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研究了二价金属离子（Ｍｇ２＋，Ｃａ２＋，Ｍｎ２＋，Ｚｎ２＋）对来源于酵母＂Ｙ．Ｌｉｐｏｌｙｔｉｃａ＂（ｗｉｌｄＷ－２９）的一种蛋白质激酶酪蛋白激酶Ｉ（ＣＫ－Ｉ）活性的影响。发现，ＣＫ－Ｉ的催化活性依赖于Ｍｇ２＋的作用，而不受Ｃａ２＋的调节；Ｚｎ２＋是ＣＫ－Ｉ的抑制剂（Ｉ０．５≈２５０μｍｏｌ／Ｌ）．若反应中存在饱和浓度的Ｍｇ２＋（１０ｍｍｏｌ／Ｌ），Ｍｎ２＋（＜５０μｍｏｌ／Ｌ）既对ＣＫ－ＩＩ有激活作用，又有抑制作用；而且，若Ｍｇ２＋不存在，Ｍｎ２＋则是ＣＫ－Ｉ的激活剂。尤其是，发现Ｍｇ２＋，Ｍｎ２＋对ＣＫ－Ｉ活性的调节作用不同，ＣＫ－Ｉ对底物中靶氨基酸的磷酸化作用就不同。当反应中存在Ｍｇ２＋（１０ｍｍｏｌ／Ｌ）而无Ｍｎ２＋时，靶氨基酸主要是丝氨酸（Ｓｅｒｉｎｅ）和苏氨酸（Ｔｈｒｅｏｎｉｎｅ），其各占被磷酸化总量的６１％和３２％，且只有极微量的酪氨酸（Ｔｙｒｏｓｉｎｅｓ）被磷酸化；当反应中仅存在Ｍｎ２＋（１０ｍｍｏｌ／Ｌ）而无Ｍｇ２＋时，靶氨基酸主要是丝氨酸、苏氨酸和酪氨酸，其各占被磷酸化总量的４２％，４１％和１５％．还发现ＣＫ－Ｉ能对合成的“聚Ｇｌｕ－Ｔｙｒ”磷酸化。这是在ＣＫ－Ｉ研究史上首次发现酪氨酸也?
The effect of divalent metal ions (Mg2 +, Ca2 +, Mn2 +, Zn2 +) on the activity of a protein kinase casein kinase I (CK-I) derived from the yeast “Y.Lipolytica” (wild W-29) was studied. It was found that the catalytic activity of CK-I depended on the action of Mg2 + and not on the regulation of Ca2 +; Zn2 + was an inhibitor of CK-I (I0.5≈250 μmol / L). If the concentration of Mg2 + (10mmol / L) and Mn2 + (<50μmol / L) in the reaction are both active and inhibitory for CK-II, and if Mg2 + is not present, Mn2 + Agent. In particular, it was found that the regulatory effects of Mg2 + and Mn2 + on CK-I activity are different, and the phosphorylation of target amino acids in the substrate by CK-I is different. When Mg2 + (10 mmol / L) and Mn2 + were present in the reaction, the target amino acids were mainly Serine and Threonine, which each accounted for 61% and 32% of the total phosphorylated, with only a very small amount Tyrosines were phosphorylated. When there was only Mn2 + (10 mmol / L) but no Mg2 + in the reaction, the target amino acids were mainly serine, threonine and tyrosine, each of which accounted for the total phosphorylated 42%, 41% and 15%. It was also found that CK-I phosphorylates the synthetic “poly Glu-Tyr”. This is the first time in the history of CK-I found that tyrosine also?