1-Anilino-8-naphthalene sulfonate (ANS) is not a desirable probe for determining the molten globule state of chymopapain.

ABSTRACT: The molten globule (MG) state of proteins is widely detected through binding with 1-anilino-8-naphthalene sulphonate (ANS), a fluorescent dye. This strategy is based upon the assumption that when in molten globule state, the exposed hydrophobic clusters of protein are readily bound by the nonpolar anilino-naphthalene moiety of ANS molecules which then produce brilliant fluorescence. In this work, we explored the acid-induced unfolding pathway of chymopapain, a cysteine proteases from Carica papaya, by monitoring the conformational changes over a pH range 1.0-7.4 by circular dichroism, intrinsic fluorescence, ANS binding, acrylamide quenching, isothermal titration calorimetry (ITC) and dynamic light scattering (DLS). The spectroscopic measurements showed that although maximum ANS fluorescen

SUBMITTER: Qadeer A 

PROVIDER: S-EPMC3510187 | biostudies-literature | 2012

REPOSITORIES: biostudies-literature