3-Hydroxy-3-methylglutaryl CoA reductase of Hevea latex: The occurrence of a heat-stable activator in the C-serum

• Main Authors: Mohd. Isa, Ramli B., Sipat, A.B.
• Format: Article
• Language: English
• Published: Elsevier BV 1982
• Online Access: http://psasir.upm.edu.my/id/eprint/115115/1/115115.pdf; http://psasir.upm.edu.my/id/eprint/115115/; https://linkinghub.elsevier.com/retrieve/pii/0006291X82918526

The effect of the C-serum (the cytosol) on the activity of 3-hydroxy-3-methylglutaryl CoA reductase in the latex of Hevea brasiliensis was investigated. Depending on the clone from which the latex was obtained, the C-serum was found to depress or activate or have little effect on the enzyme activity. Boiling the C-serum however, resulted in a consistent activation effect in all the clones examined. Optimal activation was obtained with 20 μl boiled C-serum. Dialysis or EDTA (40 mM) treatment of the boiled C-serum did not diminish the activation effect. Although not essential, dithiothreitol complemented the activation effect of the boiled C-serum and the optimal concentration was 10 mM. Trypsin digestion of the boiled C-serum resulted in the complete loss of the activation effect. The activator in the boiled C-serum was salted out by ammonium sulphate at 25 - 100% saturation. Hevein had no effect on reductase activity.