutic nanocarrier alternative to liposomes and polymeric nanoparticles. The aim of this work was to develop, characterize and evaluate LPNPs to deliver a model protein, lysozyme. Lysozyme-loaded LPNPs were prepared by using the modified w/o/w double-emulsion-solvent-evaporation method. Poly-ɛ-caprolactone (PCL) was used as polymeric core material and tripalmitin:lechitin mixture was used to form a lipid shell around the LPNPs. LPNPs were evaluated for particle size distribution, zeta potential, morphology, encapsulation efficiency, in vitro drug release, stability and cytotoxicity. The DLS measurement results showed that the particle size of LPNPs ranged from 58.04 ± 1.95 nm to 2009.00 ± 0.52 nm. The AFM and TEM images of LPNPs demonstrate that LPNPs are spherical in shape. The protein-loading capacity of LPNPs ranged from 5.81% to 60.32%, depending on the formulation parameters. LPNPs displayed a biphasic drug release pattern with a burst release within 1 h, followed by sustained release afterward. Colloidal stability results of LPNPs in different media showed that particle size and zeta potential values of particles did not change significantly in all media except of FBS 100% for 120 h. Finally, the results of a cellular uptake study showed that LPNPs were significantly taken up by 83.3% in L929 cells. We concluded that the LPNPs prepared with PCL as polymeric core material and tripalmitin:lechitin mixture as lipid shell should be a promising choice for protein delivery.

Are antimicrobial defences in bird eggs related to climatic conditions associated with risk of trans-shell microbial infection?

Science.gov (United States)

Horrocks, Nicholas Pc; Hine, Kathryn; Hegemann, Arne; Ndithia, Henry K; Shobrak, Mohammed; Ostrowski, Stéphane; Williams, Joseph B; Matson, Kevin D; Tieleman, B Irene

2014-01-01

All bird eggs are exposed to microbes in the environment, which if transmitted to the developing embryo, could cause hatching failure. However, the risk of trans-shell infection varies with environmental conditions and is higher for eggs laid in wetter environments. This might relate to generally higher microbial abundances and diversity in more humid environments, including on the surface of eggshells, as well as the need for moisture to facilitate microbial penetration of the eggshell. To protect against microbial infection, the albumen of avian eggs contains antimicrobial proteins, including lysozyme and ovotransferrin. We tested whether lysozyme and ovotransferrin activities varied in eggs of larks (Alaudidae) living along an arid-mesic gradient of environmental aridity, which we used as a proxy for risk of trans-shell infection. Contrary to expectations, lysozyme activity was highest in eggs from hotter, more arid locations, where we predicted the risk of trans-shell infection would be lower. Ovotransferrin concentrations did not vary with climatic factors. Temperature was a much better predictor of antimicrobial protein activity than precipitation, a result inconsistent with studies stressing the importance of moisture for trans-shell infection. Our study raises interesting questions about the links between temperature and lysozyme activity in eggs, but we find no support for the hypothesis that antimicrobial protein deposition is higher in eggs laid in wetter environments.

Increase in the specific radioactivity of tritium-labeled compounds obtained by tritium thermal activation method

International Nuclear Information System (INIS)

Badun, G.A.; Chernysheva, M.G.; Ksenofontov, A.L.

2012-01-01

A method of tritium introduction into different types of organic molecules that is based on the interaction of atomic tritium with solid organic target is described. Tritium atoms are formed on the hot W-wire, which is heated by the electric current. Such an approach is called 'tritium thermal activation method'. Here we summarize the results of labeling globular proteins (lysozyme, human and bovine serum albumins); derivatives of pantothenic acid and amino acids; ionic surfactants (sodium dodecylsulfate and alkyltrimethylammonium bromides) and nonionic high-molecular weight surfactants - pluronics. For the first time it is observed that if the target-compound is fixed and its radicals are stable the specific radioactivity of the labeled product can be drastically increased (up to 400 times) when the target temperature is ca. 295 K compared with the results obtained at 77 K. The influence of labeling parameters as tritium gas pressure, exposure time and W-wire temperature was tested for each target temperature that results in the optimum labeling conditions with high specific radioactivity and chemical yield of the resulting compound. (orig.)

Metal ions-binding T4 lysozyme as an intramolecular protein purification tag compatible with X-ray crystallography

Czech Academy of Sciences Publication Activity Database

Bouřa, Evžen; Bäumlová, Adriana; Chalupská, Dominika; Dubánková, Anna; Klíma, Martin

2017-01-01

Roč. 26, č. 6 (2017), s. 1116-1123 ISSN 0961-8368 R&D Projects: GA ČR(CZ) GJ17-07058Y; GA MŠk LO1302 Institutional support: RVO:61388963 Keywords : phage T4 * lysozyme * endolysin * histidine tag * protein purification * crystal structure Subject RIV: CE - Biochemistry OBOR OECD: Biochemistry and molecular biology Impact factor: 2.523, year: 2016

Short-time dynamics of lysozyme solutions with competing short-range attraction and long-range repulsion: Experiment and theory

Science.gov (United States)

Riest, Jonas; Nägele, Gerhard; Liu, Yun; Wagner, Norman J.; Godfrin, P. Douglas

2018-02-01

Recently, atypical static features of microstructural ordering in low-salinity lysozyme protein solutions have been extensively explored experimentally and explained theoretically based on a short-range attractive plus long-range repulsive (SALR) interaction potential. However, the protein dynamics and the relationship to the atypical SALR structure remain to be demonstrated. Here, the applicability of semi-analytic theoretical methods predicting diffusion properties and viscosity in isotropic particle suspensions to low-salinity lysozyme protein solutions is tested. Using the interaction potential parameters previously obtained from static structure factor measurements, our results of Monte Carlo simulations representing seven experimental lysoyzme samples indicate that they exist either in dispersed fluid or random percolated states. The self-consistent Zerah-Hansen scheme is used to describe the static structure factor, S(q), which is the input to our calculation schemes for the short-time hydrodynamic function, H(q), and the zero-frequency viscosity η. The schemes account for hydrodynamic interactions included on an approximate level. Theoretical predictions for H(q) as a function of the wavenumber q quantitatively agree with experimental results at small protein concentrations obtained using neutron spin echo measurements. At higher concentrations, qualitative agreement is preserved although the calculated hydrodynamic functions are overestimated. We attribute the differences for higher concentrations and lower temperatures to translational-rotational diffusion coupling induced by the shape and interaction anisotropy of particles and clusters, patchiness of the lysozyme particle surfaces, and the intra-cluster dynamics, features not included in our simple globular particle model. The theoretical results for the solution viscosity, η, are in qualitative agreement with our experimental data even at higher concentrations. We demonstrate that semi

INFLUENCE OF SELECTED PHARMACEUTICALS ON ACTIVATED SLUDGE DEHYDROGENASE ACTIVITY

Directory of Open Access Journals (Sweden)

Agnieszka Tomska

2016-06-01

The aim of this work was to evaluate the effect of selected antibiotics - sulfanilamide and erythromycin on activated sludge dehydrogenase activity with use of trifenyltetrazolinum chloride (TTC test. Dehydrogenases activity is an indicator of biochemical activity of microorganisms present in activated sludge or the ability to degrade organic compounds in waste water. TTC test is particularly useful for the regularity of the course of treatment, in which the presence of inhibitors of biochemical reactions and toxic compounds are present. It was observed that the dehydrogenase activity decreases with the increase of a antibiotics concentration. The lowest value of the dehydrogenase activity equal to 32.4 μmol TF / gMLSS obtained at sulfanilamide concentration 150mg / l. For this sample, an inhibition of dehydrogenase activity was 31%.

Active nematic gels as active relaxing solids

Science.gov (United States)

Turzi, Stefano S.

2017-11-01

I propose a continuum theory for active nematic gels, defined as fluids or suspensions of orientable rodlike objects endowed with active dynamics, that is based on symmetry arguments and compatibility with thermodynamics. The starting point is our recent theory that models (passive) nematic liquid crystals as relaxing nematic elastomers. The interplay between viscoelastic response and active dynamics of the microscopic constituents is naturally taken into account. By contrast with standard theories, activity is not introduced as an additional term of the stress tensor, but it is added as an external remodeling force that competes with the passive relaxation dynamics and drags the system out of equilibrium. In a simple one-dimensional channel geometry, we show that the interaction between nonuniform nematic order and activity results in either a spontaneous flow of particles or a self-organization into subchannels flowing in opposite directions.

Mnemonic activation by SPECT; Activation mnesique en TEMP

Energy Technology Data Exchange (ETDEWEB)

Migneco, O.; Darcourt, J.; Benoit, M; Malandain, G.; Thirion, J.P.; Robert, Ph.; Vidal, R.; Desvignes, Ph.; Benoliel, J.; Ayache, N.; Bussiere, F. [Universite de Nice Sophia-Antipolis, INRIA (France)

1997-12-31

Data of literature show that SPECT is able to detect cerebral activations induced by sensory-motor stimuli. The facts are not clearly established in what concerns the cognitive activations the amplitude of which is lower. We have studied an activation paradigm such as the Grober and Bruschke test which implies the long term explicit memory. It comprises a visual presentation of words followed by their indexed recall. By using a two-day protocol, 2 SPECTs were achieved in 4 healthy right-handed voluntaries as follows: one of activation (A) and one of control (B). The fifth subject benefited by a SPECT B and of an MRI. The injection for the examination A has been done during the indexed recall stage and for the examination B at the moment when the patient repeated several times the same 3 words. The SPECT data were collected 1 hour after the injection of 370 MBq of ECD making use of a 3-head camera equipped with UHR fan collimators and ending by a LMH on the reconstructed images of 8 mm. The MRI has been achieved by means of a Signa 1.5 Tesla magnet. The SPECT A and B of the subjects 1 to 4 were matched elastically to that of the subject 5 and that of the subject 5 was rigidly matched on its MRI. In this way the individual activation cards of the 4 subjects could be averaged and superimposed on the MRI of the 5. subject. One observes an internal temporal activation (maximal activation of left tonsil, +25% and right uncus, +23%) and a right cingulum activation (maximal activation, +25%), in agreement with the neuro-physiological data. The elastic matching makes possible the inter-subject averaging, what increases the signal-to-noise ratio of activation. The inter-modality rigid matching facilitates the anatomical localisation of the activation site. With these adapted tools, the cognitive activation is thus possible by SPECT and opens perspectives for early diagnosis of neurological troubles, namely of Alzheimer`s disease

Specific effect of the linear charge density of the acid polysaccharide on thermal aggregation/ disaggregation processes in complex carrageenan/lysozyme systems

NARCIS (Netherlands)

Antonov, Y.; Zhuravleva, I.; Cardinaels, R.M.; Moldenaers, P.

2017-01-01

We study thermal aggregation and disaggregation processes in complex carrageenan/lysozyme systems with a different linear charge density of the sulphated polysaccharide. To this end, we determine the temperature dependency of the turbidity and the intensity size distribution functions in complex

Potent antitumor activity of a urokinase-activated engineered anthrax toxin

Science.gov (United States)

Liu, Shihui; Aaronson, Hannah; Mitola, David J.; Leppla, Stephen H.; Bugge, Thomas H.

2003-01-01

The acquisition of cell-surface urokinase plasminogen activator activity is a hallmark of malignancy. We generated an engineered anthrax toxin that is activated by cell-surface urokinase in vivo and displays limited toxicity to normal tissue but broad and potent tumoricidal activity. Native anthrax toxin protective antigen, when administered with a chimeric anthrax toxin lethal factor, Pseudomonas exotoxin fusion protein, was extremely toxic to mice, causing rapid and fatal organ damage. Replacing the furin activation sequence in anthrax toxin protective antigen with an artificial peptide sequence efficiently activated by urokinase greatly attenuated toxicity to mice. In addition, the mutation conferred cell-surface urokinase-dependent toxin activation in vivo, as determined by using a panel of plasminogen, plasminogen activator, plasminogen activator receptor, and plasminogen activator inhibitor-deficient mice. Surprisingly, toxin activation critically depended on both urokinase plasminogen activator receptor and plasminogen in vivo, showing that both proteins are essential cofactors for the generation of cell-surface urokinase. The engineered toxin displayed potent tumor cell cytotoxicity to a spectrum of transplanted tumors of diverse origin and could eradicate established solid tumors. This tumoricidal activity depended strictly on tumor cell-surface plasminogen activation. The data show that a simple change of protease activation specificity converts anthrax toxin from a highly lethal to a potent tumoricidal agent.

Active ageing

Directory of Open Access Journals (Sweden)

Frode F. Jacobsen

2017-09-01

Full Text Available Background: The concept of active ageing has been gaining prominence in the Nordic countries and beyond. This has been reflected in policy papers in Norway and other Nordic nations. Aims: The aim of this article is to analyse the topic of active ageing in five Norwegian White Papers (2002 to 2015 and discuss those policy documents in context of relevant research literature. Methods: A qualitative document analyses is employed focusing on how active ageing, and ageing in general, is described and which concepts are employed. No ethical approval was needed. Findings: The general theme of ageing and the specific theme of active ageing are increasingly prominent in the Norwegian White Papers studied. In all documents, some assumptions regarding ageing and active ageing seem implicit, such as independence being more important than (interdependence. ‘Productive’ activities like participation in working life are stressed, while others, like reading, watching TV or watching children playing in the street, are ignored. Conclusions: The policy documents demonstrate that the topic of active ageing is growing in importance. The documents increasingly seem to stress ‘productive’ activities – those related to working life, voluntary work or sports and physical training. They exclude activities that are meaningful for many older people, like watching their grandchildren play or reading books. Implications for practice: Practitioners in older people’s care could consider reflecting on: Government documents dealing with their own practice The prevalent concept of active ageing The trend of active ageing as a facilitating or hindering factor for good care work How present discourse on active ageing may influence their attitude towards frail older persons How they wish to relate to active ageing in their own practice

Youth physical activity resource use and activity measured by accelerometry.

Science.gov (United States)

Maslow, Andréa L; Colabianchi, Natalie

2011-01-01

To examine whether use of physical activity resources (eg, parks) was associated with daily physical activity measured by accelerometry. One hundred eleven adolescents completed a travel diary with concurrent accelerometry. The main exposure was self-reported use of a physical activity resource (none /1+ resources). The main outcomes were total minutes spent in daily (1) moderate-vigorous physical activity and (2) vigorous physical activity. Using a physical activity resource was significantly associated with total minutes in moderate-vigorous physical activity. African Americans and males had significantly greater moderate-vigorous physical activity. Results from this study support the development and use of physical activity resources.

Youth Physical Activity Resources Use and Activity Measured by Accelerometry

Science.gov (United States)

Maslow, Andréa L.; Colabianchi, Natalie

2014-01-01

Objectives To examine whether utilization of physical activity resources (eg, parks) was associated with daily physical activity measured by accelerometry. Methods 111 adolescents completed a travel diary with concurrent accelerometry. The main exposure was self-reported utilization of a physical activity resource (none/1+ resources). The main outcomes were total minutes spent in daily 1) moderate-vigorous physical activity and 2) vigorous physical activity. Results Utilizing a physical activity resource was significantly associated with total minutes in moderate-vigorous physical activity. African-Americans and males had significantly greater moderate-vigorous physical activity. Conclusions Results from this study support the development and use of physical activity resources. PMID:21204684

Stated Uptake of Physical Activity Rewards Programmes Among Active and Insufficiently Active Full-Time Employees.

Science.gov (United States)

Ozdemir, Semra; Bilger, Marcel; Finkelstein, Eric A

2017-10-01

Employers are increasingly relying on rewards programmes in an effort to promote greater levels of activity among employees; however, if enrolment in these programmes is dominated by active employees, then they are unlikely to be a good use of resources. This study uses a stated-preference survey to better understand who participates in rewards-based physical activity programmes, and to quantify stated uptake by active and insufficiently active employees. The survey was fielded to a national sample of 950 full-time employees in Singapore between 2012 and 2013. Participants were asked to choose between hypothetical rewards programmes that varied along key dimensions and whether or not they would join their preferred programme if given the opportunity. A mixed logit model was used to analyse the data and estimate predicted uptake for specific programmes. We then simulated employer payments based on predictions for the percentage of each type of employee likely to meet the activity goal. Stated uptake ranged from 31 to 67% of employees, depending on programme features. For each programme, approximately two-thirds of those likely to enrol were insufficiently active. Results showed that insufficiently active employees, who represent the majority, are attracted to rewards-based physical activity programmes, and at approximately the same rate as active employees, even when enrolment fees are required. This suggests that a programme with generous rewards and a modest enrolment fee may have strong employee support and be within the range of what employers may be willing to spend.

The Effect of Simulated Flash-Heat Pasteurization on Immune Components of Human Milk

Directory of Open Access Journals (Sweden)

Brodie Daniels

2017-02-01

Full Text Available A pasteurization temperature monitoring system has been designed using FoneAstra, a cellphone-based networked sensing system, to monitor simulated flash-heat (FH pasteurization. This study compared the effect of the FoneAstra FH (F-FH method with the Sterifeed Holder method currently used by human milk banks on human milk immune components (immunoglobulin A (IgA, lactoferrin activity, lysozyme activity, interleukin (IL-8 and IL-10. Donor milk samples (N = 50 were obtained from a human milk bank, and pasteurized. Concentrations of IgA, IL-8, IL-10, lysozyme activity and lactoferrin activity were compared to their controls using the Student’s t-test. Both methods demonstrated no destruction of interleukins. While the Holder method retained all lysozyme activity, the F-FH method only retained 78.4% activity (p < 0.0001, and both methods showed a decrease in lactoferrin activity (71.1% Holder vs. 38.6% F-FH; p < 0.0001 and a decrease in the retention of total IgA (78.9% Holder vs. 25.2% F-FH; p < 0.0001. Despite increased destruction of immune components compared to Holder pasteurization, the benefits of F-FH in terms of its low cost, feasibility, safety and retention of immune components make it a valuable resource in low-income countries for pasteurizing human milk, potentially saving infants’ lives.

Importance of the CMAP Correction to the CHARMM22 Protein Force Field: Dynamics of Hen Lysozyme

OpenAIRE

Buck, Matthias; Bouguet-Bonnet, Sabine; Pastor, Richard W.; MacKerell, Alexander D.

2005-01-01

The recently developed CMAP correction to the CHARMM22 force field (C22) is evaluated from 25 ns molecular dynamics simulations on hen lysozyme. Substantial deviations from experimental backbone root mean-square fluctuations and N-H NMR order parameters obtained in the C22 trajectories (especially in the loops) are eliminated by the CMAP correction. Thus, the C22/CMAP force field yields improved dynamical and structural properties of proteins in molecular dynamics simulations.

Active-constructive-interactive: a conceptual framework for differentiating learning activities.

Science.gov (United States)

Chi, Michelene T H

2009-01-01

Active, constructive, and interactive are terms that are commonly used in the cognitive and learning sciences. They describe activities that can be undertaken by learners. However, the literature is actually not explicit about how these terms can be defined; whether they are distinct; and whether they refer to overt manifestations, learning processes, or learning outcomes. Thus, a framework is provided here that offers a way to differentiate active, constructive, and interactive in terms of observable overt activities and underlying learning processes. The framework generates a testable hypothesis for learning: that interactive activities are most likely to be better than constructive activities, which in turn might be better than active activities, which are better than being passive. Studies from the literature are cited to provide evidence in support of this hypothesis. Moreover, postulating underlying learning processes allows us to interpret evidence in the literature more accurately. Specifying distinct overt activities for active, constructive, and interactive also offers suggestions for how learning activities can be coded and how each kind of activity might be elicited. Copyright © 2009 Cognitive Science Society, Inc.

[Alterations in tears aqueous layer during cytostatics treatment].

Science.gov (United States)

Wojciechowska, Katarzyna; Wieckowska-Szakiel, Marzena; Rózalska, Barbara; Jurowski, Piotr

2013-01-01

The aim of the study was to evaluate tears secretion, pH and lysozyme activity in tears aqueous layer during chemotherapy in lung, breast and bowel cancer. 36 patients were enrolled to the study. Depending on the type of cancer and type of chemotherapy patients were divided into three groups. Group I (12 patients) diagnosed with non-small-cell lung cancer treated with PE schema (cisplatin, etoposide), Group II (12 patients) with breast cancer treated with FAC schema (fluorouracil, doxorubicin, cyclophosphamide), Group III (12 patients) with bowel cancer treated with FU/LV schema (fluorouracil, leucovorin). In all the patients: Schirmer's I test, pH measurements and lysozyme test were performed. Patients were examined before chemotherapy, after 2nd, 4th, 6th cycle. In group I and II lowering of tears secretion (p tears secretion (p tears film in all groups (p tears aqueous layer causing alterations of tears secretions. PH alterations depending on type of chemotherapy was observed. Lowering of lysozyme activity in tears was observed. All the deteriorations aggravate with duration of chemotherapy. Alterations of tears film parameters during chemotherapy may influence upon eye surface homeostasis and infectious complication. tears aqueous layer, Schirmer's test, lysozyme activity, tears pH.

Spontaneous Plasticity of Multineuronal Activity Patterns in Activated Hippocampal Networks

Directory of Open Access Journals (Sweden)

Atsushi Usami

2008-01-01

Full Text Available Using functional multineuron imaging with single-cell resolution, we examined how hippocampal networks by themselves change the spatiotemporal patterns of spontaneous activity during the course of emitting spontaneous activity. When extracellular ionic concentrations were changed to those that mimicked in vivo conditions, spontaneous activity was increased in active cell number and activity frequency. When ionic compositions were restored to the control conditions, the activity level returned to baseline, but the weighted spatial dispersion of active cells, as assessed by entropy-based metrics, did not. Thus, the networks can modify themselves by altering the internal structure of their correlated activity, even though they as a whole maintained the same level of activity in space and time.

Activity flow over resting-state networks shapes cognitive task activations.

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Cole, Michael W; Ito, Takuya; Bassett, Danielle S; Schultz, Douglas H

2016-12-01

Resting-state functional connectivity (FC) has helped reveal the intrinsic network organization of the human brain, yet its relevance to cognitive task activations has been unclear. Uncertainty remains despite evidence that resting-state FC patterns are highly similar to cognitive task activation patterns. Identifying the distributed processes that shape localized cognitive task activations may help reveal why resting-state FC is so strongly related to cognitive task activations. We found that estimating task-evoked activity flow (the spread of activation amplitudes) over resting-state FC networks allowed prediction of cognitive task activations in a large-scale neural network model. Applying this insight to empirical functional MRI data, we found that cognitive task activations can be predicted in held-out brain regions (and held-out individuals) via estimated activity flow over resting-state FC networks. This suggests that task-evoked activity flow over intrinsic networks is a large-scale mechanism explaining the relevance of resting-state FC to cognitive task activations.

pedometer-measured physical activity, self-reported physical activity

African Journals Online (AJOL)

between self-reported and pedometer-measured physical activity was also determined. Results. Average ... Methods. This was a cross-sectional study among employed South African adults. Participant ... acquired information on physical activity habits. Questions ..... How many days of monitoring predict physical activity and ...

Modeling Patterns of Activities using Activity Curves.

Science.gov (United States)

Dawadi, Prafulla N; Cook, Diane J; Schmitter-Edgecombe, Maureen

2016-06-01

Pervasive computing offers an unprecedented opportunity to unobtrusively monitor behavior and use the large amount of collected data to perform analysis of activity-based behavioral patterns. In this paper, we introduce the notion of an activity curve , which represents an abstraction of an individual's normal daily routine based on automatically-recognized activities. We propose methods to detect changes in behavioral routines by comparing activity curves and use these changes to analyze the possibility of changes in cognitive or physical health. We demonstrate our model and evaluate our change detection approach using a longitudinal smart home sensor dataset collected from 18 smart homes with older adult residents. Finally, we demonstrate how big data-based pervasive analytics such as activity curve-based change detection can be used to perform functional health assessment. Our evaluation indicates that correlations do exist between behavior and health changes and that these changes can be automatically detected using smart homes, machine learning, and big data-based pervasive analytics.

Incorporation of Socio-scientific Content into Active Learning Activities

Science.gov (United States)

King, D. B.; Lewis, J. E.; Anderson, K.; Latch, D.; Sutheimer, S.; Webster, G.; Moog, R.

2014-12-01

Active learning has gained increasing support as an effective pedagogical technique to improve student learning. One way to promote active learning in the classroom is the use of in-class activities in place of lecturing. As part of an NSF-funded project, a set of in-class activities have been created that use climate change topics to teach chemistry content. These activities use the Process Oriented Guided Inquiry Learning (POGIL) methodology. In this pedagogical approach a set of models and a series of critical thinking questions are used to guide students through the introduction to or application of course content. Students complete the activities in their groups, with the faculty member as a facilitator of learning. Through assigned group roles and intentionally designed activity structure, process skills, such as teamwork, communication, and information processing, are developed during completion of the activity. Each of these climate change activities contains a socio-scientific component, e.g., social, ethical and economic data. In one activity, greenhouse gases are used to explain the concept of dipole moment. Data about natural and anthropogenic production rates, global warming potential and atmospheric lifetimes for a list of greenhouse gases are presented. The students are asked to identify which greenhouse gas they would regulate, with a corresponding explanation for their choice. They are also asked to identify the disadvantages of regulating the gas they chose in the previous question. In another activity, where carbon sequestration is used to demonstrate the utility of a phase diagram, students use economic and environmental data to choose the best location for sequestration. Too often discussions about climate change (both in and outside the classroom) consist of purely emotional responses. These activities force students to use data to support their arguments and hypothesize about what other data could be used in the corresponding discussion to

Activity computer program for calculating ion irradiation activation

Science.gov (United States)

Palmer, Ben; Connolly, Brian; Read, Mark

2017-07-01

A computer program, Activity, was developed to predict the activity and gamma lines of materials irradiated with an ion beam. It uses the TENDL (Koning and Rochman, 2012) [1] proton reaction cross section database, the Stopping and Range of Ions in Matter (SRIM) (Biersack et al., 2010) code, a Nuclear Data Services (NDS) radioactive decay database (Sonzogni, 2006) [2] and an ENDF gamma decay database (Herman and Chadwick, 2006) [3]. An extended version of Bateman's equation is used to calculate the activity at time t, and this equation is solved analytically, with the option to also solve by numeric inverse Laplace Transform as a failsafe. The program outputs the expected activity and gamma lines of the activated material.

Activities in dementia care: A comparative assessment of activity types.

Science.gov (United States)

Lokon, Elizabeth; Sauer, Philip E; Li, Yue

2016-12-05

This exploratory study compares the impact of five activity types on the well-being of institutionalized people with dementia: the intergenerational art program Opening Minds through Art, art and music therapies, creative activities, non-creative activities, and no activities at all. We validated the Scripps Modified Greater Cincinnati Chapter Well-Being Observational Tool, and used that instrument to systematically observe N = 67 people with dementia as they participated in different activity types. People with dementia showed the highest well-being scores during Opening Minds through Art compared to all other activities. No significant well-being differences were found between creative activities led by licensed art/music therapist versus regular activity staff. Furthermore, no significant well-being differences were found between creative and non-creative activities that were both led by regular activity staff. Overall, people with dementia benefit from participating in activities, regardless of the type (creative or non-creative), or who conducts them (licensed therapists or activity staff). However, in order for people with dementia to reach significantly high levels of overall well-being, we recommend that activities are specifically designed for people with dementia and incorporate a 1:1 ratio between people with dementia and well-trained volunteers/staff members. © The Author(s) 2016.

How much locomotive activity is needed for an active physical activity level: analysis of total step counts

Directory of Open Access Journals (Sweden)

Ohkawara Kazunori

2011-11-01

Full Text Available Abstract Background Although physical activity recommendations for public health have focused on locomotive activity such as walking and running, it is uncertain how much these activities contribute to overall physical activity level (PAL. The purpose of the present study was to determine the contribution of locomotive activity to PAL using total step counts measured in a calorimeter study. Methods PAL, calculated as total energy expenditure divided by basal metabolic rate, was evaluated in 11 adult men using three different conditions for 24-hour human calorimeter measurements: a low-activity day (L-day targeted at a low active level of PAL (1.45, and a high-frequency moderate activity day (M-day or a high-frequency vigorous activity day (V-day targeted at an active level of PAL (1.75. These subjects were permitted only light activities except prescribed activities. In a separate group of 41 adults, free-living PAL was evaluated using doubly-labeled water (DLW. In both experiments, step counts per day were also measured using an accelerometer. Results In the human calorimeter study, PAL and step counts were 1.42 ± 0.10 and 8,973 ± 543 steps/d (L-day, 1.82 ± 0.14 and 29,588 ± 1,126 steps/d (M-day, and 1.74 ± 0.15 and 23,755 ± 1,038 steps/d (V-day, respectively. In the DLW study, PAL and step counts were 1.73 ± 0.15 and 10,022 ± 2,605 steps/d, and there was no significant relationship between PAL and daily step counts. Conclusions These results indicate that an enormous number of steps are needed for an active level of PAL if individuals extend physical activity-induced energy expenditure by only locomotive activity. Therefore, non-locomotive activity such as household activity should also play a significant role in increasing PAL under free-living conditions.

Older people and 'active ageing': Subjective aspects of ageing actively.

Science.gov (United States)

Stenner, Paul; McFarquhar, Tara; Bowling, Ann

2011-04-01

Following a critical overview of the active ageing concept, a thematic decomposition of 42 transcribed interviews with British people aged 72 years and over indicates that active ageing is understood in relation to physical, cognitive, psychological and social factors, but that these co-exist in complex combinations. The notion of activity in active ageing is grasped in relation to an active/passive distinction which emphasizes the enhancement or diminishment of concrete powers of activity. A 'challenge and response' framework is suggested for future research on active ageing.

Is enhanced physical activity possible using active videogames?

Science.gov (United States)

Our research indicated that 10– to 12-year-old children receiving two active Wii (TM)(Nintendo (R); Nintendo of America, Inc., Redmond, WA) console videogames were no more physically active than children receiving two inactive videogames. Research is needed on how active videogames may increase phys...

