Screening of AKAP-selective RII variants by phage selection.
A, Coomassie Blue-stained SDS-polyacrylamide gel of GST-AKAP anchoring helix fragments. B, four-step iterative scheme for enrichment of RII variant phage that are selective for a single AKAP. C, predominant RII variant sequences following phage selection with each of the 10 different AKAP baits. High-selection pressure was a 5000-fold molar excess of each competitor AKAP helix, medium-selection pressure was a 250-fold molar excess of the competitors, and None was the absence of competitor fragments.