Studies on a phospholipase B from Penicillium notatum. Substrate specificity.
1. The action of a highly purified phospholipase B from Penicillium notatum on 1-O-alk-1'-enyl-2-acyl-, 1-O-alkyl-2-acyl-, 1,2-diacyl-, 1-acyl- and 2-acyl-sn-glycero-3-phosphocholine, monoacyl-, diacyl- and triacylglycerols, cholesteryl oleate and p-nitrophenyl acetate was studied. 2. The hydrolysis products of the monoethermonoacylglycerophospholipids were identified as fatty acids, 1-O-alk-1'-enyl-sn-glycero-3-phosphocholine and 1-O-alkyl-sn-glycero-3-phosphocholine. The hydrolysis rates were in the following order: 1,2-diacyl-sn-glycero-3-phosphocholine greater than 1-O-alk-1'-enyl-2-acyl-sn-glycero-3-phosphocholine greater than 1-O-alkyl-2-acyl-sn-glycero-3-phosphocholine. 3. 1-Acyl-sn-glycero-3-phosphocholine was hydrolyzed about 15 times faster than 2-acyl-sn-glycero-3-phosphocholine. 4. Monoacylglycerols were hydrolyzed at the optimal pH 4.0, but diacyl- and triacylglycerols were not hydrolyzed at various pH values between 4.0 and 9.0. 5. Cholesteryl oleate and p-nitrophenyl acetate were not hydrolyzed.
D000085:Acetates; D002788:Cholesterol Esters / Q000378:metabolism; D005989:Glycerides / Q000378:metabolism; D005994:Glycerophosphates / Q000378:metabolism; D007525:Isoelectric Focusing; D009596:Nitrophenols / Q000378:metabolism; D010407:Penicillium / Q000201:enzymology; D010713:Phosphatidylcholines / Q000378:metabolism; D010740:Phospholipases / Q000378:metabolism*; D011092:Polyethylene Glycols / Q000494:pharmacology; D013379:Substrate Specificity
D000085:Acetates; D002788:Cholesterol Esters; D005989:Glycerides; D005994:Glycerophosphates; D009596:Nitrophenols; D010713:Phosphatidylcholines; D011092:Polyethylene Glycols; C008642:4-nitrophenyl acetate; D010740:Phospholipases