The chemical synthesis and binding affinity to the EGF receptor of the EGF-like domain of heparin-binding EGF-like growth factor (HB-EGF).
Heparin-binding EGF-like growth factor (HB-EGF), which belongs to the EGF-family of growth factors, was isolated from the conditioned medium of macrophage-like cells. To investigate the effect of N- and C-terminal residues of the EGF-like domain of HB-EGF in the binding affinity to the EGF receptor on A431 cell. We synthesized HB-EGF(44-86) corresponding to the EGF-like domain of HB-EGF and its N- or C-terminal truncated peptides. Thermolytic digestion demonstrated three disulfide bond pairings of the EGF-like domain in HB-EGF is consistent with that of human-EGF and human-TGF-alpha. HB-EGF(44-86) showed high binding affinity to EGF-receptor, like human-EGF. The truncation of the C-terminal Leu86 residue from HB-EGF(44-86), HB-EGF(45-86) or HB-EGF(46-86) caused a drastic reduction in the binding affinity to the EGF receptor. These results suggest that the EGF-like domain of HB-EGF plays an important role in the binding to the EGF receptor, and its C-terminal Leu86 residue is necessary for binding with the EGF-receptor. In addition, the deletion of the two N-terminal residues (Asp44-Pro45) from HB-EGF(44-86) caused a 10-fold decrease in relative binding affinity to the EGF receptor. This indicates that the two N-terminal residues of the EGF-like domain of HB-EGF are necessary for its optimal binding affinity to the EGF receptor.
Department of Bio-Materials, Graduate School and Research Center for Proteineous Materials, Chosun University, Kwangju 501-759, Korea. syshin@chosun.ac.kr
Song Yub
SY
Shin
Tetsuo
T
Yokoyama
Takato
T
Takenouchi
Eisuke
E
Munekata
D000595:Amino Acid Sequence; D001665:Binding Sites; D045744:Cell Line, Tumor; D004815:Epidermal Growth Factor / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism*; D066246:ErbB Receptors / Q000378:metabolism*; D066257:Heparin-binding EGF-like Growth Factor; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins; D010446:Peptide Fragments / Q000138:chemical synthesis; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D016211:Transforming Growth Factor alpha / Q000737:chemistry
C587883:HBEGF protein, human; D066257:Heparin-binding EGF-like Growth Factor; D036341:Intercellular Signaling Peptides and Proteins; D010446:Peptide Fragments; D016211:Transforming Growth Factor alpha; D004815:Epidermal Growth Factor; D066246:ErbB Receptors