rd
23 Congress of the International Union for Biochemistry and Molecular Biology
th
44 Annual Meeting of the Brazilian Society for Biochemistry and Molecular Biology
th
th
Foz do Iguaçu, PR, Brazil, August 24 to 28 , 2015
THEORETICAL MODELS APPLIED IN THE DEVELOPMENT OF A LESS
ALLERGENIC PROTEIN OF THE MITE BLOMIA TROPICALIS FOR
IMMUNOTHERAPY IN ALLERGIC RESPIRATORY DISEASES
Candido, P. A.1; Junior, O. A.2; Júnior, J. P. C.3; Taketomi, E. A.3; Contessoto, V.
G.4; Oliveira, V. M.4; Leite, V. B. P.4; Oliveira, R. J.5
1
Programa de Pós-Graduação Multicêntrico em Química de Minas Gerais (PPGMQ-MG) – UFTM,
Uberaba, Minas Gerais, Brasil
2
Laboratório de Química Computacional Medicinal (ICBN) – UFTM, Uberaba, Minas Gerais, Brasil
3
Laboratório de Alergia e Imunologia Clínica, (ICB) – UFU, Uberlândia, Minas Gerais, Brasil
4
Departamento de Física (IBILCE) – Unesp, São José do Rio Preto, São Paulo, Brasil
5
Departamento de Física (ICENE) – UFTM, Uberaba, Minas Gerais, Brasil
The Blomia tropicalis family mite is prevalent in house dust and it is primarily
responsible for allergic respiratory diseases in the world, although it is more frequent in
tropical and subtropical regions as Brazil. In this study, it was used molecular dynamics
simulations with simplified models and electrostatic calculations for the characterization
of the recombinant Blomia tropicalis allergen protein group 5 (rBlo t 5). The objective
was to produce a new allergen with the same immunological characteristics of the
native rBlo t 5, however with modified properties for the purpose of promoting the
reduction of allergenicity of the antibody IgE and increased immunogenicity of response
for applications in immunotherapy. It was obtained the file for the wild type rBlo t 5
protein structure in the Protein Data Bank (PDB code 2JMH). It was produce, by theory
and experiment, a mutant shuffle version of wild type protein (mBlo t 5). First, it was
performed coarse-grained simulation of both proteins using the structure-based model
in Gromacs (SBM) and the SMOG-Server webtool to generate the input
files.
Brazilian Society for Biochemistry and
Molecular Biology (SBBq)
rd
23 Congress of the International Union for Biochemistry and Molecular Biology
th
44 Annual Meeting of the Brazilian Society for Biochemistry and Molecular Biology
th
th
Foz do Iguaçu, PR, Brazil, August 24 to 28 , 2015
The simulations were performed only with the protein carbons alpha. Thermodynamic
analysis shows that the recombinant and the mutant Blo t 5 have similar thermalstability
of ΔF = 2.0 kbT. Second, the charge-charge interaction was used to calculate by the
technique Tanford-Kirkwood Surface Accessibility – Monte Carlo (TKSA-MC) in order to
obtain the surface electrostatic interactions by energy optimization, in both proteins. The
TKSA-MC results show an increase in stability and electrostatic interaction in the
epitope region of mBlo T 5 with relation to rBlo t 5. These theoretical results
corroborated with the experimental data, which shows that the modified allergen rBlo t 5
has a shift in antigenicity for the antibody IgG4 isotype, thus making suitable its
application as potential candidate in specific allergen immunotherapy studies.
Key words: respiratory allergy, structure-based model, electrostatic interaction
Brazilian Society for Biochemistry and
Molecular Biology (SBBq)