title: Analysis of the intermediate size proteoglycans from the developing chick limb buds.
abstract: Limb-bud proteoglycans are heterogeneous molecules which vary in their chemical and physical properties with development. This report describes proteoglycan intermediates (PG-I) that predominate in stage-34 limbs, and compares them with proteoglycan aggregates (PG-A) in stage-38 limbs. We analysed proteoglycans and their components extracted with guanidinium chloride by subjecting them to density gradient centrifugation, molecular sieve chromatography, electrophoretic separation, and selective enzymatic degradation. PG-I and PG-A have similar chondroitin sulphate composition, amino sugars, chondroitin sulphate side-chain length, glycoprotein link factors, and hyaluronic acid binding capacity, and both cross react with antisera prepared against cartilage-specific chick sternal proteoglycans. However, PG-I has lower molecular weight, lower buoyant density, and fewer chondroitin sulphate side chains on the protein core. The PG-I in the developing limb can be considered a mixture of smaller aggregates and cartilage-specific large monomers in which the former predominate.
mesh_terms: D000818:Animals; D000915:Antibody Affinity; D002499:Centrifugation, Density Gradient; D002642:Chick Embryo; D002809:Chondroitin Sulfates / Q000032:analysis; D002850:Chromatography, Gel; D005121:Extremities / Q000032:analysis / Q000196:embryology*; D007106:Immune Sera / Q000276:immunology; D008970:Molecular Weight; D011509:Proteoglycans / Q000032:analysis*; D013997:Time Factors; D014574:Uronic Acids / Q000032:analysis
chemical_list: D007106:Immune Sera; D011509:Proteoglycans; D014574:Uronic Acids; D002809:Chondroitin Sulfates