title: Structural characterization of novel chitin-binding lectins from the genus Artocarpus and their antifungal activity.
abstract: Two novel chitin-binding lectins from seeds of Artocarpus genus were described in this paper, one from A. integrifolia (jackfruit) and one from A. incisa (breadfruit). They were purified from saline crude extract of seeds using affinity chromatography on chitin column, size-exclusion chromatography and reverse-phase chromatography on the C-18 column. Both are 14 kDa proteins, made up of 3 chains linked by disulfide bonds. The partial amino acid sequences of the two lectins showed they are homologous to each other but not to other plant chitin-binding proteins. Thus, they cannot be classified in any known plant chitin-binding protein family, particularly because of their inter-chain covalent bonds. Their circular dichroism spectra and deconvolution showed a secondary structure content of beta-sheet and unordered elements. The lectins were thermally stable until 80 degrees C and structural changes were observed below pH 6. Both lectins inhibited the growth of Fusarium moniliforme and Saccharomyces cerevisiae, and presented hemagglutination activity against human and rabbit erythrocytes. These lectins were denoted jackin (from jackfruit) and frutackin (from breadfruit).
authors.affiliation: Institute of Physics of São Carlos, University of São Paulo, São Paulo, Brazil.
authors.forename: Melissa B
authors.initials: MB
authors.lastname: Trindade
authors.forename: José L S
authors.initials: JL
authors.lastname: Lopes
authors.forename: Andréa
authors.initials: A
authors.lastname: Soares-Costa
authors.forename: Ana Cristina
authors.initials: AC
authors.lastname: Monteiro-Moreira
authors.forename: Renato A
authors.initials: RA
authors.lastname: Moreira
authors.forename: Maria Luiza V
authors.initials: ML
authors.lastname: Oliva
authors.forename: Leila M
authors.initials: LM
authors.lastname: Beltramini
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000935:Antifungal Agents / Q000737:chemistry* / Q000494:pharmacology; D031622:Artocarpus / Q000737:chemistry*; D001234:Aspergillus niger / Q000187:drug effects; D002686:Chitin / Q000737:chemistry; D002942:Circular Dichroism; D005670:Fusarium / Q000187:drug effects; D006386:Hemagglutination Tests; D006801:Humans; D066298:In Vitro Techniques; D008969:Molecular Sequence Data; D037121:Plant Lectins / Q000737:chemistry* / Q000494:pharmacology; D011485:Protein Binding; D017433:Protein Structure, Secondary; D011817:Rabbits; D017386:Sequence Homology, Amino Acid; D013050:Spectrometry, Fluorescence; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D000935:Antifungal Agents; D037121:Plant Lectins; D002686:Chitin