Chemical and immunological characterization of proteoglycans of embryonic chick calvaria☆

[摘要] Proteoglycansofembryonicchickcalvarium,anoncartilagenoustissue,werecharacterizedchemicallyandimmunologically.Ofthe35SO2−4-labeledglycosaminoglycansisolatedfrom13-dayand17-day-oldchickembryos,chondroitinsulfatewasthemajorcomponent(67–88%).Heparansulfate(5–18%)andkeratansulfate(1–2.6%)werefoundinsmalleramounts.Proteoglycanswerelabeledwith35SO2−4andisolatedby4.0MguanidineHClextractionfromcalvariaof13-day-oldembryos.ThemajorproteoglycansshowedaconsiderablepolydispersityonSepharose4Band6B,andwerefoundtobemuchsmaller(70,000±7,000daltons)thancartilageproteoglycansubunitsandcontainedonlyoneortwochondroitinsulfatechainswithamolecularweightof41,000±4,000.Theresultsofdoubleimmunodiffusionstudiesandradioimmuneinhibitionassaysusingantiseraagainstchickandratcartilageproteoglycansubunitsindicatethatchickcalvariumcontainsproteoglycan(s)withatleastonespecies-specificantigenicdeterminantwhichcross-reactswithantiserumagainstchickcartilageproteoglycansubunits.Thecalvarialproteoglycansshowedasignificantreactivitytowardoneofthemonoclonalantibodiesagainstchickcartilageproteoglycansubunits,butonlyaveryweakreactivitytowardtheothersasjudgedbyradioimmuneinhibitionassays.

[学科分类] 生物科学（综合）