Figure 2.

Characterization of recombinant PcrV_NH. (A) SDS-PAGE analysis of PcrV_NH. The purity of PcrV_NH was ~96% as determined by the density of the corresponding band on a SDS-PAGE gel. (B) The chromatograms curves of protein standards and PcrV_NH were overlaid for comparison. Curves 1 to 6 represent the peaks of standard proteins, namely, blue dextran 2000, conalbumin, ovalbumin, carbonic anhydrase, ribonuclease A, and aprotinin. The corresponding elution volume was 40.0, 47.3, 54.6, 62.1, 73.8, and 88.2 ml, respectively. PcrV_NH forms a symmetrical peak at 67.3 ml. (C) Linear regression of standard proteins to calculate the molecular weight of PcrV_NH. The bar represents the Kav (gel phase-distribution coefficient) value of each protein. The standard curve was calculated as “Kav = 0.980–0.479*LogMw” (R² = 0.996). The calculated Mw of PcrV_NH was ~21.2 KDa. (D) Dynamic light scattering analysis of PcrV_NH demonstrated that it forms a symmetrical peak with a diameter of 4.0 nm.