Tannenbaum J, Tanenbaum S W, Godman G C
J Cell Physiol. 1977 May;91(2):239-48. doi: 10.1002/jcp.1040910209.
Cytochalasin B (CB) was able to compete with tritiated cytochalasin D (3H-CD) for binding sites in HEp-2 cells. The pattern of inhibition suggested that CB associates with a low affinity class of CD binding sites. Glucose and maltose did not inhibit binding of 3H-CD to isolated HEp-2 plasma membrane. Inhibition of hexose transport by CD was negligible, but CD did not block the potent inhibition of this transport by CB. These results indicate that CD does not bind to the high affinity CB receptor reportedly associated with the hexose transport system, and that this receptor cannot mediate the morphological effects of CD. Both CD and CB induced contraction-zeoisis in HEp-2 cells; CB was less potent than CD, and their effects appeared to be additive. It was concluded that the high affinity binding sites for CD and CB are different, but that these congeners share a low affinity site. Both high and low affinity sites for CD appear to mediate its morphological effects; only the low affinity class appears to be involved for CB. Possible identification of the common low affinity binding site as actomyosin (detailed in Tannenbaum et al., '77) is further discussed.
细胞松弛素B（CB）能够与氚标记的细胞松弛素D（3H-CD）竞争HEp-2细胞中的结合位点。抑制模式表明，CB与一类低亲和力的CD结合位点相关联。葡萄糖和麦芽糖不抑制3H-CD与分离的HEp-2质膜的结合。CD对己糖转运的抑制作用可忽略不计，但CD并不阻断CB对这种转运的强效抑制作用。这些结果表明，CD不与据报道与己糖转运系统相关的高亲和力CB受体结合，并且该受体不能介导CD的形态学效应。CD和CB均诱导HEp-2细胞发生收缩-胞质皱缩；CB的效力低于CD，且它们的作用似乎具有加和性。得出的结论是，CD和CB的高亲和力结合位点不同，但这些同类物共享一个低亲和力位点。CD的高亲和力和低亲和力位点似乎均介导其形态学效应；对于CB，似乎仅低亲和力类别参与其中。进一步讨论了将常见的低亲和力结合位点鉴定为肌动球蛋白的可能性（Tannenbaum等人，1977年详述）。
