The TSG-6/HC2-mediated transfer is a dynamic process shuffling heavy chains between glycosaminoglycans

J Biol Chem. 2010 Jul 16;285(29):21988-93. doi: 10.1074/jbc.M109.041046. Epub 2010 May 12.


The heavy chain (HC) subunits of the bikunin proteins are covalently attached to a single chondroitin sulfate (CS) chain originating from bikunin and can be transferred to different hyaluronan (HA) molecules by TSG-6/HC2. In the present study, we demonstrate that HCs transferred to HA may function as HC donors in subsequent transfer reactions, and we show that the CS of bikunin may serve as an HC acceptor, analogous to HA. Our data suggest that TSG-6/HC2 link HCs randomly on the CS chain of bikunin, in contrast to the ordered attachment observed during the biosynthesis. Moreover, the results show that the transfer activity is indifferent to the new HC position, and the relocated HCs are thus prone to further TSG-6/HC2-induced transfer reactions. The data suggest that HCs may be transferred directly from HA to HA without the involvement of the bikunin CS chain. The results demonstrate reversibility of the interactions between HCs and glycosaminoglycans and suggest that a dynamic shuffling of the HCs occur in vivo.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alpha-Globulins / metabolism
  • Cell Adhesion Molecules / metabolism*
  • Chondroitin Sulfates / metabolism
  • Glycosaminoglycans / metabolism*
  • Humans
  • Hyaluronic Acid / metabolism
  • Molecular Weight
  • Protein Subunits / metabolism*


  • Alpha-Globulins
  • Cell Adhesion Molecules
  • Glycosaminoglycans
  • Protein Subunits
  • TNFAIP6 protein, human
  • alpha-1-microglobulin
  • inter-alpha-inhibitor
  • Hyaluronic Acid
  • Chondroitin Sulfates