Arg302 governs the pK a of Glu325 in LacY
| Autor: | H. Ronald Kaback, Junichi Sugihara, Ana Filipa Santos Seica, Petra Hellwig, Natalia Grytsyk |
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| Přispěvatelé: | Laboratoire de Bioimagerie et Pathologies (LBP), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Biophotonique et Pharmacologie (CNRS UMR 7213), Centre National de la Recherche Scientifique (CNRS), Chimie de la matière complexe (CMC), Université de Strasbourg (UNISTRA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS) |
| Rok vydání: | 2019 |
| Předmět: |
Models
Molecular Lactose permease Monosaccharide Transport Proteins Spectrophotometry Infrared Stereochemistry Glutamic Acid Spectroscopie Arginine 010402 general chemistry 01 natural sciences chemistry.chemical_compound Deprotonation Galactosides 0103 physical sciences Multidisciplinary Symporters 010304 chemical physics biology Membrane transport protein Chemistry Permease Escherichia coli Proteins Biological Sciences Hydrogen-Ion Concentration Galactoside Major facilitator superfamily 0104 chemical sciences [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry Mutation Galactoside binding biology.protein Hydrophobic and Hydrophilic Interactions |
| Zdroj: | Proceedings of the National Academy of Sciences of the United States of America Proceedings of the National Academy of Sciences of the United States of America, National Academy of Sciences, 2019, 116 (11), pp.4934-4939. ⟨10.1073/pnas.1820744116⟩ |
| ISSN: | 1091-6490 0027-8424 |
| Popis: | Significance The alkaline pK for galactoside binding by the lactose permease of Escherichia coli correlates precisely with the pK a of Glu325, as determined by reaction-induced surface-enhanced infrared absorption spectroscopy (SEIRAS). Glu325 must be protonated for LacY to bind sugar effectively, but deprotonation is also essential for transport. SEIRAS is utilized to test the effect of mutating residues in the immediate neighborhood of Glu325 based on the rationale that interaction will alter the pK a . Neutral replacement of Arg302 with Ala has little or no effect, while replacement with positively charged Lys causes a two-pH unit acid shift. Since a number of other mutations in the vicinity have little effect, it is concluded that Arg302 is important for deprotonation of Glu325. |
| Databáze: | OpenAIRE |
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