Inter-chain acyl transfer reaction in a peptide six-helical bundle: a chemical method for regulating the interaction between peptides or proteins.

An inter-helical acyl transfer specifically occurred between the C-and N-peptides of HIV gp41 after assembly of the six-helical bundle (6HB), forming an inter-helical covalent bond that greatly enhanced 6HB stability. In the reaction, the C-peptide was modified as an acyl donor, and the N-peptide served as an acyl acceptor.