Speaker
Description
Background: The hexapeptide WKYMVm (Wm), a potent agonist of the formyl peptide receptor 2, has shown therapeutic potential in various disease models (e.g., sepsis, lung injury, and cancer). Given that peptide-based drug candidates are often limited by rapid enzymatic degradation and poor membrane permeability, this study investigated the metabolic pathways and oral dosing feasibility of Wm.
Methods: Metabolite profiling was performed using liquid chromatography-quadrupole time-of-flight-mass spectrometry (LC-QTOF-MS). The metabolic stability of Wm was evaluated using a quantitative LC-MS/MS assay in simulated gastric fluid (SGF), simulated intestinal fluid (SIF), mouse plasma, and liver S9 fractions. The obtained results from mouse plasma were simultaneously fitted to a parent-metabolite kinetic model. Intestinal permeability was predicted using the Caco-2 cell Transwell assay.
Results: Wm rapidly disappeared in SGF, SIF, mouse plasma, and liver S9 fractions (t1/2 = 5.07 ± 0.04, 5.72 ± 0.40, 4.26 ± 2.40, and 19.84 ± 2.88 min, respectively). Metabolite profiling revealed sequential N-terminal cleavage of Wm and identified KYMVm (M2), YMVm (M4), and MVm (M6) as the major metabolites. Kinetic analysis indicated that the fractions metabolized (fm) were 0.697, 0.262, and 0.041 for M2, M4, and M6, respectively. These results suggest a metabolically soft spot at the K-Y peptide bond. Given that M2 and M4 retained biological activity, their stability and permeability were assessed. Although modestly more stable than Wm, both M2 and M4 exhibited low Caco-2 permeability, comparable to that of Wm.
Conclusions: This study characterizes the metabolic and absorption-related properties of Wm and provides a practical framework for early-stage evaluation and optimization of peptide-based drug candidates.
