title: cDNA cloning and 1.75 A crystal structure determination of PPL2, an endochitinase and N-acetylglucosamine-binding hemagglutinin from Parkia platycephala seeds.
abstract: Parkia platycephala lectin 2 was purified from Parkia platycephala (Leguminosae, Mimosoideae) seeds by affinity chromatography and RP-HPLC. Equilibrium sedimentation and MS showed that Parkia platycephala lectin 2 is a nonglycosylated monomeric protein of molecular mass 29 407+/-15 Da, which contains six cysteine residues engaged in the formation of three intramolecular disulfide bonds. Parkia platycephala lectin 2 agglutinated rabbit erythrocytes, and this activity was specifically inhibited by N-acetylglucosamine. In addition, Parkia platycephala lectin 2 hydrolyzed beta(1-4) glycosidic bonds linking 2-acetoamido-2-deoxy-beta-D-glucopyranose units in chitin. The full-length amino acid sequence of Parkia platycephala lectin 2, determined by N-terminal sequencing and cDNA cloning, and its three-dimensional structure, established by X-ray crystallography at 1.75 A resolution, showed that Parkia platycephala lectin 2 is homologous to endochitinases of the glycosyl hydrolase family 18, which share the (betaalpha)8 barrel topology harboring the catalytic residues Asp125, Glu127, and Tyr182.
authors.affiliation: BioMol-Laboratory, Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Ceará, Fortaleza, Ceará, Brazil. bscavada@ufc.br
authors.forename: Benildo S
authors.initials: BS
authors.lastname: Cavada
authors.forename: Frederico B B
authors.initials: FB
authors.lastname: Moreno
authors.forename: Bruno A M
authors.initials: BA
authors.lastname: da Rocha
authors.forename: Walter F
authors.initials: WF
authors.lastname: de Azevedo
authors.forename: Rolando E R
authors.initials: RE
authors.lastname: Castellón
authors.forename: Georg V
authors.initials: GV
authors.lastname: Goersch
authors.forename: Celso S
authors.initials: CS
authors.lastname: Nagano
authors.forename: Emmanuel P
authors.initials: EP
authors.lastname: de Souza
authors.forename: Kyria S
authors.initials: KS
authors.lastname: Nascimento
authors.forename: Gandhi
authors.initials: G
authors.lastname: Radis-Baptista
authors.forename: Plínio
authors.initials: P
authors.lastname: Delatorre
authors.forename: Yves
authors.initials: Y
authors.lastname: Leroy
authors.forename: Marcos H
authors.initials: MH
authors.lastname: Toyama
authors.forename: Vicente P T
authors.initials: VP
authors.lastname: Pinto
authors.forename: Alexandre H
authors.initials: AH
authors.lastname: Sampaio
authors.forename: Domingo
authors.initials: D
authors.lastname: Barettino
authors.forename: Henri
authors.initials: H
authors.lastname: Debray
authors.forename: Juan J
authors.initials: JJ
authors.lastname: Calvete
authors.forename: Libia
authors.initials: L
authors.lastname: Sanz
mesh_terms: D000117:Acetylglucosamine / Q000378:metabolism*; D000595:Amino Acid Sequence; D001483:Base Sequence; D002688:Chitinases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D003001:Cloning, Molecular; D003460:Crystallization; D018360:Crystallography, X-Ray; D018076:DNA, Complementary / Q000302:isolation & purification; D007887:Fabaceae / Q000201:enzymology* / Q000235:genetics; D006388:Hemagglutinins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D037121:Plant Lectins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D012639:Seeds / Q000201:enzymology* / Q000235:genetics
chemical_list: D018076:DNA, Complementary; D006388:Hemagglutinins; D037121:Plant Lectins; D002688:Chitinases; D000117:Acetylglucosamine