Serine hydrolase

The serine hydrolase superfamily is one of the largest known enzyme families comprising approximately 1% of the genes in the human genome. This family includes:


 * serine proteases like trypsin
 * lipases like pancreatic lipase, hormone sensitive lipase, and triacylglycerol lipase
 * esterases
 * acetylcholinesterase
 * thioesterases
 * certain phospholipases like phospholipase A2
 * some amidases like fatty acid amide hydrolase

all of these enzymes share a catalytic mechanism that involves a catalytic triad consisting of a serine nucleophile that is activated by a proton relay involving an acidic residue (e.g. aspartate or glutamate) and a basic residue (usually histidine) although variations on this mechanism exist.