Solubilization as a method for studying self-association: Solubility of naphthalene in the bile salt sodium cholate and the complex pattern of its aggregation

1976 ◽  
Vol 65 (6) ◽  
pp. 882-886 ◽  
Author(s):  
Pasupati Mukerjee ◽  
John R. Cardinal
Keyword(s):  
Bile Salt ◽  
Sodium Cholate ◽  
Complex Pattern ◽  
Self Association

Comparison of In Vitro Binding of Bile Salt by Pectins from Various Sources

2012 ◽  
Vol 506 ◽  
pp. 274-277 ◽  
Author(s):  
K. Cheewatanakornkool ◽  
A. Chaidedgumjorn ◽  
U. Sotanaphun ◽  
S. Limsirichaikul ◽  
C. Wessapan ◽  
...  
Keyword(s):  
Bile Salt ◽  
Bile Salts ◽  
Serum Cholesterol Level ◽  
Sodium Deoxycholate ◽  
Sodium Cholate ◽  
Experimental Animals ◽  
Hypocholesterolemic Action ◽  
Acid Reaction ◽  
Layer Chromatography

Binding of bile salts by dietary fiber is believed to promote their excretion and hence to reduce the serum cholesterol level in man and experimental animals. In this study, the binding efficiency of soluble pectin from various sources, i.e., apple, citrus and pomelo, was examined. Sodium deoxycholate and sodium cholate hydrate were used as a model to represent bile salt in human body. The binding efficiency was assayed by acid reaction, thin layer chromatography (TLC) and enzyme cycling method. The results demonstrated that enzyme cycling method was the most suitable for assaying the in-vitro binding of bile salts while the TLC was not very sensitive, i.e., low amount of bile salts cannot be detected by TLC. Excess pectin from binding test could also interfere the acid reaction method even though the centrifugation was used to remove the excess pectin. When the concentration of pectin was increased, the binding efficiency with sodium deoxycholate increased. However, at 1% w/w of pectin, the binding efficiency decreased. The exception is for pomelo pectin in which the binding efficiency increased when the pectin concentration increased. With sodium cholate hydrate, only slight difference in binding efficiency was observed for all types and concentrations of pectin. The results indicate that the ability to bind bile salts of pectin might be responsible for its hypocholesterolemic action observed in experimental animals and humans.

Multiple prototropism of fisetin in sodium cholate and related bile salt media

2011 ◽  
Vol 10 (1) ◽  
pp. 66-75 ◽  
Author(s):  
Susithra Selvam ◽  
Ashok K. Mishra
Keyword(s):  
Bile Salt ◽  
Sodium Cholate

scholarly journals Self-association of unconjugated bilirubin-IX α in aqueous solution at pH 10.0 and physical-chemical interactions with bile salt monomers and micelles

1979 ◽  
Vol 179 (3) ◽  
pp. 675-689 ◽  
Author(s):  
M C Carey ◽  
A P Koretsky
Keyword(s):  
Aqueous Solution ◽  
Absorption Spectrum ◽  
Bile Salt ◽  
Bile Salts ◽  
Sodium Dodecyl ◽  
Chemical Properties ◽  
Critical Micellar Concentration ◽  
Solvent Mixtures ◽  
Physical Chemical ◽  
Self Association

Spectrophotometric measurements of bilirubin-IX alpha in water and in aqueous/organic solvent mixtures at pH 10.0 as a function of bilirubin-IX alpha concentration (approx. 0.6–400 microM) are consistent with the formation of dimers (KD - 1.5 microM) in dilute (less than 10 microM) aqueous solution and further self-aggregation to multimers at higher concentrations. Added urea (to 10M) and increases in temperature (to 62 degrees C) obliterate the dimer-multimer transition at 10 microM, but added NaCl (to 0.30 M) promotes strong aggregation of dimers over a narrow concentration range, suggesting a ‘micellization’ phenomenon. Concentrations of dioxan or ethanol greater than 60% (v/v) in water were required to obtain the absorption spectrum of bilirubin-IX alpha monomers, suggesting that both hydrophobic and electrostatic (pi-orbital) interactions are involved in stabilizing the dimeric state in water. Micellar concentrations of sodium dodecyl sulphate induced spectrophotometric shifts in the dimer absorption spectrum of bilirubin-IX alpha consistent with progressive partitioning of bilirubin-IX alpha monomers into a relatively non-polar region of the micelles and allowed a deduction of the apparent critical micellar concentration that closely approximated the literature values. The pattern of bilirubin IX alpha association with bile salts is complex, since the absorption spectrum shifts hypsochromically below and bathochromically above the critical micellar concentration of the bile salts. Consistent with these observations, bilirubin IX alpha appears to bind to the polar face of bile salt monomers and to the polar perimeter of small bile salt micelles. At higher bile salt concentrations some-bilirubin-IX alpha monomers partition into the hydrophobic interior of the bile salt micelles. Our results suggest that under physiological conditions the natural conjugates of bilirubin-IX alpha may exhibit similar physical chemical properties in bile, in that dimers, highly aggregated multimers and bile salt-associated monomers may co-exist.

Studies in Bile Salt Solutions .XIII. Hydrophobic Substrate Effects on the Esterase Activity of Bile-Salt-Stimulated Human-Milk Lipase. Hydrolysis of 4-Nitrophenyl Alkanoates and Alkyl 4-Nitrobenzoates

1986 ◽  
Vol 39 (2) ◽  
pp. 249 ◽  
Author(s):  
CJ Oconnor ◽  
ASH Mitha ◽  
P Walde
Keyword(s):  
Human Milk ◽  
Bile Salt ◽  
Binding Site ◽  
Sodium Taurocholate ◽  
Sodium Cholate ◽  
Lipase Hydrolysis ◽  
Nitrobenzoic Acid ◽  
Hydrocarbon Chains ◽  
Hydrophobic Nature ◽  
Hydrolysis Of

The pseudo-first-order rate constants of hydrolysis of a series of 4-nitrophenyl alkanoates and a series of n-alkyl esters of 4-nitrobenzoic acid and of 4-nitrophenyl hexahydrobenzoate and cyclohexyl 4-nitrobenzoate, catalysed by bile-salt-stimulated human milk lipase in the absence and presence (2 mmol dm-3) of sodium cholate/cholic acid and sodium taurocholate , have been measured at pH 7.3, 310.5 K. It has been shown that the enzyme possesses a specific esterase acyl binding site which almost completely excludes the binding therein of a cyclohexyl group. There is also present a specific alkyl binding site which can fully accommodate a cyclohexyl ring. Both binding sites are hydrophobic in nature, but although the hydrophobic nature of the alkyl binding site is affected by bile-salt stimulation, that of the acyl site is not. Hydrophobicity parameters have been calculated for hydrocarbon chains lying in the acyl and alkyl binding positions of bile-salt-stimulated human milk lipase.

Self-association of sodium cholate in isotonic saline solutions

1985 ◽  
Vol 21 (2) ◽  
pp. 103-114 ◽  
Author(s):  
John M. Beckerdite ◽  
E.T. Adams
Keyword(s):  
Isotonic Saline ◽  
Sodium Cholate ◽  
Self Association ◽  
Saline Solutions
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