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Photosystem II (PSII), the multisubunit pigment-protein complex localised in the thylakoid membranes of oxygenic photosynthetic organisms, uses light energy to drive a series of remarkable reactions leading to the oxidation of water. The products of this oxidation are dioxygen, which is released to
This mini-review outlines the involvement of the tyrosine electron carriers, Y(D) and Y(Z), in the mechanism of electron transfer from water to P680. We discuss our data and put forward our ideas on the role of Y(D) and Y(Z).
Eels seem to be a suitable model system for analysing regulatory mechanisms of drinking behavior in vertebrates, since most dipsogens and antidipsogens in mammals influence the drinking rate in the seawater eels similarly. The drinking behavior in fishes consists of swallowing alone, since they live
Nitration of tyrosine occurs under oxidative stress in vivo. The product, 3-nitrotyrosine (3NY), has a dramatically decreased quantum yield and can be used as a molecular ruler. In this study, femtosecond transient absorption spectroscopy and quantum calculations were implemented to elucidate the
The role of D2-Tyr160 (Y(D)), a photooxidizable residue in the D2 reaction center polypeptide of photosystem II (PSII), was investigated in both wild type and a mutant strain (D2-Tyr160Phe) in which phenylalanine replaces Y(D) in the cyanobacterium Synechocystis sp. (strain PCC 6803). Y(D) is the
Photosystem II (PSII) uses light energy to split water into protons, electrons and O2. In this reaction, nature has solved the difficult chemical problem of efficient four-electron oxidation of water to yield O2 without significant amounts of reactive intermediate species such as superoxide,
The O(2)-evolving complex of photosystem II catalyses the light-driven four-electron oxidation of water to dioxygen in photosynthesis. In this article, the steps leading to photosynthetic O(2) evolution are discussed. Emphasis is given to the proton-coupled electron-transfer steps involved in
Time-dependent radioactivity and solid-state 13C-NMR measurements of tyrosine entrapped in water-filled yoctolitre (10(-24) L) wells with hydrophobic walls are reported; the results indicate that such wells induce the formation of quasi solid tyrosine if they are brought in contact with 0.1 M
We propose that the interconversions of water and oxygen are catalyzed by the transition metal ions of Photosystem II and cytochrome c oxidase in remarkably similar ways. Oxygen-oxygen bond formation and cleavage occurs between two oxygen atoms that are bound as terminal ligands to two redox-active
Experiments were performed in rats to test the hypothesis that adrenal mRNA levels of tyrosine hydroxylase (TH) and the norepinephrine transporter (NET) would be modified by water deprivation via activation of the sympathetic nervous system. TH and NET mRNA levels were measured using the
The emergence of multidrug-resistant Mycobacterium tuberculosis (Mtb) strains highlights the need to develop more efficacious and potent drugs. However, this goal is dependent on a comprehensive understanding of Mtb virulence protein effectors at the molecular level. Here, we used a post-expression
In this study, complexes composed of poly-l-tyrosine (pLT) and single-walled carbon nanotubes (SWCNTs) were produced and the dispersibility of the pLT/SWCNT complexes in water by measuring the ζ potential of the complexes and the turbidity of the solution were investigated. It is found that the
Protein tyrosine phosphatase 1B (PTP1B) plays a key role as a negative regulator of insulin and leptin signalling and is therefore considered to be an important molecular target for the treatment of type 2 diabetes and obesity. Detailed structural information about the structure of PTP1B, including
Changes in water quality from source water to finished water and tap water at two conventional drinking water treatment plants (DWTPs) were monitored. Beside the routine water quality testing, Caenorhabditis elegans-based toxicity assays and the fluorescence excitation-emission matrices technique