Department of Botany, Faculty of Science, University of Tokyo, Hongo, Tokyo 113, Japan.
Plant Physiol. 1979 Mar;63(3):583-5. doi: 10.1104/pp.63.3.583.
The increment of lysine-sensitive aspartokinase (EC 2.7.2.4) activity during in vitro culture of carrot (Daucus carota, cv. Oogata sanzun) root tissue was explained in terms of derepression caused by an earlier decrease in the endogenous level of lysine, a possible end product repressor. Tissue content of free lysine decreased to about one-third of the initial level after 1 day of culture and no lysine was detected in the 2nd day. Inclusion of lysine (0.1 to 1.0 millimolar) in the culture medium resulted in a specific suppression of increase in lysine-sensitive aspartokinase activity without affecting the increase in threonine-sensitive aspartokinase activity.
在体外培养胡萝卜(Daucus carota,cv. Oogata sanzun)根组织期间,赖氨酸敏感型天冬氨酸激酶(EC 2.7.2.4)活性的增加可以用赖氨酸水平的早期降低引起的去阻遏来解释,赖氨酸可能是一种终产物阻遏物。在培养的第 1 天,组织中游离赖氨酸的含量下降到初始水平的约三分之一,第 2 天未检测到赖氨酸。在培养基中添加赖氨酸(0.1 至 1.0 毫摩尔)可特异性抑制赖氨酸敏感型天冬氨酸激酶活性的增加,而不影响苏氨酸敏感型天冬氨酸激酶活性的增加。