Hayashi T, Ip W
J Mechanochem Cell Motil. 1976 Mar;3(3):163-9.
The actin polymer, like the thin filaments of muscle, is known to be polarized as demonstrated by the well known "HMM decoration" technique to give a "herringbone" pattern pointing in one direction. The question "Does polymer formation proceed unidirectionally, or bidirectionally?" was raised and tested experimentally. Short fragments of actin polymers were prepared, fully decorated with HMM and these decorated fragments were used as initiation centers for further actin polymerization without HMM. The resultant polymers showing both decorated and undecorated portions were examined and found to consist of a large majority of "spears" i.e., the added undecorated polymer extended in the direction opposite to that direction pointed by the "herringbone" pattern. However, a few cases of polymers indicating the opposite direction of polymerization were also found. Analysis leads to the conclusion that actin polymerization is unidirectional, although further experimentation is necessary to establish this completely.
肌动蛋白聚合物，就像肌肉中的细肌丝一样，已知是极化的，这一点通过著名的“HMM 标记”技术得到了证明，该技术会产生指向一个方向的“人字形”图案。于是有人提出并通过实验检验了“聚合物形成是单向进行还是双向进行？”这个问题。制备了肌动蛋白聚合物的短片段，用 HMM 完全标记，然后将这些标记的片段用作进一步肌动蛋白聚合（不使用 HMM）的起始中心。对所得的同时显示有标记和未标记部分的聚合物进行检查，发现其中绝大多数是“矛状”结构，即添加的未标记聚合物朝着与“人字形”图案所指方向相反的方向延伸。然而，也发现了少数聚合物显示出相反聚合方向的情况。分析得出结论，肌动蛋白聚合是单向的，不过要完全证实这一点还需要进一步实验。
