Site-specific epsilon-NH2 monoacylation of pancreatic phospholipase A2. 1. Preparation and properties.
The lipid-binding domain of pancreatic phospholipases A2 contains a number of exposed, hydrophobic amino acid side chains that are involved in the binding of the enzyme to organized lipid-water interfaces. Besides these apolar residues, at least two positively charged lysine groups are present in positions 10 and 116 of the lipid-binding domain. In order to investigate the possible function of these basic side chains in the lipid-binding process, a number of specifically acylated enzyme mutants were prepared, and their kinetic and lipid-binding properties have been compared with those of the native enzymes. It is concluded that the attachment of a long-chain acyl group in an amide linkage to Lys10 or Lys116 phospholipase A2 has only a minor influence on the catalytic properties of the enzyme. On the other hand, the lipid-binding properties of the mutant enzymes appear to be considerably reinforced.
D000215:Acylation; D000818:Animals; D002417:Cattle; D007202:Indicators and Reagents; D008239:Lysine; D010179:Pancreas / Q000201:enzymology*; D010740:Phospholipases / Q000378:metabolism*; D010741:Phospholipases A / Q000378:metabolism*; D054467:Phospholipases A2; D011485:Protein Binding; D013552:Swine
D007202:Indicators and Reagents; D010740:Phospholipases; D010741:Phospholipases A; D054467:Phospholipases A2; D008239:Lysine