87216-88-4Relevant articles and documents
Specific Binding of the Tyrosine Residue in Copper(II) Complexes of Tyr-Pro-Gly-Tyr and Tyr-Gly-Pro-Tyr
Pettit, Leslie D.,Steel, Ian,Kowalik, Teresa,Kozlowski, Henryk,Bataille, Michel
, p. 1201 - 1206 (2007/10/02)
The syntheses of the tetrapeptides Tyr-Pro-Gly-Tyr and Tyr-Gly-Pro-Tyr (H3L) are reported, together with the results of a potentiometric and spectrophotometric study of their H+ and Cu2+ complexes.Proline acts as a break-point to metal-ion co-ordination when inserted into a peptide chain and in Tyr(1)-Pro(2)-Gly(3)-Tyr(4) the Pro residue enforces a bent conformation and the formation of an unusually stable complex with co-ordination through the terminal amine-N of Tyr(1), the neighbouring peptide=CO, and the OTyr- of Tyr(4).This necessitates a 17-membered chelate ring.With Tyr-Gly-Pro-Tyr there is also OTyr--C bonding but this is a result of dimer formation in 2-.