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A comparative study of two lipases from different strains of Staphylococcus aureus
J Rollof1, A Hedström, P Nilsson-Ehle
1Department of Infectious Diseases, University of Lund, Sweden.
Summary
Two Staphylococcus aureus lipases show significant differences in amino acid composition but share similar enzymatic and immunological properties, indicating they are closely related but not identical.
Area of Science:
- Biochemistry
- Microbiology
- Enzymology
Background:
- Lipases are crucial enzymes involved in various biological processes.
- Staphylococcus aureus produces lipases that contribute to its pathogenicity.
- Comparing lipases from different strains aids in understanding enzyme diversity and function.
Purpose of the Study:
- To compare lipases from two Staphylococcus aureus strains (FN 37 and TEN 5).
- To characterize their chemical, immunological, and enzymatic properties.
Main Methods:
- Purification using octyl-Sepharose chromatography.
- Characterization via SDS-PAGE, gel chromatography (Sephadex G-200), amino acid analysis, double immune diffusion, and enzymatic assays.
- Substrate specificity testing against glyceride substrates.
Main Results:
- Purified lipases revealed identical subunits (43 kD) and similar apparent molecular weights (110 kD).
- Significant differences in amino acid composition were observed (Serine predominant in FN 37, Glycine in TEN 5).
- Lipases exhibited similar immunological reactivity and enzymatic properties (salt inhibition, ion dependency, heat inactivation, substrate specificity).
Conclusions:
- Staphylococcus aureus lipases from strains FN 37 and TEN 5 are similar in enzymatic and immunological aspects.
- Despite structural similarities, notable differences in amino acid composition suggest distinct genetic origins or post-translational modifications.
- The findings highlight the subtle variations that can exist between enzymes from closely related bacterial strains.