Diuretic and natriuretic peptide compsn. (I) obtd. by carboxylic acid extrn. from mammalian heart atria. (I) has a molecular wt. of 5100-5300 and it has an amino acid residue analysis of 3.7 Asp, 1.3 Thr, 6.4 Ser, 4.8 Glx, 1.9 Pro, 7.3 Gly, 3.3 Ala, 0.9 Cys, 1.0 Val, 0.8 Met, 3.2 Leu, 1.1 Tyr, 1.8 Phe, 2.8 Lys, 1.1 His, 0.0 Trp and 5.7 Arg. The compsn. may comprise a sequence of formula (Ia). In (Ia) there is a disulphide bond between the Cys residues, and it has a molecular wt. of about 3500. (I) is obtd. by homogenation of mammalian heart atria in aq. lower carboxylic acid, esp. acetic acid, then the extract is adjusted to pH 4.5-7.6 to ppte. impurities and (I) is recovered from the soln., e.g. by gel, ion-exchange and reverse phase liq. chromatography after an initial freeze drying step. The aq. soln. may also contain HCl.
展开▼
