Parra-Diaz D, Echegoyen L, Zot H G, Puett D
Department of Chemistry, University of Miami, Coral Gables, Florida 33124, USA.
Biofactors. 1995 May;5(1):25-8.
Vanadium, believed to be an essential trace metal, exhibits numerous biological effects. Using electron spin resonance spectroscopy, we have demonstrated that vanadyl, vanadium (IV), the predominant intracellular form of vanadate (vanadium V), binds to calmodulin in the presence of physiological concentrations of magnesium, extending earlier work which showed competitive binding of vanadyl and calcium to calmodulin. In the presence of a magnesium-containing buffer, vanadyl does not lead to calmodulin activation of the calmodulin-dependent enzyme, rabbit skeletal muscle myosin light chain kinase; in the presence of calcium, vanadyl is a potent inhibitor of the calmodulin-activated form of the kinase. Thus, vanadyl can potentially interfere with some of the intracellular actions of calcium, presumably via binding to calmodulin. This observation deserves consideration in view of the potential clinical application of vanadium treatment to mimick insulin action and lower blood glucose.
钒被认为是一种必需的痕量金属，具有多种生物学效应。我们使用电子自旋共振光谱法证明，在生理浓度的镁存在下，钒酸盐（钒V）的主要细胞内形式钒酰（钒IV）与钙调蛋白结合，扩展了早期显示钒酰和钙与钙调蛋白竞争性结合的研究。在含镁缓冲液存在下，钒酰不会导致钙调蛋白依赖性酶兔骨骼肌肌球蛋白轻链激酶的钙调蛋白激活；在钙存在下，钒酰是该激酶钙调蛋白激活形式的有效抑制剂。因此，钒酰可能通过与钙调蛋白结合而潜在地干扰钙的一些细胞内作用。鉴于钒治疗模拟胰岛素作用和降低血糖的潜在临床应用，这一观察结果值得考虑。
