Results 1 to 10 of about 79,459 (141)

Low-Barrier Hydrogen Bond in Fujikurin A-D: A Computational Study. [PDF]

ACS Omega, 2022
The compounds Fujikurin A, B, and D, recently isolated from Fusarium fujikuroi, possess intramolecular low-barrier hydrogen bonds (LBHBs), which are hydrogen bonds with a very low-energy barrier for proton transfer. The isolated compounds have a hydrogen-bonded proton that appears to rapidly switch between two equilibrium states via a transition state (
Tanaka H, Kuwahata K, Tachikawa M, Udagawa T.   +3 more
europepmc   +3 more sources

Absorption wavelength along chromophore low-barrier hydrogen bonds

iScience, 2022
Summary: In low-barrier hydrogen bonds (H-bonds), the pKa values for the H-bond donor and acceptor moieties are nearly equal, whereas the redox potential values depend on the H+ position. Spectroscopic details of low-barrier H-bonds remain unclear. Here,
Masaki Tsujimura, Hiroyuki Tamura, Keisuke Saito, Hiroshi Ishikita   +3 more
doaj   +3 more sources

Vibrational analysis on the revised potential energy curve of the low-barrier hydrogen bond in photoactive yellow protein [PDF]

Computational and Structural Biotechnology Journal, 2016
Photoactive yellow protein (PYP) has a characteristic hydrogen bond (H bond) between p-coumaric acid chromophore and Glu46, whose OH bond length has been observed to be 1.21 Å by the neutron diffraction technique [Proc. Natl. Acad. Sci.
Yusuke Kanematsu, Hironari Kamikubo, Mikio Kataoka, Masanori Tachikawa   +3 more
doaj   +2 more sources

Contribution of a low-barrier hydrogen bond to catalysis is not significant in ketosteroid isomerase. [PDF]

Mol Cells, 2015
Low-barrier hydrogen bonds (LBHBs) have been proposed to have important influences on the enormous reaction rate increases achieved by many enzymes. Δ(5)-3-ketosteroid isomerase (KSI) catalyzes the allylic isomerization of Δ(5)-3-ketosteroid to its conjugated Δ(4)-isomers at a rate that approaches the diffusion limit. Tyr14, a catalytic residue of KSI,
Jang DS, Choi G, Cha HJ, Shin S, Hong BH, Lee HJ, Lee HC, Choi KY.   +7 more
europepmc   +6 more sources

Direct evidence of a low barrier hydrogen bond in the catalytic triad of a Serine protease. [PDF]

Sci Rep, 2018
AbstractSerine proteases are one of the largest groups of enzymes, found in both eukaryotes and prokaryotes, and are responsible for many different functions. The detailed information about the hydrogen-bonds in the catalytic triad (Asp…His…Ser) of these enzymes is of importance in order to fully understand the mechanism of action. The aspartate of the
Agback P, Agback T.
europepmc   +4 more sources

A low-barrier hydrogen bond mediates antibiotic resistance in a noncanonical catalytic triad. [PDF]

Sci Adv, 2018
Substrate participation in forming a catalytic triad aids in antibiotic resistance by aminoglycoside N3 -acetyltransferases.
Kumar P, Serpersu EH, Cuneo MJ.
europepmc   +4 more sources

Short hydrogen bonds in the catalytic mechanism of serine proteases [PDF]

Journal of the Serbian Chemical Society, 2008
The survey of crystallographic data from the Protein Data Bank for 37 structures of trypsin and other serine proteases at a resolution of 0.78–1.28 Å revealed the presence of hydrogen bonds in the active site of the enzymes, which are formed between the ...
VLADIMIR LESKOVAC, SVETLANA TRIVIC, DRAGINJA PERICIN, MIRA POPOVIC, JULIJAN KANDRAC   +4 more
doaj   +3 more sources

Identification of the protonation and oxidation states of the oxygen-evolving complex in the low-dose X-ray crystal structure of photosystem II

Frontiers in Plant Science, 2023
In photosystem II (PSII), the O3 and O4 sites of the Mn4CaO5 cluster form hydrogen bonds with D1-His337 and a water molecule (W539), respectively. The low-dose X-ray structure shows that these hydrogen bond distances differ between the two homogeneous ...
Keisuke Saito, Keisuke Saito, Shu Nakao, Hiroshi Ishikita, Hiroshi Ishikita   +4 more
doaj   +1 more source

Synthesis, structure, and C–H bond activation reaction of an iron(IV) terminal imido complex bearing trifluoromethyl groups

Cell Reports Physical Science, 2021
Summary: Iron terminal imido species featuring electron-withdrawing N-substituents represent an important category of reactive metal-ligand-multiple-bond intermediates in iron-catalyzed reactions.
Qing Liu, Linhong Long, Pengchen Ma, Yingjie Ma, Xuebing Leng, Jie Xiao, Hui Chen, Liang Deng   +7 more
doaj   +1 more source

Low barrier hydrogen bonds in protein structure and function

Biochimica et Biophysica Acta (BBA) - Proteins and Proteomics, 2021
Low-barrier hydrogen bonds (LBHBs) are a special type of short hydrogen bond (HB) that is characterized by the equal sharing of a hydrogen atom. The existence and catalytic role of LBHBs in proteins has been intensely contested. Advancements in X-ray and neutron diffraction methods has revealed delocalized hydrogen atoms involved in potential LBHBs in ...
M Trent, Kemp, Eric M, Lewandowski, Yu, Chen   +2 more
openaire   +3 more sources