High-resolution 1H-NMR spectroscopy at 600 MHz has been used to investigate the conformational transitions of the histidine-binding protein J of Salmonella typhimurium in solution as a function of pH and of L-histidine concentration. The dissociation constant for the binding of L-histidine to histidine-binding protein J increases from 6.0 X 10(-8) to 5.1 X 10(-7) M in going from pH 5.57 to 8.00. The conformation of this protein as observed by 1H-NMR also changes over this range of pH. However, when L-histidine is bound, the changes in conformation with pH are much smaller. Also, the pK for the single histidyl residue in histidine-binding protein J changes from 6.75 in the absence of L-histidine to 6.52 when L-histidine is bound. Earlier work in this laboratory resulted in the identification of several proton resonances believed to be at or near the L-histidine-binding site. Two of these resonances have been assigned to a tyrosine and the single histidyl residue in the histidine-binding protein J molecule.
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http://dx.doi.org/10.1016/0301-4622(84)87011-8 | DOI Listing |
J Agric Food Chem
February 2024
Department of Food Technology, Spanish National Research Council (CSIC), Institute of Marine Research (IIM-CSIC), 36208 Vigo, Spain.
The presence of biogenic amines (histamine, tyramine, putrescine, and cadaverine) in seafood is a significant concern for food safety. This review describes for the first time a shotgun quantitative proteomics strategy to evaluate and compare foodborne strains of bacteria that produce biogenic amines in seafoods. This approach recognized 35,621 peptide spectrum matches, belonging to 20,792 peptides, and 4621 proteins.
View Article and Find Full Text PDFMolecules
October 2023
Key Laboratory of Medicinal and Edible Plants Resources Development of Sichuan Education Department, School of Pharmacy, Chengdu University, Chengdu 610106, China.
Amino acid binding proteins (AABPs) undergo significant conformational closure in the periplasmic space of Gram-negative bacteria, tightly binding specific amino acid substrates and then initiating transmembrane transport of nutrients. Nevertheless, the possible closure mechanisms after substrate binding, especially long-range signaling, remain unknown. Taking three typical AABPs-glutamine binding protein (GlnBP), histidine binding protein (HisJ) and lysine/arginine/ornithine binding protein (LAOBP) in ()-as research subjects, a series of theoretical studies including sequence alignment, Gaussian network model (GNM), anisotropic network model (ANM), conventional molecular dynamics (cMD) and neural relational inference molecular dynamics (NRI-MD) simulations were carried out.
View Article and Find Full Text PDFCurr Res Struct Biol
August 2020
Simons Centre for the Study of Living Machines, National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore, 560065, India.
Two mechanisms, induced fit (IF) and conformational selection (CS), have been proposed to explain ligand recognition coupled conformational changes. The histidine binding protein (HisJ) adopts the CS mechanism, in which a pre-equilibrium is established between the open and the closed states with the ligand binding to the closed state. Despite being structurally similar to HisJ, the maltose binding protein (MBP) adopts the IF mechanism, in which the ligand binds the open state and induces a transition to the closed state.
View Article and Find Full Text PDFJ Am Chem Soc
September 2020
Department of Organic Chemistry, Weizmann Institute of Science, Rehovot 7610001, Israel.
A method for generating targeted, pattern-generating, protein surface sensors via the self-assembly of modified oligodeoxynucleotides (ODNs) is described. The simplicity by which these systems can be created enabled the development of a sensor that can straightforwardly discriminate between distinct glycoform populations. By using this sensor to identify glycosylation states of a therapeutic protein, we demonstrate the diagnostic potential of this approach as well as the feasibility of integrating a wealth of supramolecular receptors and sensors into higher-order molecular analytical devices with advanced properties.
View Article and Find Full Text PDFIUCrJ
July 2020
Structural and Computational Biology Unit, EMBL Heidelberg, Meyerhofstrasse 1, 69126 Heidelberg, Germany.
Protein-protein and protein-ligand interactions often involve conformational changes or structural rearrangements that can be quantified by solution small-angle X-ray scattering (SAXS). These scattering intensity measurements reveal structural details of the bound complex, the number of species involved and, additionally, the strength of interactions if carried out as a titration. Although a core part of structural biology workflows, SAXS-based titrations are not commonly used in drug discovery contexts.
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