Phosphatidylcholine Synthesis in Castor Bean Endosperm
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چکیده
منابع مشابه
Phosphatidylcholine synthesis in castor bean endosperm.
Three pathways for phosphatidylcholine synthesis were assayed in castor bean (Ricinus communis var. Hale) endosperm. Phosphatidylethanolamine: S-adenosylmethionine methyl transferase occurred predominantly in the endoplasmic reticulum fraction, but some activity appeared in the mitochondria. Phosphorylcholine glyceride transferase occurred exclusively in the endoplasmic reticulum. The phosphory...
متن کاملPhosphatidylcholine synthesis in castor bean endosperm : free bases as intermediates.
The methylation steps in the biosynthesis of phosphatidylcholine by castor bean (Ricinus communis L.) endosperm have been studied by pulse-chase labeling. Endosperm halves were incubated with [methyl-(14)C]S-adenosyl-l-methionine, [2-(14)C]ethanolamine, [(14)C]ethanolamine phosphate, or [(14)C]serine phosphate. The kinetics of appearance were followed in the free, phospho-, and phosphatidyl-bas...
متن کاملPhosphatidylethanolamine synthesis in castor bean endosperm.
Phosphatidylethanolamine synthesis by CDP-ethanolamine:1,2-diacylglycerol ethanolaminephosphotransferase (EC 2.7.8.1) from the endoplasmic reticulum of castor bean (Ricinus communis L. var. Hale) endosperm was characterized. The Michaelis-Menten constant of the enzyme for CDP-ethanolamine was approximately 8.0 micromolar. The pH optimum was 6.5 and a divalent cation was an absolute requirement ...
متن کاملPhosphatidylserine synthesis in castor bean endosperm.
Phosphatidylserine synthesis by the endoplasmic reticulum fraction isolated from castor bean (Ricinus communis var. Hale) endosperm was assayed by measuring the incorporation of (14)C-l-serine into chloroform-soluble material. Both phosphatidylserine and phosphatidylethanolamine were identified as products. The incorporation required calcium ions and showed an optimum pH of 7.8 in 2 mm CaCl(2)....
متن کاملPhosphatidylcholine Synthesis in Castor Bean Endosperm : Occurrence of an S-Adenosyl-l-Methionine:Ethanolamine N-Methyltransferase.
Methylethanolamine synthesis by S-adenosyl-l-methionine:ethanolamine N-methyltransferase from an extract of castor bean (Ricinus communis L. var Hale) endosperm was characterized. The apparent Michaelis-Menten constants of the enzyme for ethanolamine and S-adenosyl-l-methionine were estimated to be 6.7 and 1.4 mum, respectively, although the K(m) for ethanolamine is imprecise because of strong ...
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ژورنال
عنوان ژورنال: Plant Physiology
سال: 1992
ISSN: 0032-0889,1532-2548
DOI: 10.1104/pp.100.3.1527