The enolases of ice plant and Arabidopsis contain a potential disulphide and are redox sensitive

• Published in: Phytochemistry (Oxford) Vol. 47; no. 5; pp. 707 - 713
• Main Authors: Anderson, Louise E., Alex Dong Li, Stevens, Fred J.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Ltd 01.03.1998; Elsevier
• Subjects: Amino Acid Sequence; amino acid sequences; Analytical, structural and metabolic biochemistry; Arabidopsis; Arabidopsis - enzymology; Arabidopsis thaliana; Binding Sites; Biological and medical sciences; chemistry; cysteine; Disulfides; Disulfides - chemistry; Disulfides - metabolism; embryo (plant); Enzyme Activation; enzyme activity; Enzymes; Enzymes and enzyme inhibitors; enzymology; Fundamental and applied biological sciences. Psychology; hydro-lyases; interspecific variation; leaves; Lyases; Mesembryanthemum crystallinum; Metabolism; molecular conformation; Molecular Sequence Data; Oxidation-Reduction; Phosphopyruvate Hydratase; Phosphopyruvate Hydratase - chemistry; Phosphopyruvate Hydratase - metabolism; Plant physiology and development; Plant Proteins; Plant Proteins - chemistry; Plant Proteins - metabolism; Plants; Plants - enzymology; Protein Structure, Tertiary; redox reactions; Ricinus communis; roots; Sequence Homology, Amino Acid; Solanum lycopersicum var. lycopersicum; Zea mays; Arabidopsis thaliana; thale cress; common ice plant; Mesembryanthemum crystallinum; enolase; activity modulation; Aizoaceae; Brassicaceae; redox-sensitive cysteines; Monocotyledones; Cysteine; Active site; Lyases; Phylogeny; Regulation(control); Structure activity relation; Three dimensional structure; Cruciferae; Gramineae; Dicotyledones; Angiospermae; Lycopersicon esculentum; Euphorbiaceae; Solanaceae; Phosphopyruvate hydratase; Aminoacid sequence; Ricinus communis; Halophyte; Oxidation reduction; Zea mays; Enzyme; Disulfide bond; Spermatophyta; Experimental plant; Carbon-oxygen lyases; Hydro-lyases
• ISSN: 0031-9422; 1873-3700
• DOI: 10.1016/S0031-9422(97)00659-6

The simulated structures of the enolases of Arabidopsis and the common ice plant contain a pair of Cys residues in the correct orientation to form a disulphide bond. Formation of this disulphide might be expected to affect the positioning of several residues in the active site. The enzyme in crude extracts of these two plants is activated by oxidation. Apparently formation of the disulphide crosslink enhances catalysis. The enolases from tomato leaves, maize roots and castor bean embryos lack one of these Cys residues and are not redox sensitive. It seems possible that enolase is redox-regulated by a cytosolic thioredoxin system in a limited number of plant species including ice plant and Arabidopsis. The enolases of Arabidopsis and ice plant contain cysteine residues in a region where, if oxidized they might be expected to affect the positioning of the residues in the active site. The enzyme in crude extracts is oxidatively activated and may therefore be subject to redox regulation in vivo.