The pMAL-pIII Vector is a derivative of pMAL-p2 in which the leader sequence of maltose binding protein (MBP,malE) has been replaced with the M13 pIII leader sequence. KpnI/Acc65I and EagI sites have been introduced within the pIII leader to facilitate direct transfer of sequences selected from any of the Ph.D. phage display peptide libraries into an expression vector. The corresponding peptides are expressed as N-terminal MBP fusions which bear some similarity to M13 pIII displayed peptides.These fusions can then be easily purified fromE. coliperiplasmic space by osmotic shock followed by affinity chromatography on amylose resin. Since the peptide is expressed at the N-terminus of MBP, Factor Xa cannot be used to cleave the peptide from MBP.
Features
Alternative to chemical peptide synthesis
Subcloning of Ph.D peptides into pMAL-pIII provides monovalent MBP fusion for additional binding studies after phage panning, phage ELISA experiments.