Acyl-CoA: glycine N-acyltransferase: in vitro studies on the glycine conjugation of straight- and branched-chained acyl-CoA esters in human liver |
| |
Authors: | N Gregersen S K?lvraa P B Mortensen |
| |
Affiliation: | 1. Department of Chemical Engineering, National Taiwan University, Taipei, China;2. Institute of Nuclear Energy Research, Taoyuan, China;3. Food Industry Research and Development Institute, Hsinchu, China |
| |
Abstract: | Apparent kinetic constants (Km and Vmax values) were determined for human liver acyl-CoA: glycine acyltransferase (glycine-N-acylase) towards isobutyryl-CoA, 2-methyl butyryl-CoA, isovaleryl-CoA, butyryl-CoA, hexanoyl-CoA, octanoyl-CoA, and decanoyl-CoA. These acyl-CoA esters were selected because of their relevance to the human diseases with cellular accumulation of these esters, i.e., especially to metabolic defects in the acyl-CoA dehydrogenation steps of the branched-chain amino acids, lysine, 5-hydroxy lysine, tryptophan, and fatty acid oxidation pathways. With the acyl-CoA ester as the fixed substrate, the Km value for glycine ranged from 0.5 to 2.9 mole/liter, and with glycine as fixed substrate, the Km values for the acyl-CoA esters varied from 0.3 to 5.6 mmole/liter. It is concluded that the substrate concentration is decisive for the glycine conjugate formation and that the occurrence in urine of acylglycines reflects an intramitochondrial accumulation of the corresponding acyl-CoA ester. |
| |
Keywords: | |
本文献已被 ScienceDirect 等数据库收录! |
|