Mapping the heparin-binding site on the 13-14F3 fragment of fibronectin.
Fibronectin, a multifunctional glycoprotein of the extracellular matrix, plays a major role in cell adhesion. Various studies have revealed that the human 13th and 14th fibronectin type III domains (labeled (13)F3 and (14)F3 here) contain a heparin-binding site. Mapping of the heparin-binding sites of (13-14)F3, (13)F3, and (14)F3 by NMR chemical shift perturbation, isothermal titration calorimetry, and molecular modeling show that (13)F3 provides the dominant heparin-binding site and that the residues involved are within the first 29 amino acids of (13)F3. Predictions from earlier biochemical and modeling studies as well as the x-ray structure of (12-14)F3 were tested. It was shown that the positively charged residues that project into the solvent from the ABE face of the triple-stranded beta sheet on (13)F3 are involved in binding, but (14)F3 does not appear to contribute significantly to heparin binding.
Sachchidanand
Department of Biochemistry and Oxford Centre for Molecular Sciences, University of Oxford, South Parks Rd., Oxford OX1 3QU, United Kingdom.
Lequin
Olivier
O
Staunton
David
D
Mulloy
Barbara
B
Forster
Mark J
MJ
Yoshida
Keiichi
K
Campbell
Iain D
ID
D000595:Amino Acid Sequence; D001665:Binding Sites; D003001:Cloning, Molecular; D005353:Fibronectins / Q000737:chemistry* / Q000378:metabolism*; D006493:Heparin / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D009844:Oligosaccharides / Q000737:chemistry / Q000378:metabolism; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism
D005353:Fibronectins; D009844:Oligosaccharides; D010446:Peptide Fragments; D011994:Recombinant Proteins; D006493:Heparin