Figure 1.

SDS-PAGE analysis of recombinant protein expression and purification. The individual P-proteins and the Msp-1₁₉ control antigen were expressed in an E. coli BL21 (DE3) expression strain and purified using affinity chromatography on Ni-NTA resin. Lines: MM: molecular mass standards; lines 1 and 2: whole cell extract from Escherichia coli with an indicated expression vector without (-IPTG) and with (+IPTG) expression induction, respectively; lines 3 and 4: insoluble and soluble protein fractions, respectively; line 5: purified protein fraction eluted from the Ni column.