Abstract
Kinetical analysis of the F-GOT action gave the following results. 1. The conventional velocity versus substrate concentration plot at the velocity of the initial to maximum reaction was shown as a simple type of hyperbola. From the entire picture, the enzyme appeared to follow so-called Michaelis-Menten kinetics. 2. On Lineweaver-Burk's plot, which was utilized as a systematic approach to determining the maximum velocity (Vmax) and apparent Michaelis constant (Km) for the substrate concerned, both values were calculated as follows. (a) The Vmax against alpha-ketoglutarate concentration at a given concentration of L-aspartate at pH 7.4 in 0.1M phosphate buffer at 40°C: (2.00±0.08)×10-2 mM. (b) Apparent Kms for substrate components: [table] These findings offered helpful suggestions in explaining some types of affinity and specificity of the substrate concerned in the reaction of F-GOT. F-GOT has been classified into the general group, GOT-S. In addition, the initial steady-state velocity (Vi) afforded a basis for the illustration of the reaction of F-GOT. 3. Excess of substrate concentration resulted in a decrease in the activity of F-GOT. The activity curves of F-GOT were expressed as simple sigmoid ones. The inhibitor constant (K'i) was (1.78±0.07)×10-5. The actual condition of inhibition by excess of substrate concentration was shown in a figure.
