Immunological evidence for two distinct chondroitin sulfate proteoglycan core proteins: Differential expression in cartilage matrix deficient mice☆

摘要

Theexpressionandcoreproteinstructureoftwoproteoglycans,themajorcartilageproteoglycanisolatedfromaratchondrosarcomaandasmallmolecularweightchondroitinsulfateproteoglycanisolatedfromaratyolksactumor,havebeencompared.Thecartilageproteoglycanwasnotdetectableinthecartilagetissueofcartilagematrixdeficient(cmdcmd)neonatalmicebyimmunofluorescence,butthecmdcartilagedidreactwithantibodiesagainstthecoreproteinoftheyolksactumorproteoglycan.Radioimmunoassaysshowedthatthecoreproteinsoftheseproteoglycansarenotcross-reactivewitheachother.Analysisofthecoreproteinsbysodiumdodecylsulfate/polyacrylamidegelelectrophoresisafterchondroitinaseABCtreatmentoftheproteoglycanrevealedalargedifferenceintheirsizes.Thecartilageproteoglycancoreproteinhadamolecularweightofabout200,000whiletheyolksactumorproteoglycancoreproteinmigratedwithanapparentmolecularweightofabout20,000.Inaddition,theculturedyolksactumorcellsthatmakethesmallproteoglycandidnotreactwithantiserumagainstthecartilageproteoglycan.Theseresultsindicatethattheproteoglycanisolatedfromtheyolksactumorissimilartothesmallchondroitinsulfateproteoglycanspeciesfoundincartilageandsupporttheexistenceofatleasttwodissimilarandgeneticallyindependentchondroitinsulfateproteoglycancoreproteins.