Patent ID: 7244702
Filing Date: 2007-07-17
Classification: C07K

Abstract:
1. A method of obtaining a composition comprising cysteine-containing peptides, said method comprising: a) obtaining cell wall iron reductase from a pathogenic, DNA-producing microorganism; b) contacting the iron reductase with NTA (nitrilotriacetic acid)-bearing polystyrene beads in the presence of ferric or ferrous ion for a time and under conditions effective to bind said iron reductase with the polystyrene beads; c) removing any unbound proteins from the NTA-bearing polystyrene beads; d) separating the polystyrene beads from the proteins that are bound thereto; e) contacting the proteins of step (d) with trypsin for a time and under conditions effective to generate peptide fragments; and f) isolating the peptide fragments of step (e) that contain cysteine.