Oligomerization reactions of deoxyribonucleotides on montmorillonite clay:  the effect of mononucleotide structure, phosphate activation and montmorillonite composition on phosphodiester bond formation.
2'-d-5'-GMP and 2'-d-5'-AMP bind 2 times more strongly to montmorillonite 22A than do 2'-d-5'-CMP and 5'-TMP.  The dinucleotide d(pG)2 forms in 9.2% yield and the cyclic dinucleotide c(dpG)2 in 5.4% yield in the reaction of 2'-d-5'-GMP with EDAC in the presence of montmorillonite 22A.  The yield of d(pC)2 (2.0%) is significantly lower but comparable to that obtained from 5'-TMP.  The yield of dimers which contain the phosphodiester bond decreases as the reaction medium is changed from 0.2 M NaCl to a mixture of 0.2 M NaCl and 0.075 M MgCl2.  A low yield of d(pA)2 was observed in the condensation reaction of 5'-ImdpA on montmorillonite 22A.  The cyclic nucleotide (3',5'-cdAMP) was obtained in 14% yield from 3'-ImdpA.  The yield of d(pA)2 obtained when EDAC is used as the condensing agent increases with increasing iron content of the Na(+)-montmorillonite used as a catalyst.  Evidence is presented which shows that the acidity of the Na(+)-montmorillonite is a necessary but not sufficient factor for the montmorillonite catalysis of phosphodiester bond formation.
Ferris
J P
JP
Rensselaer Polytechnic Institute, Troy, NY 12180-3590, USA.
Kamaluddin
Ertem
G
G
D001546:Bentonite / Q000737:chemistry*; D001665:Binding Sites; D002234:Carbodiimides / Q000737:chemistry; D002384:Catalysis; D003568:Cytidine Monophosphate / Q000031:analogs & derivatives; D003838:Deoxyadenine Nucleotides / Q000737:chemistry; D003854:Deoxyribonucleotides / Q000737:chemistry*; D019143:Evolution, Molecular; D006157:Guanosine Monophosphate / Q000031:analogs & derivatives; D007093:Imidazoles / Q000737:chemistry*; D007501:Iron / Q000737:chemistry; D015636:Magnesium Chloride / Q000737:chemistry; D010755:Organophosphates / Q000737:chemistry; D000069497:Origin of Life; D012965:Sodium Chloride / Q000737:chemistry; D013698:Templates, Genetic
D002234:Carbodiimides; D003838:Deoxyadenine Nucleotides; D003854:Deoxyribonucleotides; D007093:Imidazoles; D010755:Organophosphates; D015636:Magnesium Chloride; D001546:Bentonite; C074139:1-ethyl-3-(3-dimethylaminoethyl)carbodiimide; D012965:Sodium Chloride; C012873:2'-deoxy-5'-adenosine monophosphate; D006157:Guanosine Monophosphate; D007501:Iron; D003568:Cytidine Monophosphate