가토 뇌 Protein Methylase Ⅱ에 관한 연구 = Studies on Rabbit Brain Protein Methylase Ⅱ

다국어 초록 (Multilingual Abstract)

Protein methylase II has been purified from rabbit brain approximately 1,600 folds with a 6% yield by the methods of homogenation, (NH_4)_2SO_4 saturation, S-adenosyl-L-homocysteine sepharose 4B column chromatography and hydroxyapatite column chromatography.
The enzyme shows a pH optimun around 6. The enzyme is easily inactivated by heat treatment for 5 minutes at 60℃, and when stored at -20℃ in the presence of 10% glycerol, 40% of activity has been lost in a week. Fe^2+ and Se activate this enzyme upto 16% and 22% at 2mM concentration and Ni, Zn^2+ and Cu^2+ inhibit upto 17%, 32%, 100% at 2mM respectively. The inhibition by 250μM Cu^2+ is completely recovered by 2.5mM DTT and 40% recovered by 300μM DEDTC. The apparent Km value for S-adenosyl-L-methionine was 2.2 x 10 exp (-6)M and kinetic analysis of this enzyme in the presence of 30μM cupper ion shows that the nature of the inhibition to the enzyme is noncompetitive.