A suspension cell-based interaction platform for interrogation of
membrane proteins.
Abstract
The majority of clinically approved therapeutics target membrane
proteins (MPs), highlighting the need for tools to study this important
category of proteins. To overcome limitations with recombinant MP
expression, whole cell screening techniques have been developed that
present MPs in their native conformations. Whereas many such platforms
utilize adherent cells, here we introduce a novel suspension cell-based
platform termed “biofloating” that enables quantitative analysis of
interactions between proteins displayed on yeast and MPs expressed on
mammalian cells, without need for genetic fusions. We characterize and
optimize biofloating and illustrate its sensitivity advantage compared
to an adherent cell-based platform (biopanning). We further demonstrate
the utility of suspension cell-based approaches by iterating rounds of
magnetic-activated cell sorting (MACS) selections against MP-expressing
mammalian cells to enrich for a specific binder within a yeast-displayed
antibody library. Overall, biofloating represents a promising new
technology that can be readily integrated into protein discovery and
development workflows.