The lipase activity of a partially purified lipolytic enzyme of Escherichia coli.

Escherichia coli lipase was found to have a broad pH optimum between pH 8 and 10. Long-chain acyl triacylglycerols such as trioleolglycerol were hydrolysed at a relatively slow rate, whereas, the shorter-chain acyl derivative tracapryloylglycerol was not. Triacylglycerols and diacylglycerols were broken down at a rate 10 to 15 fold greater than that for monoacylglycerol. Simple esters such as methyloleate and cetylpalmitate were hydrolysed at rates greater than that of triacyglycerol. Water-soluble esters such as p-nitrophenylacetate were not attacked. Hydrolysis of lipase substrate occurred more readily in the presence of an anionic detergent such as taurocholate. The enzyme had no marked preference for the 1- or 3-position of triacylglycerols but attacked these positions much more readily than position 2. The enzyme also catalyzed transacylation reaction with simple alcohols such as methanol or ethanol.