Figure 1. An active complex of EPO-receptor is generated by a synthetic peptide discovered by combinatorial phage display methods. Binding of the peptide dimer (yellow and orange tubes) induces a symmetric dimerization of the extracellular domain of EPO receptors, shown in the pink and purple surfaces. The figure was generated from the 1EBP protein data bank coordinates.

Figure 2. Mechanism for inactivation of serine proteases by peptide chloromethyl ketones.

Figure 3. Three-dimensional structures of the complex enzyme inhibitor (pink and yellow, respectively). In (a), trypsin is complexed to the 58-residue protein inhibitor, BPTI. In (b), trypsin is complexed to a 9-residue cyclic peptide inhibitor that mimics BPTI (courtesy of Pr. C. Gilon at the Hebrew University of Jerusalem).

Figure 4. A model depicting a probable mechanism of action of antimicrobial peptides. Peptide monomers bind to the plasma membrane of the target cell (a). Peptide polymerization (b) leads to a pore formation (c). See the text for further details.

Figure 5. Typical stepwise solid-phase synthesis of a dipeptide. For longer peptides, the deprotection through coupling steps is repeated for each additional residue. See the text for further details. Ppg, permanent protection group; Tpg, temporary protection group.