The transmembrane transport of weak acid and base metabolites depends on the local pH conditions that affect the protonation status of the substrates and the availability of co-substrates, typically protons. Different protein designs ensure the attraction of substrates and co-substrates to the transporter entry sites. These include electrostatic surface charges on the transport proteins and complexation with seemingly transport-unrelated proteins that provide substrate and/or proton antenna, or enzymatically generate substrates in place. Such protein assemblies affect transport rates and directionality. The lipid membrane surface also collects and transfers protons. The complexity in the various systems enables adjustability and regulation in a given physiological or pathophysiological situation. This review describes experimentally shown principles in the attraction and facilitation of weak acid and base transport substrates, including monocarboxylates, ammonium, bicarbonate, and arsenite, plus protons as a co-substrate.
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http://dx.doi.org/10.3390/biom12121794 | DOI Listing |
Protein Sci
January 2025
Department of Neuroscience, Biomedicine and Movement Sciences, Section of Biochemistry, University of Verona, Verona, Italy.
Human succinic semialdehyde dehydrogenase is a mitochondrial enzyme fundamental in the neurotransmitter γ-aminobutyric acid catabolism. It catalyzes the NAD-dependent oxidative degradation of its derivative, succinic semialdehyde, to succinic acid. Mutations in its gene lead to an inherited neurometabolic rare disease, succinic semialdehyde dehydrogenase deficiency, characterized by mental and developmental delay.
View Article and Find Full Text PDFJ Am Chem Soc
December 2024
Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs, Frontiers Science Center for Transformative Molecules, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China.
Compared with chiral β-amino phosphorus compounds, which can be easily derived from natural optically pure α-amino acids, obtaining chiral β-amino phosphorus derivatives remains a challenge. These derivatives, which cannot be derived from chiral natural amino acids, possess unique biological activities or potential catalytic activities. Herein, highly enantioselective hydrogenation for the preparation of chiral β-amino phosphorus derivatives from -β-enamido phosphorus compounds is reported by using a green and low-cost earth-abundant metal nickel catalyst (13 examples of 99% ee).
View Article and Find Full Text PDFJ Photochem Photobiol B
December 2024
All-Russian Collection of Microorganisms (VKM), G.K. Skryabin Institute of Biochemistry and Physiology of Microorganisms, Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences, pr. Nauki 5, 142290 Pushchino, Moscow Region, Russia.
In recent decades, most studies of microbial rhodopsins have focused on their identification and characterization in aquatic bacteria. In 2021, actinomycetes of the family Geodermatophilaceae, commonly inhabiting terrestrial ecosystems in hot and arid regions, have been reported to contain rhodopsins with DTEW, DTEF and NDQ amino acid motifs. An advanced bioinformatics analysis performed in this work additionally revealed NTQ rhodopsin and heliorhodopsins.
View Article and Find Full Text PDFNanomaterials (Basel)
December 2024
Department of Chemistry and Environment, Jiaying University, Meisong Road 100, Meizhou 514015, China.
Direct preparation of silver nanoclusters is of great significance for their applications. In this work, by selecting sodium cyanoborohydride as a weak reducing agent to control the kinetics of the reduction reaction, we successfully prepared silver nanoclusters protected by thiol-containing ligands, including mercaptosuccinic acid, cysteine, and glutathione. Based on the silver nanoclusters protected by mercaptosuccinic acid, silver-gold alloy nanoclusters were obtained through a gold doping reaction.
View Article and Find Full Text PDFJ Clin Pharmacol
December 2024
Department of Pharmaceutical Biosciences, Translational Drug Discovery and Development, Uppsala University, Uppsala, Sweden.
The absorption and bioavailability of most tyrosine kinase inhibitors are affected by gastrointestinal pH as they are weak basic lipophilic drugs. Hence, concomitant use of acid reducing agents (ARAs) is frequently restricted. Particularly comedication of crystalline dasatinib (Sprycel) and proton-pump inhibitors (PPIs) should be avoided.
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