RESUMO
The aim of this work is to determine the conformation of the nucleobase adjacent to the cleavable phosphodiester bond in the productive enzyme-substrate complex of RNA-depolymerizing enzymes. To this end the kinetic parameters of hydrolysis of UpA, 2'-C-Me- and 3'-C-Me-UpA were determined for RNase A, RNase Pb2, nuclease S1 and snake venom phosphodiesterase. In these derivatives the ranges of the allowed orientation of uridine residues are restricted due to the substitution of methyl groups for the ribose hydrogen atoms. The results described demonstrate that the proposed method is of general value for the estimation of the nucleotide glycoside angles in the productive enzyme-substrate complexes.
Assuntos
Fosfatos de Dinucleosídeos/química , Conformação de Ácido Nucleico , Diester Fosfórico Hidrolases/química , Conformação Proteica , Ribonucleases/química , Endonucleases Específicas para DNA e RNA de Cadeia Simples/química , Animais , Calorimetria , Bovinos , Fosfatos de Dinucleosídeos/metabolismo , Penicillium/enzimologia , Diester Fosfórico Hidrolases/metabolismo , Ribonuclease Pancreático/química , Ribonuclease Pancreático/metabolismo , Ribonucleases/metabolismo , Endonucleases Específicas para DNA e RNA de Cadeia Simples/metabolismo , Venenos de SerpentesRESUMO
A general method have been developed for the synthesis of 2'-C-methylnucleosides from 2,3-O-isopropylidene-2-hydroxymethyl-5-O-trityl-D-ribofuranose (2).
