Nanavati C, Fernandez J M
Department of Physiology and Biophysics, Mayo Clinic, Rochester, MN 55905.
Science. 1993 Feb 12;259(5097):963-5. doi: 10.1126/science.8438154.
The secretory granule matrix is a miniature biopolymer that consists of a charged polymer network that traps peptides and transmitters when it condenses and releases them on exocytotic decondensation. Models of exocytotic fusion have treated this matrix as a short circuit and have neglected its electrical contributions. This matrix responded to negative voltages by swelling, which was accompanied by a large increase in conductance, and to positive voltages by condensing. Thus, the matrix resembled a diode. The swollen matrix exerted large pressures on the order of 12 bar. The responses took place within milliseconds of the application of the electric field. These findings suggest that matrix decondensation, and therefore product release, is controlled by potential gradients.
分泌颗粒基质是一种微型生物聚合物，它由带电荷的聚合物网络组成，该网络在凝聚时捕获肽和递质，并在胞吐去凝聚时释放它们。胞吐融合模型将这种基质视为短路，而忽略了其电学贡献。这种基质在负电压作用下会膨胀，同时伴随着电导率的大幅增加，在正电压作用下会凝聚。因此，该基质类似于一个二极管。膨胀的基质会产生约12巴的巨大压力。这些响应在施加电场后的几毫秒内就会发生。这些发现表明，基质的去凝聚以及产物的释放是由电位梯度控制的。
