Retroviral particles are effectively purified on an affinity matrix containing peptides selected by phage-display.

Retroviral particles are expensive to manufacture, mostly due to the downstream processing steps which result in low recoveries (≈30%) and concentration factors. In this work, a dodecapeptide phage-display library was panned against retrovirus like particles expressing the envelope protein Ampho4070A (VLPs-AMPHO) and VLPs without the target protein, used as a negative control (VLPs). A depletion/selection panning protocol was successfully used to deal with the structural complexity of the target, and a total of three distinct peptide sequences displaying preferential binding towards VLPs-AMPHO were found. Peptide 3 (CAAALAKPHTENHLLT), which appeared as one lead candidate, was synthesized and immobilized onto two purification matrices, cross-linked agarose and magnetic particles. The matrices selectively bound VLPs-AMPHO and in both cases recovery yields higher than 90% were obtained when employing mild elution conditions, while maintaining viral particle morphology and size.