Balakrishnan, CV and Ravindranath, SD and Rao, NA (1974) Studies on nucleotidases in plants - Reversible denaturation of the crystalline mung bean nucleotide pyrophosphatase and the effect of adenylates on the native and renatured enzyme. In: Archives of Biochemistry and Biophysics, 164 (1). pp. 156-164.
22.pdf - Published Version
Restricted to Registered users only
Download (919Kb) | Request a copy
The crystalline mung bean nucleotide pyrophosphatase was inhibited nonlinearly by AMP, one of the products of the reaction. The partially inactive enzyme was specifically reactivated by ADP, and V at maximal activation was the same as that of the native enzyme. ATP was a linear, noncompetitive inhibitor. The kinetic evidence suggested that ADP and ATP might not be reacting at the same site as AMP. The electrophoretic mobility of the enzyme was increased by AMP, whereas ADP and ATP were without effect. The enzyme was denatured on treatment with urea or guanidine hydrochloride. The renatured and the native enzyme had the same pH (9.4) and temperature (49 °C) optimum. The Km (0.2 m ) and V (3.2) of the native enzyme increased on renaturation to 1.8 m and 8.0, respectively. In addition, renaturation resulted in desensitization of the enzyme to inhibition by low concentrations of AMP. Renaturation did not affect the reactivation of the apoenzyme by Zn2+.
|Item Type:||Journal Article|
|Additional Information:||Copyright of this article belongs to Elsevier Science.|
|Department/Centre:||Division of Biological Sciences > Biochemistry|
|Date Deposited:||29 Jan 2010 07:07|
|Last Modified:||19 Sep 2010 05:45|
Actions (login required)