Lafarge-Frayssinet C, Bertaux O, Valencia R, Frayssinet C
Biochim Biophys Acta. 1978 Apr 3;539(4):435-44. doi: 10.1016/0304-4165(78)90077-6.
Ornithine decarboxylase activity in Euglena gracilis Z was studied during the normal cell cycle and in vitamin B-12 deficiency. The cells were synchronized by means of alternating periods of light and dark. During the normal cell cycle, ornithine decarboxylase activity was very weak in the dark period, while three peaks of activity were recognized in the light period. The first peak, in the G1 phase, occurred when luminous stimulation started; the second preceded the S phase and the third was found in G2. In B-12-deficient cells, ornithine decarboxylase activity was greatly decreased and only the first peak remained. Elimination of the deficiency by addition of vitamin B-12 to the medium induced a very fast and significant increase in ornithine decarboxylase activity.
研究了纤细裸藻Z在正常细胞周期以及维生素B-12缺乏情况下的鸟氨酸脱羧酶活性。通过明暗交替的方式使细胞同步化。在正常细胞周期中，鸟氨酸脱羧酶活性在黑暗期非常微弱，而在光照期可识别出三个活性峰值。第一个峰值出现在G1期，在光照刺激开始时出现；第二个峰值先于S期出现，第三个峰值出现在G2期。在维生素B-12缺乏的细胞中，鸟氨酸脱羧酶活性大幅降低，仅保留第一个峰值。向培养基中添加维生素B-12消除缺乏状态后，鸟氨酸脱羧酶活性迅速且显著增加。
