Patent ID: 7056740
Filing Date: 2006-06-06
Classification: C07K,C12N

Abstract:
1. An in vitro method of obtaining a peptide sequence having a desired functional property, comprising: a) preparing at least one heteroduplex polynucleotide sequence wherein said heteroduplex polynucleotide sequence has at least two non-complementary nucleotide base pairs; b) mixing copies of the heteroduplex polynucleotide sequence with an effective amount of RES I or a combination of mismatch endonucleases including RES I, a proofreading enzyme, dNTPs, and a ligase enzyme; c) allowing sufficient time for non-complementary nucleotide base pairs to be converted to complementary base pairs, wherein a population of polynucleotide sequence variants result; d) expressing polynucleotide sequence variants; and e) screening or selecting variants for the desired functional property, wherein at least one of the polynucleotide sequence variants selected encode peptide sequence variants that have superior biological activity compared to the peptides encoded by the polynucleotide sequences used to form the heteroduplex.