Structural identification of β- and γ-human atrial natriuretic polypeptides

摘要: Atrial natriuretic polypeptides (ANPs) of varying chain length have been identified recently in human1 and rat2–8 atrial tissue. Their potent natriuretic–diuretic activities indicate their key role the regulation extracellular fluid volume electrolyte balance. Furthermore, human9 rat10–12 cDNAs encoding precursor cloned identified. Natriuretic–diuretic activity human extract comprises three distinct components (α, relative molecular mass (Mr) ∼ 3,000; β, Mr 6,000; γ, 13,000) 1. However, only 3,000-Mr peptide, α-human poly peptide (α-hANP), comprising 28 amino acids, has so far identified1. We report here purification sequence analysis two novel hANPs higher Mr, β- γ-hANP, both which exhibit hypotensive activity. composed 126 carries α-hANP at its carboxy terminus. The identification γ-hANP reveals that being largest form hANP, is processed directly from a 151-residue precursor9 by removal 26-residue signal peptide. In contrast, β-hANP (56 residues) an anti-parallel dimer α-hANP; such dimeric possessing bioactivity never found tissue as endogenous entity.