Hydrophobicity is the governing factor in the interaction of human serum albumin with bile salts. 2015

Narayani Ghosh, and Ramakanta Mondal, and Saptarshi Mukherjee
Department of Chemistry, Indian Institute of Science Education and Research Bhopal , Indore By-Pass Road, Bhauri, Bhopal 462 066, Madhya Pradesh, India.

The present study demonstrates a detailed characterization of the interaction of a series of bile salts, sodium deoxycholate (NaDC), sodium cholate (NaC), and sodium taurocholate (NaTC), with a model transport protein, human serum albumin (HSA). Here, steady-state and time-resolved fluorescence spectroscopic techniques have been used to characterize the interaction of the bile salts with HSA. The binding isotherms constructed from steady-state fluorescence intensity measurements demonstrate that the interaction of the bile salts with HSA can be characterized by three distinct regions, which were also successfully reproduced from the significant variation of the emission wavelength (λ(em)) of the intrinsic tryptophan (Trp) moiety of HSA. The time-resolved fluorescence decay behavior of the Trp residue of HSA was also found to corroborate the steady-state results. The effect of interaction with the bile salts on the native conformation of the protein has been explored in a circular dichroism (CD) study, which reveals a decrease in α-helicity of HSA induced by the bile salts. In accordance with this, the esterase activity of the protein-bile salt aggregates is found to be reduced in comparison to that of the native protein. Our results exclusively highlight the fact that it is the hydrophobic character of the bile salt that governs the extent of interaction with the protein. Isothermal titration calorimetry (ITC) and molecular docking studies further substantiate our other experimental findings.

UI MeSH Term Description Entries
D007700 Kinetics The rate dynamics in chemical or physical systems.
D011485 Protein Binding The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments. Plasma Protein Binding Capacity,Binding, Protein
D002942 Circular Dichroism A change from planar to elliptic polarization when an initially plane-polarized light wave traverses an optically active medium. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed) Circular Dichroism, Vibrational,Dichroism, Circular,Vibrational Circular Dichroism
D003840 Deoxycholic Acid A bile acid formed by bacterial action from cholate. It is usually conjugated with glycine or taurine. Deoxycholic acid acts as a detergent to solubilize fats for intestinal absorption, is reabsorbed itself, and is used as a choleretic and detergent. Deoxycholate,Desoxycholic Acid,Kybella,Choleic Acid,Deoxycholic Acid, 12beta-Isomer,Deoxycholic Acid, 3beta-Isomer,Deoxycholic Acid, 5alpha-Isomer,Deoxycholic Acid, Disodium Salt,Deoxycholic Acid, Magnesium (2:1) Salt,Deoxycholic Acid, Monoammonium Salt,Deoxycholic Acid, Monopotassium Salt,Deoxycholic Acid, Monosodium Salt,Deoxycholic Acid, Sodium Salt, 12beta-Isomer,Dihydroxycholanoic Acid,Lagodeoxycholic Acid,Sodium Deoxycholate,12beta-Isomer Deoxycholic Acid,3beta-Isomer Deoxycholic Acid,5alpha-Isomer Deoxycholic Acid,Deoxycholate, Sodium,Deoxycholic Acid, 12beta Isomer,Deoxycholic Acid, 3beta Isomer,Deoxycholic Acid, 5alpha Isomer
D006801 Humans Members of the species Homo sapiens. Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D001647 Bile Acids and Salts Steroid acids and salts. The primary bile acids are derived from cholesterol in the liver and usually conjugated with glycine or taurine. The secondary bile acids are further modified by bacteria in the intestine. They play an important role in the digestion and absorption of fat. They have also been used pharmacologically, especially in the treatment of gallstones. Bile Acid,Bile Salt,Bile Salts,Bile Acids,Acid, Bile,Acids, Bile,Salt, Bile,Salts, Bile
D012709 Serum Albumin A major protein in the BLOOD. It is important in maintaining the colloidal osmotic pressure and transporting large organic molecules. Plasma Albumin,Albumin, Serum
D012996 Solutions The homogeneous mixtures formed by the mixing of a solid, liquid, or gaseous substance (solute) with a liquid (the solvent), from which the dissolved substances can be recovered by physical processes. (From Grant & Hackh's Chemical Dictionary, 5th ed) Solution
D013050 Spectrometry, Fluorescence Measurement of the intensity and quality of fluorescence. Fluorescence Spectrophotometry,Fluorescence Spectroscopy,Spectrofluorometry,Fluorescence Spectrometry,Spectrophotometry, Fluorescence,Spectroscopy, Fluorescence
D013656 Taurocholic Acid The product of conjugation of cholic acid with taurine. Its sodium salt is the chief ingredient of the bile of carnivorous animals. It acts as a detergent to solubilize fats for absorption and is itself absorbed. It is used as a cholagogue and cholerectic. Cholyltaurine,Taurine Cholate,Taurocholate,Sodium Taurocholate,Taurocholate Sodium,Taurocholic Acid, (5 alpha)-Isomer,Taurocholic Acid, (7 beta)-Isomer,Taurocholic Acid, Monolithium Salt,Taurocholic Acid, Monosodium Salt,Taurocholate, Sodium

Related Publications

Narayani Ghosh, and Ramakanta Mondal, and Saptarshi Mukherjee
October 1989, General physiology and biophysics,
Narayani Ghosh, and Ramakanta Mondal, and Saptarshi Mukherjee
March 1982, Journal of lipid research,
Narayani Ghosh, and Ramakanta Mondal, and Saptarshi Mukherjee
December 1984, Biochimica et biophysica acta,
Narayani Ghosh, and Ramakanta Mondal, and Saptarshi Mukherjee
February 2018, Journal of pharmaceutical analysis,
Narayani Ghosh, and Ramakanta Mondal, and Saptarshi Mukherjee
September 1995, Biochimica et biophysica acta,
Narayani Ghosh, and Ramakanta Mondal, and Saptarshi Mukherjee
November 1989, Biochimica et biophysica acta,
Narayani Ghosh, and Ramakanta Mondal, and Saptarshi Mukherjee
March 1973, European journal of biochemistry,
Narayani Ghosh, and Ramakanta Mondal, and Saptarshi Mukherjee
February 1971, Journal of pharmaceutical sciences,
Narayani Ghosh, and Ramakanta Mondal, and Saptarshi Mukherjee
January 2004, Bioorganic & medicinal chemistry,
Narayani Ghosh, and Ramakanta Mondal, and Saptarshi Mukherjee
October 1990, Biochemical pharmacology,
Copied contents to your clipboard!