Manney T R
J Bacteriol. 1968 Aug;96(2):403-8. doi: 10.1128/jb.96.2.403-408.1968.
The activity of tryptophan synthetase in crude extracts from Saccharomyces cerevisiae is stable if the cells are cultured in a complex medium, but extremely unstable if they are cultured in a minimal medium. The difference is not the result of different inherent properties of the enzyme formed in the two cultures. Rather, there are at least two kinds of macromolecular factors that influence the stability, one inactivating tryptophan synthetase and the other protecting against this inactivation. The abundance of these factors varies with the composition of the culture medium, which accounts for the differences observed.
如果在复合培养基中培养,酿酒酵母粗提物中色氨酸合成酶的活性是稳定的,但如果在基本培养基中培养则极其不稳定。这种差异并非两种培养条件下形成的酶具有不同固有特性的结果。相反,至少有两种大分子因子会影响稳定性,一种使色氨酸合成酶失活,另一种则防止这种失活。这些因子的丰度随培养基的组成而变化,这就解释了所观察到的差异。