[Protein design based on the structure and function relationship and its clinical application].

Proteins are biopolymers which are directly involved in biological functions. Since their defects cause various diseases, proteins have been studied for a long time as the subjects of both basic and clinical medicine. Recent development of the genetic recombinant technique has made it possible to replace, add or delete any amino acid residue or any peptide portion in a protein. By utilizing this technique, we are now able to clarify more precisely than ever the structure and function relationship of a protein, and also to create various novel artificial proteins for the clinical use. In this article, I describe the proteins which are involved in blood coagulation and fibrinolysis and the regulation, and the current clinical application of the recombinant proteins. I also describe our new protein engineering technique for creation of artificial cell adhesive proteins by grafting the Arg-Gly-Asp Ser (RGDS) cell recognition signal, which was identified first in fibronectin and later in various plasma and extracellular matrix proteins. The physiological functions and possible clinical application of these artificial cell adhesive proteins thus created are also discussed.