Kinetic studies of chloride inhibition in aspartate aminotransferase activity.
The inhibitive effects of chloride anion on the activity of mitochondrial aspartate aminotransferase (L-aspartate: 2-oxoglutarate-aminotransferase EC. 2.6.1.1.) from chicken (Gallus domesticus) and turkey (Maleagris gallopavo) were studied. Steady-state velocities were obtained from a wide range of chloride concentrations. The data were fitted by rational functions of 0:2 and 1:2 for chloride, using a non-linear regression program which guaranteed the fit. The goodness of fit was improved by the use of a computer program that combined model discrimination, parameter refinement and sequential design. It was concluded that chloride aspartate aminotransferase inhibition requires a minimum velocity equation of 1:2 with regard to chloride, and a plausible kinetic mechanism for this experimental result was proposed.
Cascante
M
M
Departamento de Bioquimica i Fisiologia, Facultat de Química, Universitat de Barcelona, Catalunya, Spain.
Cortes
A
A
D000818:Animals; D001219:Aspartate Aminotransferases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D001224:Aspartic Acid / Q000378:metabolism; D002645:Chickens; D002712:Chlorides / Q000494:pharmacology*; D001330:Electronic Data Processing; D066298:In Vitro Techniques; D007656:Ketoglutaric Acids / Q000378:metabolism; D007700:Kinetics; D008433:Mathematics; D008930:Mitochondria, Liver / Q000201:enzymology; D008956:Models, Chemical; D014422:Turkeys
D002712:Chlorides; D007656:Ketoglutaric Acids; D001224:Aspartic Acid; D001219:Aspartate Aminotransferases