Three short Pro-Gly-Pro-containing peptides were tested for how well they resist being broken down by enzymes in the nose, brain, and blood — the same environments a drug must survive after intranasal administration. All three were substantially more resistant to degradation than Semax, and the study also mapped the specific breakdown products each peptide produces. Greater stability against enzymes means these smaller peptides may remain active longer after administration, which is relevant for their potential as drug candidates.
Shevchenko, K V; V'iunova, T V; Nagaev, I Iu; Andreeva, L A; Miasoedov, N F