The 40 kDa heparin-binding fragment of human plasma fibronectin, generated by chymotryptic digestion and purified by sequential affinity chromatography, supplied lyophilised, 0.5 mg. This fragment carries the C-terminal heparin-binding domain (Hep II / type III repeats 12–14) together with the CS-1 / IIICS region, the part of fibronectin that engages cell-surface proteoglycans (syndecan-4) and the α4β1 integrin. Use it to dissect proteoglycan- and integrin-dependent adhesion and cytoskeletal signalling separately from the classical RGD cell-attachment site — the functional complement to the 120 kDa cell-attachment fragment cat. 175, and a natural partner for heparin cat. 904 in binding studies.
SPECIFICATIONS
Catalogue number: 815 | Product: Fibronectin 40 kDa heparin-binding fragment (human)
Source: human plasma; donor material negative for HBsAg, HCV, HIV-1 and HIV-2
Purity: one major band at 40 kDa, with some lower bands, on SDS-PAGE
Format: lyophilised from a solution containing the product at 1 mg/mL, sodium citrate 20 mM and sodium chloride 150 mM, pH 7.4
Purification: chymotryptic digest of human plasma fibronectin, followed by affinity chromatography on gelatine agarose and heparin agarose, with subsequent gel filtration
Package size: 0.5 mg
STORAGE / RECONSTITUTION
Reconstitution: add 0.5 mL sterile pure water. Incubate 15 min at 37 °C and stir gently. Do not vortex.
Shipped at ambient temperature.
Lyophilised protein: store 1 year at −20 °C or lower.
Reconstituted protein: store at −70 °C for up to 6 months.
Avoid repeated freeze-thaw cycles.
APPLICATIONS
- Cell-attachment and integrin-signalling assays.
- Promotes cytoskeleton organisation in integrin-signalling assays.
- Coating substrate for adhesion and spreading assays that depend on the heparin-binding (Hep II) domain rather than the RGD site — run alongside the 120 kDa cell-attachment fragment cat. 175 to separate the two adhesion mechanisms.
- Ligand in solid-phase and solution binding assays with heparin, heparan sulfate and syndecans — see heparin cat. 904.
- Affinity-chromatography ligand for capture of heparin-binding partners.
APPLICATION HIGHLIGHTS — HIGH-VALUE RESEARCH NICHES
- Two-signal adhesion model: the Hep II domain supplies the syndecan-4 co-signal required for full focal-adhesion and stress-fibre formation, which the RGD fragment alone does not deliver — the classic system for dissecting integrin/proteoglycan co-operation.
- Defined fragment rather than whole fibronectin: restricting the substrate to a single domain removes the confounding contributions of the RGD, collagen- and fibrin-binding regions.
- Cytoskeletal mechanotransduction: widely used to probe RhoA / focal-adhesion-kinase signalling and traction-force generation.
- CS-1 / α4β1 biology: relevant to lymphocyte and melanoma-cell adhesion, where the alternatively spliced IIICS segment is the operative ligand.
- Plasma-derived and virally screened: a human, non-recombinant source with documented donor screening.
