Results 251 to 260 of about 464,016 (298)

Proton transfer triggered proton transfer: a self-assisted twin excited state intramolecular proton transfer

Physical Chemistry Chemical Physics, 2018
The double excited state intramolecular proton transfer (ESIPT) of 3,5-bis(2-hydroxyphenyl)-1H-1,2,4-triazole (bis-HPTA) has been investigated and found to undergo a new type of proton transfer.
Saugata Sahu, Minati Das, Aditya Kumar Bharti, G. Krishnamoorthy   +3 more
openaire   +2 more sources

Proton-Assisted Electron Transfer

The Journal of Physical Chemistry A, 1998
The case for highly selective long range “proton assisted” electron transfer in biomolecules (PA-ET), involving the hopping of protons and hydrogen atoms along H-bond chains connecting two redox sites, is discussed and analyzed on systems closely resembling typical biochemical sequences. These systems consist of an electron acceptor, an H-bond/covalent-
PELUSO, Andrea, M. Brahimi, CAROTENUTO, Maurizio, G. D. Re   +3 more
openaire   +5 more sources

A Novel Mechanism of Proton Transfer in Protonated Peptides

Journal of the American Chemical Society, 2003
The study presents quantum-chemical calculations on proton transfer in protonated N-acetylglycyl-N1-methylglycinamide (AGA) as a short oligopeptide model. All calculations employ the B3LYP functional and the 6-31++G** basis set. Two different mechanisms of proton transfer are discussed.
Petr, Kulhánek, Edward W, Schlag, Jaroslav, Koca   +2 more
openaire   +2 more sources

Catalytic roles for proton transfer and protonation in ribozymes

Biopolymers, 2003
AbstractUtilization of proton transfer in catalysis, which is well known in the mechanisms of protein enzymes, has been described only relatively recently for RNA enzymes. In this article, we present a current understanding of proton transfer by nucleic acids. Rate enhancement and specificity conferred by general acid–base catalysis are discussed.
Philip C, Bevilacqua, Trevor S, Brown, Shu-ichi, Nakano, Rieko, Yajima   +3 more
openaire   +2 more sources

The mechanism of proton transfers

Biochimica et Biophysica Acta (BBA) - General Subjects, 1972
Abstract A CNDO/2 molecular orbital calculation has been performed to study the proton transfer between two ammonia molecules as a model for a base with one lone electron pair and between two water molecules as a model for a base with two electron pairs. The hydrogen bond energy was found to have the expected angular dependence.
openaire   +2 more sources

Consequences of proton transfer in guanidine

Journal of Physical Organic Chemistry, 2003
AbstractConsequences of proton‐transfer reactions in guanidine in the solid state, solution and gas phase are discussed. Y‐delocalization, resonance and symmetry strongly influence the basicity of guanidine in the gas phase. These effects are, however, insufficient to explain the basicity of guanidine which in aqueous solution is stronger than that of ...
Ewa D. Raczynska, Michal K. Cyranski, Maciej Gutowski, Janusz Rak, Jean‐Francois Gal, Pierre‐Charles Maria, Malgorzata Darowska, Kinga Duczmal   +7 more
openaire   +1 more source

Dynamics of Proton Transfer in Bacteriorhodopsin

Journal of the American Chemical Society, 2004
Proton transfer in bacteriorhodopsin from the cytoplasm to the extracellular side is initiated from protonated asp96 in the cytoplasmic region toward the deprotonated Schiff base. This occurs in the transition from the photocycle late M state to the N state.
Yong-Sok, Lee, Morris, Krauss
openaire   +2 more sources

Proton transfer events in GFP

Physical Chemistry Chemical Physics, 2011
Proton transfer is one of the most important elementary processes in biology. Green fluorescent protein (GFP) serves as an important model system to elucidate the mechanistic details of this reaction, because in GFP proton transfer can be induced by light absorption.
DI DONATO, MARIANGELA, Luuk J. G. W. van Wilderen, Ivo H. M. van Stokkum, Thomas Cohen Stuart, John T. M. Kennis, Klaas J. Hellingwerf, Rienk van Grondelle, Marie Louise Groot   +7 more
openaire   +6 more sources

Proton transfer in catalysis by fumarase

Biochemistry, 1992
Using 3T[14C]malate it was possible to show intermolecular T-transfer to unlabeled fumarate. The rate of dissociation of ET derived from the malate was not rapid, only about as fast as required for KMcat. Because of the slow dissociation of ET derived from T-malate, the awkward complex ET-malate is readily formed. As shown by the effect of added malate
I A, Rose, J V, Warms, D J, Kuo
openaire   +2 more sources

Tuning proton conductivity and energy barriers for proton transfer

The Journal of Chemical Physics, 2021
Proton transport is critical for many technologies and for a variety of biochemical and biophysical processes. Proton transfer between molecules (via structural diffusion) is considered to be an efficient mechanism in highly proton conducting materials. Yet, the mechanism and what controls energy barriers for this process remain poorly understood.
Amanda R. Young-Gonzales, Stephen J. Paddison, Alexei P. Sokolov   +2 more
openaire   +2 more sources