Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.17 (lysozyme)
 21,489 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Heats of dilution and of saccharide binding for hen egg white lysozyme have been measured at 30 degrees, 0.1 ionic strength, and pH 7 over the range 3 to 95 mg of protein/ml. The concentration dependence of the apparent relative molar enthalpy of lysozyme derived from these results gives the thermodynamic parameters for the formation of an intermolecular contact in an indefinite (head-to-tail) self-association process as delta G 0 = -3.9 kcal/mol, delta H 0 = -6.4 kcal/mol, and delta S 0 = -8,3 e.u. Oxindolealanine-62-lysozyme does not undergo self-association reactions that can be detected calorimetrically. This derivative reacts with native lysozyme to form hybrid polymeric species with free energy and enthalpy of interaction similar to those for the polymers of native lysozyme. These results are consistent with the intermolecular contact in the self-assocaition of lysozyme being asymmetric (head-to-tail). The heat of dilution of the derivative of lysozyme in which Glu-35 is blocked as the ester with oxindolealanine-108 is like that observed for native lysozyme in acid solution and is independent of pH. The concentration difference spectrum that develops through self-association is of the shape expected for introduction of an indole chromophore into a charge-free region of the intermolecular contact. The foregoing results indicate that Glu-35 and Trp-62 are part of the contact, that perturbation of Trp-108 does not make a principle contribution to the concentration difference spectrum, and that no acid group other than Glu-35 is perturbed by self-association. There is a small change in the heat of (GlcNAc)3 binding over the range 0.005 to 0.034 M saccharide. These data give the value of -1 kcal/mol for the enthalpy change for formation of the 2:1 saccharide-enzyme complex (ES2) from ES and S.
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PMID:Self-association of lysozyme. Thermochemical measurements: effect of chemical modification of Trp-62, Trp-108, and Glu-35. 24 Aug 55

Illness caused by the consumption of contaminated food products continues to represent one of the main challenges facing food manufacturers worldwide. Even with current intervention technologies and increased hygiene measures, foodborne illness remains a significant threat to public health. This coupled with the increasing emergence of multidrug resistant pathogens has increased the need for the development of novel technologies for pathogen control. Bacterial derived peptidoglycan hydrolases represent a vast and highly diverse group of enzymes with potential for biocontrol of a range of Gram-positive and Gram-negative foodborne pathogens. In this study, we describe the identification, cloning, expression and purification of a peptidoglycan hydrolase (LysCs4) derived from Cronobacter sakazakii for biocontrol of the aforementioned infant formula pathogen itself. In silico analysis of LysCs4 revealed the gene to display greatest sequence similarity to a putative lysozyme encoded by the lytic Cronobacter phage ES2. Conserved domain analysis of LysCs4 revealed the presence of a single catalytic domain predicted to display O-Glycosyl hydrolase activity and to be a member of the GH24 family. The ability of this enzyme to hydrolyse the peptidoglycan of 25 Gram-negative strains, across 4 different genera, highlights its potential as a novel candidate for biocontrol of C. sakazakii and other Gram-negative food related pathogens.
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PMID:Characterisation of the antibacterial properties of a bacterial derived peptidoglycan hydrolase (LysCs4), active against C. sakazakii and other Gram-negative food-related pathogens. 2634 6