title: Synthesis and characterization of defensin NP-1.
abstract: Defensins are a group of small, cationic, antimicrobial proteins found in the cytoplasmic granules of neutrophils and macrophages of a variety of mammalian species. One such defensin, NP-1, isolated from rabbit neutrophils, has been shown to consist of 33 amino acids rich in arginine and cysteine residues. We have synthesized NP-1 on an Applied Biosystems Model 431A peptide synthesizer using FastMoc chemistry involving HBtu [2-1H-benzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate] activation for coupling amino acids. The linear peptide was folded by air oxidation to the biologically active form containing three disulfide bonds and purified by reverse phase chromatography. The amino acid sequence of the synthetic peptide was confirmed by Edman degradation. Molecular weight determination by plasma desorption mass spectroscopy (PDMS) gave a value of 3898.6, in agreement with the expected molecular weight of 3898. The biological activity of the synthetic peptide, as measured by its antifungal activity against several pathogenic fungi, was indistinguishable from that of the natural NP-1. Also, the CD spectrum was equivalent to that of natural NP-1, indicating conformational identity of the two species.
authors.affiliation: Pioneer Hi-Bred International, Inc., Department of Biotechnology Research, Johnston, Iowa.
authors.forename: A G
authors.initials: AG
authors.lastname: Rao
authors.forename: T
authors.initials: T
authors.lastname: Rood
authors.forename: J
authors.initials: J
authors.lastname: Maddox
authors.forename: J
authors.initials: J
authors.lastname: Duvick
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000935:Antifungal Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D001798:Blood Proteins / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D002845:Chromatography / Q000379:methods; D023082:Defensins; D004586:Electrophoresis / Q000379:methods; D015151:Immunoblotting; D008969:Molecular Sequence Data; D008970:Molecular Weight; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D011817:Rabbits
chemical_list: D000935:Antifungal Agents; D001798:Blood Proteins; D023082:Defensins