2.B.121.  The Helical Peptide-based Potassium Carrier (HPK⁺C) Family  

Lee et al. 2019 designed and synthesized a series of helical peptide-based potassium carriers 3a–3d which display rapid potassium ion transport kinetics and high potassium ion selectivity in liposomal assays (Yuan et al. 2024). These artificial carriers induce potassium ion efflux from cells, resulting in subsequent elevation of intracellular calcium levels, calpain activation, and endoplasmic reticulum (ER) stress induction. The stressed ER further elicited oxidative stress in mitochondria, enhanced reactive oxygen species production, incurred mitochondrial damage, and triggered caspase-dependent apoptotic signaling. Notably, among these peptide carriers, 3b exhibited potent anti-tumour activities both in in vitro and in vivo tumour models (Lee et al. 2019).