Isotope LabelingIsotopesPeptidesNitrogen IsotopesOxygen IsotopesCarbon IsotopesPeptide FragmentsPeptide LibraryAntimicrobial Cationic PeptidesMass SpectrometryPeptides, CyclicZinc IsotopesSulfur IsotopesDeuteriumPeptide MappingReproducibility of ResultsTandem Mass SpectrometryAmino Acid SequenceOligopeptidesChromatography, High Pressure LiquidChromatography, LiquidIron IsotopesKineticsSensitivity and SpecificityMolecular Sequence DataNatriuretic Peptide, BrainStrontium IsotopesProtein BindingReference StandardsProteomicsRadioisotope Dilution TechniqueVasoactive Intestinal PeptideCalcitonin Gene-Related PeptideCell-Penetrating PeptidesGas Chromatography-Mass SpectrometryLimit of DetectionCalibrationModels, MolecularPeptide Nucleic AcidsSpectrometry, Mass, Electrospray IonizationBinding SitesPeptide BiosynthesisIndicator Dilution TechniquesProtein ConformationPeptide YYBase SequenceMagnetic Resonance SpectroscopyAmino AcidsNatriuretic Peptide, C-TypeProtein Structure, SecondaryProteinsNatriuretic PeptidesTime FactorsCell LineAlgorithmsGastrin-Releasing PeptidePeptide HydrolasesStructure-Activity Relationship