Matern H
Biochim Biophys Acta. 1979 Aug 22;586(2):258-65. doi: 10.1016/0304-4165(79)90098-9.
Catabolite inactivation of phosphoenolpyruvate carboxykinase was studied in yeast spheroplasts using 0.9 M mannitol or 0.6 M potassium chloride as the osmotic support. In the presence of potassium chloride the rate of catabolite inactivation was nearly the same as that occurring in intact yeast cells under different conditions of incubation. However, in the presence of mannitol, catabolite inactivation in spheroplasts was prevented. The mannitol inhibition of catabolite inactivation was released by addition of ammonium or phosphate ions. At a concentration of 0.3 M ammonium or 0.06 M phosphate ions, the maximum rate of catabolite inactivation in spheroplasts suspended in mannitol was achieved and was comparable with that observed in spheroplasts incubated in 0.6 M potassium chloride as the osmotic stabilizer. Sodium sulfate (0.04 and 0.4 M) or potassium chloride (0.06 and 0.6 M) did not release the mannitol inhibition of catabolite inactivation in spheroplasts. In intact yeast cells, 0.9 M mannitol, 0.08 M ammonium or 0.1 M phosphate ions did not influence the rate of catabolite inactivation. The nature of the effect of mannitol, ammonium and phosphate ions on catabolite inactivation in yeast spheroplasts is discussed.
利用0.9M甘露醇或0.6M氯化钾作为渗透支持物，在酵母原生质球中研究了磷酸烯醇丙酮酸羧激酶的分解代谢失活。在氯化钾存在下，分解代谢失活的速率与在不同培养条件下完整酵母细胞中发生的速率几乎相同。然而，在甘露醇存在下，原生质球中的分解代谢失活被阻止。通过添加铵离子或磷酸根离子可解除甘露醇对分解代谢失活的抑制作用。在0.3M铵离子或0.06M磷酸根离子浓度下，悬浮在甘露醇中的原生质球达到了分解代谢失活的最大速率，且与在以0.6M氯化钾作为渗透稳定剂培养的原生质球中观察到的速率相当。硫酸钠（0.04M和0.4M）或氯化钾（0.06M和0.6M）不能解除甘露醇对原生质球中分解代谢失活的抑制作用。在完整酵母细胞中，0.9M甘露醇、0.08M铵离子或0.1M磷酸根离子不影响分解代谢失活的速率。讨论了甘露醇、铵离子和磷酸根离子对酵母原生质球中分解代谢失活作用的性质。
