Mucopolysaccharides of Connective Tissue* 



Albert Dorfman and Sara Schiller 



The LaRahida-Lniversity of Chicago Institute and the Departments of 

 Pediatrics and Biochemistry, University of Chicago, Chicago, III., U.S.A. 



Polysaccharides, like other macromolecules, are generally classified on 

 the basis of structure and composition. However, rapidly expanding 

 research has made feasible an examination of the relationship between 

 biological function and chemical structure. Consideration of the physio- 

 logical role of polysaccharides suggests a distinction between energy- 

 yielding and structural polysaccharides. In general, the former appear to 

 be branched glucose polymers containing a glycoside linkages. Most 

 typical of this group are starch and glycogen. In contrast, the structural 

 polysaccharides are a more complex group of substances containing diverse 

 monosaccharides. Many appear to be /S-linked polymers. Examples of 

 these are cellulose, chitin, and the acid mucopolysaccharides of mammalian 

 tissues. Other polysaccharides, such as the hemi-celluloses, pectins, and 

 bacterial capsular polysaccharides, may be regarded as structural, but 

 chemical correlations have not been clearly established, particularly with 

 regard to steric configuration of the glycoside bonds. It seems likelv that 

 with continuing investigation of chemical-biological correlations, a better 

 understanding of the physiology of these substances may be reached. 



Limitation of space does not permit an extensive review of the numerous 

 structural polysaccharides. This presentation will be confined rather to a 

 discussion of the acid mucopolysaccharides of mammalian connective 

 tissues. These compounds are linear polyanions which contain alternating 

 units of N-acetylated hexosamine and uronic acid (with one exception) ; 

 and in some cases, sulphate. They exist in the ground substance, a complex 

 mixture in which the formed elements of connective tissues are imbedded. 



Figure i illustrates a portion of the chain of chondroitin sulphuric 

 acid-A, present in high concentration in mammalian cartilage. Alternating 

 glucuronic acid and N-acetylgalactosamine units are linked glvcosidically 

 to form linear molecules. The galactosaminidic bond is 1^*4 while the 



* Original investigations reported in this communication were supported by 

 grants from The National Heart Institute of the United States Public Health 

 Service (No. H 311), The National Foundation, and The Chicago Heart Associa- 

 tion, 



