Su H D, Shoji M, Mazzei G J, Vogler W R, Kuo J F
Cancer Res. 1986 Jul;46(7):3684-7.
Selenium compounds (selenium dioxide, selenious acid, and selenic acid) were found to inhibit phospholipid/Ca2+-dependent protein kinase (protein kinase C) and the phorbol ester-stimulated phosphorylation of endogenous substrate proteins from HL60 cells. Kinetic analysis indicated that selenium dioxide (SeO2) inhibited the enzyme noncompetitively with respect to phosphatidylserine (apparent Ki, 60 microM) and Ca2+ (apparent Ki, 68 microM). The inhibitory effect of SeO2 on protein kinase C was additive to that of another inhibitor of the enzyme (alkyl-lysophospholipid) when present together. SeO2 was also equally inhibitory to myosin light chain kinase, a calmodulin/Ca2+-dependent class of protein kinase. It, however, affected only very slightly cyclic adenosine 3':5'-monophosphate-dependent protein kinase. It is suggested that inhibition of Ca2+-dependent reactions might be related to the anticarcinogenic property of selenium.
研究发现，硒化合物（二氧化硒、亚硒酸和硒酸）能够抑制磷脂/Ca2+依赖的蛋白激酶（蛋白激酶C）以及佛波酯刺激的HL60细胞内源性底物蛋白的磷酸化。动力学分析表明，二氧化硒（SeO2）对磷脂酰丝氨酸（表观抑制常数Ki为60微摩尔）和Ca2+（表观抑制常数Ki为68微摩尔）呈非竞争性抑制该酶。当与该酶的另一种抑制剂（烷基溶血磷脂）同时存在时，SeO2对蛋白激酶C的抑制作用具有加和性。SeO2对肌球蛋白轻链激酶也具有同等程度的抑制作用，肌球蛋白轻链激酶是一类钙调蛋白/Ca2+依赖的蛋白激酶。然而，它对环磷酸腺苷（cAMP）依赖的蛋白激酶影响甚微。有人提出，抑制Ca2+依赖的反应可能与硒的抗癌特性有关。
