FGL Peptide Research Guide Ireland

Overview

FGL is a synthetic peptide derived from the second fibronectin type III (FN3) module of the neural cell adhesion molecule (NCAM). Its name comes from the Phe-Gly-Leu sequence motif within that NCAM FN3 domain, a region important for NCAM's homophilic binding and downstream signalling. FGL and related NCAM-mimetic peptides were characterised primarily by the research group of Vladimir Berezin and Elisabeth Bock (University of Copenhagen / Protein Laboratory), with associated development work through Enkam Pharmaceuticals.

This compound sits in a fundamentally different evidence category to most others discussed on this site: human clinical data on FGL peptide specifically does not exist. The published literature is preclinical — rodent and in vitro studies concentrated around the Berezin/Bock Copenhagen research programme — rather than a broad, multi-lab, human-tested field. Nothing in this guide should be read as implying human efficacy or safety.

Clinical & Research Status

Mechanism of Action

NCAM (neural cell adhesion molecule) normally mediates cell-cell adhesion between neurons and contributes to synaptic plasticity, neurite outgrowth, and learning and memory processes. Part of this activity occurs via NCAM's FN3 domains transactivating the fibroblast growth factor receptor FGFR1, independent of FGF ligand binding. FGL was designed as a short synthetic peptide mimic of this specific NCAM-FGFR1 interaction — the intent being to activate FGFR1-linked downstream signalling implicated in synaptic plasticity, neurite outgrowth, and neuroprotection without requiring the full NCAM protein. This is the mechanistic rationale described in the foundational preclinical literature; it has not been confirmed in human studies.

Research Areas & Reported Effects

Synaptic Plasticity & Memory (Preclinical, Rodent)

The foundational FGL paper, Cambon K et al. 2004 (Journal of Neuroscience), reported that this synthetic NCAM mimetic peptide promoted synaptogenesis, enhanced presynaptic function, and supported memory consolidation in rodent models, including performance on spatial memory tasks such as the Morris water maze. This preclinical work established FGL's central research rationale as a potential modulator of synaptic plasticity and long-term potentiation (LTP).

Neuroprotection & Neurodegeneration Models (Preclinical)

Separate preclinical work from the Berezin/Bock-affiliated research programme (including work associated with Skibo GG and colleagues) has examined FGL's potential neuroprotective effects in rodent models relevant to ischemia/stroke and neurodegenerative processes, proposing that FGFR1-linked survival signalling underlies any protective effect observed. This remains animal-model research.

Neural Injury & Regeneration (Preclinical)

FGL has also been studied preclinically for its capacity to promote neurite outgrowth, with research interest in peripheral and central nerve injury recovery models, extending from its proposed role as an NCAM-FGFR1 mimetic supporting neurotrophic signalling.

Stress & Cognitive Decline Models (Preclinical)

Klementiev B et al. 2007 examined the NCAM mimetic peptide FGL in the context of chronic stress-induced impairments in a preclinical model, part of a broader preclinical interest in whether FGL administration could ameliorate age-related or lesion-induced memory deficits in rodents.

Research Data Summary

All entries above represent preclinical (animal or in vitro) findings. No human trial data exists for FGL peptide to date.

Stack Combinations Studied

• No stack combinations have been studied for FGL peptide in the published literature — research has used FGL as a standalone experimental compound in rodent and in vitro models

⚠️ Stack combinations listed for research reference only. Not safety or efficacy guidance.

Research Protocol Reference

experimental research protocols only — not dosing recommendations.

No human dosing protocol exists for FGL peptide, as no human trials have been conducted.

Observed Side Effects in Research

• No established human safety data exists — no human trials have been conducted
• In preclinical rodent studies, no major adverse findings have been widely reported in the literature at the doses studied

This is animal data only and cannot be extrapolated to imply human safety. The absence of reported adverse findings in a small number of preclinical studies is not equivalent to a safety profile.

Compound Data

CAS Number

Not consistently assigned in standard small-molecule CAS registries — characterised by amino acid sequence in the primary literature rather than by CAS number

Molecular Formula

14 amino acid synthetic peptide (sequence: EVYVVAENQQGKSKA) — sequence-specific, not typically reduced to a single simplified formula in the literature

Molecular Weight

Approximately 1.5–1.6 kDa (typical for a 14-mer peptide)

Half-Life

Not well characterised in humans — no human PK data exists; preclinical studies typically use direct intracerebroventricular or intraperitoneal administration in rodent models

Synonyms

FGL peptide, NCAM-FGL, FG loop peptide

Research Classification

NCAM (neural cell adhesion molecule) mimetic peptide; FGFR1 agonist/potentiator; synthetic neurotrophic peptide

Scientific References

• Cambon K et al. 2004 — A synthetic neural cell adhesion molecule mimetic peptide promotes synaptogenesis, enhances presynaptic function, and rescues hippocampal memory consolidation. — Journal of Neuroscience — [Preclinical, rodent model]
• Berezin V, Bock E et al. — Characterisation of NCAM mimetic peptides including FGL (research programme spanning multiple papers). — Journal of Neurochemistry / Neuroscience, 2000s — [Preclinical / in vitro]
• Klementiev B et al. 2007 — NCAM mimetic peptide FGL and cognitive/stress-related outcomes. — [Preclinical, rodent model]
• Skibo GG et al. (Berezin/Bock-affiliated) — Preclinical NCAM-FGL neuroprotection studies. — [Preclinical / in vitro]

The FGL literature is a relatively narrow, specialist body of preclinical work concentrated around the Berezin/Bock Copenhagen research programme, rather than a broad, multi-lab field with independent replication. Readers should weigh the evidence accordingly.