The proton/electron transfer reactions between cysteine residue (Cys) and tyrosinyl radical (Tyr•) are an important step for many enzyme-catalyzed processes. On the basis of statistical analysis protein data bank, we designed three representative models to explore possible mechanisms from Cys Tyr• in proteins. Our ab initio calculations on simplified quantum mechanical/molecular mechanical (QM/MM) real environment reveal that direct electron is difficult occur, but inserted water molecule...

The metal-free BN catalyst is a competitive candidate in oxidative dehydrogenation (ODH). popular oxidant used molecular O2, and the alternative soft oxidant, CO2 with better selectivity, difficult to activate has been less addressed. It expected that porous plenty of active edges result an improved activity, clarified reaction mechanism can also guide rational design efficient CO2-mediated (CO2 DH) catalysts. Herein, hierarchical (hpBN, 657–785 m2/g) nearly uniform mesopores (∼22 nm) rich...

An in situ XPS study of oxidation-reduction processes on three perovskite oxide electrode surfaces was carried out by incorporating the materials an electrochemical cell mounted a heated sample stage ultrahigh vacuum (UHV) chamber. Electrodes made powdered LaCr(1-x)Ni(x)O(3-delta) (x = 0.4, 1) showed changes features all elements upon redox cycling between formal Ni3+ and Ni2+ oxidation stoichiometries, indicating delocalized nature electronic states involved strong mixing O 2p to Ni 3d...

Clostridium ljungdahlii DSM 13528 represents a promising platform organism for production of whole variety different biofuels and biochemicals from syngas. Although the publication its genome gave us first possibility to understand molecular mechanism carbon utilization, reports on profiling transcriptome were unavailable. In this study, RNA-seq-based global analysis was performed compare transcriptomes C. grown CO–CO2 with those fructose. total, 1852 differentially expressed genes...

We present the first approach to excess electron solvation in a novel medium, room-temperature ionic liquid, using ab initio molecular dynamics simulation techniques this work. Results indicate that an can be solvated [dmim](+)Cl(-) IL as long-lived delocalized states and two short-lifetime localized states, one single-cation-residence parasitical type other double-cation-based state. The presence of low-lying pi*-LUMO site residence cation moiety disables C-H unit H-bond donor, while...

The ab initio calculations predict that the side chains of four aromatic amino acids (Phe, His, Tyr, and Trp residues) may promote methionine cystine residues to participate in protein electron hole transport by formation special multicenter, three-electron bonds (S∴π) between S-atoms rings. formations S∴π can efficiently lower local ionization energies, which drive moving close S-containing proteins. Additionally, proper binding energies for imply self-movement proteins dissociate these relay.

An in situ constructed a-MnO 2 /Ti 3 C F heterojunction combines the advantages of 2D layered and amorphous structures, providing abundant ion diffusion channels that facilitate rapid Zn reversible formation ZSH.

This work characterizes the adsorption characteristics of simple benzene derivatives on carbon nanotubes.

Density functional calculations were performed to investigate the interaction of side chains histidine, phenylalanine, tryptophan, and tyrosine with outer surface different charged graphene sheet (GS)/(7,7) single-walled carbon nanotube (CNT) at M06-2X-6-31+g(d,p)//M06-2X-6-31G(d) level theory, which can get insights into π–π interactions in enzyme-modified CNT electrodes. The aromatic rings amino acids prefer orient parallel plane charge states, bears signature interactions. mainly include...

Amino fragments (−NH2) are well-known to exist widely in biological systems and their protonated forms inclined trap electrons form Rydberg radicals (−NH3•) the electron-excess systems. Taking CH3–NH3+ as a mimicking group of alkylamine side-chain lysine, ab initio calculations indicate that proton/electron cooperatively transfer from CH3NH3 CH3NH2 via single-proton-coupled Rydberg-state electron (ET) mechanism with an Rydberg-orbital channel for ET outside −NHn hydrogens N–H+ → N proton...

The carbon dioxide electrochemical reduction reaction catalyzed by iron and nitrogen codoped materials is modulated the local environment, N-type, spin state of FeN 4 active center.

Abstract The possible catalytic mechanism of the reduction nitrite by copper‐containing reductases (CuNiRs) is examined using M06 function according to two copper models, which include type‐one (T1Cu) and type‐two (T2Cu) sites. Examinations confirm that protonation residues, His255 Asp98, near T2Cu site, can modulate redox states T1Cu T2Cu, but cannot directly cause electron transfer from T2Cu. hole remains at site when only one residue, or protonated. However, resides both Asp98 are Then,...

Single-atom catalysts with iron atomically dispersed on nitrogen-doped carbon matrix (FeN4C) is attractive for electrochemically converting dioxide (CO2) to monoxide (CO) or formic acid (HCOOH) due its unique properties and activity. However, the influence of oxidation state different spins Fe ion in FeN4C electrochemical mechanisms conversion CO2 CO/HCOOH remains unclear. Herein, we got insight into reduction reaction (CO2RR) catalyzed by single-Fe coordinated four pyridinic N ligands...

The peroxide-dependent coproheme decarboxylase ChdC from Geobacillus stearothermophilus catalyzes two key steps in the synthesis of heme b, i.e., sequential oxidative decarboxylations coproporphyrinogen III (coproheme III) at propionate groups P2 and P4. In binding site III, P4 are anchored by different residues (Tyr144, Arg217, Ser222 for Tyr113, Lys148, Trp156 P4); however, strong experimental evidence supports that generated Tyr144 radical acts as an unique intermediary hydrogen atom...

The paper is of relevance to weak interactions between two parallel rings close aromatic amino acids, which may participate in electron hole transport proteins. ab initio calculations reveal the possibility for formation π∴π three-electron bond rings, facilitating proteins as effective relay stations. functionality these special structures comes from their lower local ionization energies and proper binding energies, vary with different acids arrangements same according microsurroundings

This work presents a density functional theory calculational study for clarifying that peptide loops (–[peptide]n–) including the N-terminal and C-terminal oligopeptides α-helix can serve as an intriguing kind of relay elements, addition to known stations served by aromatic amino acids electron hopping migration. For these protein motifs, excess generally prefers reside at –NH3+ group in Rydberg state peptides, or –COOH dipole-bound π*-orbital α-helices. The binding ability be effectively...

A type of relay station for electron transfer in proteins, three-piece five-electron bonding, is introduced this paper, which also first proposed here. The ab initio calculations predict the formation S:Π∴S↔S∴Π:S resonance binding with an aromatic ring located middle two sulfur-containing groups, may participate electron-hole transport proteins. These special structures can lower local ionization energies to capture holes efficiently and be easily formed broken because their proper energies....

The proton-coupled electron transfer (PCET) reaction plays an important role in promoting many biological and chemical reactions. Usually, the rate of PCET increases with increase distance because long-range requires more free energy barriers. Our density functional theory calculations here reveal that mechanism occurring lysine-containing alpha(α)-helixes changes increasing number residues α-helical structure different conformations modulation excess distribution by structures. constants...