Okada S, Taniyama M, Ohba H
J Inorg Biochem. 1982 Aug;17(1):41-9. doi: 10.1016/s0162-0134(00)80228-7.
By forming a complex with calf thymus DNA, Cr(III), i.e., CrCl3 and Cr(NO3)3, significantly enhanced its template activity for in vitro RNA synthesis as assayed by 3H incorporation from [5-3H]uridine triphosphate (UTP). The extent of the augmentation in RNA synthesis was proportional to the binding ratio of Cr(III) to the template DNA. K2CrO4, on the other hand, neither bound to DNA nor enhanced its template activity. Experiments using rifampicin and heparin suggested that incorrect and nonviable initiation sites for RNA synthesis became functional in Cr(III)-bound DNA. The incorporation of [gamma-32P]adenosine triphosphate (ATP) into RNA synthesized on Cr(III)-bound DNA was 8 to 9 times greater than that on control DNA. This value was much higher than that of the 3H incorporation form [5-3H]UTP, i.e., the incorporation of 32P on Cr(III) bound DNA was 8 to 9 times greater that of 3H and less than twice that on control DNA. These results suggest that Cr(III) possibly induces the abnormal synthesis of RNA of a very low molecular weight, for most if not all the molecules, by binding to the template DNA.
通过与小牛胸腺DNA形成复合物，三价铬（即CrCl3和Cr(NO3)3）显著增强了其作为体外RNA合成模板的活性，这是通过测定从[5-3H]尿苷三磷酸（UTP）掺入3H来评估的。RNA合成增强的程度与三价铬与模板DNA的结合比率成正比。另一方面，K2CrO4既不与DNA结合，也不增强其模板活性。使用利福平（rifampicin）和肝素（heparin）的实验表明，在与三价铬结合的DNA中，不正确且无活性的RNA合成起始位点变得具有功能。在与三价铬结合的DNA上合成的RNA中，[γ-32P]三磷酸腺苷（ATP）的掺入量比对照DNA上的掺入量高8至9倍。该值远高于从[5-3H]UTP掺入3H的值，即与三价铬结合的DNA上32P的掺入量比3H的掺入量高8至9倍，且不到对照DNA上掺入量的两倍。这些结果表明，三价铬可能通过与模板DNA结合，诱导了极低分子量RNA的异常合成，即便不是所有分子，也是大多数分子。
