Oxygen toxicity from plants to people.
Over the past 30 years, acute oxygen toxicity in plants, mammals and enteric bacteria has been defined in terms of specific interactions of oxygen with a limited number of molecular targets. At least in the case of plants and mammals, response at the level of the whole organism is a consequence of oxygen's interaction with enzymes that should not exhibit oxygen sensitivity, ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco) and glutamate decarboxylase (GAD). In enteric bacteria, inhibition of acetolactate synthase (ALS), or the production of peracetic acid by this enzyme, may be a contributing factor in the inactivation of dihydroxyacid dehydratase and loss of the ability to synthesize branched-chain amino acids under conditions of hyperbaric oxygen. The facile interaction of these enzymes with oxygen has questioned our fundamental understanding of their reaction mechanisms. Could these enzymes have radical mechanisms?
Schloss
John V
JV
Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Kuwait University, PO Box 24923, Safat 13110, Kuwait. ozcitizen@aol.com
D000095:Acetolactate Synthase / Q000378:metabolism; D000446:Aldehyde-Lyases / Q000378:metabolism; D001205:Ascorbic Acid / Q000378:metabolism; D004755:Enterobacteriaceae / Q000187:drug effects / Q000378:metabolism; D005968:Glutamate Decarboxylase / Q000378:metabolism; D006801:Humans; D006836:Hydro-Lyases / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism; D010100:Oxygen / Q000009:adverse effects / Q000633:toxicity*; D010463:Peracetic Acid / Q000378:metabolism; D010944:Plants / Q000187:drug effects* / Q000378:metabolism; D011767:Pyruvate Decarboxylase / Q000378:metabolism; D012273:Ribulose-Bisphosphate Carboxylase / Q000378:metabolism
D006861:Hydrogen Peroxide; D000095:Acetolactate Synthase; D011767:Pyruvate Decarboxylase; D005968:Glutamate Decarboxylase; D012273:Ribulose-Bisphosphate Carboxylase; D000446:Aldehyde-Lyases; D006836:Hydro-Lyases; C020052:dihydroxyacid dehydratase; D010463:Peracetic Acid; D001205:Ascorbic Acid; D010100:Oxygen