Transmembrane domain interactions and residue proline 378 are essential for proper structure, especially disulfide bond formation, in the human vitamin K-dependent gamma-glutamyl carboxylase.

ABSTRACT: We used recombinant techniques to create a two-chain form (residues 1-345 and residues 346-758) of the vitamin K-dependent gamma-glutamyl carboxylase, a glycoprotein located in the endoplasmic reticulum containing five transmembrane domains. The two-chain carboxylase had carboxylase and epoxidase activities similar to those of one-chain carboxylase. In addition, it had normal affinity for the propeptide of factor IX. We employed this molecule to investigate formation of the one disulfide bond in carboxylase, the transmembrane structure of carboxylase, and the potential interactions among the carboxylase's transmembrane domains. Our results indicate that the two peptides of the two-chain carboxylase are joined by a disulfide bond. Proline 378 is important for the structure necessary for dis

SUBMITTER: Tie JK 

PROVIDER: S-EPMC2810621 | biostudies-literature | 2008 Jun

REPOSITORIES: biostudies-literature