New member of the trefoil factor family of proteins is an alpha-macroglobulin protease inhibitor.

Journal Article (Journal Article)

The amino acid sequence of the monomeric alpha-macroglobulin (alphaM) from the American bullfrog, Rana catesbiana, was determined. The mature protein consisted of 1469 amino acid residues and shared sequence identity with other members of the alphaM family of protein. The central portion of the frog monomeric alphaM contained Cys residues positioned analogously to the Cys residues in human alpha(2)-macroglobulin (alpha(2)M), known to be involved in disulfide bridges. Additionally, the frog monomeric alphaM contained six Cys residues in a approximately 60 residue COOH-terminal extension not present in previously characterized alphaMs. The spacing of the Cys residues and the overall sequence identity of this COOH-terminal extension were consistent with a trefoil motif. This is the first time a member of the trefoil factor family has been identified in the circulatory system. The "bait region" was located between Arg(675)-Lys(685) and contained mainly basic amino acid residues. The COOH-terminal receptor-binding domain was not exposed prior to proteolysis of this highly susceptible region. The proximity of the receptor-binding and trefoil domains implied that the trefoil domain is similarly concealed before bait region cleavage.

Full Text

Duke Authors

Cited Authors

  • Thøgersen, IB; Hammes, SR; Rubenstein, DS; Pizzo, SV; Valnickova, Z; Enghild, JJ

Published Date

  • July 29, 2002

Published In

Volume / Issue

  • 1598 / 1-2

Start / End Page

  • 131 - 139

PubMed ID

  • 12147353

International Standard Serial Number (ISSN)

  • 0006-3002

Digital Object Identifier (DOI)

  • 10.1016/s0167-4838(02)00360-6


  • eng

Conference Location

  • Netherlands