Open AccessIsocitrate lyase activity in halophilic archaea
Author(s) -
Oren Aharon,
Gurevich Peter
Publication year - 1995
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1995.tb07704.x
Subject(s) - haloferax volcanii , halophile , biochemistry , isocitrate lyase , haloarchaea , archaea , chemistry , halobacterium , isocitrate dehydrogenase , potassium , sodium , bacteria , biology , enzyme , glyoxylate cycle , organic chemistry , genetics , gene
Eight species of halophilic Archaea were tested for the presence of isocitrate lyase activity. High activities (up to 100 nmol min −1 mg protein −1 ) were detected in Haloferax mediterranei and Haloferax volcanii when grown in medium containing acetate as the principal carbon source. Little activity was found in representatives of the genera Halobacterium and Haloarcula . Isocitrate lyase from Haloferax mediterranei required high potassium chloride concentrations, optimal activity being found at 1.5–3 M potassium chloride and pH 7.0. Replacement of potassium chloride by sodium chloride resulted in much lower activities. Sulfhydryl compounds (cysteine, glutathione) were not stimulatory. In other properties (stimulation by magnesium ions, sensitivity to different inhibitors) the enzyme resembled isocitrate lyases from representatives of the Bacteria and Eucarya.