抄録
Protein-chondroitin sulfate A of pig embryo cartilage consists of two different types in structure and metabolism. The major part of the complex has an alkali-labile serine-linkage between the polypeptide and chondroitin sulfate A moiety which has a fully sulfated uniform chain but is of a slower metabolic rate. This type is the main component of the ground substance with collagen as a functional type.
The minor part has an alkali-stable linkage involving glutamine between the protein and immatured chondroitin sulfate A moiety which has a heterogeneously sulfated chain but is of ahigher metabolic rate. This might be a synthetic type of chondroitin sulfate in a cartilage cell.
The works with radiosulfate and radiocarbon glucose support strongly the idea that sugar polymerization precedes sulfation of the polymer.
A possible biosynthesis system of protein-polysaccharide complex is schemed.
Protein-polysaccharide complex is degraded by enzymes in two modes. Hyaluronidase type decreases viscosity of the complex solution slowly but protease type very rapidly. A crude extract of puppy epiphyseal cartilage showed the protease-type action and this would give better understandings of the biological roles of the complex.
