Purification and substrate specificity of Staphylococcus hyicus lipase

Area of Science:

• Microbiology
• Enzymology
• Biochemistry

Background:

• The lipase gene from Staphylococcus hyicus was successfully cloned and expressed in Staphylococcus carnosus.
• The expressed enzyme was secreted as an 86 kDa protein, confirmed to be cleaved at the signal peptide site.

Purpose of the Study:

• To characterize the cloned Staphylococcus hyicus lipase.
• To investigate its enzymatic activity, substrate specificity, and requirements for optimal function.

Main Methods:

• Gene cloning and expression in a heterologous host (Staphylococcus carnosus).
• Enzyme purification via proteolysis and chromatography.
• Enzymatic assays using various glycerides and phospholipids.
• Determination of molecular mass and substrate specificity.

Main Results:

• Limited tryptic digestion reduced molecular mass to 46 kDa and increased specific activity threefold.
• Enzyme activity was significantly enhanced (40-fold) by divalent cations like Sr2+ or Ca2+.
• The purified lipase demonstrated broad substrate specificity, hydrolyzing triglycerides, phosphatidylcholines, and lysophospholipids.

Conclusions:

• The Staphylococcus hyicus enzyme possesses potent lipase, phospholipase A, and lysophospholipase activities.
• Divalent cations are crucial for optimal enzyme function.
• The enzyme's broad substrate range suggests potential applications in various biotechnological processes.