CYANOBACTERIAL MICROCYSTIN-LR IS A POTENT AND SPECIFIC INHIBITOR OF PROTEIN PHOSPHATASE-1 AND PHOSPHATASE-2A FROM BOTH MAMMALS AND HIGHER-PLANTS
CYANOBACTERIAL MICROCYSTIN-LR IS A POTENT AND SPECIFIC INHIBITOR OF PROTEIN PHOSPHATASE-1 AND PHOSPHATASE-2A FROM BOTH MAMMALS AND HIGHER-PLANTS
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DOI：
10.1016/0014-5793(90)80245-e
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发表时间：
1990-05-21
期刊：
影响因子：
3.5
通讯作者：
CODD, GA
中科院分区：
文献类型：
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作者：
MACKINTOSH, C;BEATTIE, KA;CODD, GA
环七肽微囊藻素- lr抑制蛋白磷酸酶1 （PP1）和2A (PP2A)， ki值低于0.1 nM。蛋白磷酸酶2B被抑制的效力降低了1000倍，而其他6种磷酸酶和8种蛋白激酶不受影响。这些结果与用肿瘤启动子冈田酸获得的结果惊人地相似。我们发现冈田酸可以阻止微囊藻毒素- lr与PP2A的结合，蛋白抑制剂1和2可以阻止微囊藻毒素- lr与PP1的结合。我们讨论了抑制PP1和PP2A的可能性，说明了微囊藻毒素lr的极端毒性，并指出其在蛋白激酶和磷酸酶的检测和分析中的潜在价值。
The cyclic heptapeptide, microcystin-LR, inhibits protein phosphatases 1 (PP1) and 2A (PP2A) withKi, values below 0.1 nM. Protein phosphatase 2B is inhibited 1000-fold less potently, while six other phosphatases and eight protein kinases tested are unaffected. These results are strikingly similar to those obtained with the tumour promoter okadaic acid. We establish that okadaic acid prevents the binding of microcystin-LR to PP2A, and that protein inhibitors 1 and 2 prevent the binding of microcystin-LR to PP1. We discuss the possibility that inhibition of PP1 and PP2A accounts for the extreme toxicity of microcystin-LR, and indicate its potential value in the detection and analysis of protein kinases and phosphatases.