PREPARATION METHOD OF POLYPEPTIDE SPECIFICALLY RECOGNIZING PROTEIN PRESENTED ON MEMBRANE

摘要

PROBLEM TO BE SOLVED: To provide a preparation method of a polypeptide having affinity to a target protein by using a scaffold being lower molecular than 3F scaffold derived from snake venom and having a low number of cysteine residues.SOLUTION: The method comprises the following steps (a) to (e): (a) preparing a polynucleotide library comprised of the group of expression vectors capable of expressing in a gram-negative bacterium; (b) expressing each expression vector comprising the polynucleotide library in a transformed gram-negative bacterium; (c) contacting each polypeptide with a target protein in a periplasm space; (d) forming a spheroplast of the transformed gram-negative bacterium to select a polypeptide bound to the target protein; and (e) amplifying the polynucleotide in a transformed cell expressing the selected polypeptide to determine the amino acid sequence of the polypeptide which the polynucleotide codes.