Interactions and Molecular Weights of Simple Micelles and Mixed Micelles in Taurocholate and Taurocholate−Lecithin Solutions

Abstract

A quasielastic light-scattering (QLS) technique was employed to investigate simple micelles and mixed micelles formed in taurocholate (TC) and TC-lecithin (L) solutions. When the size and polydispersity of simple TC micelles were nearly unchanged with total TC concentrations, the simple TC micelles were suggested to be all of a single size. According to the relationship between the total TC concentration and the TC monomer concentration, a monomer-micelle model predicted the aggregation number (n) and the critical micellar concentration (cmc) of simple TC micelles to be 5 and 10 mM. Based on Flory's theory, the scattered intensity, the TC monomer concentration, the molecular weights of simple TC micelles, and mixed TC-L micelles were estimated to be 2138 Da and 35 840 Da. Moreover, the interaction coefficients of simple TC micelles and mixed TC-L micelles were found to be 1.30 × 10 -5 dL mol g -2 and 5.09 × 10 -6 dL mol g -2 . According to Flory's equation, the estimated interaction coefficients and the concentrations of simple TC micelles and mixed TC-L micelles resulted in different values of the proportionality constant. When the proportionality constant values were assumed to be unchanged, significant errors in the determined molecular weights of simple TC micelles and mixed TC-L micelles occurred.

Conductivity and fluorescence studies on the micellization properties of sodium cholate and sodium deoxycholate in aqueous medium at different temperatures: Effect of selected amino acids

“…Moreover, the (bile salt + protein) interactions in entero-hepatic and gallbladder bile are significant examples of (surfactant + protein) interactions that play a key role in biochemically relevant processes [20]. In spite of this, not much is known about the details of (bile salt + protein) aggregates, especially by taking amino acids as model compounds [21][22][23] and studies on the mono-dispersity [24] and poly-dispersity [25][26][27][28] of bile salt aggregates have remained a matter of controversy.…”

Steroidal Surfactants: Detection of Premicellar Aggregation, Secondary Aggregation Changes in Micelles, and Hosting of a Highly Charged Negative Substance

“…[9][10][11][12][13] In both cases, there is an initial formation of small aggregates driven by the hydrophobic interaction between the apolar faces of the rings of two molecules (back-to-back aggregation). Literature shows a great variety of the CMCs values 6,10,11,[14][15][16][17][18] that can be explained either by the slow change of the successive aggregation steps or by the experimental constraints. Regarding CHAPSO and CHAPS, literature about their aggregation properties is scarce, and it is basically centered on CHAPS.…”

A Monomer‐Micelle Model for the Formation of Simple Taurocholate Micelles

“…Nevertheless, Liu et al suggested a constant size of simple TC micelles and a monomer-micelle model for the formation of simple TC micelles due to the hydrophobic interaction of TC monomers. 7,8 Based on this model, the relationship between monomer TC concentrations (C 1 ) and total TC concentrations (C), determined using the Sephadex G-10 bead uptake method, could be fitted by a least-squares technique. [8][9][10] In addition, the aggregation number (n) and the critical micelle concentration (CMC) were estimated to be~5 and~10 mM.…”

“…7,8 Based on this model, the relationship between monomer TC concentrations (C 1 ) and total TC concentrations (C), determined using the Sephadex G-10 bead uptake method, could be fitted by a least-squares technique. [8][9][10] In addition, the aggregation number (n) and the critical micelle concentration (CMC) were estimated to be~5 and~10 mM. 8 However, the estimated value of CMC (~10 mM) 8 was higher than the reported value (~6 mM) of CMC.…”

“…[8][9][10] In addition, the aggregation number (n) and the critical micelle concentration (CMC) were estimated to be~5 and~10 mM. 8 However, the estimated value of CMC (~10 mM) 8 was higher than the reported value (~6 mM) of CMC. 11,12 Moreover, the relationship determined by the Sephadex G-10 bead uptake technique was questioned because TC dimers were also absorbed onto the beads.…”