Engineering the Structure of Human Acidic Fibroblast Growth Factor through Site Directed Mutagenesis for Increased Protein Stability

Acidic fibroblast growth factor (FGF1) is a 16 kDa protein that contains wound healing properties and regulates a range of cellular activities including cell proligeration, cell differentiation,and angiogenesis. The functions and properties of FGF1 are contingent upon its binding to heparin, a negatively charged, highly sulfonated glycosaminoglycan. Previous studies on the heparin-binding pocket of FGF1 have revealed several positively charged residues, and further the ability of certain point mutations within the binding pocket to confer greater stability to the protein. Increasing protein stability gives rise to greater potential utility of FGF1's wound healing properties for therapy of scar tissue. In attempt to engineer enhanced stability of FGF1, several new point mutations in the heparin binding pocket have been introduced and their effects on the structure and stability of FGF1 has been studied in detail. These point mutations are selectively chosen based on their vicinity within or around the heparin-binding pocket as well as the expected electrostatic interactions with surrounding residues.