title: Isolation, characterization, molecular cloning and modeling of a new lipid transfer protein with antiviral and antiproliferative activities from Narcissus tazetta.
abstract: A fetuin-binding peptide with a molecular mass of about 9kDa (designated NTP) was isolated and purified from the bulbs of Chinese daffodil, Narcissus tazetta var. chinensis L., by gel filtration and high-performance liquid chromatography, after removing the mannose-binding proteins by mannose-agarose column. Molecular cloning revealed that NTP contained an open reading frame of 354bp encoding a polypeptide of 118 amino acids which included a 26-amino-acid signal peptide. An analysis of the deduced amino acid sequence of NTP shows considerable sequence homology to the non-specific lipid transfer proteins (nsLTPs) of certain plants. Model of the three-dimensional (3D) structure of NTP exhibits an internal hydrophobic cavity which can bind lipid-like molecules and transfer a wide range of ligands. As a member of the putative non-specific lipid transfer protein of N. tazetta, NTP did not possess hemagglutinating activity toward rabbit erythrocytes. In a cell-free system, it could arrest the protein synthesis of rabbit reticulocytes. Using the in vitro antiviral assays, NTP could significantly inhibit the plaque formation by respiratory syncytial virus (RSV) and the cytopathic effect induced by influenza A (H1N1) virus, as well as the proliferation of human acute promyelocytic leukemia cells (HL-60).
authors.affiliation: Department of Biology, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong.
authors.forename: Linda S M
authors.initials: LS
authors.lastname: Ooi
authors.forename: Li
authors.initials: L
authors.lastname: Tian
authors.forename: Miaoxian
authors.initials: M
authors.lastname: Su
authors.forename: Wing-Shan
authors.initials: WS
authors.lastname: Ho
authors.forename: Samuel S M
authors.initials: SS
authors.lastname: Sun
authors.forename: Hau-Yin
authors.initials: HY
authors.lastname: Chung
authors.forename: Henry N C
authors.initials: HN
authors.lastname: Wong
authors.forename: Vincent E C
authors.initials: VE
authors.lastname: Ooi
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000998:Antiviral Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D002352:Carrier Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D049109:Cell Proliferation / Q000187:drug effects*; D018076:DNA, Complementary / Q000302:isolation & purification / Q000378:metabolism; D004912:Erythrocytes / Q000187:drug effects; D018922:HL-60 Cells; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000187:drug effects / Q000378:metabolism; D008969:Molecular Sequence Data; D031427:Narcissus / Q000737:chemistry*; D010940:Plant Proteins / Q000302:isolation & purification / Q000494:pharmacology*; D014176:Protein Biosynthesis / Q000187:drug effects; D011487:Protein Conformation; D011817:Rabbits; D012136:Respiratory Syncytial Viruses / Q000187:drug effects / Q000378:metabolism; D014779:Virus Replication / Q000187:drug effects
chemical_list: D000998:Antiviral Agents; D002352:Carrier Proteins; D018076:DNA, Complementary; D010940:Plant Proteins; C030363:lipid transfer protein