Urediospores of Puccinia spp. and other rusts are warm-temperature ice nucleators and harbor ice nucleation active bacteria

Science.gov (United States)

Morris, C. E.; Sands, D. C.; Glaux, C.; Samsatly, J.; Asaad, S.; Moukahel, A. R.; Gonçalves, F. L. T.; Bigg, E. K.

2012-10-01

In light of various features of the biology of the rust fungi and of the epidemiology of the plant diseases they cause that illustrate the important role of rainfall in their life history, we have characterized the ice nucleation activity (INA) of the aerially disseminated spores (urediospores) of this group of fungi. Urediospores of this obligate plant parasite were collected from natural infections from 7 species of weeds in France, from coffee in Brazil and from field and greenhouse-grown wheat in France, the USA, Turkey and Syria. Immersion freezing was used to determine freezing onset temperatures and the abundance of ice nuclei in suspensions of washed spores. Microbiological analyses of spores and subsequent tests of the ice nucleation activity of the bacteria associated with spores were deployed to quantify the contribution of bacteria to the ice nucleation activity of the spores. All samples of spores were ice nucleation active having freezing onset temperatures as warm as -4 °C. Spores in most of the samples carried cells of ice nucleation-active strains of the bacterium Pseudomonas syringae (at rates of less than 1 bacterial cell per 100 urediospores), but bacterial INA accounted for only a small fraction of the INA observed in spore suspensions. Changes in the INA of spore suspensions after treatment with lysozyme suggest that the INA of urediospores involves a polysaccharide. Based on data from the literature, we have estimated the concentrations of urediospores in air at cloud height and in rainfall. These quantities are very similar to those reported for other biological ice nucleators in these same substrates. We suggest that air sampling techniques have ignored the spatial and temporal variability of atmospheric concentrations that occur under conditions propitious for precipitation that could increase their local abundance intermittently. Nevertheless, we propose that the relative low abundance of warm-temperature biological ice nucleators in the

Isolation and purification of enterocin E-760 with broad antimicrobial activity against gram-positive and gram-negative bacteria.

Science.gov (United States)

Line, J E; Svetoch, E A; Eruslanov, B V; Perelygin, V V; Mitsevich, E V; Mitsevich, I P; Levchuk, V P; Svetoch, O E; Seal, B S; Siragusa, G R; Stern, N J

2008-03-01

Strain NRRL B-30745, isolated from chicken ceca and identified as Enterococcus durans, Enterococcus faecium, or Enterococcus hirae, was initially identified as antagonistic to Campylobacter jejuni. The isolate produced a 5,362-Da bacteriocin (enterocin) that inhibits the growth of Salmonella enterica serovar Enteritidis, S. enterica serovar Choleraesuis, S. enterica serovar Typhimurium, S. enterica serovar Gallinarum, Escherichia coli O157:H7, Yersinia enterocolitica, Citrobacter freundii, Klebsiella pneumoniae, Shigella dysenteriae, Pseudomonas aeruginosa, Proteus mirabilis, Morganella morganii, Staphylococcus aureus, Staphylococcus epidermidis, Listeria monocytogenes, Campylobacter jejuni, and 20 other Campylobacter species isolates. The enterocin, E-760, was isolated and purified by cation-exchange and hydrophobic-interaction chromatographies. The proteinaceous nature of purified enterocin E-760 was demonstrated upon treatment with various proteolytic enzymes. Specifically, the antimicrobial peptide was found to be sensitive to beta-chymotrypsin, proteinase K, and papain, while it was resistant to lysozyme and lipase. The enterocin demonstrated thermostability by retaining activity after 5 min at 100 degrees C and was stable at pH values between 5.0 and 8.7. However, activity was lost below pH 3.0 and above pH 9.5. Administration of enterocin E-760-treated feed significantly (P Enterocin E-760 also significantly (P < 0.05) reduced the colonization of naturally acquired Campylobacter species in market age broiler chickens when administered in treated feed 4 days prior to analysis.

Screen and effect analysis of immunostimulants for sea cucumber, Apostichopus japonicus

Science.gov (United States)

Li, Jiye; Sun, Xiuqin; Zheng, Fengrong; Hao, Linhua

2009-02-01

Immunostimulants may improve disease resistance of aquaculture animals by promoting the nonspecific immunity response of the organisms. Five types of saccharides, including chitosan, yeast polysaccharide, burdock oligosaccharide, seaweed polysaccharide and lentinus edodes polysaccharide, were screened for potential use as immunostimulants by using spectrophotometry. The saccharides were injected into Apostichopus japonicus, a sea cucumber, and the lysozyme and superoxide dismutase (SOD) activities of the coelomic fluid and epidermal slime were monitored in six consecutive days. The results show that the lysozyme activity of the animal’s coelomic fluid was significantly stimulated on day 2, day 4 and day 6 after the injection of the saccharides ( P<0.05). The effects of chitosan and yeast polysaccharide were the most notable. The lysozyme activity of the epidermal slime was significantly increased by chitosana, yeast polysaccharide, seaweed polysaccharide, and burdock oligosaccharide on day 1 and day 2 after the injection ( P<0.05). The SOD activity of the coelomic fluid was significantly promoted by the saccharides on day 2 and day 4 post-injection ( P<0.05), while the SOD activity of the epidermal slime increased on day 2. These findings indicate that chitosan and yeast polysaccharide are the most effective immunostimulants and potential healthy anti-disease feedstuff for A. japonicus.

Lectures Abandoned: Active Learning by Active Seminars

DEFF Research Database (Denmark)

Christensen, Henrik Bærbak; Corry, Aino Vonge

2012-01-01

Traditional lecture-based courses are widely criticised for be- ing less eective in teaching. The question is of course what should replace the lectures and various active learning tech- niques have been suggested and studied. In this paper, we report on our experiences of redesigning a software ......- tive seminars as a replacement of traditional lectures, an activity template for the contents of active seminars, an ac- count on how storytelling supported the seminars, as well as reports on our and the students' experiences....

Effectiveness of Nigerian Bamboo Activated with Different Activating ...

African Journals Online (AJOL)

The effectiveness of Nigerian Bamboo activated with different activating agents on the adsorption of BTX was investigated. A series of activated carbons was prepared from Nigerian bamboo, carbonized at 400oC – 500oC and impregnated with different concentrations of four acids at 800oC in a muffle furnace for 2 hours.

Activation of peroxisome proliferator-activated receptors (PPARs) by their ligands and protein kinase A activators

Science.gov (United States)

Lazennec, Gwendal; Canaple, Laurence; Saugy, Damien; Wahli, Walter

2000-01-01

The nuclear peroxisome proliferator-activated receptors (PPARs) α, β and γ activate the transcription of multiple genes involved in lipid metabolism. Several natural and synthetic ligands have been identified for each PPAR isotype but little is known about the phosphorylation state of these receptors. We show here that activators of protein kinase A (PKA) can enhance mouse PPAR activity in the absence and the presence of exogenous ligands in transient transfection experiments. The activation function 1 (AF-1) of PPARs was dispensable for transcriptional enhancement, whereas the activation function 2 (AF-2) was required for this effect. We also show that several domains of PPAR can be phosphorylated by PKA in vitro. Moreover, gel experiments suggest that PKA stabilizes binding of the liganded PPAR to DNA. PKA inhibitors decreased not only the kinase dependent induction of PPARs but also their ligand-dependent induction, suggesting that the ligands may also mobilize the PKA pathway to lead to maximal transcriptional induction by PPARs. Moreover, comparing PPARα KO with PPARα wild-type mice, we show that the expression of the ACO gene can be regulated by PKA-activated PPARα in liver. These data demonstrate that the PKA pathway is an important modulator of PPAR activity and we propose a model associating this pathway in the control of fatty acid β-oxidation under conditions of fasting, stress and exercise. PMID:11117527

Physical Activity and Health: The Benefits of Physical Activity

Science.gov (United States)

... State and Local Programs Related Topics Diabetes Nutrition Physical Activity and Health Recommend on Facebook Tweet Share Compartir ... Your Chances of Living Longer The Benefits of Physical Activity Regular physical activity is one of the most ...

Reshaping Human Antibodies: Grafting an Antilysozyme Activity

Science.gov (United States)

Verhoeyen, Martine; Milstein, Cesar; Winter, Greg

1988-03-01

The production of therapeutic human monoclonal antibodies by hybridoma technology has proved difficult, and this has prompted the ``humanizing'' of mouse monoclonal antibodies by recombinant DNA techniques. It was shown previously that the binding site for a small hapten could be grafted from the heavy-chain variable domain of a mouse antibody to that of a human myeloma protein by transplanting the hypervariable loops. It is now shown that a large binding site for a protein antigen (lysozyme) can also be transplanted from mouse to human heavy chain. The success of such constructions may be facilitated by an induced-fit mechanism.

The influence of lysozyme on mannitol polymorphism in freeze-dried and spray-dried formulations depends on the selection of the drying process

DEFF Research Database (Denmark)

Grohganz, Holger; Lee, Yan-Ying; Rantanen, Jukka

2013-01-01

Freeze-drying and spray-drying are often applied drying techniques for biopharmaceutical formulations. The formation of different solid forms upon drying is often dependent on the complex interplay between excipient selection and process parameters. The purpose of this study was to investigate...... the influence of the chosen drying method on the solid state form. Mannitol-lysozyme solutions of 20mg/mL, with the amount of lysozyme varying between 2.5% and 50% (w/w) of total solid content, were freeze-dried and spray-dried, respectively. The resulting solid state of mannitol was analysed by near......-dried formulations an increase in protein concentration resulted in a shift from ß-mannitol to a-mannitol. An increase in final drying temperature of the freeze-drying process towards the temperature of the spray-drying process did not lead to significant changes. It can thus be concluded that it is the drying...

Physical Activity

DEFF Research Database (Denmark)

Andersen, Lars Bo; Anderssen, Sigmund Alfred; Wisløff, Ulrik

2014-01-01

Andersen LB, Anderssen SA, Wisløff U, Hellénius M-L, Fogelholm M, Ekelund U. (Expert Group) Nordic Nutrition Recommendations 2012. Integrating nutrition and physical activity. Chapter: Physical Activity p. 195-217.Nordic Counsil of Ministers.......Andersen LB, Anderssen SA, Wisløff U, Hellénius M-L, Fogelholm M, Ekelund U. (Expert Group) Nordic Nutrition Recommendations 2012. Integrating nutrition and physical activity. Chapter: Physical Activity p. 195-217.Nordic Counsil of Ministers....

Substrate-Competitive Activity-Based Profiling of Ester Prodrug Activating Enzymes.

Science.gov (United States)

Xu, Hao; Majmudar, Jaimeen D; Davda, Dahvid; Ghanakota, Phani; Kim, Ki H; Carlson, Heather A; Showalter, Hollis D; Martin, Brent R; Amidon, Gordon L

2015-09-08

Understanding the mechanistic basis of prodrug delivery and activation is critical for establishing species-specific prodrug sensitivities necessary for evaluating preclinical animal models and potential drug-drug interactions. Despite significant adoption of prodrug methodologies for enhanced pharmacokinetics, functional annotation of prodrug activating enzymes is laborious and often unaddressed. Activity-based protein profiling (ABPP) describes an emerging chemoproteomic approach to assay active site occupancy within a mechanistically similar enzyme class in native proteomes. The serine hydrolase enzyme family is broadly reactive with reporter-linked fluorophosphonates, which have shown to provide a mechanism-based covalent labeling strategy to assay the activation state and active site occupancy of cellular serine amidases, esterases, and thioesterases. Here we describe a modified ABPP approach using direct substrate competition to identify activating enzymes for an ethyl ester prodrug, the influenza neuraminidase inhibitor oseltamivir. Substrate-competitive ABPP analysis identified carboxylesterase 1 (CES1) as an oseltamivir-activating enzyme in intestinal cell homogenates. Saturating concentrations of oseltamivir lead to a four-fold reduction in the observed rate constant for CES1 inactivation by fluorophosphonates. WWL50, a reported carbamate inhibitor of mouse CES1, blocked oseltamivir hydrolysis activity in human cell homogenates, confirming CES1 is the primary prodrug activating enzyme for oseltamivir in human liver and intestinal cell lines. The related carbamate inhibitor WWL79 inhibited mouse but not human CES1, providing a series of probes for analyzing prodrug activation mechanisms in different preclinical models. Overall, we present a substrate-competitive activity-based profiling approach for broadly surveying candidate prodrug hydrolyzing enzymes and outline the kinetic parameters for activating enzyme discovery, ester prodrug design, and

Immobilization of lysozyme on cotton fabrics; synthesis, characterization, and activity

Science.gov (United States)

Uncontrolled hemorrhage is the leading cause of death on the battlefield and second leading cause of death in civilian trauma. Recent animal testing using a lethal arterial injury model compared a variety of woven and non woven products with granular products, and found only one product (WoundStat) ...

Management of synchronized network activity by highly active neurons

International Nuclear Information System (INIS)

Shein, Mark; Raichman, Nadav; Ben-Jacob, Eshel; Volman, Vladislav; Hanein, Yael

2008-01-01

Increasing evidence supports the idea that spontaneous brain activity may have an important functional role. Cultured neuronal networks provide a suitable model system to search for the mechanisms by which neuronal spontaneous activity is maintained and regulated. This activity is marked by synchronized bursting events (SBEs)—short time windows (hundreds of milliseconds) of rapid neuronal firing separated by long quiescent periods (seconds). However, there exists a special subset of rapidly firing neurons whose activity also persists between SBEs. It has been proposed that these highly active (HA) neurons play an important role in the management (i.e. establishment, maintenance and regulation) of the synchronized network activity. Here, we studied the dynamical properties and the functional role of HA neurons in homogeneous and engineered networks, during early network development, upon recovery from chemical inhibition and in response to electrical stimulations. We found that their sequences of inter-spike intervals (ISI) exhibit long time correlations and a unimodal distribution. During the network's development and under intense inhibition, the observed activity follows a transition period during which mostly HA neurons are active. Studying networks with engineered geometry, we found that HA neurons are precursors (the first to fire) of the spontaneous SBEs and are more responsive to electrical stimulations

Weekday and weekend sedentary time and physical activity in differentially active children.

