Solution Behavior and Interaction of Pepsin with Carnitine Based Cationic Surfactant: Fluorescence, Circular Dichroism, and Calorimetric Studies.

The present work reports the pH-induced conformational changes of pepsin in solution at room temperature. The conformational change makes the protein surface active. The protein was found to be present in the partially denatured state at pH 8 as well as at pH 2.

Cationic vesicles of a carnitine-derived single-tailed surfactant: physicochemical characterization and evaluation of in vitro gene transfection efficiency.

Spontaneous vesicle formation in water by single-chain surfactants is rare. Here we show that in aqueous solution, a single-chain cationic surfactant 3-(dodecylcarbamoyl-2-hydroxypropyl)-trimethylammonium chloride (C12-CAR) derived from D,L-carnitine spontaneously forms vesicles with hydrodynamic diameters in the range of 30-70 nm. A detailed self-assembly study of the C12-CAR surfactant was performed for the first time by use of a combination of techniques, including surface tension, conductivity, fluorescence probe, dynamic light scattering and transmission electron microscopy.

A smart supramolecular hydrogel of N(alpha)-(4-n-alkyloxybenzoyl)-L-histidine exhibiting pH-modulated properties.

Six L-histidine-based amphiphiles, N(alpha)-(4-n-alkyloxybenzoyl)-L-histidine of different hydrocarbon chain lengths, were designed, synthesized, and examined for their ability to gelate water. Four of members of this family of amphiphiles were observed to form thermoreversible hydrogels in a wide range of pH at room temperature. The structural variations were characterized by critical gelation concentration, gelation time, gel melting temperature (T(gs)), rheology, and electron microscopy.

Birefringent physical gels of N-(4-n-alkyloxybenzoyl)-L-alanine amphiphiles in organic solvents: the role of hydrogen-bonding.

A new class of amphiphiles, N-(4-n-alkyloxybenzoyl)-L-alanine was designed and synthesized. These amphiphiles have been shown to form thermoreversible gels in organic solvents such as aromatic hydrocarbons, cyclohexane, and chlorinated hydrocarbons at room temperature. The effects of amide functionality, chain length of the hydrocarbon tail, and the chirality of the head group of the amphiphiles on the ability to promote gelation in organic solvents have been studied.

Salt-induced vesicle to micelle transition in aqueous solution of sodium N-(4-n-octyloxybenzoyl)-L-valinate.

The self-organization of a single-tailed amino acid based chiral surfactant sodium N-(4-n-octyloxybenzoyl)-L-valinate (SOBV) has been studied in water. A number of techniques like surface tension, fluorescence probe, dynamic light scattering (DLS), transmission electron microscopy (TEM), and atomic force microscopy (AFM) have been utilized for characterization of the self-assemblies. The amphiphile forms large spherical vesicles of 400-600 nm diameters in dilute aqueous solution.