Results 1 to 10 of about 68,982 (134)

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

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

Ligand-Induced Proton Transfer and Low-Barrier Hydrogen Bond Revealed by X-ray Crystallography. [PDF]

J Am Chem Soc, 2015
Ligand binding can change the pKa of protein residues and influence enzyme catalysis. Herein, we report three ultrahigh resolution X-ray crystal structures of CTX-M β-lactamase, directly visualizing protonation state changes along the enzymatic pathway: apo protein at 0.79 Å, precovalent complex with nonelectrophilic ligand at 0.89 Å, and acylation ...
Nichols DA, Hargis JC, Sanishvili R, Jaishankar P, Defrees K, Smith EW, Wang KK, Prati F, Renslo AR, Woodcock HL, Chen Y.   +10 more
europepmc   +6 more sources

Environmental Contributions to Proton Sharing in Protein Low-Barrier Hydrogen Bonds. [PDF]

Biochemistry
Abstract Hydrogen bonds (H-bonds) are central to biomolecular structure and dynamics. Although H-bonds are typically characterized by well-defined proton positions, proton delocalization can play a key role in facilitating enzyme catalysis and allostery in some systems.
Lin J, Gerlits O, Kneller DW, Weiss KL, Coates L, Clarke JL, Hix MA, Effah SY, Kovalevsky A, Walker AR, Wilson MA.   +10 more
europepmc   +2 more sources

Interrogating Low Barrier Hydrogen Bonds with Neutrons, X-rays, and Computation [PDF]

Structural Dynamics
Low barrier hydrogen bonds (LBHBs) are H-bonds where the barrier to proton transfer from the donor to the acceptor atom is comparable to the quantum mechanical zero-point energy of the interaction, resulting in proton delocalization.
Jiusheng Lin, Oksana Gerlits, Daniel W. Kneller, Kevin L. Weiss, Leighton Coates, Mark A. Hix, Solomon Y. Effah, Andrey Kovalevsky, Alice R. Walker, Mark A. Wilson   +9 more
doaj   +2 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