Change in binding affinities of 3Y1 secreted fibronectin upon desulfation of tyrosine-O-sulfate

Desulfated form of the 3Y1 secreted fibronectin was prepared by treatment with arylsulfatases. Under optimal conditions, the degrees of tyrosine-desulfation of 35S]sulfate-labeled fibronectin by arylsulfatases from Helix pomatia (Type H-1), Patalle vulgata (Type V) and Abalone entrails (Type VIII) were determined to be 55.7%, 54.9% and 76.4%. Upon desulfation of 3H]leucine-labeled fibronectin by Type H-1 or Type V arylsulfatase, gelatin-binding affinity remained unchanged; while heparin-binding affinity increased nearly 50%. Treatment with Type VIII arylsulfatase caused a considerable decrease in gelatin-binding and a slight decrease in heparin-binding affinities. Nevertheless, desulfation by all three enzymes consistently resulted in a dramatic decrease of fibrin-binding affinity, ranging from 42.1% to 64.4%.