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Identification and initial characterization of elastase activity associated with Vibrio cholerae
J M Janda1, S L Abbott, S Khashe
1Microbial Diseases Laboratory, Division of Communicable Disease Control, California Department of Health Services, 2151 Berkeley Way, Berkeley, CA 94704-1011, USA.
Current Microbiology
|July 10, 1999
Summary
Vibrio cholerae produces an elastase enzyme, primarily in its late growth phase. This metalloprotease is more abundant in broth cultures than in other Vibrio species and is inhibited by phosphoramidon.
Area of Science:
- Microbiology
- Enzymology
- Bacterial Pathogenesis
Background:
- Vibrio cholerae, a significant human pathogen, produces various virulence factors.
- Elastolytic proteases are enzymes that degrade elastin, a key component of connective tissue.
- Understanding Vibrio cholerae's enzymatic activities is crucial for comprehending its pathogenicity.
Purpose of the Study:
- To characterize the elastase produced by Vibrio cholerae O1 and non-O1 serogroups.
- To determine the optimal conditions for elastase activity and expression.
- To compare elastase production in V. cholerae with other Vibrio species.
Main Methods:
- Detection of elastolytic protease activity using 0.3% elastin agar plates and broth cultures.
- Quantification of elastase production in various V. cholerae strains.
- Enzyme inhibition assays using specific protease inhibitors.
- Determination of molecular weight via ultrafiltration and SDS-PAGE.
Main Results:
- Vibrio cholerae strains (O1 and non-O1) produce a detectable elastolytic protease.
- Maximal enzyme expression occurs in late log phase (14-18 h) with optimal activity at pH 7-8.
- V. cholerae produces significantly higher levels of elastase in broth (2-4x) compared to other Vibrio species like V. vulnificus.
- The enzyme is inhibited by phosphoramidon but not by trypsin, serine, or thiol-protease inhibitors.
- Ultrafiltration and SDS-PAGE suggest a molecular weight >30,000 for the V. cholerae elastase.
Conclusions:
- Vibrio cholerae elastase is likely an N-type metalloprotease.
- The enzyme shares characteristics with elastases from other Vibrio species.
- Elastase production is a common trait among V. cholerae strains, potentially contributing to virulence.