Chemistry of heparitin sulfate and heparin from normal tissues and from patients with Hunter syndrome.

Some structural features of heparitin sulfate excreted by patients with Hunter syndrome are described. It is shown, with the aid of heparitinases and heparinase from Flavobacterium heparinum, that the Hunter heparitin sulfate is a very complex structure composed of nine different disaccharide units containing regions akin to normal heparitin sulfate and regions akin the heparin. Two-thirds of the iduronic acid residues of Hunter heparitin sulfate are devoid of sulfate, contrasting with heparin in which most of the iduronic acid residues are sulfated. The isolation and characterization of the non-reducing ends of heparin and of the heparitin sulfates is also described. Based on these results the specificity of the heparinase and heparitinases as well as the biosynthesis of iduronic acid-containing heparin-like compounds is discussed.     

Fractionation and properties of four heparitin sulfates from beef lung tissue: Isolation and partial characterization of a homogeneous species of heparitin sulfate

Several commerical batches of heparitin sulfate extracted from beef lung tissue were fractionated into at least four distinct mucopolysaccharides by a combination of polyacrylamide and agarose gel electrophoresis. The four heparitin sulfates (A, B, C and D) were distinguished from each other and from heparin by several physical and chemical properties such as electrophoretic migration, molecular weight, presence of N-acetyl, N- and )-sulfate residues, optical rotation and enzymatic degradation. Of particular significance was the isolation of a heparitin sulfate (heparitin sulfate C) with a homogeneous molecular weight.     

Interactions between mucopolysaccharides and cationic polypeptides in aqueous solution: hyaluronic acid, heparitin sulfate, and keratan sulfate

Circular dichroism spectroscopy has been used to study the interactions of hyaluronic acid, heparitin sulfate, and keratan sulfate with cationic polypeptides. The results indicate that the presence of these mucopolysaccharides has an effect in the conformation of poly(L -lysine) and poly(L -arginine), such that the former adopts the “random” form and the latter takes up the α-helical conformation, rather than the “charged coil” form expected at neutral pH. The relative strengths of the interactions can be judged from the melting temperatures above which they are disrupted. Both the stoichiometry and the strength of the interactions depend on the position, number, and type of anionic groups attached to the polysaccharide backbone. Such considerations place the six common mucopolysaccharides in order of increasing strength of interaction: hyaluronic acid < chondroitin 4-sulfate < heparitin sulfate < chondroitin 6-sulfate < keratan sulfate ? dermatan sulfate. These differences should be paralleled by differences in the interaction of the mucopolysaccharides with collagen and fibrous proteins.