title: First insights into the diversity and functional properties of chitinases of the latex of Calotropis procera.
abstract: Chitinases (EC 3.2.1.14) found in the latex of Calotropis procera (Ait) R. Br. were studied. The proteins were homogeneously obtained after two ion exchange chromatography steps. Most proteins were identified individually in 15 spots on 2-D gel electrophoresis with isoelectric points ranging from 4.6 to 6.0 and molecular masses extending from 27 to 30 kDa. Additionally, 66 kDa proteins were identified as chitinases in SDS-PAGE. Their identities were further confirmed by mass spectrometry (MS) analysis of the tryptic digests of each spot and MS analysis of the non-digested proteins. Positive reaction for Schiff's reagent suggested the proteins are glycosylated. The chitinases exhibited high catalytic activity toward to colloidal chitin at pH 5.0, and this activity underwent decay in the presence of increasing amounts of reducing agent dithiothreitol. Spore germination and hyphae growth of two phytopathogenic fungi were inhibited only marginally by the chitinases but were affected differently. This suggested a complex relationship might exist between the specificity of the proteins toward the fungal species. The chitinases showed potent insecticidal activity against the Bruchidae Callosobruchus maculatus, drastically reducing survival, larval weight and adult emergence. It is concluded that closely related chitinases are present in the latex of C. procera, and the first experimental evidence suggests these proteins are involved more efficiently in defence strategies against insects rather than fungi.
authors: Departamento de Bioquímica e Biologia Molecular da Universidade Federal do Ceará, Campus do Pici, Cx. Postal 6033, Fortaleza, CE CEP 60451-970, Brazil. Electronic address: cleversondiniz@hotmail.com.
authors: Cleverson D T
authors: CDT
authors: Freitas
authors: Departamento de Bioquímica e Biologia Molecular da Universidade Federal do Ceará, Campus do Pici, Cx. Postal 6033, Fortaleza, CE CEP 60451-970, Brazil.
authors: Carolina A
authors: CA
authors: Viana
authors: Departamento de Bioquímica e Biologia Molecular da Universidade Federal do Ceará, Campus do Pici, Cx. Postal 6033, Fortaleza, CE CEP 60451-970, Brazil.
authors: Ilka M
authors: IM
authors: Vasconcelos
authors: Centro de Ciências da Saúde, Universidade de Fortaleza (UNIFOR), Fortaleza, CE, Brazil.
authors: Frederico B B
authors: FBB
authors: Moreno
authors: Departamento de Biologia, Universidade Federal Rural de Pernambuco, Recife, PE, Brazil.
authors: José V
authors: JV
authors: Lima-Filho
authors: Departamento de Bioquímica e Biologia Molecular da Universidade Federal do Ceará, Campus do Pici, Cx. Postal 6033, Fortaleza, CE CEP 60451-970, Brazil.
authors: Hermogenes D
authors: HD
authors: Oliveira
authors: Centro de Ciências da Saúde, Universidade de Fortaleza (UNIFOR), Fortaleza, CE, Brazil.
authors: Renato A
authors: RA
authors: Moreira
authors: Centro de Ciências da Saúde, Universidade de Fortaleza (UNIFOR), Fortaleza, CE, Brazil.
authors: Ana Cristina O
authors: ACO
authors: Monteiro-Moreira
authors: Departamento de Bioquímica e Biologia Molecular da Universidade Federal do Ceará, Campus do Pici, Cx. Postal 6033, Fortaleza, CE CEP 60451-970, Brazil. Electronic address: vramos@ufc.br.
authors: Márcio V
authors: MV
authors: Ramos
mesh_terms: D000818:Animals; D000935:Antifungal Agents / Q000494:pharmacology; D031107:Calotropis / Q000737:chemistry / Q000201:enzymology* / Q000502:physiology; D002688:Chitinases / Q000302:isolation & purification / Q000378:metabolism* / Q000494:pharmacology; D001517:Coleoptera / Q000187:drug effects; D006031:Glycosylation; D006863:Hydrogen-Ion Concentration; D007306:Insecticides / Q000494:pharmacology; D007840:Latex / Q000737:chemistry* / Q000378:metabolism; D020033:Protein Isoforms / Q000378:metabolism; D013696:Temperature
chemical_list: D000935:Antifungal Agents; D007306:Insecticides; D007840:Latex; D020033:Protein Isoforms; D002688:Chitinases
keywords: Insects; Latificers; Phytopathogens; Plant defence