High hydrostatic pressure (HHP) at 500 MPa and 50°C induces β-LG into the molten globule state. Retinol, cis-parinaric acid (CPA), and 1-anilino-naphthalene-8-sulfonate (ANS) fluorescence from pH 2.5 to 10.5 in the presence of the native and molten globule states of β-LG indicate that retinol binds to β-LG in the calyx, CPA at the surface hydrophobic site, and ANS in multiple hydrophobic sites. HHP treatment results in a decrease of β-LG affinity for retinol and CPA, suggesting conformational changes in the calyx and surface hydrophobic site of β-LG during HHP treatment. β-LG treated by HHP in the presence of N-ethylmaleimide (NEM) retains retinol affinity, suggesting that NEM protects the calyx conformation of β-LG during HHP treatment. HHP treatment of β-LG in the presence of KIO3 exhibits a great decrease of CPA affinity compared to HHP-treated β-LG in the absence of KIO3, suggesting the formation of non-native disulfide bonding at the CPA binding site.
- High pressure
- Molten globule
- cis-parinaric acid
ASJC Scopus subject areas
- Agricultural and Biological Sciences(all)