Inhibition of human gastric and pancreatic lipases by chiral alkylphosphonates. A kinetic study with 1,2-didecanoyl-sn-glycerol monolayer.
Enantiomerically pure alkylphosphonate compounds RR'P(O)PNP (R = CnH2n + 1, R' = OY with Y = Cn'H2n' + 1 with n = n' or n not equal to n'; PNP = p-nitrophenoxy) noted (RY), mimicking the transition state occurring during the carboxyester hydrolysis were synthesized and investigated as potential inhibitors of human gastric lipase (HGL) and human pancreatic lipase (HPL). The inhibitory properties of each enantiomer have been tested with the monomolecular films technique in addition to an enyzme linked immunosorbent assay (ELISA) in order to estimate simultaneously the residual enzymatic activity as well as the interfacial lipase binding. With both lipases, no obvious correlation between the inhibitor molar fraction (alpha 50) leading to half inhibition, and the chain length, R or Y was observed. (R11Y16)s were the best inhibitor of HPL and (R10Y11)s were the best inhibitors of HGL. We observed a highly enantioselective discrimination, both with the pure enantiomeric alkylphosphonate inhibitors as well as a scalemic mixture. We also showed, for the first time, that this enantioselective recognition can occur either during the catalytic step or during the initial interfacial adsorption step of the lipases. These experimental results were analyzed with two kinetic models of covalent as well as pseudo-competitive inhibition of lipolytic enzymes by two enantiomeric inhibitors.
Cavalier
J F
JF
ENSSPICAM, UMR 6516, Synthèse, Catalyse et Chiralité, Marseille, France.
Ransac
S
S
Verger
R
R
Buono
G
G
D002851:Chromatography, High Pressure Liquid; D004075:Diglycerides; D004791:Enzyme Inhibitors / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D006801:Humans; D066298:In Vitro Techniques; D007700:Kinetics; D008049:Lipase / Q000037:antagonists & inhibitors*; D009682:Magnetic Resonance Spectroscopy; D063065:Organophosphonates / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D010179:Pancreas / Q000201:enzymology; D013237:Stereoisomerism; D013270:Stomach / Q000201:enzymology; D013329:Structure-Activity Relationship
D004075:Diglycerides; D004791:Enzyme Inhibitors; D063065:Organophosphonates; C044297:1,2-didecanoylglycerol; D008049:Lipase