Department of Botany, University of Wyoming, Laramie, Wyoming 82071.
Plant Physiol. 1978 Dec;62(6):978-80. doi: 10.1104/pp.62.6.978.
CDP-diglyceride:inositol transferase in endoplasmic reticulum fractions from castor bean (Ricinus communis) endosperm was partially characterized. The enzyme had a pH optimum of 8.5 and required Mn(2+) for activity. Maximal activity was at 1.5 millimolar MnCl(2). A K(m) of 0.30 mM was calculated for myo-inositol and 1.35 millimolar was estimated for CDP-dipalmitoylglyceride. Concentrations of CDP-dipalmitoylglyceride above 1.2 millimolar inhibited the enzyme. A deoxycholate concentration of 0.1% (w/v) stimulated the reaction slightly while Triton X-100 inhibited at all concentrations tested. Some incorporation of myo-inositol into phosphatidylinositol occurred in the absence of CDP-diglyceride.
CDP-二酰基甘油：肌醇转移酶在蓖麻（Ricinus communis）胚乳的内质网部分中被部分表征。该酶的 pH 最佳值为 8.5，需要 Mn（2+）才能发挥活性。最大活性出现在 1.5 毫摩尔 MnCl（2）下。肌醇的 K（m）值为 0.30 毫摩尔，CDP-二棕榈酰甘油的 K（m）值估计为 1.35 毫摩尔。CDP-二棕榈酰甘油浓度高于 1.2 毫摩尔会抑制酶的活性。去氧胆酸钠浓度为 0.1%（w/v）时会轻微刺激反应，而 Triton X-100 在所有测试浓度下均抑制该反应。在没有 CDP-二酰基甘油的情况下，肌醇会少量掺入磷脂酰肌醇中。
