In vitro stereoselective hydrolysis of diacylglycerols by hormone-sensitive lipase.
Hormone-sensitive lipase (HSL) contributes importantly to the mobilization of fatty acids in adipocytes and shows a substrate preference for the diacylglycerols (DAGs) originating from triacylglycerols. To determine whether HSL shows any stereopreference during the hydrolysis of diacylglycerols, racemic 1,2(2,3)-sn-diolein was used as a substrate and the enantiomeric excess (ee%) of residual 1,2-sn-diolein over 2,3-sn-diolein was measured as a function of DAG hydrolysis. Enantiomeric DAGs were separated by performing chiral-stationary-phase HPLC after direct derivatization from lipolysis product extracts. The fact that the ee% of 1,2-sn-diolein over 2,3-sn-diolein increased with the level of hydrolysis indicated that HSL has a preference for 2,3-sn-diolein as a substrate and therefore a stereopreference for the sn-3 position of dioleoylglycerol. The ee% of 1,2-sn-diolein reached a maximum value of 36% at 42% hydrolysis. Among the various mammalian lipases tested so far, HSL is the only lipolytic carboxylester hydrolase found to have a pronounced stereospecificity for the sn-3 position of dioleoylglycerol.
CNRS-Université d'Aix-Marseille-Enzymologie Interfaciale et Physiologie de la Lipolyse-UPR 9025, 31, Chemin Joseph Aiguier, 13402 Marseille Cedex 20, France.
Jorge A
JA
Rodriguez
Yassine
Y
Ben Ali
Slim
S
Abdelkafi
Lilia D
LD
Mendoza
Julien
J
Leclaire
Frédéric
F
Fotiadu
Gerard
G
Buono
Frédéric
F
Carrière
Abdelkarim
A
Abousalham
D004075:Diglycerides / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D006868:Hydrolysis; D007700:Kinetics; D008066:Lipolysis; D013237:Stereoisomerism; D002787:Sterol Esterase / Q000737:chemistry / Q000378:metabolism*; D013379:Substrate Specificity
D004075:Diglycerides; D002787:Sterol Esterase; C013965:diolein