Figure 7.

Stability studies of the linear peptide, CVP-198, and the bioactive backbone cyclic peptide, CVP-199. The stability of the peptides was measured independently under tryptic degradation at 37 °C (by trypsin degradation of the peptide) and was determined by HPLC analysis (for more experimental details, see “Materials and Methods”) (n = 3). The starting time point (0 min, 100%) represents the peptide at the beginning of each experiment. Linear peptide (CVP-198) at 37 °C with trypsin (blue), and cyclic peptide (CVP-199) at 37 °C with trypsin (orange), were analyzed after 0 min, 5 min, 30 min, 60 min, and 120 min. Separation was performed by HPLC in the presence of 0.1% trifluoroacetic acid and detected by absorbance at 214 nm. Peptide amounts were calculated relative to the quantities determined at time point zero.