FIGURE 1.

a, primary sequence of kalata B1. The disulfide bonds and circular backbone are indicated with lines, and the inter-cysteine loops are labeled below the sequence. Loop 6, in which the melanocortin sequences are grafted, is highlighted in blue. b, four sequences grafted into loop 6. The lowercase f refers to d-Phe. Non-native kalata B1 residues are highlighted in red. c, structure of kalata B1 (Protein Data Bank code 1nb1), with disulfides indicated, and loop 6 highlighted in blue (62).