We have developed a technique for sensing protein-small molecule and protein-ion interactions in bulk aqueous solution by utilizing a pH sensitive dye, 5-(and-6)-carboxyfluorescein, conjugated to free lysine residues on the surfaces of designated capture proteins. The fluorescein intensity was found to change by about 6% and 15% for small molecule and ion binding, respectively. The assay works by modulating the local electric fields around a pH sensitive dye. This, in turn, alters the dye's apparent pK(A) value. Such changes may result directly from the charge on the analyte, occur through allosteric effects related to the binding process, or result from a combination of both. The assay was used to follow the binding of Ca(2+) to calmodulin (CaM) and thiamine monophosphate (ThMP) to thiamine binding protein A (TbpA). The results demonstrate a binding constant of 1.1 μM for the Ca(2+)/CaM pair and 3.2 nM for ThMP/TbpA pair, which are in excellent agreement with literature values. These assays demonstrate the generality of this method for observing the interactions of small molecules and ions with capture proteins. In fact, the assay should work as a biosensor platform for most proteins containing a specific ligand binding site, which would be useful as a simple and rapid preliminary screen of protein-ligand interactions.
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http://dx.doi.org/10.1016/j.bios.2012.05.023 | DOI Listing |
Phytomedicine
January 2025
Division of Pulmonary Diseases, State Key Laboratory of Biotherapy, and Department of Respiratory and Critical Care Medicine, West China Hospital, West China School of Medicine, Sichuan University, Chengdu, China. Electronic address:
Background: Chronic obstructive pulmonary disease (COPD) imposes a significant global health and socioeconomic burden. Exacerbations of COPD (ECOPD), characterized by heightened airway inflammation and mucus hypersecretion, adversely affect patient health and accelerate disease progression. Qingke Pingchuan (QKPC) granules, a formulation from Traditional Chinese Medicine initially prescribed for acute bronchitis, have shown unexplored potential in ECOPD management, with mechanisms of action yet to be clarified.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
December 2024
HHMI, University of Michigan, Ann Arbor, MI 48109.
Intrinsically disordered protein regions (IDRs) are well established as contributors to intermolecular interactions and the formation of biomolecular condensates. In particular, RNA-binding proteins (RBPs) often harbor IDRs in addition to folded RNA-binding domains that contribute to RBP function. To understand the dynamic interactions of an IDR-RNA complex, we characterized the RNA-binding features of a small (68 residues), positively charged IDR-containing protein, Small ERDK-Rich Factor (SERF).
View Article and Find Full Text PDFCommun Inf Syst
October 2024
Dalton Cardiovascular Research Center, University of Missouri-Columbia.
Molecular docking stands as a pivotal element in the realm of computer-aided drug design (CADD), consistently contributing to advancements in pharmaceutical research. In essence, it employs computer algorithms to identify the "best" match between two molecules, akin to solving intricate three-dimensional jigsaw puzzles. At a more stringent level, the molecular docking challenge entails predicting the accurate bound association state based on the atomic coordinates of two molecules.
View Article and Find Full Text PDFNucleic Acids Res
January 2025
Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA 92093, USA.
BindingDB (bindingdb.org) is a public, web-accessible database of experimentally measured binding affinities between small molecules and proteins, which supports diverse applications including medicinal chemistry, biochemical pathway annotation, training of artificial intelligence models and computational chemistry methods development. This update reports significant growth and enhancements since our last review in 2016.
View Article and Find Full Text PDFJ Cheminform
November 2024
MOE Key Laboratory of Bioinformatics, State Key Laboratory of Molecular Oncology, Beijing Frontier Research Center for Biological Structure, School of Pharmaceutical Sciences, Tsinghua University, Beijing, 100084, China.
Predicting protein-small molecule binding sites, the initial step in structure-guided drug design, remains challenging for proteins lacking experimentally derived ligand-bound structures. Here, we propose CLAPE-SMB, which integrates a pre-trained protein language model with contrastive learning to provide high accuracy predictions of small molecule binding sites that can accommodate proteins without a published crystal structure. We trained and tested CLAPE-SMB on the SJC dataset, a non-redundant dataset based on sc-PDB, JOINED, and COACH420, and achieved an MCC of 0.
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