Comparison of the binding of chicken alpha-macroglobulin and ovomacroglobulin to the mammalian alpha 2-macroglobulin receptor.


Journal Article

Chicken alpha-macroglobulin (alpha M) and ovomacroglobulin were purified by Ni+2 chelate chromatography. These proteins had similar subunit structure as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Chicken alpha M bound 1.0 mol and ovomacroglobulin bound 0.8 mol 125I-trypsin per mol inhibitor, respectively. Ovomacroglobulin cleared rapidly from the circulation of mice, and the clearance was inhibited by asialoorosomucoid, but native chicken alpha M cleared slowly (t 1/2 greater than 1 h). After reaction with trypsin, this alpha-macroglobulin cleared rapidly (t 1/2 = 3 min), and this clearance was inhibited by a 1000-fold molar excess of human alpha 2M-methylamine. Ovomacroglobulin-trypsin did not inhibit the binding of 0.2 nM 125I-labeled human alpha 2M-methylamine to mouse peritoneal macrophages in vitro, but chicken alpha M reacted with trypsin inhibited the binding by 50% at 1.9 nM. A kappa I of 1.1 nM was calculated for the binding of chicken alpha M-trypsin to the mammalian alpha-macroglobulin receptor. This affinity is comparable to that obtained with human and bovine alpha 2M.

Full Text

Duke Authors

Cited Authors

  • Feldman, SR; Pizzo, SV

Published Date

  • November 15, 1984

Published In

Volume / Issue

  • 235 / 1

Start / End Page

  • 267 - 275

PubMed ID

  • 6208849

Pubmed Central ID

  • 6208849

International Standard Serial Number (ISSN)

  • 0003-9861

Digital Object Identifier (DOI)

  • 10.1016/0003-9861(84)90275-3


  • eng

Conference Location

  • United States