Details

Autor(en) / Beteiligte

• Kondo, Jun
• Shibata, Hiroyuki
• Miura, Shigenori
• Yamakawa, Akira
• Sato, Koji
• Higuchi, Yoshiki
• Shukunami, Chisa
• Hiraki, Yuji

Titel

functional role of the glycosylated N-terminal domain of chondromodulin-I

Ist Teil von

• Journal of bone and mineral metabolism, 2011-01, Vol.29 (1), p.23-30

Ort / Verlag

Japan: Japan : Springer Japan

Erscheinungsjahr

2011

Link zum Volltext

Quelle

SpringerLink (Online service)

Beschreibungen/Notizen

• Chondromodulin-I (ChM-I) is a 25-kDa glycoprotein that specifically localizes in the extracellular matrix of cartilage and negatively regulates angiogenesis. ChM-I comprises two domains: an N-terminal hydrophilic domain (domain 1) containing an N-linked glycosylation site and a C-terminal hydrophobic domain (domain 2) with all four disulfide bonds that are present in this protein. We generated a nonglycosylated recombinant human ChM-I (NG-hChM-I) and compared its bioactivity with that of the glycosylated form of human ChM-I (G-hChM-I) expressed in Chinese hamster ovary cells in vitro. NG-hChM-I exhibited the growth factor/inhibitor activity in the cultures of chondrocytes and vascular endothelial cells but required markedly higher doses. Although domain 1 is predicted to be hydrophilic per se on the basis of its amino acid sequence, NG-hChM-I remains insoluble in aqueous solution as much as ΔN-hChM-I that lacks the N-terminal 37 amino acids containing an N-glycosylation site. Circular dichroism measurements revealed that the content of α-helix was calculated to be 34% in G-hChM-I, whereas the content of the characteristic secondary structures in NG-hChM-I was distinctly lower than those in G-hChM-I. These results indicate that glycosylation in domain 1 is critical for the structural integrity for biological functions of ChM-I in vitro.