Gemini Surfactant−Protein Interactions: Effect of pH, Temperature, and Surfactant Stereochemistry

Abstract

The interactions between bovine serum albumin (BSA) and gemini surfactants derived from cystine have been investigated and were compared with the conventional single-chain surfactant derived from cysteine. The influence of the stereochemistry of the gemini surfactant on its behavior toward BSA was also investigated, as well as the effects of pH and temperature. Electrical conductivity and surface tension measurements were used to obtain important system parameters such as critical aggregation concentration (cac), polymer saturation point (psp), degree of ionization (alpha), and the amount of surfactant binding to protein (M). Stereochemistry was found to influence the surface properties of the surfactants studied and their interaction with BSA but not their micellar properties in solution.

The formation of host–guest complexes between surfactants and cyclodextrins

“…Another important finding, for this set of systems, is that by increasing the spacer chain length both tails approach a situation where they are independent of each other which is reflected in an increase of K 2,1 , the value of which approaches K 1,1 values for the longest spacer [19,213]. More recently, interactions between β-CD and a dimeric cystine-derived urea surfactant ((C 8 Cys) 2 ) [293] were reported. These anionic geminis with short hydrocarbon chains form a predominant 1:1 complex with stability constants ranging from 1200 to 13100 M −1 (see Table 9), depending on the experimental technique used.…”

Chemo-enzymatic Synthesis and Properties of Novel Optically Active Cationics Containing Carbonate Linkages

“…After the reaction, the immobilized lipase CA was removed by fi ltration, and the solvent was evaporated under reduced pressure. Purifi cation was carried out by recrystallization from ethyl acetate 1.0 mL to obtain S -S12iPr with α D 27 16.8º c 0.5 in MeOH in 27 yield the theoretical yield was 50…”

“…Some of them exhibited better surface activities than the corresponding stereochemically mixed surfactants owing to much stronger intermolecular interactions between the surfactant molecules. It is also known that the chirality R or S confi guration of optically active surfactants is of crucial importance in biological properties 16,17 . However, the synthesis of optically active surfactants is complicated, generating relatively low yields.…”

‘Frustrated’ hydrogen-bonded self-associated systems as templates towards DNA incorporated nanostructure formation

“…15 Members from this class of compound were shown to exhibit similar critical micelle concentrations to sodium decanoate; 16 these properties were attributed to intermolecular hydrogen bonding interactions. In our preliminary studies, 17,18 we extended this work using similar amphiphilic monomers with the basic structure shown in Figure 1.…”