Science.gov (United States)

Fairclough, Stuart J; Boddy, Lynne M; Mackintosh, Kelly A; Valencia-Peris, Alexandra; Ramirez-Rico, Elena

2015-07-01

To investigate whether weekday-weekend differences in sedentary time and specific intensities of physical activity exist among children categorised by physical activity levels. Cross-sectional observational study. Seven-day accelerometer data were obtained from 810 English children (n=420 girls) aged 10-11 years. Daily average minday(-1) spent in moderate to vigorous physical activity were calculated for each child. Sex-specific moderate to vigorous physical activity quartile cut-off values categorised boys and girls separately into four graded groups representing the least (Q1) through to the most active (Q4) children. Sex- and activity quartile-specific multilevel linear regression analyses analysed differences in sedentary time, light physical activity, moderate physical activity, vigorous physical activity, and moderate to vigorous physical activity between weekdays and weekends. On weekdays Q2 boys spent longer in light physical activity (pboys (pphysical activity, and Q1-Q3 boys accumulated significantly more vigorous physical activity and moderate to vigorous physical activity than at weekends. There were no significant differences in weekday and weekend sedentary time or physical activity for Q4 boys. On weekdays Q2 and Q3 girls accumulated more sedentary time (pgirls did significantly more moderate physical activity (pgirls engaged in more vigorous physical activity (pphysical activity (pgirls' sedentary time and physical activity varied little between weekdays and weekends. The most active children maintained their sedentary time and physical activity levels at weekends, while among less active peers weekend sedentary time and physical activity at all intensities was lower. Low active children may benefit most from weekend intervention strategies. Copyright © 2014 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Play Equipment, Physical Activity Opportunities, and Children's Activity Levels at Childcare

Directory of Open Access Journals (Sweden)

Jessica S. Gubbels

2012-01-01

Full Text Available This study investigated the association between physical activity facilities at childcare (e.g., play equipment and physical activity of 2- and 3-year olds. Observations of physical activity intensity were performed among 175 children at 9 childcare centers in The Netherlands, using the OSRAC-P. The physical activity facilities were assessed for indoors and outdoors separately, using the EPAO instrument. Regular (single-level multivariate and multilevel linear regression analyses examined the association of the facilities and child characteristics (age and sex with children's activity levels. Various physical activity facilities were available in all childcare centers (e.g., balls. Riding toys and a small playing area were associated with lower indoor physical activity levels. Outdoor physical activity levels were positively associated with the availability of portable jumping equipment and the presence of a structured track on the playground. Portable slides, fixed swinging equipment, and sandboxes were negatively associated with outdoor activity levels. In addition, the 3-year old children were more active outdoors than the 2-year olds. In conclusion, not all physical activity facilities at childcare were indeed positively associated with children's activity levels. The current findings provide concrete leads for childcare providers regarding which factors they can improve in the physical environment to facilitate children's physical activity.

Imaging transport phenomena during lysozyme protein crystal growth by the hanging drop technique

Science.gov (United States)

Sethia Gupta, Anamika; Gupta, Rajive; Panigrahi, P. K.; Muralidhar, K.

2013-06-01

The present study reports the transport process that occurs during the growth of lysozyme protein crystals by the hanging drop technique. A rainbow schlieren technique has been employed for imaging changes in salt concentration. A one dimensional color filter is used to record the deflection of the light beam. An optical microscope and an X-ray crystallography unit are used to characterize the size, tetragonal shape and Bravais lattice constants of the grown crystals. A parametric study on the effect of drop composition, drop size, reservoir height and number of drops on the crystal size and quality is reported. Changes in refractive index are not large enough to create a meaningful schlieren image in the air gap between the drop and the reservoir. However, condensation of fresh water over the reservoir solution creates large changes in the concentration of NaCl, giving rise to clear color patterns in the schlieren images. These have been analyzed to obtain salt concentration profiles near the free surface of the reservoir solution as a function of time. The diffusion of fresh water into the reservoir solution at the early stages of crystal growth followed by the mass flux of salt from the bulk solution towards the free surface has been recorded. The overall crystal growth process can be classified into two regimes, as demarcated by the changes in slope of salt concentration within the reservoir. The salt concentration in the reservoir equilibrates at long times when the crystallization process is complete. Thus, transport processes in the reservoir emerge as the route to monitor protein crystal growth in the hanging drop configuration. Results show that crystal growth rate is faster for a higher lysozyme concentration, smaller drops, and larger reservoir heights.

Laser ablation dynamics and production of thin films of lysozyme

DEFF Research Database (Denmark)

Schou, Jørgen; Canulescu, Stela; Matei, Andreea

at the Technical University of Denmark (DTU) produced thin films of average thickness up to 300 nm, which not only contained a significant amount of intact molecules, but also maintained the bioactivity. These films were produced by a nanosecond laser in the UV regime at 355 nm with 2 J/cm2. The surprising fact......Lysozyme is a well-known protein, which is used in food processing because of its bacteriocidal properties. The mass (14307 u) is in the range, in which it easily can be controlled by mass spectrometric methods, for example by MALDI (Matrix assisted laser desorption ionisation). We have recently...... that these molecules can be transferred to a substrate as intact molecules by the violent laser impact ( ~up to 50 mJ/pulse) has not yet been understood. One issue is that up to 150 ng/pulse is removed by the laser, and much of the material is ejected from the target in relatively large chunks. We have continued...

Laser ablation dynamics and production of thin films of lysozyme

DEFF Research Database (Denmark)

Canulescu, Stela; Schou, Jørgen; Amoruso, S.

produced thin films of average thickness up to 300 nm, which not only contained a significant amount of intact molecules, but also maintained the bioactivity. These films were produced by a nanosecond laser in the UV regime at 355 nm with 2 J/cm2. The surprising fact that these molecules can be transferred......Lysozyme is a well-known protein, which is used in food processing because of its bactericidal properties. The mass (14307 amu) is in the range in which it easily can be monitored by mass spectrometric methods, for example by MALDI (Matrix assisted laser desorption ionization). We have recently...... to a substrate as intact molecules by the violent laser impact (~up to 50 mJ/pulse) has not yet been understood. One issue is that up to 150 ng/pulse is removed by the laser, and much of the material is ejected from the target in relatively large chunks. We have explored as well the excitation mechanics by laser...

Production and characterization of granular activated carbon from activated sludge

Directory of Open Access Journals (Sweden)

Z. Al-Qodah

2009-03-01

Full Text Available In this study, activated sludge was used as a precursor to prepare activated carbon using sulfuric acid as a chemical activation agent. The effect of preparation conditions on the produced activated carbon characteristics as an adsorbent was investigated. The results indicate that the produced activated carbon has a highly porous structure and a specific surface area of 580 m²/g. The FT-IR analysis depicts the presence of a variety of functional groups which explain its improved adsorption behavior against pesticides. The XRD analysis reveals that the produced activated carbon has low content of inorganic constituents compared with the precursor. The adsorption isotherm data were fitted to three adsorption isotherm models and found to closely fit the BET model with R² equal 0.948 at pH 3, indicating a multilayer of pesticide adsorption. The maximum loading capacity of the produced activated carbon was 110 mg pesticides/g adsorbent and was obtained at this pH value. This maximum loading was found experimentally to steeply decrease as the solution pH increases. The obtained results show that activated sludge is a promising low cost precursor for the production of activated carbon.

Dutch children and parents' views on active and non-active video gaming.

Science.gov (United States)

De Vet, Emely; Simons, Monique; Wesselman, Maarten

2014-06-01

Active video games that require whole body movement to play the game may be an innovative health promotion tool to substitute sedentary pastime with more active time and may therefore contribute to children's health. To inform strategies aimed at reducing sedentary behavior by replacing non-active by active gaming, opinions about active and non-active video games are explored among 8- to 12-year-old children and their parents. Six qualitative, semi-structured focus groups were held with 8- to 12-year-old children (n = 46) and four with their parents (n = 19) at three different primary schools in The Netherlands. The focus groups with children discussed game preferences, gaming context and perceived game-related parenting. The focus groups with parents addressed considerations in purchasing video games, perceived positive and negative consequences of gaming, and game-related parenting. Both children and their parents were very positive about active video games and preferred active games over non-active games. Active video games were considered more social than non-active video games, and active games were played more often together with friends and family than non-active video games. Parenting practices did not differ for active and non-active video games, although some parents were less strict regarding active games. Two conditions for practical implementation were met: children enjoyed active video games, and parents were willing to buy active video games. Active video games were preferred to non-active video games, illustrating that using active video games is a promising health promotion tool to reduce sedentary pastime in youth.

Is a Perceived Activity-Friendly Environment Associated with More Physical Activity and Fewer Screen-Based Activities in Adolescents?

Directory of Open Access Journals (Sweden)

Jaroslava Kopcakova

2017-01-01

Full Text Available Background: The aim of this study is to explore if perception of an activity-friendly environment is associated with more physical activity and fewer screen-based activities among adolescents. Methods: We collected self-reported data in 2014 via the Health Behavior in School-aged Children cross-sectional study from four European countries (n = 13,800, mean age = 14.4, 49.4% boys. We explored the association of perceived environment (e.g., “There are other children nearby home to go out and play with” with physical activity and screen-based activities using a binary logistic regression model adjusted for age, gender, family affluence and country. Results: An environment perceived as activity-friendly was associated with higher odds that adolescents meet recommendations for physical activity (odds ratio (OR for one standard deviation (SD change = 1.11, 95% confidence interval (CI 1.05–1.18 and lower odds for excessive screen-based activities (OR for 1 SD better = 0.93, 95% CI 0.88–0.98. Conclusions: Investment into an activity-friendly environment may support the promotion of active life styles in adolescence.

Active Brownian particles with velocity-alignment and active fluctuations

International Nuclear Information System (INIS)

Großmann, R; Schimansky-Geier, L; Romanczuk, P

2012-01-01

We consider a model of active Brownian particles (ABPs) with velocity alignment in two spatial dimensions with passive and active fluctuations. Here, active fluctuations refers to purely non-equilibrium stochastic forces correlated with the heading of an individual active particle. In the simplest case studied here, they are assumed to be independent stochastic forces parallel (speed noise) and perpendicular (angular noise) to the velocity of the particle. On the other hand, passive fluctuations are defined by a noise vector independent of the direction of motion of a particle, and may account, for example, for thermal fluctuations. We derive a macroscopic description of the ABP gas with velocity-alignment interaction. Here, we start from the individual-based description in terms of stochastic differential equations (Langevin equations) and derive equations of motion for the coarse-grained kinetic variables (density, velocity and temperature) via a moment expansion of the corresponding probability density function. We focus here on the different impact of active and passive fluctuations on onset of collective motion and show how active fluctuations in the active Brownian dynamics can change the phase-transition behaviour of the system. In particular, we show that active angular fluctuations lead to an earlier breakdown of collective motion and to the emergence of a new bistable regime in the mean-field case. (paper)

ActivityNet: A Large-Scale Video Benchmark for Human Activity Understanding

KAUST Repository

Heilbron, Fabian Caba

2015-06-02

In spite of many dataset efforts for human action recognition, current computer vision algorithms are still severely limited in terms of the variability and complexity of the actions that they can recognize. This is in part due to the simplicity of current benchmarks, which mostly focus on simple actions and movements occurring on manually trimmed videos. In this paper we introduce ActivityNet, a new largescale video benchmark for human activity understanding. Our benchmark aims at covering a wide range of complex human activities that are of interest to people in their daily living. In its current version, ActivityNet provides samples from 203 activity classes with an average of 137 untrimmed videos per class and 1.41 activity instances per video, for a total of 849 video hours. We illustrate three scenarios in which ActivityNet can be used to compare algorithms for human activity understanding: untrimmed video classification, trimmed activity classification and activity detection.

ActivityNet: A Large-Scale Video Benchmark for Human Activity Understanding

KAUST Repository

Heilbron, Fabian Caba; Castillo, Victor; Ghanem, Bernard; Niebles, Juan Carlos

2015-01-01

In spite of many dataset efforts for human action recognition, current computer vision algorithms are still severely limited in terms of the variability and complexity of the actions that they can recognize. This is in part due to the simplicity of current benchmarks, which mostly focus on simple actions and movements occurring on manually trimmed videos. In this paper we introduce ActivityNet, a new largescale video benchmark for human activity understanding. Our benchmark aims at covering a wide range of complex human activities that are of interest to people in their daily living. In its current version, ActivityNet provides samples from 203 activity classes with an average of 137 untrimmed videos per class and 1.41 activity instances per video, for a total of 849 video hours. We illustrate three scenarios in which ActivityNet can be used to compare algorithms for human activity understanding: untrimmed video classification, trimmed activity classification and activity detection.

Ocean Acidification Affects the Cytoskeleton, Lysozymes, and Nitric Oxide of Hemocytes: A Possible Explanation for the Hampered Phagocytosis in Blood Clams, Tegillarca granosa.

Science.gov (United States)

Su, Wenhao; Rong, Jiahuan; Zha, Shanjie; Yan, Maocang; Fang, Jun; Liu, Guangxu

2018-01-01

An enormous amount of anthropogenic carbon dioxide (CO 2 ) has been dissolved into the ocean, leading to a lower pH and changes in the chemical properties of seawater, which has been termed ocean acidification (OA). The impacts of p CO 2 -driven acidification on immunity have been revealed recently in various marine organisms. However, the mechanism causing the reduction in phagocytosis still remains unclear. Therefore, the impacts of p CO 2 -driven OA at present and near-future levels (pH values of 8.1, 7.8, and 7.4) on the rate of phagocytosis, the abundance of cytoskeleton components, the levels of nitric oxide (NO), and the concentration and activity of lysozymes (LZM) of hemocytes were investigated in a commercial bivalve species, the blood clam ( Tegillarca granosa ). In addition, the effects of OA on the expression of genes regulating actin skeleton and nitric oxide synthesis 2 ( NOS2 ) were also analyzed. The results obtained showed that the phagocytic rate, cytoskeleton component abundance, concentration and activity of LZM of hemocytes were all significantly reduced after a 2-week exposure to the future OA scenario of a pH of 7.4. On the contrary, a remarkable increase in the concentration of NO compared to that of the control was detected in clams exposed to OA. Furthermore, the expression of genes regulating the actin cytoskeleton and NOS were significantly up-regulated after OA exposure. Though the mechanism causing phagocytosis seemed to be complicated based on the results obtained in the present study and those reported previously, our results suggested that OA may reduce the phagocytosis of hemocytes by (1) decreasing the abundance of cytoskeleton components and therefore hampering the cytoskeleton-mediated process of engulfment, (2) reducing the concentration and activity of LZM and therefore constraining the degradation of the engulfed pathogen through an oxygen-independent pathway, and (3) inducing the production of NO, which may negatively

Integration of Active Video Games in Extracurricular Activity at Schools

Science.gov (United States)

Lee, Jung Eun; Huang, Charles; Pope, Zachary; Gao, Zan

2015-01-01

Active video games require players to be physically active. Dance Dance Revolution (DDR) is an interactive dancing game that requires fast-foot movement coordinated with energetic music and visuals. The Wii and Xbox Kinect games have also become good active video games for the promotion of physical activity participation. These games are much more…

Retro-binding thrombin active site inhibitors: identification of an orally active inhibitor of thrombin catalytic activity.

Science.gov (United States)

Iwanowicz, Edwin J; Kimball, S David; Lin, James; Lau, Wan; Han, W-C; Wang, Tammy C; Roberts, Daniel G M; Schumacher, W A; Ogletree, Martin L; Seiler, Steven M

2002-11-04

A series of retro-binding inhibitors of human alpha-thrombin was prepared to elucidate structure-activity relationships (SAR) and optimize in vivo performance. Compounds 9 and 11, orally active inhibitors of thrombin catalytic activity, were identified to be efficacious in a thrombin-induced lethality model in mice.

BAM! Physical Activity

Science.gov (United States)

... Smarts Links Fuel Up for Fun Power Packing Physical Activity Activity Calendar Activity Information Sheets I Heard Hurdle ... Links Sleep Game Questions Answered Under the Microscope Physical Activity Game Questions Answered Under the Microscope Lurking in ...

