title: GTP binds to α-crystallin and causes a significant conformational change.
abstract: ATP was previously reported to bind to the chaperone α-crystallin resulting in a significant effect on the protein's ability to suppress the aggregation of a thermally denatured protein. Here, we have investigated the binding of GTP to α-crystallin. Unlike ATP, binding of GTP to α-crystallin did not affect its ability to suppress the aggregation of thermally denatured rhodanese. GTP binding induced a conformational change on α-crystallin, however the degree of exposed hydrophobic surfaces, which are believed to be involved in the binding of the chaperone to denaturing proteins did not change. Here, we report that GTP binds to α-crystallin and this results in a decreased stability of the chaperone as indicated by urea denaturation.
authors.affiliation: Department of Chemistry and Biochemistry, California State University San Marcos, CA 92096-0001, United States. jmendoza@csusm.edu
authors.forename: Jose A
authors.initials: JA
authors.lastname: Mendoza
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Correa
authors.forename: Gustavo
authors.initials: G
authors.lastname: Zardeneta
mesh_terms: D000818:Animals; D002417:Cattle; D006160:Guanosine Triphosphate / Q000378:metabolism* / Q000494:pharmacology*; D011485:Protein Binding; D011487:Protein Conformation / Q000187:drug effects; D011489:Protein Denaturation / Q000187:drug effects; D055550:Protein Stability / Q000187:drug effects; D014508:Urea / Q000494:pharmacology; D038201:alpha-Crystallins / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D038201:alpha-Crystallins; D006160:Guanosine Triphosphate; D014508:Urea