Purification of deformin, an extracellular protein synthesized by Bartonella bacilliformis which causes deformation of erythrocyte membranes

摘要

A factor capable of deforming erythrocyte membranes, found in the culture supernatants of Bartonella bacilliformis, was purified 1840-fold using hydrophobic, ion exchange and gel exclusion chromatography. The final fractions contained a single detectable polypeptide species, referred to as deformin, having a molecular weight of 67 000 by SDS-PAGE and a native molecular weight of 130 000 by gel exclusion chromatography or velocity sedimentation in a glycerol gradient. Erythrocytes treated with deformin acquire trenches, indentations, and invaginations which could be reversed by Vanadate, dilauroylphosphatidylcholine (DLPC), or by raising the internal Ca2+ concentrations with the ionophore A23187. Internal vacuoles also form. Erythrocytes treated with trypsin or neuraminidase are much more sensitive to deformin than untreated erythrocytes; erythrocytes treated with phospholipase D are less sensitive to deformin. This protein may play a role in causing the severe anemia which can result as a consequence of infection by B. bacilliformis.