Identity of purified monoacylglycerol lipase, palmitoyl-CoA hydrolase and aspirin-metabolizing carboxylesterase from rat liver microsomal fractions. A comparative study with enzymes purified in different laboratories.
Two purified carboxylesterases that were isolated from a rat liver microsomal fraction in a Norwegian and a German laboratory were compared. The Norwegian enzyme preparation was classified as palmitoyl-CoA hydrolase (EC 3.1.2.2) in many earlier papers, whereas the German preparation was termed monoacylglycerol lipase (EC 3.1.1.23) or esterase pI 6.2/6.4 (non-specific carboxylesterase, EC 3.1.1.1). Antisera against the two purified enzyme preparations were cross-reactive. The two proteins co-migrate in sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. Both enzymes exhibit identical inhibition characteristics with Mg2+, Ca2+ and bis-(4-nitrophenyl) phosphate if assayed with the two substrates palmitoyl-CoA and phenyl butyrate. It is concluded that the two esterase preparations are identical. However, immunoprecipitation and inhibition experiments confirm that this microsomal lipase differs from the palmitoyl-CoA hydrolases of rat liver cytosol and mitochondria.
Mentlein
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R
Berge
R K
RK
Heymann
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E
D000818:Animals; D002265:Carboxylic Ester Hydrolases / Q000037:antagonists & inhibitors / Q000276:immunology / Q000302:isolation & purification*; D008297:Male; D008862:Microsomes, Liver / Q000201:enzymology*; D008994:Monoacylglycerol Lipases / Q000302:isolation & purification*; D010170:Palmitoyl-CoA Hydrolase / Q000037:antagonists & inhibitors / Q000276:immunology / Q000302:isolation & purification*; D051381:Rats; D011919:Rats, Inbred Strains; D013379:Substrate Specificity; D013869:Thiolester Hydrolases / Q000302:isolation & purification*
D002265:Carboxylic Ester Hydrolases; C018737:acetylsalicylic acid hydrolase; D008994:Monoacylglycerol Lipases; D013869:Thiolester Hydrolases; D010170:Palmitoyl-CoA Hydrolase