Physico‐chemical studies of micelle formation on sepia cartilage collagen solutions in acetate buffer and its interaction with ionic and nonionic micelles

Abstract

Sepia cartilage collagen (pepsin-extracted) in acetate buffer (pH = 2.98) forms micelles at a particular concentration below which they do not normally form. The critical micelle concentration (cmc) of the collagen was determined in buffer as well as in SDS, cetyltrimethylammonium bromide (CTAB) and Tween-80 micellar environments at different temperatures. Mutual interaction of collagen micelles with the ionic and nonionic micelles through the formation of the mixed micelle concept has also been found. The cmc of collagen decreased in the presence of SDS and Tween-80 micelles whereas it increased in the presence of CTAB micelles. This clearly suggests that the micelle formation of collagen is facilitated by the presence of SDS and Tween-80 and hindered by CTAB micelles. The various thermodynamic parameters were estimated from viscosity measurements and the transfer of collagen into the micelles of various surfactants and the reverse phenomenon was analyzed. This analysis has also been modelled conceptually as a different phase and the results have supported the above phenomenon. Our thermodynamic results are also able to predict the exact denaturation temperature as well as the structural order of water in the collagen in various environments. The hydrated volumes, Vh, of collagen in the above environments and intrinsic viscosity were also calculated. The low intrinsic viscosity, [?I, of collagen in an SDS environment compared to buffer and other surfactant environments suggested more workable systems in cosmetic and dermatological skin care preparations. The one and two-hydrogen-bonded models of this collagen in various environments have been analyzed. The calculated thermodynamic parameters varied with the concentration of collagen. The change of thermodynamic parameters from coil-coil to random-coil conformation upon denaturation of collagen were calculated from the amount of proline and hydroxyproline residues and compared with viscometric results. Thermodynamic results suggest that the stability of the collagen in the additive environments is in the following order: SDS > Tween-80 > buffer > CTAB.It is well known that the structure of water is important for interactions between proteins and membrane transport phenomena. These interactions are difficult to study due to the fact that the exact shapes, sizes and structure of the proteins are not clearly known. A favourable exception is collagen, consisting of triple-stranded helices which can be regarded as rigid rods. According to X-ray diffraction patterns the rods are packed in a complex lattice [l]. The important features are that the rods are aligned along the fiber axis and that the lattice expands [2] commensurate with the water content. The studies from various sources have indicated that the structure of water absorbed in collagen is different from that of water in bulk. Broad-line NMR measurements [3 -61 have shown two absorption lines instead of one. This may be the reason that the water molecules in collagen do not rotating isotropically. Moreover,...

Thermodynamics studies on tyrosine-hydantoin drug–cetyltrimethylammonium bromide mixed micellar system

“…amitriptyline hydrochloride, imipramine hydrochloride, chlorpromazine hydrochloride and, promethazine hydrochloride in presence of additives have recently been evaluated [11][12][13][14][15]. Micellar characteristics of various peptides, collagens, polymers in aqueous and non-aqueous media and their interactions with various surfactant micelles have widely been studied [16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34] in light of aggregation, H-bonding, geometry, correlation times, conformation, hydrodynamic and thermodynamic studies.…”

Effect of surfactants on the thermal, conformational and rheological properties of collagen

“…Cetyl trimethylammoniumbromide (CTAB), a cationic surfactant, on the other hand, hindered the micelle formation of the collagen owing to the repulsive effect between N + ion of CTAB and NH 3 + ion of amino acids [16,17]. The difference in the denaturation behavior of RTT collagen with various surfactants suggests the different mode of interactions present between SDS-collagen, Triton X-100 and CTAB-collagen complexes.…”

Synthesis, Characterization, and Catalytic Activity of Platinum Nanoparticles on Bovine-Bone Powder: A Novel Support

“…It is worth noticing that a calcination step is not necessary since Pt NPs were obtained by NaBH 4 as reduction agent. It is also worth pointing out that, because of the amount of treated powder (approximately 1 g), a micellar activity might also be expected since the micelle formation of sepia cartilage collagen solutions has been previously reported [30].…”