Kinetics of substrate reaction during irreversible modification of enzyme activity where the modifier is not in great excess of the enzyme

✍ Scribed by Kang-Yuan Zhao; Chen-Lu Tsou

• Publisher: Elsevier Science
• Year: 1992
• Tongue: English
• Weight: 586 KB
• Volume: 157
• Category: Article
• ISSN: 0022-5193
• DOI: 10.1016/s0022-5193(05)80666-6

✦ Synopsis

The kinetic approach previously developed (Tsou 1988, Adv. Enzymok 61,381-386) for the substrate reaction in the presence of modifier is based on the supposition that [Yo]>> [Eo]. However, the presence of the modifier in large excess of the enzyme sometimes leads to a rate of modification which is too fast to be conveniently followed. Here, a kinetic treatment is presented where the condition [Yo]>>[Eo] is not satisfied. The equations derived for the substrate reaction apply to both inhibition and activation and can be reduced to equations previously presented when [ Yo] >> [Eo]. Suitable plots based on the equations derived can be used to determine the rate constants for the binding of the modifier and the dissociation of the EY complex.