用2,4-二氯苯氧乙酸处理的黄化豇豆下胚轴中天冬氨酸转氨甲酰酶活性
Asparate transcarbamylase activity in etiolated cowpea hypocotyls treated with 2,4-dichlorophenoxyacetic Acid.
作者信息
Johnson L B, Niblett C L, Shively O D
机构信息
Department of Plant Pathology, Kansas State University, Manhattan, Kansas 66506.
出版信息
Plant Physiol. 1973 Feb;51(2):318-21. doi: 10.1104/pp.51.2.318.
Treating etiolated cowpea (Vigna unguiculata) seedlings with 2,4-dichlorophenoxyacetic acid resulted in 2.5-, 3.9-, and 6.5-fold increases in DNA, soluble protein, and RNA, respectively, over untreated controls 84 hours after treatment. Aspartate transcarbamylase activity increased within 12 hours after treatment, and by 84 hours it was almost 12-fold greater than that in the untreated controls. During that time, activity in untreated controls dropped 60%. The assay used (14)C-aspartate, which was then separated from the (14)C-ureidosuccinate product by Dowex 50 (H(+) form) column chromatography. Thin layer chromatography of the reaction product indicated that most of the carbamyl-phosphate-dependent radioactivity co-chromatographed with ureidosuccinate. The reaction has a pH optimum near 10.0 and is inhibited by uridine 5'-phosphate and succinate. The data suggest that aspartate transcarbamylase is important in pyrimidine biosynthesis in 2,4-dichlorophenoxyacetic acid-treated seedlings.
用2,4-二氯苯氧乙酸处理黄化豇豆（Vigna unguiculata）幼苗后，在处理84小时后，DNA、可溶性蛋白和RNA的含量分别比未处理的对照增加了2.5倍、3.9倍和6.5倍。天冬氨酸转氨甲酰酶活性在处理后12小时内增加，到84小时时，其活性几乎比未处理的对照高12倍。在此期间，未处理对照中的活性下降了60%。所使用的测定方法是用（14）C-天冬氨酸，然后通过Dowex 50（H(+)型）柱色谱法将其与（14）C-脲基琥珀酸产物分离。反应产物的薄层色谱表明，大多数依赖氨甲酰磷酸的放射性与脲基琥珀酸共色谱。该反应的最适pH接近10.0，并且受到5'-磷酸尿苷和琥珀酸的抑制。数据表明，天冬氨酸转氨甲酰酶在2,4-二氯苯氧乙酸处理的幼苗嘧啶生物合成中很重要。
Zotero 插件