McClay D R, Wessel G M, Marchase R B
Proc Natl Acad Sci U S A. 1981 Aug;78(8):4975-9. doi: 10.1073/pnas.78.8.4975.
The hypothesis that intercellular adhesion can be subdivided into two separable phenomena--an initial recognition event and a subsequent stabilization--is supported by the use of a cell binding assay that provides a quantitative measure of intercellular binding strengths. Radioactive single cells are brought into contact with cell monolayers at 4 degrees C in sealed compartments. The compartments are inverted and a centrifugal force is then applied to dislodge the probe cells from the monolayers. By varying the speed of centrifugation, the force maintaining associations between embryonic chicken neural retina cells was determined to be on the order of 10(-5) dyne. Topographic specificities of single neural retina cells for retinal monolayers from various regions of the retina were detected with this assay and corresponded to those observed in more traditional assays at 37 degrees C. Also observed were two time- and temperature-dependent stabilization processes in which the force required for dislodgment increased. One of the stabilization processes was sensitive to dinitrophenol and was inactive at 4 degrees C; the second was still active in metabolically blocked cells. The metabolic-dependent process resulted in interactions at least 13 times as strong as the initial binding. The metabolic-independent process resulted in about a 2-fold increase in binding strength and had a temperature dependence similar to that of membrane diffusional phenomena.
细胞间黏附可细分为两种可分离的现象——初始识别事件和随后的稳定过程，这一假说得到了一种细胞结合测定法的支持，该方法可对细胞间结合强度进行定量测量。将放射性单细胞在4℃下于密封隔室中与细胞单层接触。将隔室倒置，然后施加离心力以将探针细胞从单层中移出。通过改变离心速度，确定维持胚胎鸡神经视网膜细胞间结合的力约为10^(-5)达因。用该测定法检测了单个神经视网膜细胞对来自视网膜不同区域的视网膜单层的拓扑特异性，其与在37℃下更传统的测定法中观察到的结果一致。还观察到两个时间和温度依赖性的稳定过程，其中移出所需的力增加。其中一个稳定过程对二硝基苯酚敏感，在4℃下无活性；第二个在代谢受阻的细胞中仍有活性。代谢依赖性过程导致的相互作用强度至少是初始结合的13倍。代谢非依赖性过程导致结合强度增加约2倍，其温度依赖性与膜扩散现象相似。
