title: Structure of a lectin with antitumoral properties in king bolete (Boletus edulis) mushrooms.
abstract: A novel lectin has been isolated from the fruiting bodies of the common edible mushroom Boletus edulis (king bolete, penny bun, porcino or cep) by affinity chromatography on a chitin column. We propose for the lectin the name BEL (B. edulis lectin). BEL inhibits selectively the proliferation of several malignant cell lines and binds the neoplastic cell-specific T-antigen disaccharide, Galβ1-3GalNAc. The lectin was structurally characterized: the molecule is a homotetramer and the 142-amino acid sequence of the chains was determined. The protein belongs to the saline-soluble family of mushroom fruiting body-specific lectins. BEL was also crystallized and its three-dimensional structure was determined by X-ray diffraction to 1.15 Å resolution. The structure is similar to that of Agaricus bisporus lectin. Using the appropriate co-crystals, the interactions of BEL with specific mono- and disaccharides were also studied by X-ray diffraction. The six structures of carbohydrate complexes reported here provide details of the interactions of the ligands with the lectin and shed light on the selectivity of the two distinct binding sites present in each protomer.
authors.affiliation: Biocrystallography Laboratory, Department of Biotechnology, University of Verona, Ca Vignal 1, strada Le Grazie 15, 37134 Verona, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Bovi
authors.forename: Maria E
authors.initials: ME
authors.lastname: Carrizo
authors.forename: Stefano
authors.initials: S
authors.lastname: Capaldi
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Perduca
authors.forename: Laurent R
authors.initials: LR
authors.lastname: Chiarelli
authors.forename: Monica
authors.initials: M
authors.lastname: Galliano
authors.forename: Hugo L
authors.initials: HL
authors.lastname: Monaco
mesh_terms: D000363:Agaricales / Q000737:chemistry*; D000595:Amino Acid Sequence; D000970:Antineoplastic Agents / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002846:Chromatography, Affinity; D018360:Crystallography, X-Ray; D004305:Dose-Response Relationship, Drug; D004354:Drug Screening Assays, Antitumor; D048690:Fruiting Bodies, Fungal / Q000737:chemistry; D006801:Humans; D037102:Lectins / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D008958:Models, Molecular; D011487:Protein Conformation; D016415:Sequence Alignment; D013329:Structure-Activity Relationship
chemical_list: D000970:Antineoplastic Agents; D037102:Lectins