We investigate the conformational shift of VSG protein from Trypanosoma brucei, using the experimental (size-exclusion chromatography) and theoretical methodology (Adaptive Poisson-Boltzmann Solver). The results indicated that no shift was detected at low pH (5.0), judging by the similar folding energy of the VSG dimer. Additionally, the high protonation state (37+/43+) of the dimer was observed at low pH, which most likely was not enough to trigger the conformational shift of the dimer. The theoretical data was further confirmed by the SEC experiment (the results are not shown).