Issue 37, 2018

Amide–imide tautomerization in the glutamine side chain in enzymatic and photochemical reactions in proteins

Abstract

Amide–imide tautomerization presents a pervasive class of chemical transformations in organic chemistry of natural compounds. In this Perspective, we describe two distinctively different protein systems, in which the amide–imide tautomerization in the glutamine side chain takes place in enzymatic or photochemical reactions. First, hydrolysis of guanosine triphosphate (GTP) catalyzed by the Ras-GAP protein complex suggests the occurrence of the imide tautomer of glutamine in reaction intermediates. Second, photoexcitation of flavin-binding protein domains (BLUFs) initiates a chain of reactions in the chromophore-binding pocket, including amide–imide tautomerization of glutamine. Mechanisms of these reactions at the atomic level have been revealed in quantum mechanics/molecular mechanics (QM/MM) simulations. To reinforce conclusions on the critical role of amide–imide tautomerization of glutamine in these reactions we describe results of new quantum chemistry and QM/MM calculations for relevant molecular model systems. We reexamine results of the recent IR spectroscopy studies of BLUF domains, which provide experimental evidences of Gln tautomerization in proteins. We also propose to validate the glutamine-assisted mechanism of enzymatic GTP hydrolysis by using IR spectroscopy in a proper range of wavenumbers.

Graphical abstract: Amide–imide tautomerization in the glutamine side chain in enzymatic and photochemical reactions in proteins

Supplementary files

Article information

Article type
Perspective
Submitted
29 Jūl. 2018
Accepted
04 Sept. 2018
First published
06 Sept. 2018

Phys. Chem. Chem. Phys., 2018,20, 23827-23836

Amide–imide tautomerization in the glutamine side chain in enzymatic and photochemical reactions in proteins

B. L. Grigorenko, M. G. Khrenova and A. V. Nemukhin, Phys. Chem. Chem. Phys., 2018, 20, 23827 DOI: 10.1039/C8CP04817G

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements