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

Abstract

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.