Phospholipase A1 is a phospholipase enzyme which removes the 1-acyl. Phospholipase A1 is an enzyme that resides in a class of enzymes called phospholipase that hydrolyze phospholipids into fatty acids. There are 4 classes, which are separated by the type of reaction they catalyze. In particular, phospholipase A1 (PLA1) specifically catalyzes the cleavage at the SN-1 position of phospholipids, forming a fatty acid and a lysophospholipid.