title: Biological significance of helical conformation of acid polysaccharides.
abstract: Optical rotary dispersion spectra have been studied of methylene blue complexes of glycosaminoglycans and different derivates of chondroitin 4-sulphate (free and protein bound complexes of different molecular weights and degrees of sulphation). Structural requirements of Ch-4S induction of the extrinsic Cotton effect in methylene blue were formulated. This Cotton effect is supposed to reflect the right-handed helical structure of the polysaccharide molecules. Ch-4S displayed induced Cotton effect both in free and in protein bound form; molecular weight should exceed 2-3000 (at least 4-6 disaccharide units), degree of sulphation should exceed 3% sulphate-sulphur content (more than 0.5 sulphate per one disaccharide unit). For comparison the effect of different derivatives of Ch-4S on the rate of in vitro collagen fibril formation was investigated. Close correlation was found between the macrostructural characteristics and the possible biological effect of Ch-4S. The biological significance of the macrostructural properties of Ch-4S is discussed.
mesh_terms: D002807:Chondroitin / Q000031:analogs & derivatives*; D002809:Chondroitin Sulfates; D008751:Methylene Blue; D008968:Molecular Conformation; D008970:Molecular Weight; D009905:Optical Rotatory Dispersion; D013329:Structure-Activity Relationship; D013499:Surface Properties
chemical_list: D002807:Chondroitin; D002809:Chondroitin Sulfates; D008751:Methylene Blue