Direct photoaffinity labeling by nucleotides of the apparent catalytic site on the heavy chains of smooth muscle and Acanthamoeba myosins.
Direct photoaffinity labeling by nucleotides of the apparent catalytic site on the heavy chains of smooth muscle and Acanthamoeba myosins.
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通过平滑肌和棘阿米巴肌球蛋白重链上表观催化位点的核苷酸进行直接光亲和标记。
DOI：
10.1016/s0021-9258(19)70165-3
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发表时间：
1981
期刊：
影响因子：
--
通讯作者：
E. Korn
中科院分区：
文献类型：
--
作者：
H. Maruta;E. Korn
阿米巴肌球蛋白的重链。IA、IB和II、火鸡肌球蛋白和兔骨骼肌肌球蛋白亚片段-1被放射性ATP、ADP和UTP特异性标记，当在0 ℃下用UV光照射时，其中每一种都是肌球蛋白ATP酶活性的底物或产物。与UTP，多达0.45摩尔/摩尔的阿米巴肌球蛋白IA重链和1摩尔/摩尔的火鸡肌球蛋白重链被纳入。配体与催化位点相关的证据包括观察到反应仅与作为ATP酶活性的底物或产物的核苷酸发生，反应被ATP酶活性的抑制剂焦磷酸盐阻断，ATP以ADP形式结合，并且在标记的阿米巴肌球蛋白IA重链的有限枯草杆菌蛋白酶蛋白水解之后，该标记可能限于单个肽，用CNBr和胰蛋白酶对标记的火鸡肌球蛋白重链进行广泛切割。
The heavy chains of Acanthamoeba myosins. IA, IB and II, turkey gizzard myosin, and rabbit skeletal muscle myosin subfragment-1 were specifically labeled by radioactive ATP, ADP, and UTP, each of which is a substrate or product of myosin ATPase activity, when irradiated with UV light at 0 degrees C. With UTP, as much as 0.45 mol/mol of Acanthamoeba myosin IA heavy chain and 1 mol/mol of turkey gizzard myosin heavy chain was incorporated. Evidence that the ligands were associated with the catalytic site included the observations that reaction occurred only with nucleotides that are substrates or products of the ATPase activity; that the reaction was blocked by pyrophosphate which is an inhibitor of the ATPase activity; that ATP was bound as ADP; and that label was probably restricted to a single peptide following limited subtilisin proteolysis of labeled Acanthamoeba myosin IA heavy chain and extensive cleavage with CNBr and trypsin of labeled turkey gizzard myosin heavy chain.