Patent ID: 7101667
Filing Date: 2006-09-05
Classification: C07K,C12N,G01N,Y10S

Abstract:
1. A method of determining the structure of a peptide, comprising: a) expressing a fusion peptide comprising the peptide and a lanthanide binding tag; b) isolating said fusion peptide; c) forming a crystal of said fusion peptide in the presence of a lanthanide ion; and d) determining the two dimensional or three-dimensional crystal structure of the protein, wherein the lanthanide binding tag is a peptide that contains: (a) about 12 to about 30 amino acid residues, (b) at least two carboxylic groups and (c) at least one oxygen containing group selected from the group consisting of an backbone carbonyl group, the carboxyl terminus, Ser, Thr, Gln, Asn, or an oxygen of a bound solvent molecule and wherein the lanthanide binding tag binds a lanthanide ion with an affinity (KD) of about 1 nM to about 10 μM.