고도 호열성균 Thermus caldophilus의 Adenylate Kinase의 성질

Characteristics of Adenylate Kinase from Extreme Thermophile Thermus caldophilus GK-24

내열성 Thermus caldopilus로부터 정제된 내열성의 adenylate kinase는 nucleoside monophosphate에 대해 nucleotide triphosphate보다 높은 기질 특이성을 보여 주었다. $P',P^5$-di(adenosine-5')pentaphosphate는 여러 기질에 있어 Thermus의 adenylate kinase에 대해 경쟁적 저해제로서 작용하였다. $Mg^{2+}$ 이외 여러 가지 2가 양이온은 $Ca^{2+}, Mg^{2+}, Ba^{2+}, Fe^{2+}$ 순위로 효소활성에 필요하였으며, 효소활성은 p-chloromucuribenzoic acid와 같은 sulfurhydryl 시약에 저해되지 않았으며, 식염이나 phosphenolpyruvate을 반응액 첨가하였을 때 활성화되었다.

A thermostable adenylate kinase isolated from the sonic extracts of Thermus caldophilus cells revealed higher substrate-specificity to the nucleoside monophosphate than to the nucleoside triphosphate. A $P', P^5$-di(adenosine-5') pentaphosphate was acted as a competitive inhibitor to the various substrates. Various divalent cations were activated the enzyme activity following orders: $Mg^{2+}, Ca^{2+}, Mn^{2+}, Ba^[2+}, $ and $Fe^{2+}$-. The enzyme activity was not affected by the sulfurhydryl reagent, p-chloromeric uribenzoic acid and activated by addition of the sodium chloride or phosphoenol pyruvate to the reaction mixture.