An Insight into the Helicase Functioning Through the Hydrogen Isotope Effects

• Published in: Russian journal of physical chemistry. B Vol. 11; no. 6; pp. 974 - 977
• Main Authors: Buchachenko, A. L., Breslavskaya, N. N.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01-11-2017; Springer Nature B.V
• Subjects: Biological effects; Chemical bonds; Chemical equilibrium; Chemical Physics of Biological Processes; Chemistry; Chemistry and Materials Science; Constants; Deoxyribonucleic acid; Deuteration; Deuterium; DNA; Heavy water; Hydrogen; Hydrogen atoms; Hydrogen bonds; Hydrogen isotopes; Isotope effect; Pharmacology; Physical Chemistry; Rate constants; DNA unwinding; hydrogen isotope effect
• ISSN: 1990-7931; 1990-7923
• DOI: 10.1134/S1990793117060185

The replacement of hydrogen atoms by deuterium in hydrogen bonds of base pairs AT and GC decreases the rate of unwinding DNA by more than 30% per each unzipped base pair. In active helicases this isotope effect refers to the ratio of the rate constants for unzipping closed base pairs in protiated and deuterated DNA. In passive helicases the effect is controlled by ratio of equilibrium constants for opening and closing base pairs in protiated and deuterated DNA. Hydrogen/deuterium isotope effects on the unwindening of double strand DNA seems to explain, at least partly, biological and pharmacological effects of heavy water on living organisms and may be used as a means to explore new facets of the helicase functioning.