The participation of the human albumin domains in the thermal and chemical unfolding of this protein

GUILLERMO ALFREDO PICO; FARRUGGIA, B; RIGATUSSO, RUBÉN; RODRIGUEZ, F.; FIDELIO, G.

JOURNAL OF PROTEIN CHEMISTRY

Plenum Publishing Corporation

Lugar: NY; Año: 2001 vol. 20 p. 81 - 89

0277-8033

Fluorescence spectroscopy and differential scanning calorimetry were used to follow local and global changes in human serum albumin domains during chemical and thermal denaturation of this protein. Results suggests that thermal and chemical treatments involved an unfolding pathway of at least two steps and that domain IIA is not homogeneous. Unfolding at site I exposes a larger hydrophobic area to the solvent than at site II. The bilirubin-binding site showed atypical behavior: a significant increase in the hydrophobic area was exposed to the solvent when its binding site was denatured by guanidine hydrochloride. This result might be due to the high specificity of the bilirubin- binding site, whose binding makes an extensive conformational change in the environment of this site.