Hydride Transfer versus Hydrogen Radical Transfer in Thymidylate Synthase
نویسندگان
چکیده
منابع مشابه
Hydride transfer versus hydrogen radical transfer in thymidylate synthase.
The nature of a H-transfer in the thymidylate synthase catalyzed reaction was investigated by comparison of the wild-type enzyme with the W80M mutant. The nature of the H-transfer was not affected, as indicated by intrinsic isotope effects and their temperature dependence. These findings support a single-step hydride transfer instead of a two-step radical transfer.
متن کاملA remote mutation affects the hydride transfer by disrupting concerted protein motions in thymidylate synthase.
The role of protein flexibility in enzyme-catalyzed activation of chemical bonds is an evolving perspective in enzymology. Here we examine the role of protein motions in the hydride transfer reaction catalyzed by thymidylate synthase (TSase). Being remote from the chemical reaction site, the Y209W mutation of Escherichia coli TSase significantly reduces the protein activity, despite the remar...
متن کاملMechanistic insights into the reactions of hydride transfer versus hydrogen atom transfer by a trans-dioxoruthenium(VI) complex.
A mononuclear high-valent trans-dioxoruthenium(VI) complex, trans-[Ru(VI)(TMC)(O)2](2+) (TMC = 1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane), was synthesized and characterized by various spectroscopic techniques and X-ray crystallography. The reactivity of the trans-[Ru(VI)(TMC)(O)2](2+) complex was investigated in hydride transfer and hydrogen atom transfer reactions. The mechanism o...
متن کاملTryptophan 80 and leucine 143 are critical for the hydride transfer step of thymidylate synthase by controlling active site access.
Mutant forms of thymidylate synthase (TS) with substitutions at the conserved active site residue, Trp 80, are deficient in the hydride transfer step of the TS reaction. These mutants produce a beta-mercaptoethanol (beta-ME) adduct of the 2'-deoxyuridine-5'-monophosphate (dUMP) exocyclic methylene intermediate. Trp 80 has been proposed to assist hydride transfer by stabilizing a 5,6,7,8-tetrahy...
متن کاملThe influence of active site conformations on the hydride transfer step of the thymidylate synthase reaction mechanism.
The hydride transfer from C6 of tetrahydrofolate to the reaction's exocyclic methylene-dUMP intermediate is the rate limiting step in thymidylate synthase (TSase) catalysis. This step has been studied by means of QM/MM molecular dynamics simulations to generate the corresponding free energy surfaces. The use of two different initial X-ray structures has allowed exploring different conformationa...
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ژورنال
عنوان ژورنال: Journal of the American Chemical Society
سال: 2006
ISSN: 0002-7863,1520-5126
DOI: 10.1021/ja060196o