Keller P M, Person S, Snipes W
J Cell Sci. 1977 Dec;28:167-77. doi: 10.1242/jcs.28.1.167.
Two probes were synthesized which consist of fluorescent molecules conjugated to saturated hydrocarbon chains, 18 carbons long, to ensure their localization into cellular membranes. There is an overlap between the emission spectrum of one probe (donor) and the absorption spectrum of the other probe (acceptor). By the use of appropriate wavelengths it is possible to specifically excite the donor probe and record the fluorescence of the acceptor probe. Two cell populations, each labelled with one of the probes, were infected with a virus that causes cell fusion, mixed in equal proportions, and the fluorescence of the acceptor probe measured as a function of time after infection. An increase in fluorescence was observed beginning at the time of onset of cell fusion indicating a mixing of the fluorescent membrane molecules. An investigation of the distance dependence indicated that the increase in fluorescence was mainly due to resonance energy transfer and not to photon emission and reabsorption. Resonance energy transfer requires that the 2 probes be close together and that there be an overlap of the emission spectrum of the donor probe and the absorption spectrum of the acceptor probe. The possible application of this assay to other types of membrane fusion is noted.
合成了两种探针，它们由与18个碳原子长的饱和烃链相连的荧光分子组成，以确保它们定位于细胞膜中。一种探针（供体）的发射光谱与另一种探针（受体）的吸收光谱存在重叠。通过使用适当的波长，可以特异性地激发供体探针并记录受体探针的荧光。将分别用其中一种探针标记的两个细胞群体用一种可导致细胞融合的病毒感染，以等比例混合，然后在感染后作为时间的函数测量受体探针的荧光。在细胞融合开始时观察到荧光增加，表明荧光膜分子发生了混合。对距离依赖性的研究表明，荧光增加主要是由于共振能量转移，而不是光子发射和再吸收。共振能量转移要求两种探针靠得很近，并且供体探针的发射光谱与受体探针的吸收光谱存在重叠。文中指出了该测定法在其他类型膜融合中的可能应用。
