Membrane tether formation from outer hair cells with optical tweezers
Membrane tether formation from outer hair cells with optical tweezers
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DOI：
10.1016/s0006-3495(02)75493-3
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发表时间：
2002-03-01
影响因子：
3.4
通讯作者：
Brownell, WE
中科院分区：
文献类型：
--
作者：
Li, ZW;Anvari, B;Brownell, WE
光镊被用来表征外毛细胞（OHC）质膜的机械性能，通过拉系绳与4.5 μ m聚苯乙烯珠。在静态和动态条件下测量了系绳形成力和系绳力。从OHC侧壁（499 +/-152 pN）形成系链所需的力大于从OHC基底端（142 +/-49 pN）形成系链所需的力。拉栓所需的力的差异与广泛的细胞骨架框架相一致，该框架与被称为皮质晶格的外侧壁相关联。在静态条件下，通过测量不同系绳长度的系绳力来估计OHC侧壁的表观质膜刚度为3.71 pN/mum，OHC基端的表观质膜刚度为4.57 pN/mum。通过以不同速率牵拉系链同时连续记录系链力来测量有效膜粘度，并估计在2.39至5.25 pN.s/mum的范围内。粘滞力最有可能是由质膜脂质与OHC皮质晶格和/或整合膜蛋白之间的粘性相互作用引起的。这些研究所提供的信息对OHC外侧壁的机械性能是重要的了解OHC电活动的机制。
Optical tweezers were used to characterize the mechanical properties of the outer hair cell (OHC) plasma membrane by pulling tethers with 4.5-mum polystyrene beads. Tether formation force and tether force were measured in static and dynamic conditions. A greater force was required for tether formations from OHC lateral wall (499 +/- 152 pN) than from OHC basal end (142 +/- 49 pN). The difference in the force required to pull tethers is consistent with an extensive cytoskeletal framework associated with the lateral wall known as the cortical lattice. The apparent plasma membrane stiffness, estimated under the static conditions by measuring tether force at different tether length, was 3.71 pN/mum for OHC lateral wall and 4.57 pN/mum for OHC basal end. The effective membrane viscosity was measured by pulling tethers at different rates while continuously recording the tether force, and estimated in the range of 2.39 to 5.25 pN.s/mum. The viscous force most likely results from the viscous interactions between plasma membrane lipids and the OHC cortical lattice and/or integral membrane proteins. The information these studies provide on the mechanical properties of the OHC lateral wall is important for understanding the mechanism of OHC electromotility.