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Antimicrobial peptide

Protegrin-1

Protegrin-1 (PG-1) is an 18-residue arginine-rich antimicrobial peptide from porcine leukocytes.

By The Peptides Codex Editorial TeamIndividual review date not recorded

Page data last changed: . Chemistry registry snapshot: . Registry refreshes and identity assessments are separate from scientific content review.

Length
18 aa
Class
Antimicrobial peptide
Function
Beta-hairpin pore-forming host-defense peptide (research)
Context
Antimicrobial-peptide research (not an approved drug)

A disulfide-stabilized beta-hairpin AMP with rapid, broad-spectrum microbicidal activity in research models.

Also known as: PG-1 · protegrin

Part of the Foundational & therapeutic peptides cluster

Overview

Protegrin-1 (PG-1) is an 18-residue arginine-rich antimicrobial peptide from porcine leukocytes. Two disulfide bonds lock it into an antiparallel beta-hairpin that forms membrane pores, giving rapid broad-spectrum activity in research. Its high activity against mammalian cells has limited systemic development; it remains a research peptide.

Source & context

Biological / chemical source: Porcine leukocytes (cathelicidin family)

Primary research or clinical context: Antimicrobial-peptide research (not an approved drug)

Beta-hairpin architecture

Unlike helical AMPs, protegrin-1 folds into a rigid beta-hairpin held by two cysteine disulfide bridges, with six cationic arginines. This scaffold enables fast membrane pore formation and is a favored template in AMP structure-activity research.

Research context and limits

In vitro, PG-1 is rapidly bactericidal against MRSA, Pseudomonas and other pathogens at low concentrations. However, notable hemolytic activity toward mammalian cells has driven design of safer analogs. This page is educational and describes research findings, not therapy.

Sequence

One-letter sequence commonly cited for Protegrin-1 (educational; isoforms and modifications may differ):

RGGRLCYCRRRFCVCVGR

RGGRLCYCRRRFCVCVGR

Protegrin-118 aa · C88H147N37O19S4 · ≈ 2,155.6 DaPEPTIDESCODEX.COMN-terminus →→ C-terminusR+1G2G3R+4L5C6Y7C8R+9R+10R+11F12C13V14C15V16G17R+18nonpolarpolaracidicbasicGly / Pronon-canonical (X)Hydropathy (Kyte–Doolittle): ▮ hydrophobic (cyan) / ▮ hydrophilic (rose) · Side-chain charge at pH 7: + / −
Protegrin-1 — Structure cardDownload SVG
R1G2G3R4L5C6Y7C8R9R10R11F12C13V14C15V16G17R18
Helical wheel projection

Residues plotted ~100° apart around an α-helix — clustering of one color reveals an amphipathic face.

Analyze sequences in the playground →

Structure & chemistry

Molecular identity & reference confidence

Source-supported reference

Reference values are taken from the cited molecular record or curated profile. A database match is not independent laboratory verification; modifications, counter-ions, and formulations can change the measured mass.

Molecular form
Protegrin-1 (source record; form not independently established)
Species
Not established by this molecular identity audit
Termini (N / C)
Not specified / Not specified

Average reference mass

Reference policy updated: 2026-10-05

Molecular formula
C88H147N37O19S4
Average reference mass
≈ 2,155.6
Identifiers
  • PubChem CID: 16130513
  • CAS RN: 168831-77-4

Chemistry values: PubChem · fetched 2026-10-01.

Concentration math

Protegrin-1 — reconstitution calculator

Enter how much peptide is in the vial and how much diluent (e.g. bacteriostatic water) is added. The tool returns the resulting solution concentration — and, for any amount you type, the volume it corresponds to. This is educational arithmetic, not a dosing recommendation.

Reference form: Protegrin-1 (source record; form not independently established)Average reference mass: 2,155.6 Da

Syringe graduation
Solution concentration
5 mg/mL5,000 mcg/mL
mcg

Enter an amount to see the volume it corresponds to.

