Songyu Wang is a senior scientist at Protein Design group of Discovery Protein Science at Amgen Inc, South San Francisco. Her main responsibilities are to use structural-based protein engineering approach to design immunogens and novel tool molecules to impact various pipeline programs. She is also actively involved in sequence-based designs of multispecific surrogates to support in vitro and in vivo studies. Her other major role is to use her expertise in protein biochemistry to develop multi-step purification strategies for challenging proteins and complex multispecifics to ensure the delivery of high-quality proteins for downstream studies.
Prior to joining Amgen in 2017, Songyu was a Research Fellow at Harvard Medical School, researching on in vitro reconstitution of a membrane network using purified components. She completed her PhD training in molecular and cellular biology at National University of Singapore in 2011.
Purification of multispecific antibody-based molecules and recombinant extracellular domains of secretory proteins is often challenging due to increased molecular complexity which could lead to a low expression titer. To overcome this challenge, we generally design a panel of exploratory formats or explore different antibody clones to screen for the optimized versions. This required us to set up a high throughput purification platform to quickly deliver a panel of molecules with high purity at about one-mg scale for screening purposes. To this end, we used CETAC coupled with AKTA to set up three two-step tandem purification methods and optimized the purification strategies based on the complexity and the expression titer of molecules. This shortened the cycle time three to five-fold. We concluded that protein A followed by gel filtration is most robust because it efficiently removes the aggregates and unwanted species and importantly, it delivers all the final molecules in the same formulation buffer which facilitates the downstream screening process.