An investigation of the equilibrium of the reaction {L-aspartate(aq)+2-oxoglutarate(aq)=oxaloacetate(aq)+L-glutamate(aq)}

✍ Scribed by Nand Kishore; Yadu B. Tewari; Robert N. Goldberg

• Publisher: Elsevier Science
• Year: 1998
• Tongue: English
• Weight: 164 KB
• Volume: 30
• Category: Article
• ISSN: 0021-9614
• DOI: 10.1006/jcht.1998.0404

✦ Synopsis

This reaction, catalysed by aspartate transaminase, was studied over the ranges 283.15 F . y1 Ž . T r KF303.15, 6.94 F pH F 7.13, and 0.163 F I r mol kg F 0.167, where T is m temperature and I is ionic strength. The instability of the oxaloacetate in solution required m the use of an experimental procedure that was brief. Thus, the procedure used was to measure the change in the chromatographic response ⌬ R of the oxaloacetate chromatographic peak that accompanied the reaction. Values of ⌬ R were measured for several solutions under near equilibrium conditions. The chromatographic response ⌬ R is expected to be zero for a solution that is at equilibrium with regard to the above reaction and prior to the addition of the enzyme. The results were used to calculate the standard molar Gibbs energy m apparent equilibrium constant K Ј for the overall biochemical reaction is calculated to have XT . y1 the value 0.147; the standard transformed Gibbs energy change ⌬ G s 4.96 kJ mol r m under these conditions.