衣藻纤毛的轴丝弯曲刚度暗示单分子马达力超过 5 pN

中文摘要 AI 辅助

纤毛和鞭毛的规则弯曲波为分子马达的集体动力学提供了一个标志性模型系统。已知纤毛轴丝中动力蛋白马达的规则排列，使我们能够将介观纤毛特性（如轴丝弯曲刚度）与微观马达特性（如单个马达施加的力）联系起来。我们利用先前对衣藻轴丝弯曲刚度的估计，估算了轴丝中动力蛋白分子马达集合产生的主动力。将该力除以最大可能的活跃马达头数量，可得出单个马达头产生的峰值力的下限为 >10 pN，这超过了分子马达典型的失速力（<5 pN）。这一差异表明，要么微管和轴丝的弯曲刚度先前被高估，要么密集马达阵列中的集体力产生可以超过单个马达预期贡献的总和。

英文摘要

The regular bending waves of cilia and flagella provide an iconic model system for the collective dynamics of molecular motors. The known regular arrangement of dynein motors in a cilium's axoneme allows us to connect mesoscopic cilia properties, such as axonemal bending stiffness, to microscopic motor properties, such as the force exerted by an individual motor. We estimate the active force generated by the collection of dynein molecular motors in $\mathit{Chlamydomonas}$ axonemes using previous estimates of its bending stiffness. Divided by the maximal possible number of active motor heads, this provides a lower bound of ${>}10\,\mathrm{pN}$ for the peak force generated by a motor head, which exceeds typical stall forces ${<}5\,\mathrm{pN}$ of molecular motors. This discrepancy suggests that either the bending stiffness of microtubules and axonemes was previously overestimated, or that collective force generation in dense motor arrays can surpass the sum of expected contributions of individual motors.

发表机构

• TU Dresden（德累斯顿工业大学）
• Cluster of Excellence Physics of Life, TU Dresden（德累斯顿大学生命物理卓越集群）
• B CUBE, TU Dresden（德累斯顿大学B CUBE中心）

机构由 AI 辅助整理，请以论文原文为准。