Sequences of some tyrosine- and tryptophan-containing peptide hormones exhibiting potent antioxidant properties
| Name | Structure |
|---|---|
| LHRH (human) | PyrHWSYGLRPG-amide |
| LHRH (salmon) | PyrHWSYGWLPG-amide |
| FSHRF | PyrHWSHDWKPG-amide |
| [Leu]enkephalin | YGGFL |
| [Met]enkephalin | YGGFM |
| Oxytocin | CYIQNCPLG-amide (oxidized form) |
| Vasopressin | CYFQNCPRG-amide (oxidized form) |
| Angiotensin I | DRVYIHPFHL |
| Angiotensin II | DRVYIHPF |
As shown for LHRH, [Leu]enkephalin, angiotensin II, and oxytocin in Fig. 1, the peptides listed here were found to be antioxidants in three paradigms of antioxidant activity: globular protein oxidation as induced by peroxyl radical initiators, LDL oxidation as induced by metal ions, and lipid peroxidation as induced by ascorbate. Specifically, all the peptides showed significant protective activities in the phycoerythrin assay at a concentration of 200 nM. The combined effects of different peptides were additive.
Pyr, pyroglutamate. Tyrosine and tryptophan residues are in boldface type.