Purification and primary structure determination of two Bowman-Birk type trypsin isoinhibitors from Cratylia mollis seeds

Two Bowman-Birk type trypsin inhibitors (CmTI1 and CmTI2) were purified from Cratylia mollis seeds by acetone precipitation, ion exchange, gel filtration and reverse-phase chromatography. CmTI1 and CmTI2, with 77 and 78 amino acid residues, respectively, were sequenced in their entirety and show a high structural similarity to Bowman-Birk inhibitors from other Legummosae. the putative reactive sites of CmTI1 are a lysine residue at position 22 and a tyrosine residue at position 49. Different reactive sites, as identified by their alignment with related inhibitors, were found for CmTI2: lysine at position 22 and leucine at position 49. the dissociation constant K-i of the complex with trypsin is 1.4 nM. the apparent molecular mass is 17 kDa without DDT and 11 kDa with reducing agent and heating. (c) 2005 Elsevier B.V. All rights reserved.Universidade Federal de São Paulo, Escola Paulista Med, Dept Bioquim, BR-04044020 São Paulo, SP, BrazilUFPE, CBB, Dept Bioquim, BR-50670420 Recife, PE, BrazilLMU Munchen, Chirurg Klin & Poliklin, Klin Chem & Klin Biochem Abt, Munich, GermanyUniversidade Federal de São Paulo, Escola Paulista Med, Dept Bioquim, BR-04044020 São Paulo, SP, BrazilWeb of Scienc

Evaluation of seed coagulant Moringa oleifera lectin (cMoL) as a bioinsecticidal tool with potential for the control of insects

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Lectins have demonstrated significant levels of protection against different pests when expressed in transgenic plants. The effects of the coagulant Moringa oleifera lectin (cMoL) on moth flour (Anagasta kuehniella) were tested by incorporating the protein in an artificial diet at levels of 0.5%, 1% and 2% (w/w), respectively. cMoL showed a dose-dependent effect on average larval weight and a series of nutritional disturbances. A significant increase in total development time of 15 days was observed in the group fed with cMoL at 1%, increasing the rate of pupal mortality by 27.6%. The A. kuehniella midgut proteases were unable to digest cMoL for up to 12 h of incubation. The lectin presented a tight binding to a chitin column, suggesting that the insecticidal activity of cMoL involves carbohydrate-lectin interactions on the surface of the digestive tract, with glycoproteins and others glycolsylated structures in the midgut and resistance to enzymatic digestion. (C) 2010 Elsevier Ltd. All rights reserved.462498504Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Programa de Apoio a Nucleos de Excelencia (PRONEX/FACEPE)Fundacao de Apoio ao Desenvolvimento do Ensino, Ciencia e Tecnologia do Estado de Mato Grosso do Sul (FUNDECT)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES