Structure of avian thymic hormone, a high-affinity avian beta-parvalbumin, in the Ca2+-free and Ca2+-bound states.

ABSTRACT: Originally isolated on the basis of its capacity to stimulate T-cell maturation and proliferation, avian thymic hormone (ATH) is nevertheless a parvalbumin, one of two beta-lineage isoforms expressed in birds. We recently learned that addition of Ca(2+)-free ATH to a solution of 8-anilinonaphthalene-1-sulfonate (ANS) markedly increases ANS emission. This behavior, not observed in the presence of Ca(2+), suggests that apolar surface area buried in the Ca(2+)-bound state becomes solvent accessible upon Ca(2+) removal. In order to elucidate the conformational alterations that accompany Ca(2+) binding, we have obtained the solution structure of the Ca(2+)-free protein using NMR spectroscopy and compared it to the Ca(2+)-loaded protein, solved by X-ray crystallography. Although the metal-ion-bi

SUBMITTER: Schuermann JP 

PROVIDER: S-EPMC3091166 | biostudies-literature | 2010 Apr

REPOSITORIES: biostudies-literature