The mitogenic activity of a heparin-binding fibronectin fragment (Mr 35,000) produced by cathepsin D digestion.
Fibronectin was partially digested using the lysosomal proteinase cathepsin D and the fragments produced tested for their effect on the rate of DNA synthesis in quiescent Chinese Hamster Fibroblasts (CH23). A mitogenically active digest was produced after digestion of fibronectin with cathepsin D for 2 to 3h at a 1:200 (w/w) ratio of enzyme to substrate at 37 degrees C. Affinity chromatography of the active digest on both gelatin and heparin 4BCl columns demonstrated that the active fragment was gelatin-nonbinding but heparin-binding, and therefore derived from one of the two or three heparin binding domains of intact fibronectin. The active fragment was found to have a Mr35,000 by gel filtration on sephacryl S200. A dose-response curve of the mitogenic fragment purified by gel filtration against DNA synthesis showed it to be maximally active at a concentration of approximately 10 micrograms/ml.
Savill
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Ayad
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D000818:Animals; D002402:Cathepsin D / Q000494:pharmacology*; D002417:Cattle; D002850:Chromatography, Gel; D006224:Cricetinae; D003412:Cricetulus; D004247:DNA / Q000096:biosynthesis; D005353:Fibronectins / Q000494:pharmacology*; D006493:Heparin / Q000378:metabolism*; D008934:Mitogens / Q000494:pharmacology*; D008970:Molecular Weight; D010446:Peptide Fragments / Q000494:pharmacology*; D014945:Wound Healing
D005353:Fibronectins; D008934:Mitogens; D010446:Peptide Fragments; D006493:Heparin; D004247:DNA; D002402:Cathepsin D