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,...
The investigation presents the metabolic changes in the carbohydrate components of glycoproteins in several tissues of adjuvant arthritic rats. The experimental arthritis induces a significant modification of total carbohydrate moieties of glycoproteins in arthritic tissues. In both acute and chronic phases of the disease, the adjuvant arthritis caused a significant increase in the levels of carbohydrate moieties of tissue glycoproteins viz. total hexose, hexosamine, fucose, sialic acid, total neutral sugar content and neutral sugar monosaccharides. In addition, the urinary excretions of hexosamine and uronic acid in arthritic rats were found to be elevated significantly. The data from the investigation clearly indicate that the experimental arthritis induces an increased glycoprotein synthesis in most of the tissues examined.
The distribution of various collagen types was studied in rat fibrosarcoma. Collagens extracted from fibrosarcoma tissue were characterized by the criteria of solubility in NaCl, SDS-PAGE, ion exchange chromatography, CNBr peptide mapping and amino acid analysis. Fibrosarcoma was found to produce excess amount of type V, type I trimer and type III collagens; comparatively, type I collagen and total collagen content were noticed to decrease in fibrosarcoma. We observe that the increase in type V collagen content in fibrosarcoma might be due to the enhanced transcription of type V collagen gene. Increased type I trimer collagen in fibrosarcoma might be attributed to the differential expression of alpha 1(I) and alpha 2(I) gene and might also be due to the expression of a different gene for type I trimer collagen.
The effects of the percutaneous transport of vehicles and the transport of P-aminopropionitrile (PAPN) in vehicles were studied in rats. The bioavailability of topically administered PAPN was determined by measuring the degree of collagen cross-linking inhibition in the underlying granuloma tissue. Granulomas were induced by subcutaneous implantation of polyvinylalcohol sponges. From the 4th to 12th days postimplantation, a 20 mg/cm2 dose of PAPN fumarate was applied. Vehicles employed included dimethylsulfoxide (DMSO), urea, and occlusion. DMSO significantly enhanced the effect of PAPN in reducing the cross-linking of collagen. PAPN administered onto urea-pretreated skin and followed by occlusion in the granuloma tissue was more effective than PAPN in 30% DMSO, but only in the parameter reflecting extractibility of collagen into urea or thiocyanate solutions. The results suggest that PAPN administered topically in an appropriate vehicle penetrates the granuloma tissue and affects collagen polymerization. Though PAPN was topically administered, a systemic effect from the drug was evident, as documented by lower body weight of treated rats. o 1988 Society for Experimental Biology and Medicine.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.