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Induction of glyoxylate cycle enzymes in rat liver upon food starvation
Author(s) -
Popov Vasily N.,
Igamberdiev Abir U.,
Schnarrenberger Claus,
Volvenkin Sergei V.
Publication year - 1996
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(96)00668-0
Subject(s) - malate synthase , glyoxylate cycle , isocitrate lyase , biochemistry , enzyme , ammonium sulfate precipitation , ammonium , ammonium sulfate , microbody , chemistry , biology , chromatography , size exclusion chromatography , catalase , organic chemistry
The key enzymes of the glyoxylate cycle, isocitrate lyase and malate synthase, have been detected in liver of foodstarved rats. Activities became measurable 3 days and peaked 5 days after the beginning of starvation. Both enzymes were found in the peroxisomal cell fraction after organelle fractionation by isopycnic centrifugation. Isocitrate lyase was purified 112‐fold by ammonium sulfate precipitation, and chromotography on DEAE‐cellulose and Toyopearl HW‐65. The specific activity of the purified enzyme was 9.0 units per mg protein. The K m (isocitrate) was 68 μM and the pH optimum was at pH 7.4. Malate synthase was enriched 4‐fold by ammonium sulfate precipitation. The enzyme had a K m (acetyl‐CoA) of 0.2 μM, a K m (glyoxylate) of 3 mM and a pH optimum of 7.6.