title: Plasminogen kringle 4 binds the heptapeptide fragment 44-50 of the plasminogen N-terminal peptide.
abstract: The interaction between the plasminogen kringle 4 module and a synthetic peptide corresponding to the tryptic heptapeptide fragment Ala-Phe-Gln-Tyr-His-Ser-Lys (AFQYHSK), segment 44-50 of the plasminogen N-terminal peptide (Wiman and Wallén, Eur J Biochem 1975; 50:489-494), has been investigated by 1H-NMR spectroscopy. AFQYHSK, as well as the shorter fragments thereof, FQYHSK, QYHSK and YHSK, all bound to kringle 4 with equilibrium association constant (Ka) values ranging between 2.5 and 8.5 mM-1. The NMR evidence also indicates that binding is mediated by the canonical kringle lysine binding site and involves the C-terminal Lys residue of the ligand peptide. The results (a) support a potential interaction between plasminogen Lys-binding kringles and the N-terminal activation peptide, and (b) unambiguously demonstrate the capability of such kringles to bind polypeptides ending with C-terminal lysine.
authors.affiliation: Department of Chemistry, Carnegie Mellon University, Pittsburgh, PA 15213, USA.
authors.forename: V
authors.initials: V
authors.lastname: Ramesh
authors.forename: N
authors.initials: N
authors.lastname: Rajan
authors.forename: R A
authors.initials: RA
authors.lastname: Laursen
authors.forename: M
authors.initials: M
authors.lastname: Llinás
mesh_terms: D000595:Amino Acid Sequence; D006801:Humans; D007700:Kinetics; D018082:Kringles; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000378:metabolism*; D010958:Plasminogen / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding; D017434:Protein Structure, Tertiary
chemical_list: D010446:Peptide Fragments; D010958:Plasminogen