Tumminia S J, Koretz J F, Landau J V
Center for Biophysics, Rensselaer Polytechnic Institute, Troy, NY 12180-3590.
Biochim Biophys Acta. 1989 Dec 21;999(3):300-12. doi: 10.1016/0167-4838(89)90013-7.
Column-purified myosin at pH 7.0 will reproducibly aggregate into filaments of known average length and structure when dialyzed against a low ionic strength medium under controlled conditions. When exposed to increased hydrostatic pressure, followed by quick return to atmospheric pressure, the original filaments shorten linearly with increasing pressure; in addition, a second population of filaments is seen, presumably the result of reaggregation of myosin after release of pressure. This second population is about 0.5 microns long, bipolar, and about half the diameter of the original filaments. The number of these filaments, but not their physical characteristics, is a function of the shortening of the original filament population. Both the remnants of the original population and the new aggregates, once formed, are stable over time and at room temperature. The addition of C-protein to myosin solutions before filament preparation results in a filament population of slightly shorter length. When these filaments are exposed to increased hydrostatic pressure, they are more resistant to disaggregation than myosin filaments without C-protein. However, like the filaments prepared in the absence of C-protein, a second population of shorter, thinner filaments is visible after exposure to pressure.
在pH 7.0条件下经柱纯化的肌球蛋白，在可控条件下对低离子强度介质进行透析时，会反复聚集成平均长度和结构已知的细丝。当暴露于增加的静水压力下，随后迅速恢复到大气压时，原始细丝会随着压力增加而线性缩短；此外，还会观察到第二批细丝，推测是压力释放后肌球蛋白重新聚集的结果。这批细丝长约0.5微米，呈双极状，直径约为原始细丝的一半。这些细丝的数量而非其物理特性，是原始细丝群体缩短程度的函数。原始群体的残余部分和新形成的聚集体一旦形成，在室温下随时间推移都是稳定的。在制备细丝之前向肌球蛋白溶液中添加C蛋白，会导致细丝群体的长度略短。当这些细丝暴露于增加的静水压力下时，它们比不含C蛋白的肌球蛋白细丝更抗解聚。然而，与在无C蛋白情况下制备的细丝一样，暴露于压力后会出现第二批更短、更细的细丝。
