The design principle of a thermostable functional protein has been proposed
by demonstrating genetic engineering synthesis of a thermostable cell adhe
sion protein. The cell adhesive peptide sequence, Arg-Gly-Asp (RGD), was in
corporated into the elastin-based polyhexapeptide, whose repeating unit is
Ala-Pro-Gly-Val-Gly-Val (APGVGV). The resulting protein possesses cell adhe
sion activity approximately 80% of fibronectin. After autoclaving at 120 de
grees C for 20 min, the protein retained over 90% of cell adhesion activity
, while the activity of autoclaved fibronectin decreased to 50%.