Sodium dodecyl sulfate-polyacrylamide gel electrophoresis for screening nonaggregating human antibody heavy chain variable domains

Abstract

Antibody heavy chain variable domains (V(H)s) form a significant class of biologics. With V(H) display libraries-the primary source of V(H) binders-unwanted aggregating V(H)s are coselected, sometimes overwhelmingly, alongside nonaggregating V(H)s. Thus, methods enabling efficient screening for nonaggregating V(H)s are highly valuable. Here, we found that on nonreducing sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) gels, nonaggregating V(H)s migrate faster than expected, giving underestimated molecular weights (MWs), whereas aggregating ones migrate slower, giving overestimated MWs. Our finding can be applied to large-scale screening for nonaggregating V(H)s and possibly other proteins, in particular in display library settings, by SDS-PAGE.