Identification of a cysteine residue at the active site of Escherichia coli isocitrate lyase

H. G. Nimmo, F. Douglas, C. Kleanthous, D. G. Campbell, C. MacKintosh

    Research output: Contribution to journalArticle

    15 Citations (Scopus)

    Abstract

    Escherichia coli isocitrate lyase was inactivated by iodacetate in a pseudo-first-order process. Complete inactivation was associated with the incorporation of only one carboxymethyl group per enzyme subunit. The substrate and products of the enzyme protected against inactivation, suggesting that the reactive group may be located at the active site. Isolation and sequencing of a carboxymethylated peptide showed that the modified residue was a cysteine, in the sequence Cys-Gly-His-Met-Gly-Gly-Lys. The reactivity of isocitrate lyase to iodoacetate declined with pH, following a titration curve for a group of pKa 7.1. The Km of the enzyme for isocritrate declined over the same pH range
    Original languageEnglish
    Pages (from-to)431-435
    Number of pages5
    JournalBiochemical Journal
    Volume261
    Issue number2
    Publication statusPublished - 1989

    Cite this

    @article{7aea3f5b93144b85bf3d62f33b348333,
    title = "Identification of a cysteine residue at the active site of Escherichia coli isocitrate lyase",
    abstract = "Escherichia coli isocitrate lyase was inactivated by iodacetate in a pseudo-first-order process. Complete inactivation was associated with the incorporation of only one carboxymethyl group per enzyme subunit. The substrate and products of the enzyme protected against inactivation, suggesting that the reactive group may be located at the active site. Isolation and sequencing of a carboxymethylated peptide showed that the modified residue was a cysteine, in the sequence Cys-Gly-His-Met-Gly-Gly-Lys. The reactivity of isocitrate lyase to iodoacetate declined with pH, following a titration curve for a group of pKa 7.1. The Km of the enzyme for isocritrate declined over the same pH range",
    author = "Nimmo, {H. G.} and F. Douglas and C. Kleanthous and Campbell, {D. G.} and C. MacKintosh",
    year = "1989",
    language = "English",
    volume = "261",
    pages = "431--435",
    journal = "Biochemical Journal",
    issn = "0264-6021",
    publisher = "Portland Press",
    number = "2",

    }

    Identification of a cysteine residue at the active site of Escherichia coli isocitrate lyase. / Nimmo, H. G.; Douglas, F.; Kleanthous, C.; Campbell, D. G.; MacKintosh, C. .

    In: Biochemical Journal, Vol. 261, No. 2, 1989, p. 431-435.

    Research output: Contribution to journalArticle

    TY - JOUR

    T1 - Identification of a cysteine residue at the active site of Escherichia coli isocitrate lyase

    AU - Nimmo, H. G.

    AU - Douglas, F.

    AU - Kleanthous, C.

    AU - Campbell, D. G.

    AU - MacKintosh, C.

    PY - 1989

    Y1 - 1989

    N2 - Escherichia coli isocitrate lyase was inactivated by iodacetate in a pseudo-first-order process. Complete inactivation was associated with the incorporation of only one carboxymethyl group per enzyme subunit. The substrate and products of the enzyme protected against inactivation, suggesting that the reactive group may be located at the active site. Isolation and sequencing of a carboxymethylated peptide showed that the modified residue was a cysteine, in the sequence Cys-Gly-His-Met-Gly-Gly-Lys. The reactivity of isocitrate lyase to iodoacetate declined with pH, following a titration curve for a group of pKa 7.1. The Km of the enzyme for isocritrate declined over the same pH range

    AB - Escherichia coli isocitrate lyase was inactivated by iodacetate in a pseudo-first-order process. Complete inactivation was associated with the incorporation of only one carboxymethyl group per enzyme subunit. The substrate and products of the enzyme protected against inactivation, suggesting that the reactive group may be located at the active site. Isolation and sequencing of a carboxymethylated peptide showed that the modified residue was a cysteine, in the sequence Cys-Gly-His-Met-Gly-Gly-Lys. The reactivity of isocitrate lyase to iodoacetate declined with pH, following a titration curve for a group of pKa 7.1. The Km of the enzyme for isocritrate declined over the same pH range

    M3 - Article

    VL - 261

    SP - 431

    EP - 435

    JO - Biochemical Journal

    JF - Biochemical Journal

    SN - 0264-6021

    IS - 2

    ER -