Link protein has greater affinity for versican than aggrecan.
The function of link protein in stabilizing the interaction between aggrecan and hyaluronan to form aggrecan aggregates, via the binding of link protein to the aggrecan G1 domain and hyaluronan, is well established. However, it is not known whether link protein can function with similar avidity with versican, another member of the large hyaluronan-binding proteoglycan family that also binds to hyaluronan via its G1 domain. To address this issue, we have compared the interaction of the versican and aggrecan G1 domains with link protein and hyaluronan using recombinant proteins expressed in insect cells and BIAcore analysis. The results showed that link protein could significantly improve the binding of both G1 domains to hyaluronan and that its interaction with VG1 is of a higher affinity than that with AG1. These observations suggest that link protein may function as a stabilizer of the interaction, not only between aggrecan and hyaluronan in cartilage, but also between versican and hyaluronan in many tissues.
Shi
Shuiliang
S
Joint Diseases Laboratory, Shriners Hospitals for Children, 1529 Cedar Avenue, Montreal, Quebec, Canada H3G 1A6.
Grothe
Suzanne
S
Zhang
Yiping
Y
O'Connor-McCourt
Maureen D
MD
Poole
A Robin
AR
Roughley
Peter J
PJ
Mort
John S
JS
D053674:Aggrecans; D000818:Animals; D001681:Biological Assay; D001710:Biotin / Q000494:pharmacology; D019921:Biotinylation; D002356:Cartilage / Q000378:metabolism; D011508:Chondroitin Sulfate Proteoglycans / Q000378:metabolism*; D004247:DNA / Q000737:chemistry; D017931:DNA Primers / Q000494:pharmacology; D004220:Disulfides / Q000737:chemistry; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D016326:Extracellular Matrix Proteins; D006801:Humans; D007313:Insecta; D007700:Kinetics; D037181:Lectins, C-Type; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D011506:Proteins / Q000502:physiology*; D011509:Proteoglycans / Q000378:metabolism*; D011994:Recombinant Proteins / Q000737:chemistry; D020349:Surface Plasmon Resonance; D013997:Time Factors; D053675:Versicans; D000099249:Proteoglycan Link Protein
D053674:Aggrecans; D001710:Biotin; D011508:Chondroitin Sulfate Proteoglycans; D004247:DNA; D017931:DNA Primers; D004220:Disulfides; D016326:Extracellular Matrix Proteins; D037181:Lectins, C-Type; D011506:Proteins; D011509:Proteoglycans; D011994:Recombinant Proteins; D053675:Versicans; D000099249:Proteoglycan Link Protein; C508322:VCAN protein, human