The role of coiled-coil α-Helices and disulfide bonds in the assembly and stabilization of cartilage matrix protein subunits: A mutational analysis

Dominik R Haudenschild, M. Mehrdad Tondravi, Urs Hofer, Qian Chen, Paul F. Goetinck

Research output: Contribution to journalArticle

36 Scopus citations


Cartilage matrix protein (CMP) exists as a disulfide-bonded homotrimer in the matrix of cartilage. Each monomer consists of two CMP-A domains that are separated by an epidermal growth factor-like domain. A heptad repeat-containing tail makes up the carboxyl-terminal domain of the protein. The secreted form of CMP contains 12 cysteine residues numbered C1 through C12. Two of these are in each of the CMP-A domains, six are in the epidermal growth factor-like domain, and two are in the heptad repeat-containing tail. Two major categories of mutant CMPs were generated to analyze the oligomerization process of CMP: a mini-CMP and a heptadless full-length CMP. The mini-CMP consists of the CMP-A2 domain and the heptad repeat-containing tail. In addition, a number of mutations affecting C9 through C12 were generated within the full-length, the mini-, and the heptad-less CMPs. The mutational analysis indicates that the heptad repeats are necessary for the initiation of CMP trimerization and that the two cysteines in the heptad repeat-containing tail are both necessary and sufficient to form intermolecular disulfide bonds in either full-length or mini-CMP. The two cysteines within a CMP-A domain form an intradomain disulfide bond.

Original languageEnglish (US)
Pages (from-to)23150-23154
Number of pages5
JournalJournal of Biological Chemistry
Issue number39
StatePublished - Sep 29 1995
Externally publishedYes


ASJC Scopus subject areas

  • Biochemistry

Cite this