Premium
The utilization of alanine, glutamic acid, and serine as amino acid substrates for glycine N ‐acyltransferase
Author(s) -
van der Westhuizen Francois H.,
Pretorius Petrus J.,
Erasmus Elardus
Publication year - 2000
Publication title -
journal of biochemical and molecular toxicology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.526
H-Index - 58
eISSN - 1099-0461
pISSN - 1095-6670
DOI - 10.1002/(sici)1099-0461(2000)14:2<102::aid-jbt6>3.0.co;2-h
Subject(s) - glycine , chemistry , serine , acyltransferase , amino acid , alanine , biochemistry , electrospray ionization , glutamic acid , stereochemistry , enzyme , mass spectrometry , chromatography
The conjugation of benzoyl‐CoA with the aliphatic and acidic amino acids by glycine N ‐acyltransferase, as well as the amides of the latter group, was investigated. Bovine and human liver benzoyl‐amino acid conjugation were investigated using electrospray ionization tandem mass spectrometry (ESI‐MS‐MS). Bovine glycine N ‐acyltransferase catalyzed conjugation of benzoyl‐CoA with Gly (Km Gly = 6.2 mM), Asn (Km Asn = 129 mM), Gln (Km Gln = 353 mM), Ala (Km Ala = 1573 mM), Glu (Km Glu = 1148 mM) as well as Ser in a sequential mechanism. In the case of the human form, conjugation with Gly (Km Gly = 6.4 mM), Ala (Km Ala = 997 mM), and Glu was detected. The presence of these alternative conjugates did not inhibit bovine glycine N ‐acyltransferase activity significantly. Considering the relatively low levels at which these conjugates are formed, it is unlikely that they will have a significant contribution to acyl‐amino acid conjugation under normal conditions in vivo. However, their cumulative contribution to acyl‐amino acid conjugation under metabolic disease states may prove to have a useful contribution to detoxification of elevated acyl‐CoAs. © 2000 John Wiley & Sons, Inc. J Biochem Toxicol 14: 102–109, 2000