A novel strategy for defining critical amino acid residues involved in protein/glycosaminoglycan interactions.
The binding of proteins to glycosaminoglycans (GAGs) is the prerequisite for a large number of cellular processes and regulatory events and is associated to many pathologies. However, progress in the understanding of these mechanisms has been hampered by the lack of simple and comprehensive analytical tools for the identification of the structural attributes involved in protein/saccharide interaction. Characterization of GAG binding motifs on proteins has so far relied on site-directed mutagenesis studies, protein sequence mapping using synthetic peptides, molecular modeling, or structural analysis. Here, we report the development of a novel approach for identifying protein residues involved in the binding to heparin, the archetypal member of the GAG family. This method, which uses native proteins, is based on the formation of cross-linked complexes of the protein of interest with heparin beads, the proteolytic digestion of these complexes, and the subsequent identification of the heparin binding containing peptides by N terminus sequencing. Analysis of the CC chemokine regulated on activation, normal T-cell expressed, and secreted (RANTES), the envelope glycoprotein gC from pseudorabies virus and the laminin-5 alpha 3LG4/5 domain validated the techniques and provided novel information on the heparin binding motifs present within these proteins. Our results highlighted this method as a fast and valuable alternative to existing approaches. Application of this technique should greatly contribute to facilitate the structural study of protein/GAG interactions and the understanding of their biological functions.
Institut de Biologie Structurale, CNRS-CEA-UJF, 41 rue Horowitz, 38027 Grenoble cedex 01, France. vives@ibs.fr
Romain R
RR
Vivès
Elodie
E
Crublet
Jean-Pierre
JP
Andrieu
Jean
J
Gagnon
Patricia
P
Rousselle
Hugues
H
Lortat-Jacob
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis* / Q000378:metabolism; D001665:Binding Sites; D002460:Cell Line; D018946:Chemokine CCL5 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D003432:Cross-Linking Reagents; D006025:Glycosaminoglycans / Q000737:chemistry / Q000378:metabolism*; D006493:Heparin / Q000737:chemistry / Q000378:metabolism; D011558:Herpesvirus 1, Suid / Q000737:chemistry; D006801:Humans; D007797:Laminin / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D008863:Microspheres; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism; D010447:Peptide Hydrolases / Q000378:metabolism; D011506:Proteins / Q000737:chemistry* / Q000378:metabolism*; D011994:Recombinant Proteins; D020539:Sequence Analysis, Protein; D013329:Structure-Activity Relationship; D014162:Transfection; D014759:Viral Envelope Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
D000596:Amino Acids; D018946:Chemokine CCL5; D003432:Cross-Linking Reagents; D006025:Glycosaminoglycans; D007797:Laminin; D010446:Peptide Fragments; D011506:Proteins; D011994:Recombinant Proteins; D014759:Viral Envelope Proteins; C042966:pseudorabies virus glycoproteins; C095567:laminin alpha 3; D006493:Heparin; D010447:Peptide Hydrolases