Joyce G F, Inoue T, Orgel L E
J Mol Biol. 1984 Jun 25;176(2):279-306. doi: 10.1016/0022-2836(84)90425-x.
Poly(C, U) random copolymer templates direct the oligomerization of 2-MeImpG and 2-MeImpA, resulting in the production of a variety of oligo/(G,A)s. The efficiency of monomer incorporation into newly synthesized oligomers is greater for 2-MeImpG than for 2-MeImpA, and decreases for both monomers as the uracil content of the template increases. The relatively poor incorporation of adenine is partly due to an intrinsically less efficient incorporation reaction, and partly due to the masking of uracil sites by G X U non-complementary pairing. The efficiency of adenine incorporation can be improved by decreasing the concentration of 2-MeImpG and increasing the concentration of 2-MeImpA in the reaction mixture. The oligomeric product distribution can be characterized in detail using high-pressure liquid chromatography on an RPC-5 column. Oligomers are separated on the basis of chain length, base composition, and phospho-diester-linkage isomerism. The 3'----5' regiospecificity of monomer addition to template-bound oligomers is lower for 2-MeImpA than for 2-MeImpG. The presence of an adenine residue at the 2'(3') terminus of the acceptor strand lowers the regiospecificity of 2-MeImpA addition even further.
聚（C，U）无规共聚物模板指导2-甲基肌苷G和2-甲基肌苷A的寡聚化，从而产生多种寡聚/（G，A）产物。2-甲基肌苷G掺入新合成寡聚物中的单体效率高于2-甲基肌苷A，并且随着模板中尿嘧啶含量的增加，两种单体的掺入效率均降低。腺嘌呤掺入相对较差部分是由于掺入反应本身效率较低，部分是由于G×U非互补配对掩盖了尿嘧啶位点。通过降低反应混合物中2-甲基肌苷G的浓度并增加2-甲基肌苷A的浓度，可以提高腺嘌呤的掺入效率。使用RPC-5柱上的高压液相色谱可以详细表征寡聚产物分布。寡聚物根据链长、碱基组成和磷酸二酯键异构性进行分离。2-甲基肌苷A向模板结合寡聚物上添加单体的3'→5'区域特异性低于2-甲基肌苷G。受体链2'（3'）末端存在腺嘌呤残基会进一步降低2-甲基肌苷A添加的区域特异性。
