Patent ID: 9580707
Date: 2017-02-28
CPC Classifications: A61P,C07K,C12N,C12Q,C40B

Claim:
1. A method for isolating an antimicrobial peptide comprising: obtaining a microbial cell culture comprising microbial cells transformed with a plasmid wherein the microbial cells are transformed with different plasmids, each plasmid comprising a nucleic acid sequence encoding a random peptide wherein expression of the random peptide is under the control of an inducible arabinose promoter, wherein the nucleic acid sequence encoding the random peptide comprises a DNK(NNK) N is A, T, C or G; K is T or G; and D is A, T, or G; and n is 10-49; culturing the microbial cell culture under a condition that represses expression of the random peptides; controllably expressing a random peptide library by (i) removing the condition that represses expression from the microbial cell culture; and (ii) adding arabinose to the microbial cell culture, wherein the nucleic acid sequence of the plasmid further encodes a leader peptide and wherein following controllable expression, the leader peptide is at the N-terminus of the random peptide, wherein the microbial cell is a Gram-negative microbial cell comprising a periplasm and wherein the leader peptide targets the random peptide to the periplasm of the Gram negative microbial cell, wherein the leader peptide is an alkaline phosphatase leader peptide; evaluating the microbial cell culture for evidence of an antimicrobial bacteriolytic, bacteriostatic, or bacteriocidal phenotype and if an antimicrobial phenotype is present; isolating a nucleic acid sequence encoding a peptide leading to the antimicrobial phenotype.