Cholic acid is a naturally occurring detergent and belongs to the group of bile acids, which function as emulsifier of neutral lipids in the mammalian digestion tract. It is synthesized in the liver from cholesterol. After further derivatization to glycocholic and taurocholic acid, it is secreted into the bile. The sodium salt of cholic acid is mainly isolated from bovine bile.

Na-cholate is an important surfactant in membrane chemistry. It is an excellent solubilizer for numerous membrane components like receptors, enzymes, pigments, and phospholipids. The receptors of e.g. sigma, adenosine, acetylcholine, and gonadotropin have been successfully solubilized by Na-cholate

Na-cholate is ideal for the reconstitution of functional proteins by the dialysis removal method, a particularly gentle process. Because of its low association number and its high CMC-value, this surfactant permits the incorporation of receptors into liposomes.

The anionic surfactant Na-cholate is frequently employed in chromatography, especially for electrokinetic chromatography in pharmaceutical analysis.

Synonym: Sodium cholate

CAS-registry number [361-09-1]

Molecular formula: C₂₄H₃₉O4 . Na

Relative molecular mass (M_r): 430.5

Classification: Anionic surfactant

Literature specifications:
•    Critical micellar concentration (CMC): 7 – 16.2 mM
•    Aggregation number (N_a): 2 - 7
•    Critical micellar temperature (CMT): <0 °C
•    Partial specific volume (v): 0.771 cm3/g
•    Hydrophilic-lipophilic balance (HLB): 18
•    Acid dissociation exponent (pK_a): 5.2

Bibliography

Reconstitution Experiments

Paternostre, M.T., Roux, M. a. Rigaud, J.L. (1988) Mechanisms of membrane protein insertion into liposomes during reconstitution proce¬dures involving the use of detergents. 1. Solubil¬ization of large unilamellar liposomes (pre¬pared by reverse-phase evaporation) by Triton X-100, octyl glucoside and sodium cholate. Biochemistry 27, 2668-77.

Fafournoux, P., Dudenhausen, E.E. a. Kilberg, M.S. (1989) Solubilization and recon¬stitution characteristics of hepatic system A-mediated amino acid transport. J. Biol. Chem. 264, 4805-11.

Kolena, J. (1989) Functional reconstitution of rat ovarian LH-hCG receptor into proteoliposomes. FEBS Lett. 250, 425-8.

Lopez-Corcuera, B. a. Aragon, C. (1989) Solubil¬ization and reconstitution of the sodium-and¬ chloride-coupled glycine transporter from rat spinal cord. Eur. J. Biochem. 181, 519-24.

Nicchitta, C.V. a. Blobel, G. (1990) Assembly of translocation-competent proteoliposomes from detergent-solubilized rough microsomes. Cell 60, 259-69.

Watanabe, M., Nicchitta, C.V. a. Blobel, G. (1990) Reconstitution of protein translocation from detergent-solubilized Escherichia coli inverted vesicles. PrIA protein-deficient vesicles effi¬ciently translocate precursor proteins. Proc. Natl. Acad. Sci. U.S.A. 87, 1960-4.

Yamashita, T. a. Kawakita, M. (1992) Reconstitution of Na⁺/H⁺-antiporter of bovine renal brush-border membrane into proteoliposomes and detection of a 110 kDa protein cross-reactive with antibodies against a human Na⁺/H⁺-antiporter partial peptide in antiport-active fractions after partial fractionation. J. Biochem. 111, 162-7.

Solubilization and Characterization of Enzymes

Timouyasse, L., Prigent, A.F., Nemoz, G., Lagarde, M. a. Pacheco, H. (1989) Differential susceptibility to biological detergents of the particulate cGMP-stimulated phosphodiester¬ase from rat heart: preservation of the alloste¬ric properties of the solubilized enzyme. Bio¬chem. Int. 19, 287-99.

Zolfaghari, R., Harrison, E.H., Ross, A.C. a. Fisher, F.A. (1989) Expression in Xenopus oocytes of rat liver mRNA coding for a bile salt-depend¬ent cholesteryl ester hydrolase. Proc. Natl. Acad. Sci. U.S.A. 86, 6913-6.

Mayr, J.A. et al. (1996) Identification of a novel, Ca²⁺-dependent phospholipase D with preference for phosphatidylserine and phosphatidylethanolamine in Saccharomyces cerevisiae. FEBS Lett. 393, 236-40.

Sakamoto, J. et al. (2001) Cytochrome c oxidase contains an extra charged amino acid cluster in a new type of respiratory chain in the amino-acid-producing Gram-positive bacterium Corynebacterium glutamicum. Microbiology 147, 2865-71.

Solubilization and Characterization of Rezeptors

Kavanaugh, M.P., Parker, J., Bobker, D.H., Keana, J.F.W. a. Weber, E. (1989) Solubilization and characterization of o-receptors from guinea pig brain membranes. J. Neurochem. 53, 1575-80.

Nakata, H. a. Fujisawa, H. (1989) 5 '-N-Ethylcar¬boxamide[³H]adenosine binding sites of mouse mastocytoma P815 cell membranes: characterization and solubilization. J. Biochem. 105, 888-93.

Gagliardini, V. et al. (1994) Solubilization and characterization of d-fenfluramine binding sites from bovine cerebral cortex. Life Sciences 54, 1109-18.

Rinken, A. et al (1994) Solubilization of muscarinic receptor subtypes from baculovirus infected Sf9 insect cells. Biochem. Pharmacol. 48, 1245-51.

Solubillization and Character of Various Proteins/Protein Complexes

Ransnaes, L.A. a. Insel, P.A. (1989) Quantitation of a guanine nucleotide binding regulatory protein by an enzyme-linked immunosorbent competition assay. Anal. Biochem. 176, 185-90.

Solubilization and Characterization of Phospholipids

Bayerl, T.M., Werner, G.D., Sackmann, E. (1989) Solubilization of DMPC and DPPC vesicles by detergents below their critical micellization concentration: high-sensitivity differential scanning calorimetry, Fourier transform infra¬red spectroscopy and freeze-fracture electron microscopy reveal two interaction sites of detergents in vesicles. Biochim. Biophys. Ada 984, 214-24.

Malloy, R. C., Bin ford, J.S. Jr. (1990) Enthalpy titration and solubilization of dimyristoylphos¬phatidylcholine vesicles with bile salts. J. Phys. Chem. 94, 337-45.

Pearce, J.M. a. Komoroski, R.A. (2000) Analysis of phospholipid molecular species in brain by (31)P NMR spectroscopy. Magn. Reson. Med. 44, 215-23.

Chromatographic Separations

Miyashita, Y., Terabe, S. a. Nishi, H. (1990) Separation of some antibiotics and corticosteroids by micellar electrokinetic capillary chromatography using P/ACE System 2000. Chromatogram 11, 7-8

Nishi, H., Fukuyama, T., Matsuo, M. a. Terabe, S. (1990) Separation and determination of the ingredients of a cold medicine by micellar electrokinetic chromatography with bile salts. J. Chromatogr. 498, 313-23.

Mast, N. et al. (2004) Expression of human cytochrome P450 46A1 in Escherichia coli effects of N- and C-terminal modifications. Arch. Biochem. Biophys. 428, 99-108.