Phage display screening in low dielectric media

Here we report the first application of phage display screening in low dielectric media. Two series of phage clones with affinity for α-chymotrypsin (CT) were selected from a Ph.D.TM-C7C library, using either a buffer or acetonitrile in buffer (50%, v/v). The affinity of lysates, individual clones or selected cyclic peptides for the enzyme was studied by examining their influence on CT activity. Peptides displayed on phage selected in buffer provided significant protection from enzyme autolysis resulting in marked increase in CT activity (>100%). Phage selected in ACN provided some, albeit weak, protection from the detrimental influence on CT from ACN. In conclusion, the results demonstrate the potential for the application of phage display screening protocols to targets in media of low dielectricity. Copyright © 2008 John Wiley & Sons, Ltd.