Single adhesive nanofibers from a live diatom have the signature fingerprint of modular proteins
Single adhesive nanofibers from a live diatom have the signature fingerprint of modular proteins
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DOI：
10.1529/biophysj.105.062489
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发表时间：
2005-12-01
影响因子：
3.4
通讯作者：
Wetherbee, R
中科院分区：
文献类型：
--
作者：
Dugdale, TM;Dagastine, R;Wetherbee, R
利用原子力显微镜原位研究了硅藻活细胞分泌的细胞-基质粘合剂的粘附和力学性能。由此产生的力曲线具有规则的锯齿图案，模块化蛋白质的特征指纹，并且当在尖端和表面之间桥接时，可以反复拉伸和松弛，从而精确地重叠锯齿曲线（高达; 600个连续循环）。在0.8 μ m/s的加载速率下，峰的平均断裂力为0.794 +/- 0.007（平均值+/- SE）nN，平均持续长度为0.026 +/- < 0.001（平均值+/- SE）nm（使用蠕虫状链模型拟合）。我们提出，我们正在拉动单个粘性纳米纤维，每个纳米纤维都是由一定数量的模块化蛋白质组成的内聚单元。此外，我们可以观察和区分时，多达三个粘合剂纳米纤维被拉基于力和持久性长度的多峰分布。键断裂所需的高力、高延展性（类似于1.2 μ m）以及松弛时的准确和快速重折叠，一起提供了非常适合这种污损硅藻的细胞-基质粘附的强而柔韧的性质，并使我们能够理解负责粘附强度的机制。
The adhesive and mechanical properties of a cell-substratum adhesive secreted by live diatom cells were examined in situ using atomic force microscopy. The resulting force curves have a regular saw-tooth pattern, the characteristic fingerprint of modular proteins, and when bridged between tip and surface can repeatedly be stretched and relaxed resulting in precisely overlaying saw-tooth curves (up to; 600 successive cycles). The average rupture force of the peaks is 0.794 +/- 0.007 (mean +/- SE) nN at a loading rate of 0.8 mu m/s and the average persistence length is 0.026 +/- < 0.001 (mean +/- SE) nm (fit using the worm-like chain model). We propose that we are pulling on single adhesive nanofibers, each a cohesive unit composed of a set number of modular proteins aligned in register. Furthermore, we can observe and differentiate when up to three adhesive nanofibers are pulled based upon multimodal distributions of force and persistence length. The high force required for bond rupture, high extensibility (similar to 1.2 mu m), and the accurate and rapid refolding upon relaxation, together provide strong and flexible properties ideally suited for the cell-substratum adhesion of this fouling diatom and allow us to understand the mechanism responsible for the strength of adhesion.