These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


PUBMED FOR HANDHELDS

Search MEDLINE/PubMed


  • Title: [Purification and properties of dipeptidyl amino-peptidase I from chicken liver (author's transl)].
    Author: Barceló F, Vives N, Bozal J.
    Journal: Rev Esp Fisiol; 1980 Sep; 36(3):321-30. PubMed ID: 7433753.
    Abstract:
    Dipeptidyl aminopeptidase I (E.S. 3.4.14.1) from chicken liver was purified by the following steps: homogenization at pH 5, thermic precipitation, acetone fractionation and Sephadex G-100, DEAE-cellulose and organomercurial-Sepharose column fractionations. The purified enzyme appears to be homogeneous by polyacrylamide gel electrophoresis at both pH 4.5 and 8.3 and has an isoelectric point of 5.7 +/- 0.05. The molecular weight of the enzyme reale 167,000 +/- 17,000 on the Sephadex G-150 column chromatography. The optimum pH for hydrolysis of Gly-Phe-p-nitroanilide (GPNA) and Gly-Phe-B-naphthylamide was 5.8. The value of Km for the hydrolysis of GPNA was estimated at 3.3 mM. The enzyme required halide ions for activity and was activated by thiol reagents (dithiothreitol, cysteine and 2-mercaptoethanol). Accordingly, DAP I was inhibited by thiol-blocking reagents (PCMB, IAA, Hg2+). The enzyme oxidation with oxygen current was fostered by chloride anion (50 nM); nevertheless the activity was recovered when cysteine was present in the incubation mixture; the latter, besides, seems to perform as enzyme protector.
    [Abstract] [Full Text] [Related] [New Search]