Theimer R R, Wanner G, Anding G
Cytobiologie. 1978 Oct;18(1):132-44.
Cells of the Neurospora crassa slime mutant grown in sucrose medium exhibited low activities of glyoxysomal marker enzymes isocitrate lyase (ICL), malate synthetase (MS), and malate dehydrogenase. Transfer of the cells to a medium containing acetate as sole carbon source ("acetate medium") induced a strong increase in the activities of these enzymes in both the soluble and the crude particulate cell fraction. Soluble isocitrate lyase activity increased rapidly after a lag phase of about 45 minutes. Addition of 0.1 mM cycloheximide to the acetate medium 3 hours after transfer of the cells halted the rise of isocitrate lyase activity in either cell fraction, but the inhibition of the incorporation of ICL activity into the particulate cell fraction was delayed by 1 hour. Addition of 20 g/l glucose resulted in the immediate decrease of both soluble and particulate ICL activities. Transfer to acetate medium induced no change in the activities of other microbody marker enzymes such as catalase, uricase or D-amino acid oxidase. Resolution of crude homogenates of "slime" cells by sucrose density gradient centrifugation yielded two major protein bands: A mitochondrial band at a density of 1.180 kg/l showing maximum activites of fumarase, isocitrate dehydrogenase and cytochrome c oxidase, and a microbody-rich band which obviously consisted of two types of organelles with different biochemical properties. Maximum activities of ICL and MS sedimented at a density of 1.21 kg/l while the peaks of particulate uricase and catalase activities were recovered at 1.24 kg/l.
在蔗糖培养基中生长的粗糙脉孢菌黏液突变体的细胞,其乙醛酸循环体标记酶异柠檬酸裂解酶(ICL)、苹果酸合酶(MS)和苹果酸脱氢酶的活性较低。将这些细胞转移到以乙酸盐作为唯一碳源的培养基(“乙酸盐培养基”)中,可诱导这些酶在可溶性细胞组分和粗颗粒细胞组分中的活性大幅增加。可溶性异柠檬酸裂解酶活性在约45分钟的延迟期后迅速增加。在细胞转移至乙酸盐培养基3小时后,向其中添加0.1 mM环己酰亚胺,可阻止任一细胞组分中异柠檬酸裂解酶活性的升高,但ICL活性掺入颗粒细胞组分的抑制作用延迟了1小时。添加20 g/l葡萄糖会导致可溶性和颗粒性ICL活性立即下降。转移至乙酸盐培养基不会引起其他微体标记酶(如过氧化氢酶、尿酸酶或D-氨基酸氧化酶)活性的变化。通过蔗糖密度梯度离心法分离“黏液”细胞的粗匀浆,得到两条主要蛋白带:一条线粒体带,密度为1.180 kg/l,显示出延胡索酸酶、异柠檬酸脱氢酶和细胞色素c氧化酶的最大活性;另一条富含微体的带,显然由两种具有不同生化特性的细胞器组成。ICL和MS的最大活性在密度为1.21 kg/l处沉降,而颗粒性尿酸酶和过氧化氢酶活性的峰值在1.24 kg/l处回收。