13054-03-0 3-de((4R)-4-Hydroxy-L-proline)-5-de-L-alanineantiarrhythmic peptide (cattle atrium) Antiarrhythmic peptide (cattle atrium), 3-de((4R)-4-hydroxy-L-proline)-5-de-L-alanine- Gly-pro-gly-gly Glycyl-prolyl-glycyl-glycine T-GPGG