Room-temperature electron spin relaxation of nitroxides immobilized in trehalose: Effect of substituents adjacent to NO-group

Room-temperature electron spin relaxation of nitroxides immobilized in trehalose: Effect of substituents adjacent to NO-group Full article

Journal

Journal of Magnetic Resonance
ISSN: 1090-7807

Output data

Year: 2016, Volume: 266, Pages: 1-7 Pages count : DOI: 10.1016/j.jmr.2016.02.014

Tags

Pulse dipole EPR; Spin labels; Nitroxides; Electron spin relaxation; Trehalose

Authors

Kuzhelev Andrey A. ^1,3 , Strizhakov Rodion K. ^1,2 , Krumkacheva Olesya A. ^2,3 , Polienko Yuliya F. ^1,3 , Morozov Denis A. ^1,3 , Shevelev Georgiy Yu. ^3,4 , Pyshnyi Dmitrii V. ⁴ , Kirilyuk Igor A. ^1,3 , Fedin Matvey V. ^2,3 , Bagryanskaya Elena G. ^1,3

Affiliations

1	(Данные Web of science) SB RAS, NN Vorozhtsov Novosibirsk Inst Organ Chem, Lavrentiev Ave 9, Novosibirsk 630090, Russia
2	(Данные Web of science) SB RAS, Int Tomog Ctr, Inst Skaya Str 3a, Novosibirsk 630090, Russia
3	(Данные Web of science) Novosibirsk State Univ, Pirogova Str 2, Novosibirsk 630090, Russia
4	(Данные Web of science) SB RAS, Inst Chem Biol & Fundamental Med, Lavrentiev Ave 9, Novosibirsk 630090, Russia

Trehalose has been recently promoted as efficient immobilizer of biomolecules for room-temperature EPR studies, including distance measurements between attached nitroxide spin labels. Generally, the structure of nitroxide influences the electron spin relaxation times, being crucial parameters for room-temperature pulse EPR measurements. Therefore, in this work we investigated a series of nitroxides with different substituents adjacent to NO-moiety including spirocyclohexane, spirocyclopentane, tetraethyl and tetramethyl groups. Electron spin relaxation times (T-1, T-m) of these radicals immobilized in trehalose were measured at room temperature at X- and Q-bands (9/34 GHz). In addition, a comparison was made with the corresponding relaxation times in nitroxide-labeled DNA immobilized in trehalose. In all cases phase memory times T-m, were close to 700 ns and did not essentially depend on structure of substituents. Comparison of temperature dependences of T-m at T = 80-300 K shows that the benefit of spirocyclohexane substituents well-known at medium temperatures (similar to 100-180 K) becomes negligible at 300 K. Therefore, unless there are specific interactions between spin labels and biomolecules, the room temperature value of T-m in trehalose is weakly dependent on the structure of substituents adjacent to NO-moiety of nitroxide. The issues of specific interactions and stability of nitroxide labels in biological media might be more important for room temperature pulsed dipolar EPR than differences in intrinsic spin relaxation of radicals. (C) 2016 Elsevier Inc. All rights reserved.

Kuzhelev A.A. , Strizhakov R.K. , Krumkacheva O.A. , Polienko Y.F. , Morozov D.A. , Shevelev G.Y. , Pyshnyi D.V. , Kirilyuk I.A. , Fedin M.V. , Bagryanskaya E.G.
Room-temperature electron spin relaxation of nitroxides immobilized in trehalose: Effect of substituents adjacent to NO-group
Journal of Magnetic Resonance. 2016. V.266. P.1-7. DOI: 10.1016/j.jmr.2016.02.014 WOS Scopus РИНЦ

Published print:

May 1, 2016

Web of science	WOS:000375510100001
Scopus	2-s2.0-84960915811
Elibrary	27097072
OpenAlex	W2294128269