ACTIVATION OF PROTEIN-KINASE ISOZYMES BY CYCLIC-NUCLEOTIDE ANALOGS USED SINGLY OR IN COMBINATION - PRINCIPLES FOR OPTIMIZING THE ISOZYME SPECIFICITY OF ANALOG COMBINATIONS
ACTIVATION OF PROTEIN-KINASE ISOZYMES BY CYCLIC-NUCLEOTIDE ANALOGS USED SINGLY OR IN COMBINATION - PRINCIPLES FOR OPTIMIZING THE ISOZYME SPECIFICITY OF ANALOG COMBINATIONS
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DOI：
10.1111/j.1432-1033.1985.tb09010.x
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发表时间：
1985-01-01
期刊：
影响因子：
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通讯作者：
DOSKELAND, SO
中科院分区：
文献类型：
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作者：
OGREID, D;EKANGER, R;DOSKELAND, SO
cAMP类似物（104），其中大多数在腺嘌呤部分进行了修饰，作为cAMP依赖性蛋白激酶I（来自兔或大鼠骨骼肌）和激酶II（来自牛心脏或大鼠骨骼肌）的激活剂进行了试验。当单独试验时，只有2-苯基-1，N6-乙烯基-cAMP作为激酶II的激活剂显示出比激酶I高得多（7倍）的效力。含有8-氨基修饰的类似物优先活化激酶I，一些作为激酶I的活化剂比激酶II的活化剂有效10倍以上。当组合2种类似物时，在固定浓度的另一种（引发）类似物存在下确定半最大激活每种同工酶所需的1种（互补）类似物的浓度。分析了组合测试的类似物对同工酶I和II的亚基内结合位点（A，B）的亲和力。将互补类似物优先激活1种同工酶的程度相对于平均位点选择性作图，即，（亲和力A B同工酶I.亲和力A/B同工酶II）1/2。该图产生一条直线，其斜率反映了引发类似物区分同工酶上同源位点的能力。这意味着类似物对的同工酶鉴别能力可以从类似物对酶的位点A和B的亲和力定量预测。这也意味着对赋予高平均位点选择性或区分同源同工酶位点的能力的类似物的那些特征的系统分析将促进新的、甚至更具同工酶选择性的类似物的合成。
cAMP analogs (104), most of them modified in the adenine moiety, were tested as activators of cAMP-dependent protein kinase I (from rabbit or rat skeletal muscle) and kinase II (from bovine heart or rat skeletal muscle). When tested singly, only 2-phenyl-1, N6-etheno-cAMP showed a considerably (7-fold) higher potency as an activator of kinase II than of kinase I. Analogs containing an 8-amino modification preferentially activated kinase I, some being more than 10-fold more potent as activators of kinase I than kinase II. When 2 analogs were combined, the concentration of 1 (complementary) analog required to half-maximally activate each isozyme was determined in the presence of a fixed concentration of another (priming) analog. Analogs tested in combination had been analyzed for their affinity for the intrasubunit binding sites (A,B) of isozyme I and II. The degree to which complementary analogs preferentially activated 1 isozyme was plotted against the mean site selectivity, i.e., (affinity A B isozyme I .cntdot. affinity A/B isozyme II)1/2. This plot produced a straight line, the slope of which reflected the ability of the priming analog to discriminate homologous sites on the isozymes. This means that the isozyme discriminating power of an analog pair can be quantitatively predicted from the affinity of the analogs for site A and B of the enzymes. It also means that a systematic analysis of those features of analogs imparting a high mean site selectivity or the ability to discriminate between homologous isozyme sites will facilitate the synthesis of new, even more isozyme-selective analogs.