alpha-Crystallin facilitates the reactivation of hydrogen peroxide-inactivated rhodanese.
It was previously shown that rhodanese, inactivated with hydrogen peroxide, could only be reactivated in the presence of a reductant or the substrate thiosulfate if these reagents were added soon after inactivation and if the oxidant was removed. Here, we report on the facilitated reactivation (75%) of hydrogen peroxide-inactivated rhodanese by the chaperone alpha-crystallin. Reactivation by the chaperone still required a reductant and thiosulfate. Without alpha-crystallin, but in the presence of the reductant and thiosulfate, the inactivated enzyme regained about 39% of its original activity. The alpha-crystallin-assisted reactivation of hydrogen peroxide-inactivated rhodanese was independent of ATP. Further, we found, that alpha-crystallin interacted transiently, but could not form a stable complex with hydrogen peroxide-inactivated rhodanese. Unlike in prior studies that involved denaturation of rhodanese through chemical or thermal means, we have clearly shown that alpha-crystallin can function as a molecular chaperone in the reactivation of an oxidatively inactivated protein.
Department of Chemistry, California State University at San Marcos, San Marcos, California, 92096-0001, USA.
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D000255:Adenosine Triphosphate / Q000737:chemistry; D000817:Anilino Naphthalenesulfonates; D000818:Animals; D002417:Cattle; D003459:Crystallins / Q000737:chemistry* / Q000494:pharmacology*; D004591:Electrophoresis, Polyacrylamide Gel; D004789:Enzyme Activation / Q000187:drug effects*; D004793:Enzyme Reactivators / Q000737:chemistry* / Q000494:pharmacology; D005456:Fluorescent Dyes; D006861:Hydrogen Peroxide / Q000737:chemistry* / Q000494:pharmacology; D008274:Magnesium / Q000737:chemistry; D008623:Mercaptoethanol / Q000737:chemistry; D018832:Molecular Chaperones / Q000737:chemistry / Q000494:pharmacology; D010658:Phenylglyoxal / Q000737:chemistry; D011188:Potassium / Q000737:chemistry; D013884:Thiosulfate Sulfurtransferase / Q000737:chemistry / Q000378:metabolism*; D013885:Thiosulfates / Q000737:chemistry
D000817:Anilino Naphthalenesulfonates; D003459:Crystallins; D004793:Enzyme Reactivators; D005456:Fluorescent Dyes; D018832:Molecular Chaperones; D013885:Thiosulfates; D008623:Mercaptoethanol; C035763:5,5'-bis(8-(phenylamino)-1-naphthalenesulfonate); D000255:Adenosine Triphosphate; D006861:Hydrogen Peroxide; D013884:Thiosulfate Sulfurtransferase; D008274:Magnesium; D010658:Phenylglyoxal; D011188:Potassium