Assessing adult leisure activities: an extension of a self-report activity questionnaire.

Science.gov (United States)

Jopp, Daniela S; Hertzog, Christopher

2010-03-01

Everyday leisure activities in adulthood and old age have been investigated with respect to constructs such as successful aging, an engaged lifestyle, and prevention of age-related cognitive decline. They also relate to mental health and have clinical value, as they can inform diagnosis and interventions. In the present study, the authors enhanced the content validity of the Victoria Longitudinal Study activity questionnaire by adding items on physical and social activities and validated a shortened version of the questionnaire. The proposed leisure activity model included 11 activity categories: 3 types of social activities (i.e., activities with close social partners, group-centered public activity, religious activities), physical activities, developmental activities, experiential activities, crafts, game playing, TV watching, travel, and technology use. Confirmatory factor analyses validated the proposed factor structure in 2 independent samples. A higher order model with a general activity factor fitted the activity factor correlations with relatively little loss of fit. Convergent and discriminant validity for the activity scales were supported by patterns of their correlations with education, health, depression, cognition, and personality. In sum, the scores derived from of the augmented Victoria Longitudinal Study activity questionnaire demonstrate good reliability, and validity evidence supports their use as measures of leisure activities in young, middle-aged, and older individuals. PsycINFO Database Record (c) 2010 APA, all rights reserved.

Correlation between calculated molecular descriptors of excipient amino acids and experimentally observed thermal stability of lysozyme

DEFF Research Database (Denmark)

Meng-Lund, Helena; Friis, Natascha; van de Weert, Marco

2017-01-01

for lysozyme in combination with 13 different amino acids using high throughput fluorescence spectroscopy and kinetic static light scattering measurements. On the theoretical side, around 200 2D and 3D molecular descriptors were calculated based on the amino acids' chemical structure. Multivariate data...... prominent stabilizing factor for both responses, whereas hydrophilic surface properties and high molecular mass density mostly had a positive influence on the unfolding temperature. A high partition coefficient (logP(o/w)) was identified as the most prominent destabilizing factor for both responses...

Physical Activity Guidelines

Science.gov (United States)

... use this site. health.gov Physical Activity Guidelines Physical Activity Physical activity is key to improving the health of the Nation. Based on the latest science, the Physical Activity Guidelines for Americans is an essential resource for ...

Elevation of oleate-activated phospholipase D activity during thymic atrophy

Science.gov (United States)

Lee, Youngkyun; Song, Soo-Mee; Park, Heung Soon; Kim, Sungyeol; Koh, Eun-Hee; Choi, Myung Sun; Choi, Myung-Un

2002-01-01

Various phospholipases are thought to be associated with the in vitro apoptosis of thymocytes. In the present study, the in vivo phospholipase D (PLD) activity of rat thymus was studied after whole-body X-irradiation or injection of dexamethasone (DEX). Using exogenous [14C]dipalmitoyl phosphatidylcholine (PC) as the substrate, an elevation of oleate-activated PLD activity was observed during thymic atrophy. The activity increases were sevenfold at 48 hr after 5-Gy irradiation and fourfold at 72 hr after injection of 5 mg/kg DEX. The elevation of PLD activity appeared to parallel extensive thymus shrinkage. An increased level of thymic phosphatidic acid (PA), the presumed physiological product of PLD action on PC, was also detected. By comparing the acyl chains of PA with those of other phospholipids, PA appeared to originate from PC. To assess the role of PLD during thymic atrophy, thymocytes and stromal cells were isolated. Although thymocytes themselves exhibited significant PLD activation, the major elevation in PLD activity (greater than fourfold) was found in isolated stromal cells. PLD was also activated during in vitro phagocytosis of apoptotic thymocytes by the macrophage-like cell line P388D1. This in vitro phagocytosis was significantly inhibited by PLD action blockers, such as 2,3-diphosphoglycerate and 1-butanol. These observations strongly suggest that the alteration of oleate-activated PLD activity is part of an in vivo event in the progression of thymic atrophy, including phagocytic clearance of apoptotic thymocytes. PMID:12460188

Study of Lysozyme-Loaded Poly-L-Lactide (PLLA Porous Microparticles in a Compressed CO2 Antisolvent Process

Directory of Open Access Journals (Sweden)

Xiao-Qian Su

2013-08-01

Full Text Available Lysozyme (LSZ-loaded poly-L-lactide (PLLA porous microparticles (PMs were successfully prepared by a compressed CO2 antisolvent process in combination with a water-in-oil emulsion process using LSZ as a drug model and ammonium bicarbonate as a porogen. The effects of different drug loads (5.0%, 7.5% and 10.0% on the surface morphology, particle size, porosity, tapped density and drug release profile of the harvested PMs were investigated. The results show that an increase in the amount of LSZ added led to an increase in drug load (DL but a decrease in encapsulation efficiency. The resulting LSZ-loaded PLLA PMs (LSZ-PLLA PMs exhibited a porous and uneven morphology, with a density less than 0.1 g·cm−3, a geometric mean diameter of 16.9–18.8 μm, an aerodynamic diameter less than 2.8 μm, a fine particle fraction (FPF of 59.2%–66.8%, and a porosity of 78.2%–86.3%. According to the results of differential scanning calorimetry, the addition of LSZ improved the thermal stability of PLLA. The Fourier transform infrared spectroscopy analysis and circular dichroism spectroscopy measurement reveal that no significant changes occurred in the molecular structures of LSZ during the fabrication process, which was further confirmed by the evaluation of enzyme activity of LSZ. It is demonstrated that the emulsion-combined precipitation with compressed antisolvent (PCA process could be a promising technology to develop biomacromolecular drug-loaded inhalable carrier for pulmonary drug delivery.

Increasing Youth Physical Activity with Activity Calendars

Science.gov (United States)

Eckler, Seth

2016-01-01

Physical educators often struggle with ways to get their students to be active beyond the school day. One strategy to accomplish this is the use of physical activity calendars (PACs). The purpose of this article is to support the use of PACs and give practical advice for creating effective PACs.

Activating AMP-activated protein kinase by an α1 selective activator compound 13 attenuates dexamethasone-induced osteoblast cell death

International Nuclear Information System (INIS)

Guo, Shiguang; Mao, Li; Ji, Feng; Wang, Shouguo; Xie, Yue; Fei, Haodong; Wang, Xiao-dong

2016-01-01

Excessive glucocorticoid (GC) usage may lead to non-traumatic femoral head osteonecrosis. Dexamethasone (Dex) exerts cytotoxic effect to cultured osteoblasts. Here, we investigated the potential activity of Compound 13 (C13), a novel α1 selective AMP-activated protein kinase (AMPK) activator, against the process. Our data revealed that C13 pretreatment significantly attenuated Dex-induced apoptosis and necrosis in both osteoblastic-like MC3T3-E1 cells and primary murine osteoblasts. AMPK activation mediated C13′ cytoprotective effect in osteoblasts. The AMPK inhibitor Compound C, shRNA-mediated knockdown of AMPKα1, or dominant negative mutation of AMPKα1 (T172A) almost abolished C13-induced AMPK activation and its pro-survival effect in osteoblasts. On the other hand, forced AMPK activation by adding AMPK activator A-769662 or exogenous expression a constitutively-active (ca) AMPKα1 (T172D) mimicked C13's actions and inhibited Dex-induced osteoblast cell death. Meanwhile, A-769662 or ca-AMPKα1 almost nullified C13's activity in osteoblast. Further studies showed that C13 activated AMPK-dependent nicotinamide adenine dinucleotide phosphate (NADPH) pathway to inhibit Dex-induced reactive oxygen species (ROS) production in MC3T3-E1 cells and primary murine osteoblasts. Such effects by C13 were almost reversed by Compound C or AMPKα1 depletion/mutation. Together, these results suggest that C13 alleviates Dex-induced osteoblast cell death via activating AMPK signaling pathway. - Highlights: • Compound 13 (C13) attenuates dexamethasone (Dex)-induced osteoblast cell death. • C13-induced cytoprotective effect against Dex in osteoblasts requires AMPK activation. • Forced AMPK activation protects osteoblasts from Dex, nullifying C13's activities. • C13 increases NADPH activity and inhibits Dex-induced oxidative stress in osteoblasts.

Activating AMP-activated protein kinase by an α1 selective activator compound 13 attenuates dexamethasone-induced osteoblast cell death

Energy Technology Data Exchange (ETDEWEB)

Guo, Shiguang [Department of Intensive Care Unit, Huai' an First People' s Hospital, Nanjing Medical University, Huai' an (China); Mao, Li [Department of Endocrinology, Huai' an First People' s Hospital, Nanjing Medical University, Huai' an (China); Ji, Feng, E-mail: huaiaifengjidr@163.com [Department of Orthopedics, Huai' an First People' s Hospital, Nanjing Medical University, Huai' an (China); Wang, Shouguo; Xie, Yue; Fei, Haodong [Department of Orthopedics, Huai' an First People' s Hospital, Nanjing Medical University, Huai' an (China); Wang, Xiao-dong, E-mail: xiaodongwangsz@163.com [The Center of Diagnosis and Treatment for Children' s Bone Diseases, The Children' s Hospital Affiliated to Soochow University, Suzhou (China)

2016-03-18

Excessive glucocorticoid (GC) usage may lead to non-traumatic femoral head osteonecrosis. Dexamethasone (Dex) exerts cytotoxic effect to cultured osteoblasts. Here, we investigated the potential activity of Compound 13 (C13), a novel α1 selective AMP-activated protein kinase (AMPK) activator, against the process. Our data revealed that C13 pretreatment significantly attenuated Dex-induced apoptosis and necrosis in both osteoblastic-like MC3T3-E1 cells and primary murine osteoblasts. AMPK activation mediated C13′ cytoprotective effect in osteoblasts. The AMPK inhibitor Compound C, shRNA-mediated knockdown of AMPKα1, or dominant negative mutation of AMPKα1 (T172A) almost abolished C13-induced AMPK activation and its pro-survival effect in osteoblasts. On the other hand, forced AMPK activation by adding AMPK activator A-769662 or exogenous expression a constitutively-active (ca) AMPKα1 (T172D) mimicked C13's actions and inhibited Dex-induced osteoblast cell death. Meanwhile, A-769662 or ca-AMPKα1 almost nullified C13's activity in osteoblast. Further studies showed that C13 activated AMPK-dependent nicotinamide adenine dinucleotide phosphate (NADPH) pathway to inhibit Dex-induced reactive oxygen species (ROS) production in MC3T3-E1 cells and primary murine osteoblasts. Such effects by C13 were almost reversed by Compound C or AMPKα1 depletion/mutation. Together, these results suggest that C13 alleviates Dex-induced osteoblast cell death via activating AMPK signaling pathway. - Highlights: • Compound 13 (C13) attenuates dexamethasone (Dex)-induced osteoblast cell death. • C13-induced cytoprotective effect against Dex in osteoblasts requires AMPK activation. • Forced AMPK activation protects osteoblasts from Dex, nullifying C13's activities. • C13 increases NADPH activity and inhibits Dex-induced oxidative stress in osteoblasts.

Passive maternal exposure to environmental microbes selectively modulates the innate defences of chicken egg white by increasing some of its antibacterial activities.

Science.gov (United States)

Bedrani, Larbi; Helloin, Emmanuelle; Guyot, Nicolas; Réhault-Godbert, Sophie; Nys, Yves

2013-06-07

Egg defence against bacterial contamination relies on immunoglobulins (IgY) concentrated in the yolk and antimicrobial peptides/proteins predominantly localized in the egg white (EW). Hens contaminated with pathogenic microorganisms export specific IgYs to the egg (adaptative immunity). No evidence of such regulation has been reported for the antimicrobial peptides/proteins (innate immunity) which are preventively secreted by the hen oviduct and are active against a large range of microbes. We investigated whether the egg innate defences can be stimulated by the environmental microbial contamination by comparing the antimicrobial activity of EW of hens raised in three extreme breeding conditions: Germ-free (GF), Specific Pathogen Free (SPF) and Conventional (C) hens. The difference in the immunological status of GF, SPF and C hens was confirmed by the high stimulation of IL-1β, IL-8 and TLR4 genes in the intestine of C and SPF groups. EW from C and SPF groups demonstrated higher inhibitory effect against Staphylococcus aureus (13 to 18%) and against Streptococcus uberis (31 to 35%) as compared to GF but showed similar activity against Salmonella Enteritidis, Salmonella Gallinarum, Escherichia coli and Listeria monocytogenes. To further investigate these results, we explored putative changes amongst the three main mechanisms of egg antimicrobial defence: the sequestration of bacterial nutrients, the inactivation of exogenous proteases and the direct lytic action on microorganisms. Lysozyme activity, chymotrypsin-, trypsin- and papain-inhibiting potential of EW and the expression of numerous antimicrobial genes were not stimulated suggesting that these are not responsible for the change in anti-S. aureus and anti-S. uberis activity. Moreover, whereas the expression levels of IL-1β, IL-8 and TLR4 genes were modified by the breeding conditions in the intestine of C and SPF groups they were not modified in the magnum where egg white is formed. Altogether, these data

Adolescents' Views on Active and Non-Active Videogames: A Focus Group Study.

Science.gov (United States)

Simons, Monique; de Vet, Emely; Hoornstra, Sjoukje; Brug, Johannes; Seidell, Jaap; Chinapaw, Mai

2012-06-01

Active games require whole-body movement and may be an innovative tool to substitute sedentary pastime with more active time and may therefore contribute to adolescents' health. To inform strategies aimed at reducing sedentary behavior by replacing non-active with active gaming, perceptions and context of active and non-active gaming are explored. Six focus groups were conducted with adolescents 12-16 years old representing a range of education levels. A semistructured question route was used containing questions about perceptions and the context of gaming. The adolescents had positive attitudes toward active gaming, especially the social interactive aspect, which was greatly appreciated. A substantial number of adolescents enjoyed non-active games more than active ones, mainly because of better game controls and more diversity in non-active games. Active games were primarily played when there was a social gathering. Few game-related rules and restrictions at home were reported. Given the positive attitudes of adolescents and the limited restrictions for gaming at home, active videogames may potentially be used in a home setting as a tool to reduce sedentary behavior. However, to make active games as appealing as non-active games, attention should be paid to the quality, diversity, and sustainability of active games, as these aspects are currently inferior to those of traditional non-active games.

Immotile Active Matter: Activity from Death and Reproduction

Science.gov (United States)

Kalziqi, Arben; Yanni, David; Thomas, Jacob; Ng, Siu Lung; Vivek, Skanda; Hammer, Brian K.; Yunker, Peter J.

