1 ) a recovery in the size of the proteoglycan , 2 ) a marked decrease in the ability to interact with hyaluronic acid , 3 ) an increase in galactosamine/glucosamine and a gradual decrease in glucosamine/amino acid ratio , and 4 ) an increase in serine and glycine and a decrease in half cysteine and methionine content of the core protein .
C0002520
amino acid
C0017890
glycine