Morris S J, Schovanka I
Biochim Biophys Acta. 1977 Jan 4;464(1):53-64. doi: 10.1016/0005-2736(77)90370-4.
Centrifugation of crude preparations of chromaffin granules on iso-osmotic continuous gradients of sucrose and metrizamide produce granule fractions of high purity without pelleting. These granules have a buoyant density of 1.123 at 300 mosM, which increases to 1.222 at 1800 mosM. Exchange of water for 2H2O greatly increases the density of the granules. An apparent water space for the granules can be calculated from the difference in density in 2H2O and water. The water space of 0.63 at 300 mosM diminishes as the osmolality of the suspension medium is increased, suggesting that the granule membrane is a good osmometer and that the core contains a large osmotically active water space. Other separation methods for chromaffin granules are discussed in terms of these results.
将嗜铬颗粒的粗制品在蔗糖和甲泛葡胺的等渗连续梯度上进行离心，可产生高纯度的颗粒级分，且不会形成沉淀。这些颗粒在300 mosM时的浮力密度为1.123，在1800 mosM时增加到1.222。用水替换为2H2O会大大增加颗粒的密度。颗粒的表观水空间可根据其在2H2O和水中密度的差异来计算。在300 mosM时水空间为0.63，随着悬浮介质渗透压的增加而减小，这表明颗粒膜是一个良好的渗透压计，且颗粒核心包含一个大的具有渗透活性的水空间。根据这些结果对嗜铬颗粒的其他分离方法进行了讨论。
