Proton-accepting properties of the divalent carbon atom in carbodiphosphoranes and their simple derivatives as well as in carbenes have been investigated. Both these groups of chemical compounds may be characterized by the formula CL2, where L is a sigma electron donor. Therefore, the carbon atom within both these systems, being in its atomic state, can have one or two lone electron pairs and, ...

A Zn(II) amidinium porphyrin is the excited-state electron donor (D) to a naphthalene diimide acceptor (A) appended with either a carboxylate or sulfonate functionality. The two-point hydrogen bond (...[H(+)]...) formed between the amidinium and carboxylate or sulfonate functionalities establishes a proton-coupled electron transfer (PCET) pathway for charge transfer. The two D...[H(+)]...A asse...

Catalysis of the hydration of CO2 by human carbonic anhydrase isozyme II (HCA II) is sustained at a maximal catalytic turnover of 1 mus-1 by proton transfer between a zinc-bound solvent and bulk solution. This mechanism of proton transfer is facilitated via the side chain of His64, which is located 7.5 A from the zinc, and mediated via intervening water molecules in the active-site cavity. Thre...

In this work, we have investigated a novel distal proton shuttle mechanism of ribosome catalyzed peptide bond formation reaction. The reaction was found to follow a two-step mechanism. A distal water molecule located about 6.1 Å away from the attacking amine plays as a proton acceptor and results in a charge-separated intermediate that is stabilized by the N terminus of L27 and the A-site A76 5...

We have measured the fluorescence decay of I-hydroxypyrene-1,3,6-trisulfonate due to proton transfer to solvent in water-methanol mixtures. The data agree quantitatively with the reversible, diffusion-influenced proton-transfer mechanism in all solutions. No significant deviations from a short-time exponential decay or a long-time power law decay were found that could support a recently suggest...

The proton NMR spectrum of yeast tRNAVal 1 has been studied using nuclear Overhauser effect (NOE), including comparison of NOE patterns between purine C8 deuterated and nondeuterated samples. Studies of the downfield region enable us to reliably assign many resonances in the acceptor and D stems. Prominent among these reliable assignments is that of the unusual base pair U psi, which is made he...

The front cover artwork is provided by the groups of Assoc. Prof. Anastasia V. Bochenkova (Lomonosov Moscow State University) and Lars H. Andersen (Aarhus University). image shows quantum nature wavelength-dependent excited-state proton transfer in gas-phase H-bonded complexes GFP chromophore with an anionic acceptor. Read full text Article at 10.1002/cphc.202100068.

Oxidative phosphorylation involves the coupling of ATP synthesis to the proton-motive force that is generated typically by a series of membrane-bound electron transfer complexes, which ultimately reduce an exogenous terminal electron acceptor. This is not the case with Pyrococcus furiosus, an archaeon that grows optimally near 100 degrees C. It has an anaerobic respiratory system that consists ...