Fat Metabolism in Higher Plants: LXII. Stearl-acyl Carrier Protein Desaturase from Spinach Chloroplasts.
نویسندگان
چکیده
Stearyl-acyl carrier protein desaturase (EC 1.14.99.6), present in the stroma fraction of spinach (Spinacia oleracea) chloroplasts, rapidly desaturated enzymatically prepared stearyl-acyl carrier protein to oleic acid. No other substrates were desaturated. In addition to stearyl-acyl carrier protein, reduced ferredoxin was an essential component of the system. The electron donor systems were either ascorbate, dichlorophenolindophenol, photosystem I and light, or NADPH and ferredoxin-NADP reductase. The desaturase was more active in extracts prepared from chloroplasts obtained from immature spinach leaves than from mature leaves. Stearyl-acyl carrier protein desaturase also occurs in soluble extracts of avocado (Persea americana Mill.) mesocarp and of developing safflower (Carthamus tinctorius) seeds.
منابع مشابه
Expression of Holo and Apo Forms of Spinach Acyl Carrier Protein-l in Leaves of Transgenic Tsbacco Plants
Acyl carrier protein (ACP) is a chloroplast-localized cofactor of fatty acid synthesis, desaturation, and acyl transfer. We have transformed tobacco with a chimeric gene consisting of the tobacco ribulose-1 ,&bisphosphate carboxylase promoter and transit peptide and the sequence encoding the mature spinach ACP-I. Spinach ACP-I was expressed in the transformed plants at levels twofold to threefo...
متن کاملExpression of holo and apo forms of spinach acyl carrier protein-I in leaves of transgenic tobacco plants.
Acyl carrier protein (ACP) is a chloroplast-localized cofactor of fatty acid synthesis, desaturation, and acyl transfer. We have transformed tobacco with a chimeric gene consisting of the tobacco ribulose-1,5-bisphosphate carboxylase promoter and transit peptide and the sequence encoding the mature spinach ACP-I. Spinach ACP-I was expressed in the transformed plants at levels twofold to threefo...
متن کاملActivity of acyl carrier protein isoforms in reactions of plant Fatty Acid metabolism.
Two forms of spinach acyl carrier protein (ACP-I and ACP-II) have recently been characterized and found to be expressed in a tissue-specific manner (JB Ohlrogge, TM Kuo, 1985 J Biol Chem 260: 8032). To examine possible different functions for these ACP isoforms, we have tested purified preparations of spinach leaf ACP-I and ACP-II and Escherichia coli ACP in several in vitro reactions of fatty ...
متن کاملEnzymatic desaturation of stearyl acyl carrier protein.
Stearyl acyl carrier protein, chemically prepared from 1-W stearic acid and Escherichia co2i acyl carrier protein, is desaturated to oleic acid by extracts of photoauxotrophic Euglena gracilis and of spinach. The soluble stearyl acyl carrier protein desaturase system from Eug~ena has been separated into three components, a reduced triphosphopyridine nucleotide oxidase, the desaturase, and a non...
متن کاملDirect desaturation of intact galactolipids by a desaturase solubilized from spinach (Spinacia oleracea) chloroplast envelopes.
In plants, polyenoic fatty acids are synthesized by desaturase enzymes which use acyl groups of membrane lipids as substrates. To provide direct 'in vitro' evidence for this reaction, we solubilized envelope membranes from spinach (Spinacia oleracea) chloroplasts with Triton X-100 to release a membrane-bound n-6 desaturase. In the presence of oxygen and reduced ferredoxin, the solubilized enzym...
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ورودعنوان ژورنال:
- Plant physiology
دوره 54 4 شماره
صفحات -
تاریخ انتشار 1974