Internal motions and dynamics of macromolecules are essential to understand their structure and their functions [1]. Such internal motions might mediate conformational change transmission or non covalent interactions for oligomerization processes, two mechanisms dominantly hypothesized for signal transduction of transmembrane receptors. The receptors of tyrosine kinase family, implicated in cellular transformation processes are identified as potent oncogenes and structural changes may result from ligand binding or single amino acid replacement. Such changes are associated with increased kinase activity, leading to oncogenic potential. In the case of the c-erbB2 encoded protein, the activating mutation is located in the transmembrane domain at position 659 [2] and the single Val to Glu amino acid replacement results in constitutive activation of the intrinsic protein kinase activity of the receptor and transformation [3]. Because c-erbB2 is a single membrane spanning protein, one expects the transmembrane segment as a module for signal transmission.