Cation exchange surface-mediated denaturation of an aglycosylated immunoglobulin (IgG1).

Cation exchange chromatography of an aglycosylated IgG1 resulted in two distinct peaks during gradient elution. The early eluting peak contained <1% high molecular weight (HMW) species, while the later peak contained 23% HMW species. Analysis by hydrogen-deuterium exchange and Fourier transform infrared spectroscopy (FTIR) indicated that aggregate formation and generation of the second peak were caused by antibody denaturation on the resin surface.

Anion binding mediated precipitation of a peptibody.

Purpose: Understand the underlying mechanism governing the salt-induced precipitation of a basic (pI = 8.8) protein, Peptibody A (PbA), in acidic solutions.

Methods: The rate, extent, and reversibility of PbA precipitation was monitored over 4-weeks as a function of pH (3.