Polymerization and gelation of actin studied by fluorescence photobleaching recovery.
Polymerization and gelation of actin studied by fluorescence photobleaching recovery.
复制标题
通过荧光光漂白恢复研究肌动蛋白的聚合和凝胶化。
DOI：
10.1021/bi00258a022
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发表时间：
1982
期刊：
影响因子：
2.9
通讯作者：
Frieden,C
中科院分区：
文献类型：
--
作者：
Tait,JF;Frieden,C
乔纳森·F. Tail和Carl Frieden* 摘要：以碘乙酰氨基四甲基罗丹明标记的微量（5%）肌动蛋白为荧光探针，用荧光光漂白恢复技术研究了兔骨骼肌肌动蛋白的聚合。该衍生物的荧光在聚合时增加50%，因此聚合物形成的速率和程度可以从光漂白实验中使用的相同样品测量。当在适合于跟踪聚合肌动蛋白扩散的条件下进行光漂白实验时，在1 mg/mL和2 mM Mg ~（2+）下的聚合过程如下：（1）在聚合物显著聚集之前，所有的肌动蛋白扩散太快而无法观察。(2)当聚合物形成时，其以（~ 0.05-0.5）X 10 - 8 cm 2/s范围内的表观扩散系数扩散。(3)在聚合完成之前，长丝变得固定化（表观扩散系数<<2 X 10-μ cm 2/s）。第二阶段可能代表聚合物的生长，其扩散受到与其他聚合物的相互作用的阻碍;第三阶段归因于纤维在聚合物中的固定。
Jonathan F. Tail and Carl Frieden* abstract: The polymerization of rabbit skeletal muscle actin was studied with the technique of fluorescence photobleaching recovery by using trace amounts (5%) of actin labeled with (iodoacetamido) tetramethylrhodamine as the fluorescent probe. This derivative’s fluorescence increases 50% upon polymerization, so the rate and extent of polymer formation can be measured from the same sample used in the photo-bleaching experiment. When photobleaching experiments are done under conditionssuitable for following the diffusion of polymeric actin, the progress of polymerization at 1 mg/mL and 2 mM Mg2+ is as follows:(1) Prior to significant accu-mulation of polymer, all the actin diffuses too rapidly to be observed.(2) As polymer forms, it diffuses with an apparent diffusion coefficient in the range of (~ 0.05-0.5) X 10" 8 cm2/s.(3) Before completion of polymerization, filaments become immobilized (apparent diffusion coefficient «2 X 10~ u cm2/s). The second stage probably represents growing polymers whose diffusion is hindered by interaction with otherpolymers; the third stage is attributed to immobilization of filaments in