Glycosaminoglycans and Proteoglycans of Skin

The content of GAG in human skin is about 2-3 mg/g fresh tissue (2). The major 

present in similar amounts, are hyaluronan (HA) (previously called 

Small LeucIne-RIch Repeat Protelns/Proteoglycans 

The covalent structure of decorin is illustrated in Fig. 2. This proteoglycan consists of a protein core of a single polypeptide chain of 329 or 330 amino acids (depending on species), close to the Al-terminus of which is usually attached one sulfated GAG chain (12). In chicken, there is a second form of decorin that carries two GAG chains (13). 

DS and CS chains connect to the proteoglycan protein cores by a tetrasac-charide (o-glucuronosyl- (3-1,3-D-galactosyl- (3-1,3-o-galactosyl- (3-1,4-o-xylose). The single GAG chain of decorin is attached, via an O-glycoside link from this xylose, to residue 4 (serine) of the mature protein core (12). 

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