DNA aptamer affinity ligands for highly selective purification of human plasma-related proteins from multiple sources

- Practical examples of DNA aptamer affinity chromatography are given.
- Purification of various therapeutic proteins from different medias including one of the most complex: the plasma.
- Confirmation of the high selectivity of this molecular class.
- Illustration of the high resistance harsh cleaning/sanitization conditions.

Nucleic acid aptamers are promising ligands for analytical and preparative-scale affinity chromatography applications. However, a full industrial exploitation requires that aptamer-grafted chromatography media provide a number of high technical standards that remained largely untested. Ideally, they should exhibit relatively high binding capacity associated to a very high degree of specificity. In addition, they must be highly resistant to harsh cleaning/sanitization conditions, as well as to prolonged and repeated exposure to biological environment. Here, we present practical examples of aptamer affinity chromatography for the purification of three human therapeutic proteins from various sources: Factor VII, Factor H and Factor IX. In a single chromatographic step, three DNA aptamer ligands enabled the efficient purification of their target protein, with an unprecedented degree of selectivity (from 0.5% to 98% of purity in one step). Furthermore, these aptamers demonstrated a high stability under harsh sanitization conditions (100 h soaking in 1 M NaOH). These results pave the way toward a wider adoption of aptamer-based affinity ligands in the industrial-scale purification of not only plasma-derived proteins but also of any other protein in general.