Ferris J P, Ertem G, Agarwal V
Department of Chemistry, Rensselaer Polytechnic Institute, Troy, NY 12180-3590.
Orig Life Evol Biosph. 1989;19(2):165-78. doi: 10.1007/BF01808150.
The reaction of the 5'-AMP with water soluble carbodiimide (EDAC) in the presence of Na+-montmorillonite 22A results in the formation of 2',5'-(pA)2 (18.9%), 3',5'-(pA)2 (11%), and AppA (4.8%). When poly(U) is used in place of the clay the product yields are 2',5'-(pA)2 (15.5%), 3',5'-(pA)2 (3.7%) and AppA (14.9%). The 3',5'-cyclic dinucleotide, 3',5'-c(pA)2, is also formed when poly(U) is used. AppA is the principal reaction product when neither clay nor poly(U) is present in the reaction mixture. Products which contain the phosphodiester bond are formed at different ionic strengths, pH and temperatures using Na+-montmorillonite. Phosphodiester bond formation was not observed when Cu2+-montmorillonite was used or when DISN was used in the place of EDAC. The extent catalysis of phosphodiester bond formation varied with the particular clay mineral used. Those Na+-clays which bind 5'-AMP more strongly are better catalysts. Cu2+-montmorillonite, which binds 5'-AMP strongly, exhibits no catalytic activity.
在Na⁺-蒙脱石22A存在的情况下，5'-AMP与水溶性碳二亚胺（EDAC）反应生成2',5'-(pA)2（产率18.9%）、3',5'-(pA)2（产率11%）和AppA（产率4.8%）。当使用聚（U）代替粘土时，产物产率为2',5'-(pA)2（15.5%）、3',5'-(pA)2（3.7%）和AppA（14.9%）。使用聚（U）时还会形成3',5'-环二核苷酸3',5'-c(pA)2。当反应混合物中既不存在粘土也不存在聚（U）时，AppA是主要反应产物。使用Na⁺-蒙脱石时，在不同的离子强度、pH值和温度下会形成含有磷酸二酯键的产物。使用Cu²⁺-蒙脱石或用二异丙基碳二亚胺（DISN）代替EDAC时未观察到磷酸二酯键的形成。磷酸二酯键形成的催化程度因所使用的特定粘土矿物而异。那些与5'-AMP结合更强的Na⁺-粘土是更好的催化剂。强烈结合5'-AMP的Cu²⁺-蒙脱石没有催化活性。
