Structure and Inhibition of the neu-erbB-2 Receptor.
Final rept. 1 Sep 96-31 Aug 98
YALE UNIV NEW HAVEN CT
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The neuerbB-2 gene encodes a 185 kD receptor tyrosine kinase which is constitutively activated by either gene overexpression or by a single mutation, valine to glutamic acid, at position 664 within its hydrophobic transmembrane domain. The goal of the research project has been to obtain the high resolution structure of the receptor transmembrane domain and to establish the mechanism by which the Glu664 mutation leads to receptor activation. Based on NMR-derived distance constraints, we have found that Glu664 drives dimerization of the transmembrane domain through hydrogen-bonding interactions. Moreover, Gly665 and Ala661 pack in the dimer interface and stabilize the helix dimer through van der Waals interactions. The polar threonine residues at positions 662 and 657 also serve to stabilize the dimer through hydrogen bonding interactions. The observation of deuterium exchange of four engineered cysteines in the C-terminus of the transmembrane domain is consistent with a large helix crossing angle. Based on these studies we suggest that specific inhibitors to the activated neu sequence should target the polar threonine and glutamic acid residues, as well as the van der Waals surfaces created by Gly665 and Ala661, both of which have small side chains and allow good packing interactions.
- Medicine and Medical Research