Understanding the collagen GFOGER motif
Peptides are short chains of amino acids (typically consisting of 2-50 amino acids) that contribute to a wide range of biological functions and can be found naturally in the body. They are able to mimic some aspects of protein function, and are relatively easy to synthesise. One such peptide is GFOGER, whose name is derived from the amino acids Glycine-Phenylalanine-Hydroxyproline-Glycine-Glutamic Acid-Arginine found in collagen. This sequence primarily binds to integrins α2β1 and α1β1 which not only anchor cells to the matrix but also influence cell behaviour, such as proliferation, migration, and differentiation.
GFOGER vs Collagen – What’s the Difference?
Collagen is a natural protein that is predominantly extracted from bovine or porcine sources but can also be isolated from other sources, including human cells. GFOGER is a synthetic peptide that contains the specific sequence from collagen that mimics its properties. As such, GFOGER is able to promote several important biological process (e.g. cell adhesion, migration, etc.) by binding to many of the same integrins that collagen binds to.
Collagen is widely used in a variety of fields, including medicine, tissue engineering, cosmetics and food. In tissue engineering, collagen provides structural support as a scaffold and maintains tissue integrity. GFOGER is typically used in combination with biomaterials and functions as a ligand for specific integrins to enhance cellular responses
Whilst collagen extraction is relatively cheap compared to GFOGER synthesis, the most common sources are derived from animals which raises ethical concerns. Peptide synthesis allows for controlled production without the need for animal-derived materials.
GFOGER is commonly added as a motif to hydrogels, such as the PeptiGel® Plus series offered by Cell Guidance Systems. These are animal-free, fully synthetic tuneable, peptide-based hydrogels that contain GFOGER along with RGD to endear the gel with the bioactive properties of collagen and fibronectin, but without the issues such as ethical concerns and biocontamination that accompany animal-derived material.
What Can GFOGER Do?
There are a wide range of applications in biomedical research and clinical settings using GFOGER:
- Cell Adhesion Studies: GFOGER is often used in studies to investigate cell adhesion and migration. By binding to specific integrins, it helps researchers understand how cells interact with the extracellular matrix.
- Tissue Engineering: GFOGER can be used to enhance cell attachment and growth on biomaterials. Its interaction with integrins can promote better integration of engineered tissues with native tissues.
- Cancer Research: GFOGER is used to understand how cancer cells adhere to and invade surrounding tissues. It can be used to help analyse the role of integrins in tumour progression and metastasis.
- Drug Development: GFOGER is used to screen for compounds that might affect integrin interactions. This can lead to the identification of new therapeutic targets or treatments for diseases, such as cancer, related to cell adhesion and migration.
- Diagnostic Applications: GFOGER-based assays can be developed to detect and analyse integrin expression or activity, which can be useful in diagnosing certain diseases or monitoring disease progression.
GFOGER Applications in Research and Medicine
Bone Regeneration: GFOGER-modified biomaterials can support the growth and differentiation of osteoblasts. Studies have shown that scaffolds functionalized with GFOGER promote greater bone formation and integration with existing tissue, without external cells or growth factors, offering an alternative to traditional bone grafts.
Cartilage Repair: Damaged cartilage has a limited capacity to regenerate on its own due to the tissue’s avascular nature. Integrating GFOGER into hydrogels and scaffolds provides a solution by promoting the adhesion of chondrocytes and supporting cartilage matrix deposition. A study has shown that GFOGER promotes chondrogenesis in bone mesenchymal stem cells to regenerate damaged cartilage.
Wound Healing: In wound healing applications, GFOGER can be used to enhance the interaction between biomaterials and skin cells, such as fibroblasts and keratinocytes. GFOGER binds to integrins α1β1 and α2β1, which are critical for cells like fibroblasts and endothelial cells to adhere to collagen in the extracellular matrix. By promoting interactions between cells and the collagen matrix, GFOGER helps in rebuilding the ECM in a way that supports proper wound closure.
IMAGE PeptiGel functionalized with GFOGER fused to the PetiGel motif CREDIT: Cell Guidance Systems Ltd