Purification and characterization of integrin alpha 9 beta 1.

Abstract

A new beta 1-containing integrin was isolated from rat liver by affinity chromatography on Sepharose conjugated with the peptide GRGDSPC. The interaction was weakened but not abolished when the arginine and/or aspartic acid in the peptide were replaced with lysine and glutamic acid, respectively. In contrast, the cysteine was necessary for binding of the integrin. The beta 1-associated protein, referred to as alpha 9, had an N-terminal amino acid sequence related to but distinct from previously described integrin alpha-subunits. In addition, an internal peptide sequence was obtained which confirmed that the protein is a new member of the family of integrin alpha-subunits. An antiserum raised against a synthetic peptide corresponding to amino acids 1-16 of alpha 9 reacted specifically with this protein and was used to identify alpha 9 in several tissues. The integrin alpha 9 beta 1 was not retained on Sepharose conjugated with Englebreth-Holm-Swarm tumor (EHS)-laminin, collagen type I, or a 105-kDa cell-binding fragment of fibronectin. However, it did bind specifically to EHS-laminin and collagen type I adsorbed to plastic microtiter wells. The sites of the interactions were localized to fragment E8 of EHS-laminin and to cyanogen bromide fragment 8 of collagen alpha 1(I) and were not inhibited by soluble RGD-containing peptides. The results indicate that alpha 9 beta 1 is a widely distributed laminin/collagen receptor which may have additional, yet unidentified ligands.

• Authors: E Forsberg, B Ek, A Engström, S Johansson
• Journal: Experimental cell research (Exp Cell Res) Vol. 213 Issue 1 Pg. 183-90 (Jul 1994) ISSN: 0014-4827 [Print] United States
• PMID: 8020590 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Fibronectins
• Integrins
• Laminin
• Oligopeptides
• Receptors, Collagen
• Receptors, Laminin
• Collagen

Topics

• Amino Acid Sequence
• Animals
• Chromatography, Affinity
• Collagen (metabolism)
• Electrophoresis, Polyacrylamide Gel
• Fibronectins (metabolism)
• Humans
• Integrins (chemistry, isolation & purification, metabolism)
• Kidney (metabolism)
• Laminin (metabolism)
• Liver (metabolism)
• Molecular Sequence Data
• Molecular Weight
• Muscles (metabolism)
• Myocardium (metabolism)
• Oligopeptides
• Organ Specificity
• Protein Binding
• Rats
• Receptors, Collagen
• Receptors, Laminin (chemistry, isolation & purification, metabolism)
• Sequence Homology, Amino Acid
• Spleen (metabolism)
• Tumor Cells, Cultured