Acyl glycerol hydrolases: inhibitors, interface and catalysis

Area of Science:

• Enzymology
• Structural Biology
• Biochemistry

Background:

• Significant advancements in determining lipase structures over the past five years.
• Structural insights have illuminated the phenomenon of interfacial activation, often explained by 'lid' opening.
• This structural interpretation has recently been extended to phospholipase A2.

Purpose of the Study:

• To detail the mechanisms of lipase behavior, including substrate and inhibitor binding.
• To investigate interactions between the hydrophobic face of lipases and hydrophobic molecules.
• To elucidate the role of the oxyanion hole in lipolytic catalysis using cutinase point mutants.

Main Methods:

• X-ray crystallography and other structural biology techniques to determine lipase and phospholipase A2 structures.
• Analysis of substrate and inhibitor binding modes through structural comparisons.
• Site-directed mutagenesis of cutinase to study the function of specific residues, such as in the oxyanion hole.

Main Results:

• Structural basis for interfacial activation via 'lid' opening elucidated for lipases and extended to phospholipase A2.
• Detailed understanding of substrate/inhibitor binding and hydrophobic interactions of lipases.
• Mutagenesis studies provide insights into the catalytic role of the oxyanion hole in lipolytic enzymes.

Conclusions:

• Structural biology has provided a mechanistic understanding of lipase function and interfacial activation.
• These findings advance the comprehension of enzyme catalysis and interactions with hydrophobic environments.
• Further studies on enzyme mutants confirm the importance of specific catalytic residues like the oxyanion hole.