title: Purification, characterization, and molecular cloning of a novel antifungal lectin from the roots of Ophioglossum pedunculosum.
abstract: A novel mannan-specific lectin was isolated from the roots of a traditional Chinese herbal medicine, Ophioglossum pedunculosum through ion-exchange chromatography and gel filtration. With a molecular mass of 19,835.7 Da demonstrated by MALDI-TOF analysis, this novel agglutinin was designated as O. pedunculosum agglutinin (OPA), specifically agglutinating human O erythrocytes and rabbit erythrocytes. The hemagglutination could be strongly inhibited by mannan and thyroglobulin, the activity of which was stable in pH range of 4.0-8.0 and at temperatures below 50 °C. Chemical modification studies indicated that tryptophan and arginine residues were essential for its hemagglutinating activity. Meanwhile, it showed antifungal activities toward Sclerotium rolfsii and Fusarium graminearum. In addition, to amplify cDNA of OPA by 3'/5'-rapid amplification of cDNA ends (RACE), the N-terminal 30 amino acids sequence of OPA was determined, and degenerate primers were designed. The obtained full-length cDNA of OPA contained 885 bp with an open-reading frame of 600 bp encoding a precursor protein of 199 amino acids, while the mature protein had 170 amino acids.
authors.affiliation: School of Life Sciences, Sichuan University, Chengdu 610064, China.
authors.forename: Xue-Mei
authors.initials: XM
authors.lastname: He
authors.forename: Na
authors.initials: N
authors.lastname: Ji
authors.forename: Xiao-Cong
authors.initials: XC
authors.lastname: Xiang
authors.forename: Ping
authors.initials: P
authors.lastname: Luo
authors.forename: Jin-Ku
authors.initials: JK
authors.lastname: Bao
mesh_terms: D000373:Agglutinins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification* / Q000494:pharmacology; D000595:Amino Acid Sequence; D000818:Animals; D000935:Antifungal Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D001483:Base Sequence; D003001:Cloning, Molecular; D029624:Ferns / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D005658:Fungi / Q000187:drug effects; D006386:Hemagglutination Tests; D006801:Humans; D037102:Lectins / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification* / Q000494:pharmacology; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification* / Q000494:pharmacology; D018517:Plant Roots / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011817:Rabbits; D016415:Sequence Alignment
chemical_list: D000373:Agglutinins; D000935:Antifungal Agents; D037102:Lectins; D010940:Plant Proteins