Apparent heterogeneity in the pIII-peptide fusion protein in single-phage clones isolated from peptide libraries

作者：Noppe Wim^*; Galaev Igor Yu; Mattiasson Bo; Deckmyn Hans

来源：Protein Engineering Design and Selection, 2011, 24(9): 721-726.

DOI：10.1093/protein/gzr033

• supermacroporous cryogel
• pIII fusion protein
• heterogeneity

Ligand homogeneity is an important issue in affinity chromatography. Using phages expressing peptides on the pIII protein, a heterogeneity in the binding of monoclonal phages was observed during affinity chromatography on supermacroporous cryogels. Fractions with different apparent binding affinities could be separated by stepwise elution. When these different fractions were re-applied, the respective differences in affinity were retained. However, when phage fractions with different apparent affinities were first amplified, an offspring was generated with again variable affinities. As the sequence of the peptide insert was the same, the heterogeneity must be ascribed to differences in avidity and although no direct evidence could be generated, we hypothesize that this is possibly due to phages displaying different numbers of the same peptide as a consequence of either proteolytic or packaging events during the amplification step in Escherichia coli.

• 出版日期2011-9