GTP binds to α-crystallin and causes a significant conformational change

• Published in: International journal of biological macromolecules 2012-05, Vol.50 (4), p.895-898
• Main Authors: Mendoza, Jose A., Correa, Matthew D., Zardeneta, Gustavo
• Format: Article
• Language: English
• Subjects: adenosine triphosphate; alpha-Crystallins - chemistry; alpha-Crystallins - metabolism; Animals; Cattle; Chaperone; denaturation; GTP; guanosine triphosphate; Guanosine Triphosphate - metabolism; Guanosine Triphosphate - pharmacology; hydrophobicity; Protein Binding; Protein conformation; Protein Conformation - drug effects; Protein Denaturation - drug effects; Protein stability; Protein Stability - drug effects; proteins; thiosulfate sulfurtransferase; urea; Urea - pharmacology; α-Crystallin
• ISSN: 0141-8130; 1879-0003
• DOI: 10.1016/j.ijbiomac.2012.02.015

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.