title: First report of a glutamine-rich antifungal peptide with immunomodulatory and antiproliferative activities from family Amaryllidaceae.
abstract: This represents the first report of purification of a glutamine-rich antifungal peptide from family Amarylliaceace. The peptide, designated as nartazin, was purified from the bulbs of the Chinese daffodil Narcissus tazetta var. chinensis by means of ion-exchange chromatography and affinity chromatography. Its molecular mass was 7.1kDa, as determined by SDS-PAGE and gel filtration. Nartazin stimulated proliferation of mouse splenocytes and bone marrow cells but inhibited proliferation of leukemia L1210 cells. It also inhibited translation in a cell-free rabbit reticulocyte lysate system. The sequence of its first 20 N-terminal residues was characterized by an abundance of glutamine. The peptide possessed antifungal activity on four phytopathogenic fungi. Its activity was retained after incubation with bovine trypsin and chymotrypsin (enzyme: substrate ratio 1:10 w/w) at 37 degrees C for 1h but was attenuated after treatment with proteinase K. The data revealed its pronounced resistance to proteolytic digestion.
authors.affiliation: Department of Biochemistry, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China.
authors.forename: Kin Tak
authors.initials: KT
authors.lastname: Chu
authors.forename: Tzi Bun
authors.initials: TB
authors.lastname: Ng
mesh_terms: D000818:Animals; D000935:Antifungal Agents / Q000302:isolation & purification / Q000378:metabolism* / Q000494:pharmacology; D000970:Antineoplastic Agents / Q000302:isolation & purification / Q000378:metabolism* / Q000494:pharmacology; D001854:Bone Marrow Cells / Q000187:drug effects; D002417:Cattle; D049109:Cell Proliferation; D002478:Cells, Cultured; D005658:Fungi / Q000187:drug effects; D005973:Glutamine / Q000378:metabolism*; D007155:Immunologic Factors / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism* / Q000494:pharmacology; D019668:Liliaceae / Q000737:chemistry*; D008264:Macrophages / Q000187:drug effects; D051379:Mice; D008970:Molecular Weight; D010455:Peptides / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism* / Q000494:pharmacology; D010936:Plant Extracts / Q000737:chemistry / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology; D010940:Plant Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism* / Q000494:pharmacology; D011817:Rabbits; D013154:Spleen / Q000166:cytology / Q000187:drug effects
chemical_list: D000935:Antifungal Agents; D000970:Antineoplastic Agents; D007155:Immunologic Factors; D010455:Peptides; D010936:Plant Extracts; D010940:Plant Proteins; C495391:nartazin; D005973:Glutamine