Keyora Skin Systems Nutrition – Collagen Tripeptides EP-3: The Gly-Pro-Hyp Structure-to-Bioactivity Evidence Framework: From Collagen Triple-Helix Chemistry to Sequence-Specific Fibroblast Responses

Hydrolysed collagen preparations are often compared by serving mass, average molecular weight, or total tripeptide content, although none of these measures independently establishes the dose or biological activity of a specific peptide. Keyora Skin Systems Nutrition – Collagen Tripeptides EP-3 develops the Keyora Molecular Sequence-to-Bioactivity Framework and the Keyora Peptide Identity Matrix to distinguish collagen structural chemistry, amino-acid composition, intact Gly-Pro-Hyp (GPH), human peptide exposure, experimental cellular responses, and preparation-specific skin outcomes. Chapter 1 examines Gly-X-Y periodicity, glycine-dependent triple-helix packing, proline conformational constraints, and hydroxyproline stereochemistry. It distinguishes sequences embedded within native collagen from free peptides released through hydrolysis. Chapter 2 defines glycine, proline, and hydroxyproline as measurable constituents while separating free amino acids, peptide-bound residues, total amino-acid composition, and sequence-resolved peptide quantities. Analytical hydrolysis and amino-acid chromatography cannot reconstruct intact GPH concentration. Chapter 3 identifies GPH as a chemically defined tripeptide (approximately 285.3 Da), distinct from Pro-Hyp, Hyp-Gly, Gly-Pro, and other Gly-X-Y family members. Targeted, appropriately calibrated LC-MS/MS is needed to establish its actual quantity. Human investigations by Yamamoto et al. (2016) and Chae et al. (2023) support preparation-dependent circulating peptide exposure, while gastrointestinal experiments describe possible GPH processing into Pro-Hyp and intestinal passage. These findings do not establish human dermal delivery. Chapter 4 separates molecule-specific biological evidence. Chae et al. reported GPH-associated preservation of selected extracellular-matrix-related transcripts in oxidatively stressed dermal fibroblasts; Lee et al. (2019) investigated MMP-1 and type I procollagen responses in ultraviolet-challenged models. Ohara et al. (2010) separately linked Pro-Hyp to STAT3-associated HAS2 expression, hyaluronic acid synthesis, and fibroblast proliferation. Pro-Hyp mechanisms cannot automatically be attributed to intact GPH, and a direct GPH receptor has not been established in the reviewed experiments. Human trials by Kim et al. (2018), Lee et al. (2024), and Miyanaga et al. (2021) reported selected skin responses using different collagen preparations; systematic reviews also identify quality-, funding-, and endpoint-dependent uncertainty. Chapter 5 applies the Peptide Identity Matrix to Keyora’s tilapia-scale-derived ingredient: 1,500 mg per two-tablet serving, reported 459 Da average molecular weight, declared 30% tripeptide fraction, and over 50% combined Gly + Pro + Hyp composition. Approximately 450 mg of total tripeptides follows only if 30% is validated as a mass fraction; the intact GPH dose remains unestablished. Neither human pharmacokinetics nor randomized skin efficacy of the complete Keyora formula has been demonstrated here. EP-3 concludes that molecular sequence, administered dose, systemic exposure, cellular bioactivity, and clinical skin benefit are distinct evidence objects. Their integration requires sequence-specific measurement and preparation-matched human validation, not extrapolation from ingredient mass or mechanistic plausibility.