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Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: BACKGROUND, RESULTS. Meshes: Amino Acid Sequence, Binding Sites, Fibroblast Growth Factor 2, Heparin, Hepatocyte Growth Factor, Magnetic Resonance Spectroscopy, Models, Molecular, Molecular Sequence Data, Protein Folding, Protein Structure, Secondary.
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Does the solution structure of the N-terminal domain of hepatocyte growth factor reveal a potential heparin-binding site? Context: Hepatocyte growth factor (HGF) is a multipotent growth factor that transduces a wide range of biological signals, including mitogenesis, motogenesis, and morphogenesis. The N-terminal (N) domain of HGF, containing a hairpin-loop region, is important for receptor binding and the potent biological activities of HGF. The N domain is also the primary binding site for heparin or heparan sulfate, which enhances, receptor/ligand oligomerization and modulates receptor-dependent mitogenesis. The rational design of artificial modulators of HGF signaling requires a detailed understanding of the structures of HGF and its receptor, as well as the role of heparin proteoglycan; this study represents the first step towards that goal. We report here a high-resolution structure of the N domain of HGF. This first structure of HGF reveals a novel folding topology with a distinct pattern of charge distribution and indicates a possible heparin-binding site.
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The hairpin-loop region of the N domain plays a major role in stabilizing the structure and contributes to a putative heparin-binding site, which explains why it is required for biological functions. These results suggest several basic and/or polar residues that may be important for use in further mutational studies of heparin binding. Final Decision: yes