Biochemical Analysis of a Novel Lipolytic Enzyme YvdO from Bacillus subtilis 168

The predicted amino acid sequence of Bacillus subtilis yvdO exhibits similarity to that of the proteins belonging to the patatin family of lipolytic enzymes. In the present study, YvdO was overproduced in Escherichia coli and purified, and its enzymatic properties were determined. YvdO hydrolyzed p-nitrophenyl fatty acid esters. The enzyme was specific to middle-chain fatty acids, and its optimum pH was approximately 7.5. It maintained 86% of its initial activity after incubation for 30 min at 80 degrees C, and its secondary structure was retained at up to 80 degrees C. Free myristic acid was detected as the product of the reaction with YvdO and 1-myristoly-2-lyso-sn-glycero-3-phosphocholine, while YvdO did not hydrolyze 1,2-dimyristoly-sn-glycero-3-phosphocholine. These results suggest that YvdO is a novel thermostable lipolytic enzyme that has the ability to hydrolyze lysophospholipids.