Crosslinking profiles of M. tb ICD2. A. UV crosslinking profile, B. Chemical crosslinking using glutaraldehyde, C. Glutaraldehyde crosslinking with substrate (Isocitrate) and coenzyme (NADP). UV crosslinking profile clearly shows a band corresponding to a homodimeric species. Chemical crosslinking with glutaraldehyde in presence and absence of NADP and Isocitrate was more efficient and showed bands corresponding to both dimer and trimer forms of M.tb ICD 2. D. The gel filtration assay under an intermediate (500 mM) salt concentration revealed a peak representing a mixture of trimeric and dimeric species. The collected elution fractions were run on 7% SDS-PAGE. D (Inset): The calibration curve plotted as Ve/Vo versus log of molecular mass for calculating molecular weights of the oligomeric assembly.