Cry1A(b)16 toxin from Bacillus thuringiensis: Theoretical refinement of three-dimensional structure and prediction of peptides as molecular markers for detection of genetically modified organisms.
Transgenic maize produced by the insertion of the Cry transgene into its genome became the second most cultivated crop worldwide. Cry gene from Bacillus thuringiensis kurstaki expresses protein derivatives of crystalline endotoxins which confer insect resistance onto the maize crop. Mandatory labeling of processed food containing or made by genetically modified organisms is in force in many countries, so, it is very urgent to develop fast and practical methods for GMO identification, for example, biosensors. In the absence of an available empirical structure of Cry1A(b)16 protein, a theoretical model was effectively generated, in this work, by homology modeling and molecular dynamics simulations based on two available homologous protein structures. Molecular dynamics simulations were carried out to refine the selected model, and an analysis of its global structure was performed. The refined models of Cry1A(b)16 showed a standard fold and structural characteristics similar to those seen in Bacillus thuringiensis Cry1A(a) insecticidal toxin and Bacillus thuringiensis serovar kurstaki Cry1A(c) toxin. After in silico analysis of Cry1A(b)16, two immunoreactive candidate peptides were selected and specific polyclonal antibodies were produced resulting in antibody-peptide interaction. Biosensing devices are expected to be developed for detection of the Cry1A(b) protein as a marker of transgenic maize in food. Proteins 2017; 85:1248-1257. © 2017 Wiley Periodicals, Inc.
REQUIMTE-LAQV, Instituto Superior de Engenharia do Porto, Instituto Politécnico do Porto, Porto, Portugal.
Alexandra
A
Plácido
REQUIMTE-LAQV, Instituto Superior de Engenharia do Porto, Instituto Politécnico do Porto, Porto, Portugal.
Andreia
A
Coelho
Grupo de Química Quântica Computacional e Planejamento de Fármaco, GQQCPF, Departamento de Química, Universidade Estadual do Piauí, UESPI, Teresina, Brasil.|Laboratório de Pesquisa em Sistemas de Informação, LaPeSI, Departamento de Informação, Ambiente, Saúde e Produção Alimentícia, Instituto Federal do Piauí, Teresina, Brasil.
Lucas
L
Abreu Nascimento
Núcleo de Pesquisa em Biodiversidade e Biotecnologia, Biotec, Campus Ministro Reis Velloso, Universidade Federal do Piauí, Parnaíba, Brasil.
Andreanne
A
Gomes Vasconcelos
REQUIMTE-LAQV, Instituto Superior de Engenharia do Porto, Instituto Politécnico do Porto, Porto, Portugal.
Maria
M
Fátima Barroso
Núcleo de Pesquisa em Biodiversidade e Biotecnologia, Biotec, Campus Ministro Reis Velloso, Universidade Federal do Piauí, Parnaíba, Brasil.
Joilson
J
Ramos-Jesus
Laboratório de Pesquisas em Leishmanioses, Instituto de Doenças Tropicais Natan Portela, IDTNP, Teresina, Piauí, Brasil.
Vladimir
V
Costa
Grupo de Química Quântica Computacional e Planejamento de Fármaco, GQQCPF, Departamento de Química, Universidade Estadual do Piauí, UESPI, Teresina, Brasil.
Francisco
F
das Chagas Alves Lima
REQUIMTE-LAQV, Instituto Superior de Engenharia do Porto, Instituto Politécnico do Porto, Porto, Portugal.
Cristina
C
Delerue-Matos
Grupo de Química Quântica Computacional e Planejamento de Fármaco, GQQCPF, Departamento de Química, Universidade Estadual do Piauí, UESPI, Teresina, Brasil.|Laboratório de Pesquisa em Sistemas de Informação, LaPeSI, Departamento de Informação, Ambiente, Saúde e Produção Alimentícia, Instituto Federal do Piauí, Teresina, Brasil.
Ricardo
R
Martins Ramos
IPEEC-CONICET, Consejo Nacional de Investigaciones Científicas y Técnicas, Puerto Madryn, Argentina.
Mariela M
MM
Marani
Área de Morfologia, Faculdade de Medicina, FM, Campus Universitário Darcy Ribeiro, Universidade de Brasília, UnB, Brasília, Brasil.
José
0000-0002-1096-3236
J
Roberto de Souza de Almeida Leite
D020816:Amino Acid Motifs; D000818:Animals; D000906:Antibodies / Q000737:chemistry / Q000302:isolation & purification; D001413:Bacillus thuringiensis / Q000737:chemistry / Q000276:immunology; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000737:chemistry* / Q000276:immunology; D001427:Bacterial Toxins / Q000737:chemistry* / Q000276:immunology; D001665:Binding Sites; D004731:Endotoxins / Q000737:chemistry* / Q000276:immunology; D005504:Food Analysis / Q000379:methods*; D006460:Hemolysin Proteins / Q000737:chemistry* / Q000276:immunology; D007114:Immunization; D007118:Immunoassay; D056004:Molecular Dynamics Simulation; D010455:Peptides / Q000008:administration & dosage / Q000138:chemical synthesis / Q000276:immunology; D030821:Plants, Genetically Modified; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D020033:Protein Isoforms / Q000737:chemistry / Q000276:immunology; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D051381:Rats; D040681:Structural Homology, Protein; D003313:Zea mays / Q000235:genetics* / Q000276:immunology
D000906:Antibodies; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004731:Endotoxins; D006460:Hemolysin Proteins; D010455:Peptides; D020033:Protein Isoforms; C030956:insecticidal crystal protein, Bacillus Thuringiensis
Bacillus thuringiensis; Cry1A(b)16; homology modeling; molecular dynamics simulation