PHAGE-DISPLAYED LIBRARIES FOR THE SELECTION OF OPTIMAL AFFINITY PEPTIDES FOR PROTEIN-PURIFICATION USING NI-NITRILOTRIACETIC ACID CHROMATOGRAPHY

A random hexapeptide library, cloned in bacteriophage, was used to sel ect affinity peptides using nickel-nitrilotriacetic acid (Ni-NTA) colu mns. The screening protocol was successful by isolating peptides shari ng common features and, in most cases, common amino acid sequences wer e isolated (e.g. WHHHPH, AQHHHH). Ni-NTA chromatography of the fusion phage of the selected peptides exhibited a more homogeneous elution be havior (i.e. elution in one peak) than the most commonly used His(6) p eptide (elution in multiple peaks).