Memorias do Instituto Oswaldo Cruz (Nov 2010)

Analysis of membrane protein genes in a Brazilian isolate of Anaplasma marginale

  • Daniel SG Junior,
  • Flábio R Araújo,
  • Nalvo F Almeida Junior,
  • Said S Adi,
  • Luciana M Cheung,
  • Stenio P Fragoso,
  • Carlos AN Ramos,
  • Renato Henrique M de Oliveira,
  • Caroline S Santos,
  • Gisele Bacanelli,
  • Cleber O Soares,
  • Grácia MS Rosinha,
  • Adivaldo H Fonseca

DOI
https://doi.org/10.1590/S0074-02762010000700001
Journal volume & issue
Vol. 105, no. 7
pp. 843 – 849

Abstract

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The sequencing of the complete genome of Anaplasma marginale has enabled the identification of several genes that encode membrane proteins, thereby increasing the chances of identifying candidate immunogens. Little is known regarding the genetic variability of genes that encode membrane proteins in A. marginale isolates. The aim of the present study was to determine the degree of conservation of the predicted amino acid sequences of OMP1, OMP4, OMP5, OMP7, OMP8, OMP10, OMP14, OMP15, SODb, OPAG1, OPAG3, VirB3, VirB9-1, PepA, EF-Tu and AM854 proteins in a Brazilian isolate of A. marginale compared to other isolates. Hence, primers were used to amplify these genes: omp1, omp4, omp5, omp7, omp8, omp10, omp14, omp15, sodb, opag1, opag3, virb3, VirB9-1, pepA, ef-tu and am854. After polimerase chain reaction amplification, the products were cloned and sequenced using the Sanger method and the predicted amino acid sequence were multi-aligned using the CLUSTALW and MEGA 4 programs, comparing the predicted sequences between the Brazilian, Saint Maries, Florida and A. marginale centrale isolates. With the exception of outer membrane protein (OMP) 7, all proteins exhibited 92-100% homology to the other A. marginale isolates. However, only OMP1, OMP5, EF-Tu, VirB3, SODb and VirB9-1 were selected as potential immunogens capable of promoting cross-protection between isolates due to the high degree of homology (over 72%) also found with A. (centrale) marginale.

Keywords