THE REGULATION OF FATTY-ACID CHAIN ELONGATION IN RAT-LIVER MICROSOMES - ROLE OF FASTING AND COASH

被引：3

作者：

REICHELT, WH ^{[1
]}

GRAV, HJ ^{[1
]}

CHRISTIANSEN, EN ^{[1
]}

机构：

[1] UNIV OSLO,INST NUTR RES,N-0316 OSLO 3,NORWAY

来源：

BIOCHIMICA ET BIOPHYSICA ACTA-LIPIDS AND LIPID METABOLISM | 1994年 / 1214卷 / 02期

关键词：

FATTY ACID ELONGATION; COASH; FASTING; MICROSOME; ENZYME KINETICS; (RAT); (LIVER);

D O I：

10.1016/0005-2760(94)90033-7

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

The elongation system for palmitic acid in rat liver microsomes was decreased to 1/3 by fasting, while the elongation of eicosapentaenoic acid was not sensitive to fasting. The rate of eicosapentaenoic acid elongation in the fed state was 50% higher than using palmitic acid as a substrate. The saturated and polyunsaturated fatty acyl-CoA substrates exhibited positive cooperativity on the rate-limiting condensing step in the elongation system, with a Hill constant of approx. 2. An inhibition by CoASH on the total elongation reaction as well as on the condensation step was demonstrated using acyl-CoA substrates, and followed a hyperbolic pattern. The concentrations giving a 50% inhibition (30-70 mu M) were in the range found in rat hepatocyte cytosol, indicating that free CoASH has the potential to act as a physiological regulator.

引用

页码：109 / 114

页数：6

共 21 条

[1]

ASHBROOK JD, 1975, J BIOL CHEM, V250, P2333

[2] PURIFICATION AND CHARACTERIZATION OF A LONG-CHAIN ACYL-COA HYDROLASE FROM RAT-LIVER MICROSOMES [J].