MOLECULAR-CLONING OF THE CDNA FOR RAT HEPATIC, BILE SALT-DEPENDENT CHOLESTERYL ESTER RETINYL ESTER HYDROLASE DEMONSTRATES IDENTITY WITH PANCREATIC CARBOXYLESTER LIPASE

Rat liver homogenates contain a neutral lipid eater hydrolase that req uires millimolar concentrations of bile salts for maximal activity in catalyzing the hydrolysis of cholesteryl esters and retinyl esters in vitro. Previous studies have demonstrated that this hepatic hydrolase resembles rat pancreatic carboxylester lipase because it reacts with a specific pancreatic carboxylester lipase antibody and the eight N-ter minal amino acids of the hepatic protein are identical to those of the pancreatic enzyme, Nonetheless, the exact molecular relationship betw een the hepatic and pancreatic enzymes is unclear. In the present stud y, a rat hepatic cDNA encoding the enzyme was cloned, Sequence analysi s demonstrated that this cDNA corresponds to the full-length mature pa ncreatic carboxylester lipase (EC not equal 3.1.1.13), In individual a nimals the hepatic and pancreatic cDNA sequences were identical, Howev er, among rats there were sequence variations, suggesting a polymorphi c nature for this rat gene.