PROPERTIES OF A HEPARIN-BINDING PEPTIDE DERIVED FROM BOVINE LACTOFERRIN

A heparin-binding peptide was isolated from a proteolytic hydrolysate of bovine lactoferrin by affinity chromatography using an immobilized heparin column. Analysis of amino acid sequences at the N-terminus sho wed that this heparin-binding peptide is derived from the region begin ning at the 17th amino acid residue of the bovine lactoferrin sequence . The molecular mass of this peptide was 3195.5 as measured by matrix- assisted laser desorption-time of flight mass spectrometry. This pepti de is the same as the bactericidal peptide lactoferricin(R) B. In an a queous environment, this peptide displays mainly a P-sheet structure a nd an unordered structure as assessed by measurements of circular dich roism spectra. When this peptide was mixed with heparin, a distinct sp ectral change was induced because of conformational alteration of the peptide. This spectral change was reversible. Analysis of data from pe ptide synthesis indicated that binding by the sequence Arg(28)-Met(29) -Lys(30)-Lys(31) of bovine lactoferrin is significant and that there i s a synergistic contribution from Lys(18)-Cys(19)-Arg(20)-Arg(21), and Arg(38)-Arg(39).