In this research, we introduced a D-B-A system to induce and probe PT across peptides using UAAs that serve as the light-triggered proton D and A. By comparing the PT across a peptide containing titratable oxo-amino-acids to a peptide with hydrophobic residues in different solvents we revealed some expected and some surprising findings. The expected one is that titratable amino acids can support PT across a peptide segment. Nevertheless, we further proved that PT across titratable amino acids can occur not only in a polar environment but even in a pure aprotic environment. Using ultrafast measurements, we revealed that the peptide-assisted PT process is happening on the picosecond time scale. In nature, PT across proteins commonly has much slower time scales due to the necessity of maintaining PT directionality, which is usually due to a slower structural change of the protein. In contrast, in our new model system, the large PMF from the excited D to A dictates directionality, and the PT across the peptide segment can be directly explored. The most surprising finding is that hydrophobic peptides can also support PT while having a PMF, whereas the α-helical structure and the polar environment (solvent) are suggested to be essential. In such conditions, the polar solvent can bridge between the polar backbone of the helix and facilitate PT. While discussing the inner pathways within proteins, the polar environment can consist of polar (non-titratable) residues. For a future outlook, the next immediate step will consist of incorporating these UAAs into proteins, which will allow initiating and visualizing PT pathways within them, a project we are working on nowadays. GC acknowledges financial support by the European Union's NextGenerationEU Programme with the IPHOQS Infrastructure (IR0000016, ID D2B8D520, CUP B53C22001750006) "Integrated Infrastructure Initiative in Photonic and Quantum Sciences". NA acknowledges financial support by UKRI awards, Horizon Europe guarantee scheme grant (number R/185766-11-1): "ProtonsInProteins".