The Journal of Medical Microbiology, Vol 41, Issue 6 378-383, Copyright © 1994 by Society for General Microbiology
Skin reactivity and fibronectin-binding property of TB66 (66-kDa protein of Mycobacterium tuberculosis)
R. G. Deshpande, M. B. Khan, D. A. Bhat and R. G. Navalkar
Department of Microbiology and Immunology, Morehouse School of Medicine, Atlanta, Georgia 30310.
A 66-kDa protein (TB66) was purified from culture filtrate (CF) and cell
sonicate (CS) of Mycobacterium tuberculosis H37Rv by immobilised metal
affinity chromatography (IMAC) on a Ni-nitrilotriacetic acid (NTA) column.
TB66 was found to be a fibronectin-binding protein as determined by ELISA
and could be purified by affinity chromatography with
fibronectin-Sepharose. A similar 66-kDa protein could be isolated also from
M. bovis, M. bovis BCG, M. africanum and M. tuberculosis H37Ra by IMAC, but
not from any other mycobacteria. The NH2-terminal amino-acid sequence of
TB66 from H37Rv and M. bovis was identical and showed 85% homology with the
N-terminal sequence of bovine serum albumin (BSA). A monoclonal antibody
(MAb) OD4AG3 recognised a heat-stable and trypsin-sensitive epitope near
the C-terminal end of TB66. This MAb also recognised the 66-kDa protein
isolated from the other members of the M. tuberculosis complex. In tests of
immunogenicity, TB66 elicited a delayed type hypersensitivity reaction in
guinea-pigs immunised with either TB66 or with M. tuberculosis H37Rv. TB66
also elicited an antibody response in immunised guinea-pigs and stimulated
murine macrophages to produce tumour necrosis factor.
