Duysak T, Afzal AR, Jung CH. Determination of glutathione-binding to proteins by fluorescence spectroscopy.
Biochem Biophys Res Commun 2021;
557:329-333. [PMID:
33895474 DOI:
10.1016/j.bbrc.2021.04.016]
[Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 04/06/2021] [Indexed: 01/12/2023]
Abstract
Glutathione (GSH) is the most abundant non-protein thiol and its cellular concentration has been reported as 17 mM in Escherichia coli. This study introduces a label-free method to determine the binding affinity of GSH to proteins, utilizing the intrinsic fluorescence of proteins; the dissociation constants of GSH for d-arabinose 5-phosphate isomerase KdsD, fumarase C, malate dehydrogenase, and RNA polymerase subunit α have been determined as 96 ± 8, 246 ± 42, 292 ± 78, and 296 ± 97 μM, respectively. The dissociation constants, less than 2% of the cellular concentration of GSH, suggests that protein-GSH interactions are strong enough to make all of the GSH-binding sites occupied fully. The method described here may be applicable to other proteins.
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