There is a symbiotic relationship between the evolution of fundamental theory and the winning of experimentally-based knowledge. The impact of the General Chemiosmotic Theory on our understanding of the nature of membrane transport processes is described and discussed. The history of experimental studies on transport catalysed by ionophore antibiotics and the membrane proteins of mitochondria and bacteria are used to illustrate the evolution of knowledge and theory. Recent experimental approaches to understanding the lactose-H+ symport protein of Escherichia coli and other sugar porters are described to show that the lack of experimental knowledge of the three-dimensional structures of the proteins currently limits the development of theories about their molecular mechanism of translocation catalysis.
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OCTN1 mediates acetylcholine transport in the A549 lung cancer cells: possible pathophysiological implications.
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Laboratory of Biochemistry, Molecular Biotechnology and Molecular Biology, Department DiBEST (Biologia, Ecologia, Scienze Della Terra), University of Calabria, Arcavacata di Rende, Italy.
A role for acetylcholine in cell proliferation, epithelial mesenchymal transition and invasion has been well assessed and related to the presence of the non-neuronal cholinergic system in lung cancer. For the operation of this non-neuronal system, acetylcholine should be released by a transporter mediated non-quantal process. OCTN1 is one of the transporters able to catalyse acetylcholine efflux and .
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Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, UK.
Fe(II)- and 2-oxoglutarate (2OG)-dependent dioxygenases use 2OG and O cofactors to catalyse substrate oxidation and yield oxidised product, succinate, and CO. Simultaneous detection of substrate and cofactors is difficult, contributing to a poor understanding of the dynamics between substrate oxidation and 2OG decarboxylation activities. Here, we profile 5-methylcytosine (C)-oxidising Ten-Eleven Translocation (TET) enzymes using MS and H NMR spectroscopy methods and reveal a high degree of substrate oxidation-independent 2OG turnover under a range of conditions.
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