Analysis of gp120 CDC451-binding peptides affinity selected from the biased random mutagenesis library and analysis of the “X6 NNK” m2-based phage display library. A. Analysis of the biased random mutagenesis library. 24 randomly selected phages from the biased random mutagenesis m1-based library and 23 affinity selected phages obtained after screening of the biased random mutagenesis m1-based library against gp120 CDC451 were sequenced. The sequences were used as input for the MEME Suite motif analysis software [60, 61] and two logos were produced (random peptides top and affinity-selected peptides bottom). The sequences of the m1, 2A6 (standard screening) and m2 (stringent biopaning) peptides are provided for comparison. B. Analysis of the “X6 NNK” m2-based library. Logos were prepared from the sequences of 20 randomly sampled phages of the “X6 NNK” m2-based library (upper logo) and those of 41 affinity selected phages obtained by screening the library with envelope as described in the text (lower logo). The sequence of m3-peptide is provided for comparison.