Spectroscopic investigation on the interaction of CHAPS, the zwitterionic steroidal surfactant, with bovine and human serum albumins: A comparative study

CHAPS, the zwitterionic derivative of cholic acid, has garnered significant research attention owing to its biocompatibility, electro-neutrality over a wide pH range, and non-denaturing nature towards proteins. The escalating demand of CHAPS in biomedical and pharmaceutical industries mandates information on its interaction with various biological macromolecules, especially proteins. The present study involves a comprehensive investigation on the interaction of CHAPS in a wide concentration range (0.001 mM-32 mM), with two extensively used transport proteins, BSA (Bovine Serum Albumin) and HSA (Human Serum Albumin). The study suggests a concentration dependent sequential interaction of CHAPS in discreet stages with the two proteins. A detailed study using warfarin and ibuprofen as site markers provides information about the sites of interaction at different stages. The study indicates significant difference in the effect of CHAPS on these two homologous proteins in terms of their esterase-like activity and effect of chemical denaturant. Moreover, a comparison between CHAPS and its structural bile salt analogues, Sodium cholate and Sodium taurocholate, towards their interaction and effect on the two serum albumins, reveals the mildness of CHAPS towards the proteins, thus endorsing it as a more suitable drug carrier in comparison to its bile salt analogues.