Achar S B, Weisman R A
Biochim Biophys Acta. 1980 May 7;629(2):225-34. doi: 10.1016/0304-4165(80)90096-3.
The adenylate cyclase activity of Acanthamoeba castellanii (Neff) was studied in extracts prepared after breaking cells in the Potter-Elvehjem homogenizer. The adenylate cyclase activity of cells is low during the exponential growth phase, but then rises 2--4-fold during the stationary phase to a peak, roughly at the time that cyst forms are detectable in the culture. A 2--4-fold activity rise to a peak also occurs 4--8 h after late log cells are transferred to a non-nutrient encystment medium, a time which is shortly before numbers of cyst forms can be detected in the culture. The pattern of activity observed when stationary phase cells are transferred to encystment medium is complex and depends in part on whether the cultures have exhibited the peak of cyclase activity and have begun to initiate cyst formation prior to the transfer. Within the usual time frame after transfer to encystment medium, early logarithmic phase cells do not exhibit a 2--4-fold rise of cyclase activity and they do not encyst. The results suggest a relationship between encystment and the pattern of rise and fall in cyclase specific activity. Fractionation of the homogenate of trophozoites indicated that adenylate cyclase activity was associated with the particulate microsomal fraction.
在使用波特-埃尔维希姆匀浆器破碎细胞后制备的提取物中，研究了卡氏棘阿米巴（内夫株）的腺苷酸环化酶活性。细胞的腺苷酸环化酶活性在指数生长期较低，但在稳定期会升高2至4倍，达到峰值，大致在培养物中可检测到包囊形式的时候。当对数后期细胞转移到无营养的包囊化培养基中4至8小时后，也会出现2至4倍的活性升高并达到峰值，这个时间刚好在培养物中可检测到包囊形式数量之前不久。当稳定期细胞转移到包囊化培养基中时观察到的活性模式很复杂，部分取决于培养物在转移前是否已经出现环化酶活性峰值并开始形成包囊。在转移到包囊化培养基后的通常时间范围内，对数早期细胞不会出现环化酶活性2至4倍的升高，也不会形成包囊。结果表明包囊化与环化酶比活性的升降模式之间存在关联。滋养体匀浆的分级分离表明，腺苷酸环化酶活性与微粒体部分相关。
