Chemical modification of arginine residues of lung galaptin and fibronectin. Effects on fibroblast binding.

Lung galaptin bound to lung fibroblasts with a Kd of 190 nM, and this binding could be inhibited by 20 mM-lactose. Selective modifications of the arginine residues of galaptin with cyclohexane-1,2-dione did not change its lectin activity or its binding to fibroblasts. By contrast, modification of the arginine residues of plasma fibronectin resulted in a marked diminution of protein-fibroblast binding. Selective modification of arginine residues may provide a useful probe for -Arg-Gly-Asp-Xaa cell-binding sequences of proteins.