Project Summary
The goal of this STTR Phase I project is to demonstrate the feasibility of developing the first universal affinity
membrane for the rapid, selective, one-step purification of difficult-to-purify proteins. Despite the urgency for
expanding the application of gene editing systems and accelerating vaccine and antibody test development,
the rapid purification of critical proteins such as CRISPR-Cas9 and the SARS-COV2 spike protein with high
yield, high purity, and high activity remains a difficult challenge. The proposed innovation will benefit public
health and have a significant impact on the biopharmaceutical industry by addressing this challenge. The
products of this innovation will be first-in-market universal affinity membrane chromatography columns based
on TriAltus’ ultrahigh affinity CL7/Im7 purification system. Research will be done in partnership with Clemson
University and the University of Alabama at Birmingham. Purification of CRISPR-Cas9 protein from E. coli
lysate will be used as a demonstration case for evaluating the performance of the affinity membrane
innovation. The Specific Aims of this Phase I study are to (1) Synthesize and characterize Im7-activated affinity
membranes and (2) Test prototype affinity membrane columns for capture purification of CRISPR-Cas9. In
Specific Aim 1, we will establish the feasibility of synthesizing the affinity membranes by immobilizing four Im7
ligand variants at high density on polymer-grafted macroporous membranes. We will measure protein binding
capacity, recovery, and column reusability in screening experiments using purified, CL7-tagged CRISPR-Cas9.
In Specific Aim 2, we will quantify and benchmark performance for capture step purification of CRISPR-Cas9
from E. Coli lysate. We will measure Cas9 binding capacity, recovery, purity, and activity. In Phase II, the team
plans to comprehensively evaluate the roles that synthesis conditions and membrane support structure play on
binding capacity; delineate operating ranges that maximize productivity, recovery, purity, and activity;
collaborate with a membrane technology company on research to establish a scalable process to produce
membrane columns for external validation; and conduct field research with external partners and prospective
customers. Commercialization will bring the first universal affinity membrane chromatography column to the
market. Market entry for the new column products will be to research and development scientists. The columns
will provide a universal platform for the rapid, cost-effective purification of tag-free proteins with high yield,
purity, and activity. By simplifying purification protocols and reducing purification times, products derived from
this membrane innovation will have a major impact in the race to develop new protein drugs, gene therapies,
vaccines, and antibody test kits.