CHEMICAL SYNTHESIS AND BIOLOGICAL-ACTIVITY OF THE EGF-LIKE DOMAIN OF HEPARIN-BINDING EPIDERMAL GROWTH FACTOR-LIKE GROWTH-FACTOR (HB-EGF)

Heparin-binding epidermal growth factor-like growth factor (HB-EGF) is a recently discovered member of the epidermal growth factor (EGF) fam ily. This novel growth factor possesses the EGF-like domain in the car boxyl portion, In order to evaluate the biological function of the EGF -like domain in HB-EGF, human HB-EGF(44-86) corresponding to the EGF-l ike domain was synthesized by the solid-phase procedure using the Fmoc strategy. It was confirmed by amino acid microsequencing of cystine-c ontaining fragments derived from thermolytic digestion that the patter n of three disulfide bond pairings in synthetic HB-EGF(44-86) was cons istent with that of EGF and transforming growth factor-alpha (TGF-alph a). The homogeneity of the synthetic peptide was confirmed by analytic al RP-HPLC, amino acid analysis and fast atom bombardment mass spectro meter (FAB-MS). Compared with h-EGF, the EGF-like domain of human HB-E GF showed a comparable mitogenic activity in the proliferation of NIH/ 3T3 fibroblast cells. These results suggest that the EGF-like domain o f human HB-EGF may play an important role in mitogenic activity. (C) M unksgaard 1994.