====================================================================== PEPTIDE RX · COMPOUNDING LAB SPEC SHEET RESEARCH USE ONLY · NOT FOR HUMAN OR ANIMAL CONSUMPTION · NOT FDA APPROVED ====================================================================== Code ID: PRX-GHSR-001 Designed: 2026-05-01T21:03:45.375679+00:00 Target: GHSR1a (Growth hormone secretagogue receptor 1a (ghrelin receptor)) UniProt: Q92847 Use-case lane: metabolic Pocket mode: ortho · Binding mode: agonist Binding tier: very_strong Gates passed: 3/5 Evidence grade: D Reg. status: class_2_research_only PDA envelope: eb9d1888ba1cf2ce62a8beb1d2b96d91da7a71f03d9d97eefcbf01ca949a31f7 ---------------------------------------------------------------------- SEQUENCE (one-letter IUPAC-20) ---------------------------------------------------------------------- PMGVYGPCLW ---------------------------------------------------------------------- PHYSICOCHEMICAL PROPERTIES ---------------------------------------------------------------------- Length: 10 aa (short peptide) Molecular weight: 1122.37 Da Isoelectric point (pI): 5.52 Net charge at pH 7.4: -0.47 GRAVY (hydrophobicity): 0.62 Aliphatic index: 68.0 ε280 (oxidized cystines): 6990 M⁻¹·cm⁻¹ ε280 (reduced): 6990 M⁻¹·cm⁻¹ A280 per mg/mL: 6.2279 Aromatic residues (W/Y/F): 2 Charged residues: 2 ---------------------------------------------------------------------- RECOMMENDED SYNTHESIS ---------------------------------------------------------------------- Method: Solid-phase peptide synthesis (SPPS) Strategy: Fmoc-SPPS, standard side-chain protecting groups Target purity: ≥ 98.0% by analytical RP-HPLC Rationale: Sequence is short enough for cost-effective Fmoc-SPPS on Wang or Rink-amide resin. Single-coupling for most residues; double-couple any β-branched or aromatic stretches. ---------------------------------------------------------------------- RECOMMENDED MODIFICATIONS ---------------------------------------------------------------------- • Head-to-tail or disulfide cyclization Rationale: GPCR-targeting short peptides usually benefit from conformational restriction; head-to-tail or i,i+4 disulfide cyclization typically improves binding and proteolytic stability. ---------------------------------------------------------------------- QC RELEASE PANEL — REQUIRED FROM COMPOUNDING LAB ---------------------------------------------------------------------- 1. Analytical RP-HPLC (≥ purity target, single peak ≥ 95% area) 2. ESI-MS or MALDI-TOF (monoisotopic mass within ±1 Da of theoretical) 3. Amino-acid composition (within ±5% of theoretical) 4. Residual TFA / scavenger by ¹⁹F-NMR or ion-pair HPLC (≤ 0.05% w/w) 5. Endotoxin (LAL test, ≤ 1 EU/mg recommended for cell-culture use) 6. Karl-Fischer water content (≤ 5%) ---------------------------------------------------------------------- STORAGE ---------------------------------------------------------------------- Lyophilized powder, sealed under argon or nitrogen, in amber vial: −80 °C for long-term (>3 months) or −20 °C for working stock (<3 months). Avoid repeated freeze-thaw. ---------------------------------------------------------------------- RECONSTITUTION (RESEARCH USE ONLY) ---------------------------------------------------------------------- Reconstitute in 1% acetic acid in sterile water, then dilute into research buffer (cysteines are oxidation-prone) at 1 mg/mL working stock. Aliquot single-use volumes to minimize freeze-thaw. Use within 24 h once thawed; ≤ 30 days at +4 °C in solution. ---------------------------------------------------------------------- DESIGN NOTES ---------------------------------------------------------------------- • Hydrophobic sequence (GRAVY > 0.5) — expect aggregation and low aqueous solubility. Add 5–10% DMSO co-solvent or consider PEGylation for solubility. • Methionine present — degas all buffers; methionine oxidation during long-term storage is the most common purity loss. • Odd cysteine count — disulfide topology is ambiguous. Specify intended pairing on the order form or request the lab cap with an Acm protecting group. ---------------------------------------------------------------------- DISCLAIMERS ---------------------------------------------------------------------- This document is a research-use-only design specification. It is NOT a prescription, NOT a recommendation for human or animal use, NOT an approved drug, and NOT a guarantee of biological activity. The peptide described is a Phase 4 computational prediction, not an experimentally validated molecule. The compounding lab is responsible for compliance with all applicable regulations in its jurisdiction. All designs by Peptide RX carry a Peptide Design Attestation (PDA) cryptographic envelope hash (above) that binds the design to the exact pipeline, model versions, and biosecurity policy used at design time. A verifier recomputing the PDA with different weights or a different policy will diverge — this is the platform's tamper- evidence guarantee. Exported 2026-05-05T10:42:12.168510+00:00 ======================================================================