The Amino Acid Sequence of β-Galactosidase III. THE SEQUENCE OF NH2- AND COOH-TERMINAL TRYPTIC PEPTIDES

摘要: The method of Bruton and Hartley for the isolation short NH2-terminal sequences peptides has been applied to β-galactosidase. Maleyl-β-galactosidase was hydrolyzed with thermolysin digest acidified. After passage through Dowex 50, Thr-Met obtained from eluate. This procedure extended. For a larger peptide, maleyl-protein treated trypsin, subjected additional hydrolysis carboxypeptidase B. peptide mixture acidified, centrifuged, filtered 50. From eluate an octapeptide purified which corresponded portion tridecapeptide isolated previously another hydrolysate. sequence determined be Thr-Met-Ile-Thr-Asp-Ser-Leu-Ala-Val-Val-Leu-Gln-Arg. Another modification this is proposed COOH-terminal peptide. Following may maleylated before normally not expected adsorbed resin. In case β-galactosidase decapeptide such in fraction insoluble at pH 4. Its found Tyr-His-Ser-Gln-Val-Leu-Tyr-Cys-Gln-Lys. These procedures NH2- useful other proteins.