Results 261 to 270 of about 207,343 (281)
Some of the next articles are maybe not open access.
Low barrier hydrogen bonds within salicylate mono-anions
Tetrahedron, 2001Abstract Progressive incorporation of electron-withdrawing substituents into the aromatic ring of salicylic acid selectively acidifies the ArOH group, until the intrinsic pKa values of the ArOH and ArCO2H groups become matched, as in the case of 3-chloro-5-nitrosalicylic acid.
William L. Mock, Layne A. Morsch
openaire +1 more source
ChemInform Abstract: Low‐Barrier Hydrogen Bonds and Enzymic Catalysis.
ChemInform, 1994AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
W. W. CLELAND, M. M. KREEVOY
openaire +1 more source
Follow the Protons: A Low-Barrier Hydrogen Bond Unifies the Mechanisms of the Aspartic Proteases
Accounts of Chemical Research, 2001Seven proton transfers in five steps participate in a catalytic turnover of an aspartic protease. The Rosetta Stone for elucidating their role is a low-barrier hydrogen bond that holds the two aspartic carboxyls in a coplanar conformation. The proton of this bond shuttles between oxygens during chemical steps via hydrogen tunneling, unlike in previous ...
Dexter B Northrop
exaly +3 more sources
Are There Really Low-Barrier Hydrogen Bonds in Proteins? The Case of Photoactive Yellow Protein
Journal of the American Chemical Society, 2014For a long time, low-barrier hydrogen bonds (LBHBs) have been proposed to exist in many enzymes and to play an important role in their catalytic function, but the proof of their existence has been elusive. The transient formation of an LBHB in a protein system has been detected for the first time using neutron diffraction techniques on a photoactive ...
Marc, Nadal-Ferret +3 more
openaire +2 more sources
The low-barrier hydrogen bond in enzymic catalysis
2010Publisher Summary This chapter describes the various aspects of the low-barrier hydrogen bond in enzymic catalysis. Hydrogen bonds come in a continuum of bond lengths and strengths. The first examples of enzymatic reactions where low-barrier hydrogen bonds played a role involved enolization of the substrate to change the p K of a key group in the ...
openaire +1 more source
Spectral Signatures of Proton-Transfer Dynamics at the Cusp of Low-Barrier Hydrogen Bonding
The Journal of Physical Chemistry Letters, 2018Despite their importance in diverse chemical and biochemical processes, low-barrier hydrogen bonds remain elusive targets to classify and interpret spectroscopically. Here the correlated nature of hydrogen bonding and proton transfer in the low-barrier regime has been probed for the ground and excited electronic states of 6-hydroxy-2-formylfulvene by ...
Zachary N. Vealey +2 more
openaire +2 more sources
Transient low-barrier hydrogen bond in the photoactive state of green fluorescent protein
Physical Chemistry Chemical Physics, 2015A transient low-barrier hydrogen bond has been found directly after photoexcitation using quantum dynamics to study the excited-state process in GFP.
Marc Nadal-Ferret +3 more
openaire +2 more sources
Low-Barrier Hydrogen Bond in the Catalytic Triad of Serine Enzymes
1998Acetylcholinesterase (AChE) and chymotrypsin are serine enzymes whose catalytic mechanism involves a nucleophilic attack (serine) and a general acid-base moiety (histidine). The incipient imidiazolium which is formed as a result of the nucleophilic attack by serine is stabilized by the negatively charged carboxylate (Glu or Asp).
Rohit Medhekar +4 more
openaire +1 more source
A New Concept for the Mechanism of Action of Chymotrypsin: The Role of the Low-Barrier Hydrogen Bond
Biochemistry, 1997The basicities of the diad H57-D102 at N(epsilon)2 in the tetrahedral complexes of chymotrypsin with the peptidyl trifluoromethyl ketones (TFK) N-acetyl-L-Leu-DL-Phe-CF3 and N-acetyl-DL-Phe-CF3 have been studied by 1H-NMR. The protons bridging His 57 and Asp 102 in these complexes are engaged in low-barrier hydrogen bonds (LBHBs).
C S, Cassidy, J, Lin, P A, Frey
openaire +2 more sources