Bacillus sphaericus penicillin V acylase: purification, substrate specificity, and active-site characterization

Area of Science:

• Biochemistry
• Enzymology
• Microbiology

Background:

• Penicillin V acylase is an important enzyme in the pharmaceutical industry.
• Understanding its properties and catalytic mechanisms is essential for enzyme engineering and application.

Purpose of the Study:

• To purify Penicillin V acylase from Bacillus sphaericus.
• To characterize its substrate specificity and identify key amino acid residues involved in catalysis.

Main Methods:

• Enzyme purification to homogeneity.
• Enzyme activity assays with various penicillin derivatives.
• Chemical modification of enzyme with lysine-specific reagents.
• Kinetic studies and titration experiments.

Main Results:

• Penicillin V acylase was purified with a 15% yield.
• The enzyme showed high specificity for penicillin V and penicillin G, with minimal hydrolysis of other related compounds.
• Unsubstituted side chains on substrate molecules enhanced hydrolysis rates.
• Lysine-modifying reagents rapidly inactivated the enzyme.
• Kinetics and titration data implicated lysine in the enzyme's catalytic function.

Conclusions:

• Bacillus sphaericus produces a highly specific Penicillin V acylase.
• Lysine residues play a critical role in the catalytic activity of this enzyme.
• These findings contribute to the understanding of penicillin acylase mechanisms and potential applications.