Wesley Asher
e-mail: washer@mail.rochester.edu
Research:
We have developed peptide fusion tags covalently modified with heme c, known as heme tags, that bind irreversibly a L-histidine immobilized Sepharose (HIS) resin for affinity purification of recombinant proteins expressed in Escherichia coli and for protein quantification. The heme-tag-HIS purification method couples the ease of affinity purification with the convenience of visible detection for protein tracking. Additionally, we are exploring the use of the heme tag as a site-specific fluorescence resonance energy transfer (FRET) acceptor for studying protein folding and unfolding. By labeling proteins with an appropriate FRET donor dye, the heme tag can be used as a site-specific quencher for obtaining distance specific unfolding data.