Characterization of the gene encoding a 60-kilodalton Babesia bovis merozoite protein with conserved and surface exposed epitopes

Mol Biochem Parasitol. 1991 May;46(1):45-52. doi: 10.1016/0166-6851(91)90197-e.


A clone expressing a surface exposed, conserved epitope of a 60-kDa merozoite polypeptide was identified in a cDNA library constructed from a cloned Mexico strain of Babesia bovis. Sequencing of the 1.9-kb insert (pBv60) revealed an open reading frame encoding a 65-kDa polypeptide with a signal peptide and a tandemly repeated region. Monoclonal antibody 23/56.156, which binds a surface exposed epitope on the native polypeptide, specifically immunoprecipitated [35S]methionine-labeled polypeptides ranging from 60-30 kDa from pBv60 directed transcription and translation. Antibodies raised in rabbits against recombinant polypeptide reacted with the live merozoite surface in a polar immunofluorescence pattern, immunoprecipitated the native 60-kDa polypeptide, and were used to deplete the polypeptide by adsorption from a preparation of native [35S]methionine-labeled merozoite antigen. Restriction enzyme analysis indicated a single gene copy and the absence of introns. Hybridization demonstrated the presence of the gene in Mexico, Australia 'L', and Texas strains of B. bovis, but not in Babesia bigemina. A slightly different hybridization pattern was present in uncloned Australia 'L' B. bovis, indicating sequence diversity in the Bv60 gene among isolates. Cloning and structural analysis of pBv60 provides a source of defined antigen for determining the role of conserved merozoite surface epitopes in protective immunity against babesiosis.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Antigens, Protozoan / genetics*
  • Antigens, Surface / genetics*
  • Babesia / genetics*
  • Babesia / immunology
  • Base Sequence
  • Blotting, Southern
  • Cloning, Molecular
  • DNA, Protozoan
  • Epitopes
  • Molecular Sequence Data
  • Open Reading Frames
  • Precipitin Tests
  • Sequence Alignment


  • Antigens, Protozoan
  • Antigens, Surface
  • DNA, Protozoan
  • Epitopes

Associated data

  • GENBANK/M59473
  • GENBANK/M59474
  • GENBANK/M61203
  • GENBANK/M61204
  • GENBANK/M61205
  • GENBANK/M61206
  • GENBANK/M61207
  • GENBANK/M61208
  • GENBANK/S43018
  • GENBANK/S78950