Eker A P
Biochem J. 1985 Jul 15;229(2):469-76. doi: 10.1042/bj2290469.
Butane-2,3-dione inhibits the enzymic activity of Streptomyces griseus photoreactivating enzyme (PRE). Some characteristics of the inhibition, notably the enhancement by borate buffer and the reversibility, indicate that arginine residues are modified. From the kinetics of inhibition it can be concluded that a single essential arginine residue is involved. U.v.-irradiated DNA, the substrate for PRE, protects the enzyme against inactivation by butane-2,3-dione. This suggests that the essential arginine residue is situated in or near the u.v.-irradiated-DNA-binding site. Non-irradiated DNA at higher concentrations also protects against inactivation, indicating that PRE can form non-specific complexes. From the ratio of complex constants obtained from protection experiments with non-irradiated and u.v.-irradiated DNA it appears that PRE preferably binds to dimer sites.
丁二酮-2,3-二酮抑制灰色链霉菌光复活酶(PRE)的酶活性。这种抑制作用的一些特性,特别是硼酸盐缓冲液的增强作用和可逆性,表明精氨酸残基被修饰。从抑制动力学可以得出结论,涉及一个单一的必需精氨酸残基。PRE的底物紫外线照射的DNA可保护该酶不被丁二酮-2,3-二酮灭活。这表明必需精氨酸残基位于紫外线照射的DNA结合位点内或附近。较高浓度的未照射DNA也能防止酶失活,这表明PRE可以形成非特异性复合物。从用未照射和紫外线照射的DNA进行保护实验得到的复合物常数的比值来看,PRE似乎更倾向于结合二聚体位点。