2018-01-01

Unlike equilibrium atomic solids, biofilms—soft solids composed of bacterial cells—do not experience significant thermal fluctuations at the constituent level. However, living cells stochastically reproduce and die, provoking a mechanical response. We investigate the mechanical consequences of cellular death and reproduction by measuring surface-height fluctuations of biofilms containing two mutually antagonistic strains of Vibrio cholerae that kill one another on contact via the type VI secretion system. While studies of active matter typically focus on activity via constituent mobility, here, activity is mediated by reproduction and death events in otherwise immobilized cells. Biofilm surface topography is measured in the nearly homeostatic limit via white light interferometry. Although biofilms are far from equilibrium systems, measured surface-height fluctuation spectra resemble the spectra of thermal permeable membranes but with an activity-mediated effective temperature, as predicted by Risler, Peilloux, and Prost [Phys. Rev. Lett. 115, 258104 (2015), 10.1103/PhysRevLett.115.258104]. By comparing the activity of killer strains of V. cholerae with that of genetically modified strains that cannot kill each other and validating with individual-based simulations, we demonstrate that extracted effective temperatures increase with the amount of death and reproduction and that death and reproduction can fluidize biofilms. Together, these observations demonstrate the unique physical consequences of activity mediated by death and reproduction events.

Physical activity energy expenditure in Dutch adolescents: contribution of active transport to school, physical education, and leisure time activities.

Science.gov (United States)

Slingerland, Menno; Borghouts, Lars B; Hesselink, Matthijs K C

2012-05-01

Detailed knowledge about physical activity energy expenditure (PAEE) can guide the development of school interventions aimed at reducing overweight in adolescents. However, relevant components of PAEE have never been objectively quantified in this population. This study investigated the contribution of active transport to and from school, physical education (PE), and leisure time activities to total PAEE during a regular school week in adolescents. Seventy-three adolescents (mean age: 15.7 years) wore an individually calibrated combined heart rate-acceleration monitor and kept an activity diary during a regular school week. Branched equation modeling was used to calculate PAEE of the specific activity categories, and their relative contribution to total PAEE was determined. Active transport and PE contributed 30.0% and 17.4%, respectively, to school-related PAEE. Active transport to and from school contributed 15% to total PAEE. Youth with a high physical activity level (PAL) spent 4 hours less in sedentary behavior than subjects with a medium or low PAL (F = 77.415 (2.70), p activities (F = 10.583 (2.70), p Active transport and PE contribute significantly to PAEE during school hours in adolescents. To achieve an increase in total PAEE in the least active group of adolescents, promising strategies might be to reduce inactive behavior, increase participation in leisure time sports, and possibly to replace inactive for active jobs. © 2012, American School Health Association.

Prevalence of active trachoma two years after control activities ...

African Journals Online (AJOL)

The prevalence of TF/TI showed significant reduction (p-value <0.001) in all five districts and overall in the two regions. Conclusion: Trachoma control activities over a two-year period in two regions in Ghana had led to significant reduction in the prevalence of active disease. Integrated surveillance and active monitoring will ...

Macrophage activating activity of pyrrole alkaloids from Morus alba fruits.

Science.gov (United States)

Kim, Seon Beom; Chang, Bo Yoon; Jo, Yang Hee; Lee, Sang Hoon; Han, Sang-Bae; Hwang, Bang Yeon; Kim, Sung Yeon; Lee, Mi Kyeong

2013-01-09

The fruits of Morus alba have been traditionally used as a tonic to enhance immune responses. The macrophage activating constituents of Morus alba fruits were purified using various column chromatography techniques. The structures of isolated compounds were determined on the basis of spectroscopic data interpretation such as 1D and 2D NMR analysis. The macrophage activating activities of isolated compounds were evaluated by measuring the production of nitric oxide, TNF-α and IL-12 in RAW 264.7 cells. The phagocytic activity was also evaluated. Five pyrrole alkaloids, 5-(hydroxymethyl)-1H-pyrrole-2-carboxaldehyde (1), 2-formyl-1H-pyrrole-1-butanoic acid (2), 2-formyl-5-(hydroxymethyl)-1H-pyrrole-1-butanoic acid (3), 2-formyl-5-(methoxymethyl)-1H-pyrrole-1-butanoic acid (4) and Morrole A (5) were isolated from the fruits of Morus alba. Morrole A (5) is first reported in nature and other pyrrole alkaloids (1-4) are first reported from Morus species. Among the isolated compounds, compounds 3 and 4 significantly activated macrophage activity by the enhancement of nitric oxide, TNF-α and IL-12 production, and the stimulation of phagocytic activity in RAW 264.7 cells. Pyrrole alkaloids, including a new compound, were isolated from Morus alba fruits. These compounds activated macrophage activity in RAW 264.7 cells. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Transcriptional activation of peroxisome proliferator-activated receptor-γ requires activation of both protein kinase A and Akt during adipocyte differentiation

International Nuclear Information System (INIS)

Kim, Sang-pil; Ha, Jung Min; Yun, Sung Ji; Kim, Eun Kyoung; Chung, Sung Woon; Hong, Ki Whan; Kim, Chi Dae; Bae, Sun Sik

2010-01-01

Research highlights: → Elevated cAMP activates both PKA and Epac. → PKA activates CREB transcriptional factor and Epac activates PI3K/Akt pathway via Rap1. → Akt modulates PPAR-γ transcriptional activity in concert with CREB. -- Abstract: Peroxisome proliferator-activated receptor-γ (PPAR-γ) is required for the conversion of pre-adipocytes. However, the mechanism underlying activation of PPAR-γ is unclear. Here we showed that cAMP-induced activation of protein kinase A (PKA) and Akt is essential for the transcriptional activation of PPAR-γ. Hormonal induction of adipogenesis was blocked by a phosphatidylinositol 3-kinase (PI3K) inhibitor (LY294002), by a protein kinase A (PKA) inhibitor (H89), and by a Rap1 inhibitor (GGTI-298). Transcriptional activity of PPAR-γ was markedly enhanced by 3-isobutyl-1-methylxanthine (IBMX), but not insulin and dexamethasone. In addition, IBMX-induced PPAR-γ transcriptional activity was blocked by PI3K/Akt, PKA, or Rap1 inhibitors. 8-(4-Chlorophenylthio)-2'-O-methyl-cAMP (8-pCPT-2'-O-Me-cAMP) which is a specific agonist for exchanger protein directly activated by cAMP (Epac) significantly induced the activation of Akt. Furthermore, knock-down of Akt1 markedly attenuated PPAR-γ transcriptional activity. These results indicate that both PKA and Akt signaling pathways are required for transcriptional activation of PPAR-γ, suggesting post-translational activation of PPAR-γ might be critical step for adipogenic gene expression.

Criminalisation of Activism

DEFF Research Database (Denmark)

Uldam, Julie

Different forms of political participation involve different challenges. This paper focuses on challenges to radical activism and particularly the criminalisation of activism.......Different forms of political participation involve different challenges. This paper focuses on challenges to radical activism and particularly the criminalisation of activism....

Physical active rest in education of active personality of students

Directory of Open Access Journals (Sweden)

Zaycev V.P.

2010-10-01

Full Text Available Meaningfulness of physical recreation is rotined in education of active personality of students. Research material is literary sources on this issue. Factors which influence on an educate function of personality of students are considered. Application of physical recreation is grounded for education of active personality of students. It is marked that physical recreation in pedagogical process decides educate, educational, health and social tasks. It positively influences on education of active personality of students. It is rotined that in education of active personality of students an important role is played by their research activity.

Effect of long-term oral administration of an immunostimulant diet on innate immunity in sea bass (Dicentrarchus labrax).

Science.gov (United States)

Bagni, M; Archetti, L; Amadori, M; Marino, G

2000-12-01

Immunostimulants represent a modern and promising tool in aquaculture, enhancing the resistance of cultured fish to disease and stress. This study investigated the effect of a combination of dietary glucans, alpha-tocopherol and ascorbic acid on the innate immune response of cultured sea bass (Dicentrarchus labrax). After 5 weeks of adaptation on a commercial diet containing 100 p.p.m. ascorbic acid and 200 p.p.m. alpha-tocopherol, sea bass were switched to a diet supplemented with 2% beta-1.3/beta-1.6 glucans and ascorbic acid and alpha-tocopherol at 500 p.p.m. The supplemented diet was given at 2% of body weight per day over a 2-week period, every 3 months. Plasma lysozyme concentration, content and distribution of major plasma proteins and complement activity were measured prior to feeding the supplemented diet and after 40 weeks. Alternative pathways of complement activation and lysozyme activity were both significantly enhanced in fish fed on glucans and elevated doses of vitamins. No significant differences were observed in protein content or in albumin/globulin ratio. Compared to lysozyme activity, which showed marked individual variation, complement-mediated haemolytic activity has been shown to be a more reliable indicator of sea bass immunocompetence. Further studies are in progress to clarify the effect of each dietary component on the innate immune response and disease resistance.

Molecular packing, hydrogen bonding, and fast dynamics in lysozyme/trehalose/glycerol and trehalose/glycerol glasses at low hydration

OpenAIRE

Lerbret, Adrien; Affouard, Frédéric

2017-01-01

Water and glycerol are well-known to facilitate the structural relaxation of amorphous protein matrices. However, several studies evidenced that they may also limit fast ($\\sim$ pico-nanosecond, ps-ns) and small-amplitude ($\\sim$ \\AA ) motions of proteins, which govern their stability in freeze-dried sugar mixtures. To determine how they interact with proteins and sugars in glassy matrices and, thereby, modulate their fast dynamics, we performed molecular dynamics (MD) simulations of lysozyme...

Accessibility, activity participation and location of activities

DEFF Research Database (Denmark)

Næss, Petter

2006-01-01

By investigating relationships between residential location and the availability of facilities, location of activities, trip distances, activity participation and trip frequencies, this paper seeks to contribute to a more detailed and nuanced understanding of the relationships between residential...... location and the amount of daily-life travel in an urban region. The empirical data are from a comprehensive study of residential location and travel in Copenhagen Metropolitan Area. Differences between inner- and outer-area residents in activity frequencies and trip frequencies are modest and partly...... outweigh each other. However, differences in trip distances due to the location of the dwelling relative to concentrations of facilities translate into substantially longer total travelling distances among suburbanites than among inner-city residents....

Comparison of passive and active leisure activities and life satisfaction with aging.

Science.gov (United States)

Cho, Dongwook; Post, Jay; Kim, Sung Kyeom

2018-03-01

Many older adults face limitations to participating in active leisure activities as a result of their physical constraints from aging. Passive leisure activities become alternative leisure activities for older adults as a result of limited physical capacity. The present study sought to determine whether there exists a difference in the frequency of participation in passive and active leisure activities, and the effect of participation in passive and active leisure activities on the life satisfaction level of old adults. A total of 460 participants aged 60-95 years were randomly selected from 21 sites in the USA. The Life Satisfaction Index - Z and the Meaningful Activity Participation Assessment were analyzed to examine older adults' life satisfaction and frequency of active or passive activities. The results showed that participation in passive leisure activities, such reading, talking on the telephone and watching TV/listening to the radio, is more frequent among older adults (P = 0.000). The regression coefficient found that club/organization or volunteering (P = 0.008), homemaking/maintenance (P = 0.017) and traveling (P = 0.017) for active leisure activities were statistically significant predictors of Life Satisfaction Index - Z for older adults. The current study shows that older adults spent much more times participating in passive leisure activities, such as radio/watching TV, talking on the phone and reading. The result also showed that active leisure activities, such as club/organization or volunteering, home making/maintenance and traveling, were significant predictors of life satisfaction for older adults controlling for covariates. The current study suggests marketing and programming plans to overcome the constraints that influence older adults' life satisfaction. Geriatr Gerontol Int 2018; 18: 380-386. © 2017 Japan Geriatrics Society.

Platelet activating factor activity in the phospholipids of bovine spermatozoa

Energy Technology Data Exchange (ETDEWEB)

Parks, J.E.; Hough, S.; Elrod, C. (Cornell Univ., Ithaca, NY (USA))

1990-11-01

Platelet activating factor (PAF) has been detected in sperm from several mammalian species and can affect sperm motility and fertilization. Because bovine sperm contain a high percentage of ether-linked phospholipid precursors required for PAF synthesis, a study was undertaken to determine the PAF activity of bovine sperm phospholipids. Total lipids of washed, ejaculated bull sperm were extracted, and phospholipids were fractionated by thin-layer chromatography. Individual phospholipid fractions were assayed for PAF activity on the basis of (3H)serotonin release from equine platelets. PAF activity was detected in the PAF fraction (1.84 pmol/mumol total phospholipid) and in serine/inositol (PS/PI), choline (CP), and ethanolamine phosphoglyceride (EP) and cardiolipin (CA) fractions. Activity was highest in the CP fraction (8.05 pmol/mumol total phospholipid). Incomplete resolution of PAF and neutral lipids may have contributed to the activity in the PS/PI and CA fractions, respectively. Phospholipids from nonsperm sources did not stimulate serotonin release. Platelet activation by purified PAF and by sperm phospholipid fractions was inhibited by the receptor antagonist SRI 63-675. These results indicate that bovine sperm contain PAF and that other sperm phospholipids, especially CP and EP, which are high in glycerylether components, are capable of receptor-mediated platelet activation.

Activity Engagement and Activity-Related Experiences: The Role of Personality.

Science.gov (United States)

Newton, Nicky J; Pladevall-Guyer, Jana; Gonzalez, Richard; Smith, Jacqui

2016-08-12

The associations of personality with activity participation and well-being have been well studied. However, less is known concerning the relationship between personality and specific aspects of activity engagement in older adults. We conducted a fine-grained examination of the effects of extraversion and conscientiousness on reported activity engagement-which we define as participation, time allocated, and affective experience-during 8 everyday activities. Data were obtained using a day reconstruction measure from a subgroup of participants in the 2012 Health and Retirement Study (HRS: N = 5,484; mean age = 67.98 years). We found mixed support for hypotheses suggesting that specific personality traits would be associated with activity participation, time allocated, and activity-affective experience. For example, extraverts were more likely to socialize and experienced higher socializing-related positive affect, but did not spend more time socializing. Results are discussed in light of the value of including personality in, and its contribution to, studies of activity engagement in later life. In addition, the need to acknowledge the complexity of the concept of activity engagement in future research is highlighted. © The Author 2016. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Effects of medicinal herbs "Plantago asiatica", "Houttuynia cordata" and "Mentha haplocalyx" on non-specific immune responses of cobia (Rachycentron canadum).

Science.gov (United States)

Wu, Yu-Sheng; Chen, Yin-Yu; Ueng, Pien-Sheng; Nan, Fan-Hua

2016-11-01

This study investigated the effects of orally administered Plantago asiatica, Houttuynia cordata, and Mentha haplocalyx on the growth and nonspecific immune responses of cobia (Rachycentron canadum). The nonspecific immune parameters assessed were weight gain, feed conversion ratio, superoxide anion (O 2 - ) production, superoxide dismutase (SOD) activity, phagocytic rate, phagocytic index, lysozyme activity, serum albumin and globulin, and albumin:globulin (A/G) ratio. The growth experiment indicated that 6-week dietary treatments did not significantly affect on the growth of cobia. Nonspecific immune responses showed that O 2 - production, SOD and lysozyme activity, and phagocytosis were significantly increased after the oral administration of P. asiatica and H. cordata, and the serum albumin:globulin ratio (A/G) gradually decreased. In this study, treatment of the Mentha haplocalyx on the cobia didn't present with the inducing of the phagocytosis ability compared with the treatment of P. asiatica and H. cordata. We suggest that oral administration of the 10 g/kg or 20 g/kg of the P. asiatica and H. cordata is exactly inducing the phagocytosis, ROS production, lysozyme activity and SOD production in the cobia. Copyright © 2016 Elsevier Ltd. All rights reserved.

