Screening of peptide affinity tags using immobilised metal affinity chromatography in 96-well plate format.

A method for high throughput screening of Green Fluorescent Proteins carrying metal binding tags in bacteria was developed. A random four amino acids tag-peptide library was successfully generated in E. coli. A 96-microtiter plate assembled with metal-iminodiacetic acid small cryogel columns was used for library screening. For the first time we were able to simultaneously screen a metal binding peptide tags library obtained from E. coli against different metal ions. From screening 25 different tags, three clones were able to bind to all metal ions studied (Ni2+, Zn2+, Co2+ and Cd2+). It was clearly demonstrated that the new construct could facilitate the screening of large peptide libraries.