Fibronectin Molecular Weight Calculator
Here’s a detailed table that provides all the essential information you need to know about Fibronectin, including its types, molecular weights, biological functions, and structural features.
| Aspect | Details |
|---|---|
| Fibronectin Types | – Plasma Fibronectin (pFN): Found in blood plasma – Cellular Fibronectin (cFN): Produced by cells in tissues (extracellular matrix) |
| Molecular Weight of Plasma Fibronectin | ~440,000 g/mol per subunit |
| Molecular Weight of Cellular Fibronectin | ~500,000 g/mol per subunit |
| Common Number of Subunits | – 1 subunit: Monomer form (less common) – 2 subunits: Dimer form (most common), disulfide-bonded |
| Total Molecular Weight (Dimer) | – Plasma Fibronectin (dimer): ~880,000 g/mol – Cellular Fibronectin (dimer): ~1,000,000 g/mol |
| Subunit Structure | Each subunit is composed of three types of repeating domains: Type I, Type II, and Type III |
| Location | – Plasma Fibronectin: Circulating in blood plasma – Cellular Fibronectin: Found in the extracellular matrix |
| Biological Functions | – Cell Adhesion: Binds cells to extracellular matrix components (e.g., collagen, fibrin) – Tissue Repair: Plays a key role in wound healing – Cell Migration: Involved in embryonic development and immune response |
| Fibronectin Binding Sites | – Integrin Receptors: Binds to cell surface integrins via RGD (Arg-Gly-Asp) sequence – Collagen, Fibrin: Provides binding sites for other matrix proteins |
| Role in Wound Healing | Promotes the formation of a provisional matrix for tissue repair by binding fibrin and other proteins at injury sites |
| Role in Cancer | Fibronectin overexpression is often linked to cancer progression and metastasis, helping cancer cells adhere and migrate |
| Structural Variants | Alternative splicing generates multiple isoforms of fibronectin with slightly different functional roles |
| Production | – Plasma Fibronectin: Synthesized by liver hepatocytes – Cellular Fibronectin: Produced by fibroblasts and other cells in tissues |
| Clinical Relevance | – Elevated plasma fibronectin levels are associated with certain diseases, including cardiovascular disease – Fibronectin is used in tissue engineering and biomaterials for wound healing scaffolds |
Detailed Breakdown:
1. Types of Fibronectin:
- Plasma Fibronectin (pFN): Primarily circulates in the blood and is involved in blood clotting, wound healing, and immune response.
- Cellular Fibronectin (cFN): Found in tissues and produced by various cell types (e.g., fibroblasts), playing an important role in the structural integrity of the extracellular matrix (ECM).
2. Molecular Weight:
- Plasma Fibronectin: Typically around 440,000 g/mol for a single subunit. When in its common dimer form (two subunits), the total molecular weight is ~880,000 g/mol.
- Cellular Fibronectin: Has a slightly larger molecular weight of ~500,000 g/mol for each subunit, leading to a total molecular weight of ~1,000,000 g/mol for the dimer form.
3. Structural Features:
- Subunit Composition: Each subunit is made up of three types of repeating units or domains:
- Type I Domain: Contains binding sites for fibrin.
- Type II Domain: Contains binding sites for collagen.
- Type III Domain: Includes the RGD (Arg-Gly-Asp) sequence, critical for binding to integrins on cell surfaces.
- Dimer Form: The two fibronectin subunits are linked by disulfide bonds at the C-terminus.
4. Biological Functions:
- Cell Adhesion: Fibronectin helps cells adhere to the extracellular matrix and facilitates interactions between cells and the matrix.
- Wound Healing: Fibronectin plays a major role in tissue repair by helping to form a temporary matrix that supports wound healing.
- Development: Essential for processes such as cell migration during embryonic development and the formation of new tissues.
5. Clinical Significance:
- Cardiovascular Disease: Plasma fibronectin levels are often monitored in cardiovascular diseases, where elevated levels may indicate a risk of blood clot formation or vascular complications.
- Cancer: Fibronectin is associated with cancer progression, as tumor cells can exploit fibronectin to enhance their ability to migrate and invade surrounding tissues.
- Biomaterials: Due to its role in cell adhesion and tissue repair, fibronectin is used in biomedical research for creating scaffolds in tissue engineering and wound healing applications.
Fibronectin in Disease:
- Cancer Metastasis: Fibronectin helps cancer cells to migrate and invade new tissues, aiding in the metastasis process. Overexpression of fibronectin is observed in several types of cancer.
- Fibrosis: Excessive fibronectin production can contribute to fibrosis, the thickening and scarring of connective tissue.
This table and detailed explanation provide an overview of fibronectin, its molecular weight, biological significance, and clinical relevance. Understanding fibronectin’s structure and function is crucial in cell biology, tissue engineering, and medical research.