Yamaguchi M, Sakurai T
Department of Environmental Biochemistry, School of Pharmaceutical Sciences, University of Shizuoka, Japan.
Mol Cell Biochem. 1992 Mar 4;110(1):25-9. doi: 10.1007/BF02385002.
The effect of regucalcin, a calcium-binding protein isolated from rat liver cytosol, on deoxyuridine 5'-triphosphatase (dUTPase) in the cytosol of rat liver was investigated. Addition of Ca2+ up to 5.0 microM to the enzyme reaction mixture caused a significant decrease of dUTPase activity, while Zn2+, Cd2+, Co2+, Al3+, Mn2+ and Ni2+ (10 microM) did not have an appreciable effect. The Ca(2+)-induced decrease of dUTPase activity was reversed by the presence of regucalcin; the effect was complete at 1.0 microM of the protein. Regucalcin had no effect on the basal activity of the enzyme. Meanwhile, the reversible effect of regucalcin on the Ca2+ (10 microM)-induced decrease of dUTPase activity was not altered by the coexistence of Cd2+ or Zn2+ (10 microM). The present data suggest that liver cytosolic dUTPase is uniquely regulated by Ca2+ of various metals, and that the Ca2+ effect is reversed by regucalcin.
研究了从大鼠肝脏细胞质中分离出的钙结合蛋白调钙素对大鼠肝脏细胞质中脱氧尿苷5'-三磷酸酶（dUTPase）的影响。向酶反应混合物中添加高达5.0微摩尔的Ca2+会导致dUTPase活性显著降低，而10微摩尔的Zn2+、Cd2+、Co2+、Al3+、Mn2+和Ni2+则没有明显影响。调钙素的存在可逆转Ca(2+)诱导的dUTPase活性降低；在1.0微摩尔该蛋白时效果完全。调钙素对该酶的基础活性没有影响。同时，Cd2+或Zn2+（10微摩尔）的共存不会改变调钙素对Ca2+（10微摩尔）诱导的dUTPase活性降低的可逆作用。目前的数据表明，肝脏细胞质中的dUTPase受各种金属的Ca2+独特调节，且Ca2+的作用可被调钙素逆转。