Multi-day activity scheduling reactions to planned activities and future events in a dynamic model of activity-travel behavior

Science.gov (United States)

Nijland, Linda; Arentze, Theo; Timmermans, Harry

2014-01-01

Modeling multi-day planning has received scarce attention in activity-based transport demand modeling so far. However, new dynamic activity-based approaches are being developed at the current moment. The frequency and inflexibility of planned activities and events in activity schedules of individuals indicate the importance of incorporating those pre-planned activities in the new generation of dynamic travel demand models. Elaborating and combining previous work on event-driven activity generation, the aim of this paper is to develop and illustrate an extension of a need-based model of activity generation that takes into account possible influences of pre-planned activities and events. This paper describes the theory and shows the results of simulations of the extension. The simulation was conducted for six different activities, and the parameter values used were consistent with an earlier estimation study. The results show that the model works well and that the influences of the parameters are consistent, logical, and have clear interpretations. These findings offer further evidence of face and construct validity to the suggested modeling approach.

Multi-day activity scheduling reactions to planned activities and future events in a dynamic model of activity-travel behavior

NARCIS (Netherlands)

Nijland, L.; Arentze, T.A.; Timmermans, H.J.P.

2014-01-01

Modeling multi-day planning has received scarce attention in activity-based transport demand modeling so far. However, new dynamic activity-based approaches are being developed at the current moment. The frequency and inflexibility of planned activities and events in activity schedules of

Multi-Day Activity Scheduling Reactions to Planned Activities and Future Events in a Dynamic Model of Activity-Travel Behavior

NARCIS (Netherlands)

Nijland, L.; Arentze, T.; Timmermans, H.

2014-01-01

Modeling multi-day planning has received scarce attention in activity-based transport demand modeling so far. However, new dynamic activity-based approaches are being developed at the current moment. The frequency and inflexibility of planned activities and events in activity schedules of

RESPIROMETRIC ACTIVITY OF ACTIVATED SLUDGE AND BIOFILM IN IFAS-MBBR SYSTEM

Directory of Open Access Journals (Sweden)

Paula Piechna

2017-07-01

Full Text Available The aim of the presented study was: a assessment of activity of microorganisms developed in form of activated sludge and biofilm, b indirect assessment of the role of analyzed biocoenoses in removal of organic compounds in hybrid reactor with moving bed. Oxygen uptake rate tests (OUR have been used, and obtained results were presented as volumetric activity (expressed in mg O2/L · h and mass activity (expressed as mg O2/g VTS · h. Tests were conducted for three different variants, in which, as the biomass: 1 biofilm was used, 2 activated sludge was used, 3 biofilm and activated sludge were used. The biomass was collected from aerobic reactor from a wastewater treatment plant working in IFAS-MBBR system. The highest volumetric activity was observed for variant with biofilm and activated sludge, and the lowest for variant with biofilm only. Nonetheless, the highest value of oxygen uptake rate related to total volatile solids was observed for variant with biofilm and the lowest for activated sludge. Obtained results suggest, that during this research, at the wastewater treatment plant, the main role in removal of organic pollutants played the biomass developed in form of activated sludge.

Toxicity tests, antioxidant activity, and antimicrobial activity of chitosan

Science.gov (United States)

Kurniasih, M.; Purwati; Dewi, R. S.

2018-04-01

Chitosan is a naturally occurring cationic biopolymer, obtained by alkaline deacetylation of chitin. This research aims to investigate the toxicity, antioxidant activity and antibacterial activity of chitosan from shrimp chitin. In this study, chitin extracted from shrimp waste material. Chitin is then deacetylation with 60% NaOH so that chitosan produced. Degrees of deacetylation, molecular weight, toxicity test, antioxidant activity and antimicrobial activity of chitosan then evaluated. Toxicity test using Brine Shrimp Lethality Test. The antioxidant analysis was performed using DPPH method (2, 2-diphenyl-1-picrylhydrazyl) and FTC method (ferric thiocyanate) in which the radical formed will reduce Ferro to Ferri resulting in a complex with thiocyanate. To determine the antibacterial activity of Staphylococcus aureus, antifungal in Candida albicans and Aspergillus niger by measuring antimicrobial effects and minimum inhibitory concentrations (MIC). Based on the result of research, the value of degrees of deacetylation, molecular weight, and LC50 values of chitosan synthesis was 94,32, 1052.93 g/mol and 1364.41 ppm, respectively. In general, the antioxidative activities increased as the concentration of chitosan increased. MIC value of chitosan against S. aureus, C. albicans, and A. niger was 10 ppm, 15.6 ppm, and 5 ppm, respectively.

Physical activity behavior and related characteristics of highly active eighth-grade girls.

Science.gov (United States)

Taverno Ross, Sharon E; Dowda, Marsha; Beets, Michael W; Pate, Russell R

2013-06-01

Although girls are generally less physically active than boys, some girls regularly engage in high levels of physical activity (PA); however, very little is known about these girls and how they differ from those who are less physically active. This study examined the PA behavior and related characteristics of highly active adolescent girls and compared them with those who are less active. Data from 1,866 eighth-grade girls from six field centers across the United States participating in the Trial of Activity for Adolescent Girls (TAAG) were included in the present analysis. Mixed-model analysis of variance examined differences in sociodemographic, anthropometric, psychosocial, and physical activity (accelerometry and self-report) variables between high- and low-active girls; effect sizes were calculated for the differences. High-active girls were taller, had lower body mass indices and body fat, and were less sedentary. High-active girls scored higher on self-efficacy, enjoyment of PA, self-management strategies, outcome-expectancy value, and support from family and friends than low-active girls. Low-active girls participated in more leisure time and educational sedentary activities than high-active girls. High-active girls participated in more PA classes/lessons outside of school, team sports, and individual sports. They were also more likely to participate in sports in an organized setting in the community or at school than low-active girls. Health promotion efforts should focus on decreasing the amount of time girls spend in sedentary activities and replacing that time with organized PA opportunities; such efforts should seek to minimize perceived barriers and increase self-efficacy and support for PA. Copyright © 2013 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

Heterogeneous Active Matter

Science.gov (United States)

Kolb, Thomas; Klotsa, Daphne

Active systems are composed of self-propelled (active) particles that locally convert energy into motion and exhibit emergent collective behaviors, such as fish schooling and bird flocking. Most works so far have focused on monodisperse, one-component active systems. However, real systems are heterogeneous, and consist of several active components. We perform molecular dynamics simulations of multi-component active matter systems and report on their emergent behavior. We discuss the phase diagram of dynamic states as well as parameters where we see mixing versus segregation.

Lactoferrin, myeloperoxidase, lysozyme and eosinophil cationic protein in exudate in delayed type hypersensitivity

DEFF Research Database (Denmark)

Lerche, A; Bisgaard, H; Christensen, J D

1988-01-01

allergic patients with nickel challenge in the chamber medium showed a time-dependent increase of mononuclear cells, eosinophils and basophils and a concomitant decrease of polymorphonuclear granulocytes, characteristic of a combined specific and unspecific inflammation. The morphology of the exudate...... in contact allergic patients exposed to nickel showed a dominance of polymorphonuclear granulocytes throughout the study period, while mononuclear cells, eosinophils and basophils were detected at a much lower quantity and with a considerable delay. Further, we studied the kinetics of the leucocyte granule...... proteins: lactoferrin, myeloperoxidase, lysozyme and eosinophil cationic protein in exudate fluid in a parallel test. A significant higher flux was found for all during the second day of allergen exposure compared to contact allergic patients without allergen challenge as well as normal volunteers...

Acute activation, desensitization and smoldering activation of human acetylcholine receptors.

Directory of Open Access Journals (Sweden)

Barbara G Campling

Full Text Available The behavioral effects of nicotine and other nicotinic agonists are mediated by AChRs in the brain. The relative contribution of acute activation versus chronic desensitization of AChRs is unknown. Sustained "smoldering activation" occurs over a range of agonist concentrations at which activated and desensitized AChRs are present in equilibrium. We used a fluorescent dye sensitive to changes in membrane potential to examine the effects of acute activation and chronic desensitization by nicotinic AChR agonists on cell lines expressing human α4β2, α3β4 and α7 AChRs. We examined the effects of acute and prolonged application of nicotine and the partial agonists varenicline, cytisine and sazetidine-A on these AChRs. The range of concentrations over which nicotine causes smoldering activation of α4β2 AChRs was centered at 0.13 µM, a level found in smokers. However, nicotine produced smoldering activation of α3β4 and α7 AChRs at concentrations well above levels found in smokers. The α4β2 expressing cell line contains a mixture of two stoichiometries, namely (α4β22β2 and (α4β22α4. The (α4β22β2 stoichiometry is more sensitive to activation by nicotine. Sazetidine-A activates and desensitizes only this stoichiometry. Varenicline, cytisine and sazetidine-A were partial agonists on this mixture of α4β2 AChRs, but full agonists on α3β4 and α7 AChRs. It has been reported that cytisine and varenicline are most efficacious on the (α4β22α4 stoichiometry. In this study, we distinguish the dual effects of activation and desensitization of AChRs by these nicotinic agonists and define the range of concentrations over which smoldering activation can be sustained.

ActivitySim: large-scale agent based activity generation for infrastructure simulation

Energy Technology Data Exchange (ETDEWEB)

Gali, Emmanuel [Los Alamos National Laboratory; Eidenbenz, Stephan [Los Alamos National Laboratory; Mniszewski, Sue [Los Alamos National Laboratory; Cuellar, Leticia [Los Alamos National Laboratory; Teuscher, Christof [PORTLAND STATE UNIV

2008-01-01

The United States' Department of Homeland Security aims to model, simulate, and analyze critical infrastructure and their interdependencies across multiple sectors such as electric power, telecommunications, water distribution, transportation, etc. We introduce ActivitySim, an activity simulator for a population of millions of individual agents each characterized by a set of demographic attributes that is based on US census data. ActivitySim generates daily schedules for each agent that consists of a sequence of activities, such as sleeping, shopping, working etc., each being scheduled at a geographic location, such as businesses or private residences that is appropriate for the activity type and for the personal situation of the agent. ActivitySim has been developed as part of a larger effort to understand the interdependencies among national infrastructure networks and their demand profiles that emerge from the different activities of individuals in baseline scenarios as well as emergency scenarios, such as hurricane evacuations. We present the scalable software engineering principles underlying ActivitySim, the socia-technical modeling paradigms that drive the activity generation, and proof-of-principle results for a scenario in the Twin Cities, MN area of 2.6 M agents.

Leisure-time physical activity in relation to occupational physical activity among women.

Science.gov (United States)

Ekenga, Christine C; Parks, Christine G; Wilson, Lauren E; Sandler, Dale P

2015-05-01

The objective of this study is to examine the association between occupational physical activity and leisure-time physical activity among US women in the Sister Study. We conducted a cross-sectional study of 26,334 women who had been employed in their current job for at least 1 year at baseline (2004-2009). Occupational physical activity was self-reported and leisure-time physical activity was estimated in metabolic equivalent hours per week. Log multinomial regression was used to evaluate associations between occupational (sitting, standing, manually active) and leisure-time (insufficient, moderate, high) activity. Models were adjusted for age, race/ethnicity, education, income, geographic region, and body mass index. Only 54% of women met or exceeded minimum recommended levels of leisure-time physical activity (moderate 32% and high 22%). Women who reported sitting (prevalence ratio (PR)=0.82, 95% confidence interval (CI): 0.74-0.92) or standing (PR=0.84, 95% CI: 0.75-0.94) most of the time at work were less likely to meet the requirements for high leisure-time physical activity than manually active workers. Associations were strongest among women living in the Northeast and the South. In this nationwide study, low occupational activity was associated with lower leisure-time physical activity. Women who are not active in the workplace may benefit from strategies to promote leisure-time physical activity. Published by Elsevier Inc.

Crowding of white shrimp Litopenaeus vananmei depresses their immunity to and resistance against Vibrio alginolyticus and white spot syndrome virus.

Science.gov (United States)

Lin, Yong-Chin; Chen, Jiann-Chu; Chen, Yu-Yuan; Yeh, Su-Tuen; Chen, Li-Li; Huang, Chien-Lun; Hsieh, Jen-Fang; Li, Chang-Che

2015-07-01

Immunity parameters and the expression levels of several immune-related proteins, including lipopolysaccharide and β-glucan binding protein (LGBP), peroxinectin (PX), intergin β (IB), prophenoloxidase (proPO) I, proPO II, α2-macroglobulin (α2-M), cytosolic mangangese superoxide dismutase (cytMnSOD), mitochondria manganese superoxide dismutase (mtMnSOD), catalase, glutathione peroxidase (GPx), lysozyme, and penaeidin 3a were examined in white shrimp Litopenaeus vannamei reared at stocking densities of 2, 10, 20, 30, and 40 shrimp L(-1) after 3, 6, and 12 h. All immune parameters including haemocyte count, phenoloxidase (PO) activity, respiratory burst (RB), superoxide dismutase (SOD) activity, lysozyme activity, and haemolymph protein were negatively related to density and time. The PO activity, SOD activity, and lysozyme activity of shrimp reared at 10 shrimp L(-1) after 12 h significantly decreased. The transcript levels of these immune-related proteins were down-regulated in shrimp reared at 20, 30, and 40 shrimp L(-1) after 12 h. Phagocytic activity and clearance efficiency to Vibrio alginolyticus were significantly lower in shrimp reared at 30 and 40 shrimp L(-1) after 12 h. The mortality rates of shrimp reared at 20 and 40 shrimp L(-1) were significantly higher than shrimp reared at 2 shrimp L(-1) over 12-144 h and 12-48 h, respectively. Shrimp reared at high densities (>10 shrimp L(-1)) exhibited decreased resistance against pathogens as evidenced by reductions in immune parameters together with decreased expression levels of immune-related proteins, indicating perturbations of the immune system. Copyright © 2015 Elsevier Ltd. All rights reserved.

Physical Activity Basics

Science.gov (United States)

... Weight Breastfeeding Micronutrient Malnutrition State and Local Programs Physical Activity Basics Recommend on Facebook Tweet Share Compartir How much physical activity do you need? Regular physical activity helps improve ...

Simultaneous fluorescent gram staining and activity assessment of activated sludge bacteria.

Science.gov (United States)

Forster, Scott; Snape, Jason R; Lappin-Scott, Hilary M; Porter, Jonathan

2002-10-01

Wastewater treatment is one of the most important commercial biotechnological processes, and yet the component bacterial populations and their associated metabolic activities are poorly understood. The novel fluorescent dye hexidium iodide allows assessment of Gram status by differential absorption through bacterial cell walls. Differentiation between gram-positive and gram-negative wastewater bacteria was achieved after flow cytometric analysis. This study shows that the relative proportions of gram-positive and gram-negative bacterial cells identified by traditional microscopy and hexidium iodide staining were not significantly different. Dual staining of cells for Gram status and activity proved effective in analyzing mixtures of cultured bacteria and wastewater populations. Levels of highly active organisms at two wastewater treatment plants, both gram positive and gram negative, ranged from 1.5% in activated sludge flocs to 16% in the activated sludge fluid. Gram-positive organisms comprised Gram status and activity within activated sludge samples over a 4-day period showed significant differences over time. This method provides a rapid, quantitative measure of Gram status linked with in situ activity within wastewater systems.

