This paper describes a molecular strategy to restore adhesion of cells to surfaces that otherwise do not present ligands that can mediate adhesion. The approach is based on a carbonic anhydrase fusion protein that binds benzenesulfonamides and that also includes the RGD peptide motif that can bind to cell-surface integrin adhesion receptors. In this way, the fusion protein can bind to a monolayer that presents the benzenesulfonamide ligand, thereby positioning the RGD peptide at the surface, where it can mediate the adhesion and spreading of cells. This strategy may provide a general method for promoting the adhesion of cells to non-natural surfaces or to defective biological matrices.