Rational Design of Acidic Human Fibroblast Growth Factor (hFGF-1) with Increased Stability and Mitogenic Activity

Human acidic fibroblast growth factor (hFGF-1) belongs to a superfamily of 22 fibroblast growth factors (FGFs) that have a high affinity to heparin. It is a 16kD protein, which is involved in many cellular functions, such as, cell proliferation, cell differentiation, angiogenesis, tumor growth, and wound healing. In wound healing, the blood coagulation cascade is triggered to clog the wound. One of the proteases that participates in wound healing is thrombin, which converts fibrinogen to fibrin. Thrombin also cleaves wild type hFGF-1 and consequently decreases its wound healing potency. Thrombin is shown to specifically cleave FGF-1 at Arg136. In this context, in the present study we have designed several site-directed mutants at Arg136 to understand the role of this residue not only on the stability of FGF-1 but also on the FGF signaling process. The results of this study will be discussed in detail.