The interaction of the human serum albumin (HSA), bovine serum albumin (BSA) with cholesterol has
been investigated. The basic binding interaction was studied by FTIR and fluorescence spectroscopy.
From spectral analysis cholesterol showed a strong ability to quench the intrinsic fluorescence of HSA
and BSA through a static quenching mechanism. The binding constant (k) between HSA and cholesterol
is estimated to be K=2.14 × 103 M-1 at 293 K while between BSA and cholesterol is estimated to be
K=.1.12 × 103 M-1 at the same temperature. FTIR spectroscopy with Fourier self-deconvolution technique
was used to determine the protein secondary structure and cholesterol binding mechanisms. The observed
spectral changes indicate a higher percentage of H-bonding between cholesterol and -helix compared to
the percentage of H-bonding to cholesterol and -sheets.This work is supported by the German
Research Foundation DFG grant No. DR228/24-
