Broom A D, Uchic M E, Uchic J T
Biochim Biophys Acta. 1976 Mar 17;425(3):278-86. doi: 10.1016/0005-2787(76)90254-9.
The enzymatic polymerization by polynucleotide phosphorylase of 6-chloro-9-(beta-D-ribofuranosyl)purine 5'-diphosphate to poly(6-chloropurinylic acid) and its conversion to poly(6-thioninosinic acid) is described. The sulfur isostere of poly(I) was found not to form a complex with poly(C), but to form a self-association complex with a Tm around 295 degrees K. The sedimentation velocities, pKa and Tm values of the polymer have been examined under various conditions. A two (or more) stranded helical array is suggested as the most probable structure. Thermal loss of the thione chromophore was noted for poly- (S6I), S6IMP and S6I; the degradation product from S6I was shown to be inosine.
描述了通过多核苷酸磷酸化酶将6-氯-9-(β-D-呋喃核糖基)嘌呤5'-二磷酸酶促聚合成聚(6-氯嘌呤酸)及其转化为聚(6-硫代肌苷酸)的过程。发现聚(I)的硫类似物不与聚(C)形成复合物,而是形成一种自缔合复合物,其解链温度约为295 K。在各种条件下检查了该聚合物的沉降速度、pKa和解链温度值。有人提出双(或更多)链螺旋排列是最可能的结构。观察到聚(S6I)、S6IMP和S6I的硫酮发色团有热损失;S6I的降解产物显示为肌苷。