The kinetics and shear threshold of transient and rolling interactions of L-selectin with its ligand on leukocytes
The kinetics and shear threshold of transient and rolling interactions of L-selectin with its ligand on leukocytes
复制标题
DOI：
10.1073/pnas.95.20.11631
复制
发表时间：
1998-09-29
影响因子：
11.1
通讯作者：
Springer, TA
中科院分区：
文献类型：
--
作者：
Alon, R;Chen, SQ;Springer, TA
通过选择素的滚动和瞬时粘附的动力学可能取决于选择素：配体键的动力学和机械特性，以及细胞特性，包括受体锚定到细胞膜和细胞骨架。已知动力学取决于选择素并且也可能是配体依赖性的。在这里，我们研究了白细胞与固定在基质上的 L-选择素的瞬时和滚动相互作用的动力学。值得注意的是，所检查的所有性质都与当侧向相反时所观察到的性质相似，即，当L-选择素配体位于底物上时以及当配体从HEV中分离出来而不是存在于白细胞上时。相似的特性包括滚动速度、支持滚动所需的高于 0.4 dyn/cm(2) 的阈值剪切应力、L-选择蛋白系链键的 k(off) 度为 7.0 至 6.8 s(-1)，以及机械键长为 0.24 至 0.20 埃。我们的结果反对 L-选择素脱落介导滚动的模型。此外，快速和抗力动力学特性表明，L-选择素专门用于动态地将白细胞束缚到血管壁和粘附白细胞。
The kinetics of rolling and transient adhesions through selectins may depend on the kinetics and mechanical properties of the selectin:ligand bond, as well as on cellular properties including receptor-anchoring to the cell membrane and cytoskeleton. Kinetics are known to depend on the selectin and may also be ligand dependent. Here, we study the kinetics of transient and rolling interactions of leukocytes with L-selectin immobilized on a substrate. Remarkably, ail properties examined are similar to those seen when the sidedness is opposite, i.e., when the L-selectin ligand is on the substrate and when the ligand is isolated from HEV rather than present on leukocytes. The similar properties include rolling velocity, a threshold shear stress above 0.4 dyn/cm(2) required to support rolling, a k(off)degrees of 7.0 to 6.8 s(-1) for the L-selectin tether bond, and a mechanical bond length of 0.24 to 0.20 Angstrom. Our results argue against a model in which L-selectin shedding mediates rolling. Furthermore, the fast and force-resistant kinetic properties suggest that L-selectin is specialized dynamically for tethering leukocytes to vessel walls and adherent leukocytes.