Cloning and production of the B2t (1), 2B2t (2), 4B2t (3) and 8B2t (4) recombinant proteins.

<p>(A) 1% agarose gel stained with ethidium bromide and (B) 15% acrylamide gel stained with Comassie blue, showing the polynucleotides and purified recombinant proteins. The molecular weights are indicated in base pairs (A) and kilodaltons (B): (1) B2t 213 pb, 8.3 kDa; (2) 2B2t, 446 pb, 16.9 kDa; (3) 4B2t, 874 pb, 31.3 kDa and (4) 8B2t, 1,738 pb, 60.1 kDa. In (B), 10 µl of the supernatant of each recombinant protein purified from 1 litre of culture was loaded to compare the final concentration of each recombinant protein obtained from the same volume of culture.