Thymidine phosphorylase from Escherichia coli: tight-binding inhibitors as enzyme active-site titrants.
Thymidine phosphorylase (EC 2.4.2.4) catalyses the reversible phosphorolysis of pyrimidine 2'-deoxynucleosides, forming 2-deoxyribose-1-phosphate and pyrimidine. 5-Chloro-6-(2-imino-pyrrolidin-1-yl)methyl-uracil hydrochloride (TPI, 1) and its 5-bromo analogue (2), 6-(2-amino-imidazol-1-yl)methyl-5-bromo-uracil (3) and its 5-chloro analogue (4) act as tight-binding stoichiometric inhibitors of recombinant E. coli thymidine phosphorylase, and thus can be used as the first active-site titrants for it using either thymidine or 5-nitro-2'-deoxyuridine as substrate.
Wolfson Centre for Rational Structure-Based Design of Molecular Diagnostics, School of Pharmacy and Pharmaceutical Sciences, University of Manchester, Manchester M13 9PL, UK.
Abdul
A
Gbaj
Philip N
PN
Edwards
Philip
P
Reigan
Sally
S
Freeman
Mohammed
M
Jaffar
Kenneth T
KT
Douglas
D001665:Binding Sites; D003857:Deoxyuridine / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D004926:Escherichia coli / Q000201:enzymology*; D008958:Models, Molecular; D011485:Protein Binding; D011994:Recombinant Proteins / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000378:metabolism; D013379:Substrate Specificity; D013936:Thymidine / Q000378:metabolism; D013939:Thymidine Phosphorylase / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000378:metabolism
D004791:Enzyme Inhibitors; D011994:Recombinant Proteins; D013939:Thymidine Phosphorylase; D013936:Thymidine; D003857:Deoxyuridine