Characterization of sdAb monomer and combodies.

<p>(A). Primary structure of monomer and combodies of the sdAbs used in our study are shown. (B) Size-exclusion chromatography of BR 2.3, 26424 and 26434. The size of the monomeric and multimeric sdAbs was analyzed through Sephadex 200 chromatography and the elution positions have been depicted. (C) The size of BR 2.3, 26424 and 26434 has been further confirmed through SDS-PAGE. BR 2.3 elutes as a 14 kDa monomer in both reducing (+DTT) and non-reducing (-DTT) conditions. Combodies 26424 and 26434 elutes as 25 kDa protein in reducing conditions and appears to be more than 130 kDa in non-reducing SDS-PAGE, suggesting pentamerization of the coiled-coil peptide. (D) The monomeric and pentameric sdAbs were further analyzed in Western blot. The purified proteins were run in a 12% SDS-PAGE in both reducing and non-reducing conditions. The antibodies were detected using Mouse anti-<i>myc</i> IgG and HRP-labeled goat anti-mouse IgG followed by chemiluminiscence detection. The figure depicts Western blot for 26434 and BR 2.3.