Department of Botany, University of Liverpool, Liverpool, U.K..
Planta. 1971 Dec;98(4):279-84. doi: 10.1007/BF00380228.
Germinating jack bean cotyledons liberated (14)CO2 when fed (14)C-guanidoxy-canavanine but did not accumulate any (14)C-compounds other than the applied canavanine. This suggested that the canavanine was being degraded by the action of canavanase to canaline and urea, the urea then being converted to ammonia and carbon dioxide by the action of urease. Hydroxyurea and acetohydroxamic acid (both inhibitors of urease activity) strongly inhibited the liberation of (14)CO2 from (14)C-guanidoxy-canavanine by the cotyledons but neither compound induced the accumulation of (14)C-urea within the tissues. This inhibitory action of hydroxyurea on (14)CO2 output was thought to be due at least in part, to this inhibition of canavanase activity.
发芽的刀豆子叶在饲喂 (14)C-胍基羟丙氨酸时释放 (14)CO2，但除了施用的刀豆氨酸外，没有积累任何其他 (14)C 化合物。这表明刀豆氨酸在刀豆氨酸酶的作用下被降解为胍丙氨酸和尿素，然后尿素在脲酶的作用下转化为氨和二氧化碳。羟基脲和乙酰氧肟酸（均为脲酶活性抑制剂）强烈抑制子叶从 (14)C-胍基羟丙氨酸中释放 (14)CO2，但这两种化合物都没有诱导组织内积累 (14)C-尿素。羟基脲对 (14)CO2 释放的这种抑制作用至少部分归因于对刀豆氨酸酶活性的抑制。
