ISSN 1075-2617 Conformational constraints in angiotensin IV to probe the role of Tyr2, Pro5 and Phe6 (pages 545–553) Aneta Lukaszuk, Heidi Demaegdt, Isabelle Van den Eynde, Patrick Vanderheyden, Georges Vauquelin and Dirk Tourwé Article first published online: 28 APR 2011 | DOI: 10.1002/psc.1365 Molecular modeling study of the opioid receptor interactions with series of cyclic deltorphin analogu..