Faithin Omaha eBook Collection

Download or read book Mechanistic Studies of the Class I Ribonucleotide Reductase from Escherichia Coli written by Erin Jelena Artin and published by . This book was released on 2006 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: (Cont.) The work described in this thesis makes use of two mechanism-based inhibitors, 20 - azido - 20 - deoxyuridine - 50 - diphosphate (N3UDP) and 20 - deoxy - 20,20 - difluorocytidine - 50 - diphosphate (dFdCDP), and one active site mutant, E441Q R1, to further our understanding of the catalytic capabilities of RNR. The results provide strong support for a 30 - ketodeoxynucleotide intermediate postulated to lie on the normal reduction pathway, as well as for the elimination of nitrogenous base in the active site of R1 during inhibition. The studies further show that under physiologically relevant reducing conditions, inhibition of RNR by the clinically important nucleotide analog dFdCDP is a result of covalent modification. An essential part of these studies was the development of a robust, high-yielding enzymatic method for the selective 50 - phosphorylation of cytidine, 20 - deoxycytidine, 20 - deoxyuridine and their analogs that are not amenable to standard chemical phosphorylation methods.