albumin - publications
Prototropism of [2,2'-bipyridyl]-3,3'-Diol in Albumin-SDS Aggregates.
J Phys Chem B. 2012 Aug 22;
Authors: De D, Santra K, Datta A
In this present investigation, attempt is made to use [2,2'-bipyridyl]-3,3'-diol (BP(OH)2) as a marker to study albumin-SDS interactions and to obtained structural information about these aggregates. It is also intended to contemplate the effect of these aggregates on the excited state proton transfer dynamics of BP(OH)2. Steady state and time resolved fluorescence spectroscopic techniques are employed to elucidate the nature of interaction of two homologous carrier proteins, human serum albumin (HSA) and bovine serum albumin (BSA) with negatively charged surfactant sodium dodecyl sulphate (SDS). Both spectral and temporal behavior of BP(OH)2 in these albumin-SDS aggregates strongly affirms an initial competitive binding of SDS in high energy binding sites of albumin. Unlike normal SDS micelles, absence of formation of monocation of BP(OH)2 at negatively charged interface of SDS is rationalized by the screening of the micellar interface in presence of denatured protein which wraps around these surfactant aggregates. An enhanced extent of excited state proton transfer is manifested by a corresponding increase in fluorescence quantum yield of BP(OH)2 in these aggregates. Temporal evolution of BP(OH)2 at different emission wavelength fortifies the formation of normal micelles post saturation. All our observations are found to corroborate with necklace and bead model proposed for protein-surfactant aggregates.
PMID: 22913628 [PubMed - as supplied by publisher]