Educational concentration mathematics only. This tool does not recommend a dose, amount, or protocol, and nothing here is medical advice. Many peptides are not authorized by Health Canada for human use — see our reconstitution and bacteriostatic-water guides for context.

Open the Protegrin-1 calculator on its own page →

FAQ about Protegrin-1

What is Protegrin-1?+

Protegrin-1 (PG-1) is an 18-residue arginine-rich antimicrobial peptide from porcine leukocytes. Two disulfide bonds lock it into an antiparallel beta-hairpin that forms membrane pores, giving rapid broad-spectrum activity in research. Its high activity against mammalian cells has limited systemic development; it remains a research peptide.

What Canadian product status is recorded for Protegrin-1?+

Canadian product status for Protegrin-1 has not been verified in this profile. No verified record here does not mean no authorization exists. Status depends on the product, formulation and use; consult Health Canada's product records.

What is the typical length of Protegrin-1?+

Protegrin-1 is commonly described as approximately 18 amino acids (Antimicrobial peptide).

Related peptides

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Gut hormone
Motilin is a 22-amino-acid gut hormone secreted by endocrine cells of the small intestine. It coordinates the migrating motor complex, the wave of contractions that clears the digestive tract between meals, earning it the nickname the housekeeper of the gut.
Obestatin
Gut hormone
Obestatin is a 23-amino-acid peptide cleaved from the same preproghrelin precursor that produces ghrelin. It was originally proposed to oppose ghrelin's appetite-stimulating effects, though its physiology and receptor remain actively debated in the research literature.
Albiglutide
Incretin mimetic (GLP-1 receptor agonist)
Albiglutide is a GLP-1 receptor agonist created by genetically fusing two modified GLP-1 sequences to human serum albumin, giving it a long half-life suited to once-weekly dosing. Approved as Tanzeum and Eperzan in 2014, it was later withdrawn from the market for commercial reasons and is now a historical case study.
Neurotensin
Neuropeptide
Neurotensin is a 13-amino-acid neuropeptide found in the brain and gut. Research examines its interactions with dopamine signaling and its roles as a neuromodulator and local hormone.

References & further reading

  1. 1.Bolosov et al. (2023). Design of Protegrin-1 Analogs with Improved Antibacterial Selectivity. Pharmaceutics
  2. 2.Javed et al. (2024). Antimicrobial and immunomodulatory activities of porcine cathelicidin Protegrin-1. Mol Immunol
  3. 3.Rizzetto et al. (2025). Protegrin-1 and Analogues Against Acinetobacter baumannii: A Narrative Review. Pharmaceuticals (Basel)
  4. 4.Tang et al. (2023). Repurposing Antimicrobial Protegrin-1 as a Dual-Function Amyloid Inhibitor via Cross-seeding. ACS Chem Neurosci
  5. 5.Pan et al. (2021). Protegrin-1 Regulates Porcine Granulosa Cell Proliferation via the EGFR-ERK1/2/p38 Signaling Pathway in vitro. Front Physiol
  6. 6.Mohanram et al. (2014). Cysteine deleted protegrin-1 (CDP-1): anti-bacterial activity, outer-membrane disruption and selectivity. Biochim Biophys Acta
  7. 7.Hosseini Goki et al. (2024). Novel antimicrobial peptides based on Protegrin-1: In silico and in vitro assessments. Microb Pathog
  8. 8.Li et al. (2022). Protegrin-1 inhibits porcine ovarian granulosa cell apoptosis from H(2)O(2)-induced oxidative stress via the PERK/eIF2α/CHOP signaling pathway in vitro. Theriogenology
  9. 9.PMC — Protegrin-1: a broad-spectrum, rapidly microbicidal peptide with in vivo activity
  10. 10.Wikipedia — Protegrin
Disclaimer: Educational content only. Not medical advice. Not instructions for human use. Research peptides and unapproved products may be restricted or illegal to market for human consumption in your jurisdiction. Consult qualified professionals and applicable law.
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