High-affinity binding of interferon-gamma to a basement membrane complex (matrigel).
AUTOR(ES)
Lortat-Jacob, H
RESUMO
Recently it was demonstrated that growth factors are bound to the extracellular matrix, and can regulate cell behavior. Using three different types of binding assays, we have examined the interaction of interferon-gamma with a basement membrane produced by the Engelbreth-Holm-Swarm tumor. Basement membrane was found to bind interferon-gamma in both a time- and concentration-dependent manner. Equilibrium binding analysis revealed a high-affinity site with a dissociation constant of 1.5 10(-9) M and a maximum binding capacity of 1.6 10(9) sites/mm2 of basement membrane. Competition studies show that the binding is inhibited by heparan sulfate, suggesting that basement membrane-heparan sulfate proteoglycan could be the binding site. This interaction was clearly confirmed by native polyacrylamide gel electrophoresis and dot-blot analysis with purified basement membrane molecules. Furthermore, the carboxy-terminal part of the interferon-gamma molecule contains an amino acid cluster, very closely related to a consensus sequence, present in more than 20 proteins known to bind sulfated glycosaminoglycans such as heparin. These data demonstrate a possible role of extracellular matrix components in storing cytokines and in modulating the cellular response to such factors.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=329877Documentos Relacionados
- High-affinity binding of the basement membrane proteins collagen type IV and laminin to the gastric pathogen Helicobacter pylori.
- Interferon gamma signals via a high-affinity multisubunit receptor complex that contains two types of polypeptide chain.
- Actin polymerization induced by a motility-related high-affinity cytochalasin binding complex from human erythrocyte membrane
- Cloning of murine interferon gamma receptor cDNA: expression in human cells mediates high-affinity binding but is not sufficient to confer sensitivity to murine interferon gamma.
- Contribution of a p75 interleukin 2 binding peptide to a high-affinity interleukin 2 receptor complex.
