通过原子力显微镜测量的胆碱能突触小泡弹性特性的变化。

Laney D E, Garcia R A, Parsons S M, Hansma H G

Department of Physics, University of California, Santa Barbara 93106, USA.

Biophys J. 1997 Feb;72(2 Pt 1):806-13. doi: 10.1016/s0006-3495(97)78714-9.

Cholinergic synaptic vesicles from Torpedo californica have been probed with the atomic force microscope in aqueous buffers to map and measure their elastic properties. Elastic properties were mapped with a new atomic force microscope technique known as force mapping. Force mapping of vesicles showed that the centers of the vesicles are harder or stiffer than the peripheral areas in the three buffers that were investigated. These were an isoosmotic buffer, a hypoosmotic buffer, and an isoosmotic buffer with 5 mM CaCl2 added. The hardness of the vesicular centers was quantified by calculation of the elastic modulus. Elastic moduli were in the range of 2-13 x 10(5) Pa. Vesicular centers were hardest in calcium-containing buffer and softest in isoosmotic buffer. Hypotheses are presented for the composition and function of the hard centers.

用原子力显微镜在水性缓冲液中对加州电鳐的胆碱能突触小泡进行了探测，以绘制并测量其弹性特性。通过一种名为力映射的新原子力显微镜技术对弹性特性进行了映射。小泡的力映射显示，在所研究的三种缓冲液中，小泡的中心比周边区域更硬或更具刚性。这三种缓冲液分别是等渗缓冲液、低渗缓冲液以及添加了5 mM氯化钙的等渗缓冲液。通过计算弹性模量对小泡中心的硬度进行了量化。弹性模量在2 - 13×10⁵ Pa范围内。小泡中心在含钙缓冲液中最硬，在等渗缓冲液中最软。文中提出了关于硬中心的组成和功能的假设。