Lipolytic acyl hydrolase (LAH), an activity which is thought to be involved in the response of tubers to pathogens. Can use p-nitrophenyl esters as substrates with highest activity on p-nitrophenyl caprate (C10). Also active on mono-acylglycolphosphocholines and diacylphospholipids, with highest specific activities observed were obtained with the synthetic phospholipids diC8PCho and diC9PCho. Mono-olein and myverol can also be hydrolyzed. Inhibited by methyl-p-nitrophenyl-octylphosphonate. At pH 8.0, the highest specific activity is observed with phospholipids such as diC8PCho and diC9PCho and with p-nitrophenyl esters such as p-nitrophenyl caprate. The nitrogen atoms of the two glycine residues in the GGXR motif define the oxyanion hole, and stabilize the oxyanion that forms during the nucleophilic attack by the catalytic serine during substrate cleavage. Patatin have a dual role as a somatic storage protein and as an enzyme involved in host resistance. This tuber protein represents approximately 40% of the total protein in mature tubers. Belongs to the patatin family.