Figure 4. Native SmGBP is a membrane –associated protein.

S. mansoni peripheral and integral membrane proteins were fractionated by sequential extraction in high salt, alkaline pH and urea, as described in the text. Aliquots of the supernatants after extraction in 2 M NaCl (S1), bicarbonate buffer, pH 11.3 (S2), 4 M urea (S3) and the final pellet (P4) were immunoblotted with peptide-purified anti-SmGBP antibody. The antibody recognized two major bands corresponding to the monomer and predicted dimer in the S3 supernatant after 4 M urea extraction as well as in the final pellet.