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Kinetics of 2‐monoacylglycerol acyl migration in model chylomicra
Author(s) -
Lyubachevskaya Galina,
BoyleRoden Elizabeth
Publication year - 2000
Publication title -
lipids
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.601
H-Index - 120
eISSN - 1558-9307
pISSN - 0024-4201
DOI - 10.1007/s11745-000-0652-5
Subject(s) - monoacylglycerol lipase , isomerization , chemistry , hydrolysis , triglyceride , lipoprotein lipase , acyl group , metabolism , hexane , glycerol , medicinal chemistry , stereochemistry , chromatography , biochemistry , organic chemistry , enzyme , cholesterol , catalysis , alkyl , endocannabinoid system , receptor
In the metabolism of triacylglycerol (TG)‐rich lipoproteins, 2‐monoacylglycerols (2‐MG) are produced by lipoprotein lipase (LPL) hydrolysis of TG. The metabolic fate of 2‐MG is not known with certainty. 2‐MG that accumulate on the chylomicra surface have been proposed to isomerize spontaneously to 1(3)‐MG, which are then hydrolyzed by LPL to free fatty acids and glycerol. In this study the rate and the effect of acyl chain saturation on the spontaneous acyl migration of 2‐MG in in vitro model chylomicra emulsions were determined. After 1 h of incubation at 37°C, less than 20% of 2‐monoolein (2‐MO) or 2‐monopalmitin (2‐MP) spontaneously isomerized to 1(3)‐MO or 1(3)‐MP, respectively. Accordingly, it was concluded that spontaneous isomerization of 2‐MG is not the major mechanism for 2‐MG metabolism post‐TG hydrolysis in chylomicra. Isomerization rates, expressed as decrease in percentage of 2‐MG remaining per hour, were −5.12 and −5.86 in water, and −0.43 and −0.41 in hexane for 2‐MO and 2‐MP, respectively. There was no significant difference between the isomerization rates of 2‐MO and 2‐MP. Thus, in the present study, saturation of the MG acyl chain did not influence spontaneous acyl migration in either water or hexane, but isomerization of 2‐MG was faster in water than in hexane.