Are the Fusion Processes Involved in Birth, Life and Death of the Cell Depending on Tilted Insertion of Peptides into Membranes?

Various peptide segments have been modeled as asymmetric amphipathic α-helices. Theoretical calculations have shown that they insert obliquely into model membranes. They have been named “tilted peptidesʹ’. Molecular modeling results reported here also evidence the presence of tilted peptides in ADM-1 protein of Caenorhabditis elegans that may be involved in fusion events, in meltrin α, a protein implicated in myoblast fusion, in hemagglutinin of influenza virus, in the E2 glycoprotein of rubella virus, in the S protein of hepatitis B virus, in a subdomain of Ebola virus and in the malaria CS protein. Experimental results have indicated that tilted peptide fragments may be involved in cellular life events like sperm–egg fecondation, muscle development, protein translocation through signal sequences and cellular death caused by viral infection or parasite infestation. We speculate that membrane destabilization by these tilted peptides may be an important common step in life processes involving fusion phenomena.