Binding of PkNBPXb-II and native PkNBPXb to enzymatically treated rhesus monkey erythrocytes. (A) PkNBPXb-II cells were tested for relative binding in adhesion (rosetting) assays to rhesus monkey erythrocytes that were either untreated, or treated with chymotrypsin (CT), trypsin (T), or neuraminidase (NA), * p-value <0.05 and *** p-value <0.001. (B) Native PkNBPXb binding was tested in erythrocyte binding assays with rhesus monkey erythrocytes that were untreated or treated with CT, T, or NA. Total supernatants (TS) and comparable eluates from untreated rhesus monkey erythrocytes (R) incubated without supernatants were also applied to the SDS-PAGE gels and transferred to nitrocellulose membranes. The immunoblot was probed with an anti-PkNBPXb antibody . (C) A negative binding control was included using duplicate aliquots of the RBC samples tested in B whereby anti-PkMSP3/140 antibody recognizes the native protein in the supernatant only.