Protease activated receptors (PARS) mediation in gyroxin biological activity

International Nuclear Information System (INIS)

Silva, Jose Alberto Alves da

2009-01-01

Gyroxin is a serine protease enzyme from the South American rattlesnake (Crotalus durissus terrificus) venom; it is only partially characterized and has multiple activities. Gyroxin induces blood coagulation, blood pressure decrease and a neurotoxic behavior named barrel rotation. The mechanisms involved in this neurotoxic activity are not known. Whereas gyroxin is a member of enzymes with high potential to become a new drug with clinical applications such as thrombin, batroxobin, ancrod, tripsyn and kalicrein, it is important to find out how gyroxin works. The analysis on agarose gel electrophoresis and circular dichroism confirmed the molecules' integrity and purity. The gyroxin intravenous administration in mice proved its neurotoxicity (barrel rotation). In vivo studies employing intravital microscopy proved that gyroxin induces vasodilation with the participation of protease activated receptors (PARs), nitric oxide and Na+K+ATPase. The leukocytes' adherence and rolling counting indicated that gyroxin has no pro inflammatory activity. Gyroxin induced platelet aggregation, which was blocked by inhibitors of PAR1 and PAR4 receptors (SCH 79797 and tcY-NH 2 , respectively). Finally, it was proved that the gyroxin temporarily alter the permeability of the blood brain barrier (BBB). Our study has shown that both the protease-activated receptors and nitric oxide are mediators involved in the biological activities of gyroxin. (author)

Activated carbon from peach stones using phosphoric acid activation at medium temperatures.

Science.gov (United States)

Kim, Dong-Su

2004-01-01

In the present study, the activation features of phosphoric acid have been investigated using waste peach stones as the raw material in the production of granular activated carbon. Thermogravimetry/differential thermal analysis was conducted to characterize the thermal behavior of peach stone and titration method was used to evaluate the adsorption capacity of the produced activated carbon. It was observed that the iodine value of the activated carbon increased with activation temperature. However, temperatures higher than 500 degrees C caused a thermal destruction, which resulted in the decrease of the adsorption capacity. Activation longer than 1.5 h at 500 degrees C resulted in thermal degradation of the porous structure of the activated carbon. The adsorption capacity was enhanced with increasing of amounts of phosphoric acid, however, excessive phosphoric acid caused a decrease in the iodine value. In addition, it was found that the carbon yields generally decreased with activation temperature and activation time. Scanning electron microscopy analysis was conducted to observe the changes in the poros structure of the activated carbon produced in different temperatures. Activation of carbon by phosphoric acid was found to be superior to that by CaCl2 and gas activation. The activated carbon produced from peach stone was applied as an adsorbent in the treatment of synthesized wastewater containing cadmium ion and its adsorption capacity was found to be as good as that of the commercial one.

Active8! Technology-Based Intervention to Promote Physical Activity in Hospital Employees.

Science.gov (United States)

Blake, Holly; Suggs, L Suzanne; Coman, Emil; Aguirre, Lucia; Batt, Mark E

2017-03-01

Increase physical activity in health care employees using health messaging, and compare e-mail with mobile phone short-message service (SMS) as delivery channels. Randomized controlled trial Setting. U.K. hospital workplace. Two hundred ninety-six employees (19-67 years, 53% of study Web site visitors). Twelve-week messaging intervention designed to increase physical activity and delivered via SMS (n =147) or e-mail (n =149); content tailored using theory of planned behavior (TPB) and limited to 160 characters. Baseline and 6, 12, and 16 weeks. Online measures included TPB constructs, physical activity behavior on the Global Physical Activity Questionnaire, and health-related quality of life on the Short-Form 12. General linear models for repeated measures. Increase in duration (mean h/d) of moderate work-related activity and moderate recreational activity from baseline to 16 weeks. Short-lived increase in frequency (d/wk) of vigorous recreational activity from baseline to 6 weeks. Increase in duration and frequency of active travel from baseline to 16 weeks. E-mails generated greater changes than SMS in active travel and moderate activity (work and recreational). Minimal physical activity promotion delivered by SMS or e-mail can increase frequency and duration of active travel and duration of moderate intensity physical activity at work and for leisure, which is maintained up to 1 month after messaging ends. Both channels were useful platforms for health communication; e-mails were particularly beneficial with hospital employees.

CBP Active Dumping and Active Countervailing (AD/CVD) Cases

Data.gov (United States)

Department of Homeland Security — The datasets provide information from CBP's reference files on active anti-dumping and active countervailing cases. This data includes associated case numbers (if...

Multiple active forms of thrombin. IV. Relative activities of meizothrombins

Energy Technology Data Exchange (ETDEWEB)

Doyle, M.F.; Mann, K.G. (Univ. of Vermont College of Medicine, Burlington (USA))

1990-06-25

The prothrombin activation intermediates meizothrombin and meizothrombin(desF1) (meizothrombin that has been autoproteolyzed to remove fragment 1) have been obtained in a relatively pure, active form with minimal autolysis, making them suitable for enzymatic characterization. When compared at equimolar concentrations, alpha-thrombin, fragment 1.2+ alpha-thrombin, meizothrombin(desF1), and meizothrombin have approximately 100, 100, 10, and 1% activity, respectively, toward the macromolecular substrates factor V, fibrinogen, and platelets. The difference in activity of these four enzymes cannot be attributed to alterations in the catalytic triad, as all four enzymes have nearly identical catalytic efficiency toward the chromogenic substrate S2238. Further, the ability of meizothrombin and meizothrombin(desF1) to activate protein C was 75% of the activity exhibited by alpha-thrombin or fragment 1.2+ alpha-thrombin. All four enzymes bind to thrombomodulin, as judged by the enhanced rate of protein C activation upon preincubation of the enzymes with thrombomodulin. The extent of rate enhancement varied, with meizothrombin/thrombomodulin exhibiting only 50% of the alpha-thrombin/thrombomodulin rate. This difference in rate is not due to a decreased affinity of the meizothrombin for thrombomodulin since the apparent dissociation constants for the alpha-thrombin-thrombomodulin complex and the meizothrombin-thrombomodulin complex are virtually identical. The difference in the observed rate is due in part to the higher Km for protein C exhibited by the meizothrombin-thrombomodulin complex. Incubation of the thrombomodulin-enzyme complex with phospholipid vesicles caused an increase in the protein C activation rates. The kinetic constants for protein C activation in the presence of phospholipid are virtually identical for these enzyme-thrombomodulin complexes.

Multiple active forms of thrombin. IV. Relative activities of meizothrombins

International Nuclear Information System (INIS)

Doyle, M.F.; Mann, K.G.

1990-01-01

The prothrombin activation intermediates meizothrombin and meizothrombin(desF1) (meizothrombin that has been autoproteolyzed to remove fragment 1) have been obtained in a relatively pure, active form with minimal autolysis, making them suitable for enzymatic characterization. When compared at equimolar concentrations, alpha-thrombin, fragment 1.2+ alpha-thrombin, meizothrombin(desF1), and meizothrombin have approximately 100, 100, 10, and 1% activity, respectively, toward the macromolecular substrates factor V, fibrinogen, and platelets. The difference in activity of these four enzymes cannot be attributed to alterations in the catalytic triad, as all four enzymes have nearly identical catalytic efficiency toward the chromogenic substrate S2238. Further, the ability of meizothrombin and meizothrombin(desF1) to activate protein C was 75% of the activity exhibited by alpha-thrombin or fragment 1.2+ alpha-thrombin. All four enzymes bind to thrombomodulin, as judged by the enhanced rate of protein C activation upon preincubation of the enzymes with thrombomodulin. The extent of rate enhancement varied, with meizothrombin/thrombomodulin exhibiting only 50% of the alpha-thrombin/thrombomodulin rate. This difference in rate is not due to a decreased affinity of the meizothrombin for thrombomodulin since the apparent dissociation constants for the alpha-thrombin-thrombomodulin complex and the meizothrombin-thrombomodulin complex are virtually identical. The difference in the observed rate is due in part to the higher Km for protein C exhibited by the meizothrombin-thrombomodulin complex. Incubation of the thrombomodulin-enzyme complex with phospholipid vesicles caused an increase in the protein C activation rates. The kinetic constants for protein C activation in the presence of phospholipid are virtually identical for these enzyme-thrombomodulin complexes

Don't worry, be active: positive affect and habitual physical activity.

Science.gov (United States)

Pasco, Julie A; Jacka, Felice N; Williams, Lana J; Brennan, Sharon L; Leslie, Eva; Berk, Michael

2011-12-01

The aim of ths study was to examine the association between habitual physical activity and positive and negative affect. This cross-sectional study included 276 women aged 20 +, from the Geelong Osteoporosis Study. Habitual physical activity and other lifestyle exposures were assessed by questionnaire, concurrent with anthropometric assessments. Physical activity was categorized as very active, moderately active or sedentary. Positive and negative affect scores were derived from the validated 20 item Positive and Negative Affect Schedule (PANAS) self-report and were categorized into tertiles. There was a pattern of lower positive affect scores for lower levels of physical activity. With very active as the reference category, the odds for having a positive affect score in the highest tertile were sequentially lower for those who were moderately active (OR = 0.53, 95%CI 0.28-1.01) and sedentary (OR = 0.28, 95%CI 0.10-0.75). Associations were sustained after adjusting for body mass index and polypharmacy (OR = 0.50, 95%CI 0.26-0.96 and OR = 0.25, 95%CI 0.09-0.72, respectively). These associations were not explained by age, negative affect score or other exposures. No association was detected between physical activity and negative affect scores. This study reports that higher positive affect scores, encompassing emotions such as interest, excitement, enthusiasm and alertness, are associated with higher levels of habitual physical activity. These observations warrant further investigations into possible mechanistic interplay between neurobiological and psychosocial factors that underpin this association.

[Enthalpy stabilization of chicken egg lysozyme in aqueous dimethylsulfoxide solutions].

Science.gov (United States)

Kovrigin, E L; Kirkitadze, M D; Potekhin, S A

1996-01-01

Scanning microcalorimetry data have been used to plot the dependences of the denaturation enthalpy of hen egg lysozyme on dimethylsulfoxide concentration at fixed temperatures. It has been shown that at dimethylsulfoxide concentrations below 40% (v/v) the enthalpy does not depend on pH of the medium. An increase of dimethylsulfoxide concentrations in this range leads to a linear growth of enthalpy. The rate of enthalpy growth decreases with the temperature increase. The denaturation enthalpy begins to considerably depend on pH at dimethylsulfoxide concentrations more than 40%. Spectroscopy data indicate that conformational changes occur in the protein in this range of concentrations already at room temperature, whereas according to scanning microcalorimetry, they take place at much higher temperatures. This difference is probably due to a decrease of the real temperature of protein melting below room temperature and a very inhibited character of the denaturational transition. This results in a decrease of calorimetric enthalpy at acidic pH owing to incomplete protein renaturation upon calorimeter cooling to the starting point.

Physical Activity During School

DEFF Research Database (Denmark)

Østergaard, Lars Domino

It is important, not only on health grounds, to exercise and to be physically active. In school, physical activities have shown to improve the students’ academic behaviour resulting in improved attention and information processing as well as enhanced coping. To stimulate and motivate students...... to be even more active during school hours further enhancing their academic behaviour, it is important to know when, why and how they are active, and their attitude towards different types of physical activities. Therefore, the aim of this study was to categorize the physical activities attended by students...... during school hours and to elucidate their attitude towards the different types of activities. The data consisted of observations of lessons followed by group interviews. Analyses of the observations revealed six categories of physical activities, varying from mandatory physical activities, activities...

Effective interactions in lysozyme aqueous solutions: a small-angle neutron scattering and computer simulation study.

Science.gov (United States)

Abramo, M C; Caccamo, C; Costa, D; Pellicane, G; Ruberto, R; Wanderlingh, U

2012-01-21

We report protein-protein structure factors of aqueous lysozyme solutions at different pH and ionic strengths, as determined by small-angle neutron scattering experiments. The observed upturn of the structure factor at small wavevectors, as the pH increases, marks a crossover between two different regimes, one dominated by repulsive forces, and another one where attractive interactions become prominent, with the ensuing development of enhanced density fluctuations. In order to rationalize such experimental outcome from a microscopic viewpoint, we have carried out extensive simulations of different coarse-grained models. We have first studied a model in which macromolecules are described as soft spheres interacting through an attractive r(-6) potential, plus embedded pH-dependent discrete charges; we show that the uprise undergone by the structure factor is qualitatively predicted. We have then studied a Derjaguin-Landau-Verwey-Overbeek (DLVO) model, in which only central interactions are advocated; we demonstrate that this model leads to a protein-rich/protein-poor coexistence curve that agrees quite well with the experimental counterpart; experimental correlations are instead reproduced only at low pH and ionic strengths. We have finally investigated a third, "mixed" model in which the central attractive term of the DLVO potential is imported within the distributed-charge approach; it turns out that the different balance of interactions, with a much shorter-range attractive contribution, leads in this latter case to an improved agreement with the experimental crossover. We discuss the relationship between experimental correlations, phase coexistence, and features of effective interactions, as well as possible paths toward a quantitative prediction of structural properties of real lysozyme solutions. © 2012 American Institute of Physics

Activation and micropore structure determination of activated carbon-fiber composites

Energy Technology Data Exchange (ETDEWEB)

Jagtoyen, M.; Derbyshire, F.; Kimber, G. [Univ. of Kentucky, Lexington, KY (United States). Center for Applied Energy Research

1997-09-05

Rigid, high surface area activated carbon fiber composites have been produced with high permeabilities for environmental applications in gas and water purification. These novel monolithic adsorbents can be produced in single pieces to a given size and shape. The project involves a collaboration between the Oak Ridge National Laboratory (ORNL) and the Center for Applied Energy Research (CAER), University of Kentucky. The carbon fiber composites are produced at the ORNL and activated at the CAER using different methods, with the aims of producing a uniform degree of activation, and of closely controlling pore structure and adsorptive properties. The main focus of the present work has been to find a satisfactory means to uniformly activate large samples of carbon fiber composites and produce controlled pore structures. Several environmental applications have been explored for the activated carbon fiber composites. One of these was to evaluate the activated composites for the separation of CH{sub 4}-CO{sub 2} mixtures, and an apparatus was constructed specifically for this purpose. The composites were further evaluated in the cyclic recovery of volatile organics. The activated carbon fiber composites have also been tested for possible water treatment applications by studying the adsorption of sodium pentachlorophenolate, PCP.

Physical Activity Assessment

Science.gov (United States)

Current evidence convincingly indicates that physical activity reduces the risk of colon and breast cancer. Physical activity may also reduce risk of prostate cancer. Scientists are also evaluating potential relationships between physical activity and other cancers.