Furukawa Kazuaki, Nakashima Hiroshi, Kashimura Yoshiaki, Torimitsu Keiichi
NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato Wakamiya, Atsugi, Kanagawa, Japan 243-0198. furukawa@ nttbrl.jp
Langmuir. 2008 Feb 5;24(3):921-6. doi: 10.1021/la702695f. Epub 2007 Dec 22.
We report on the determination of fluorescence resonance energy transfer (FRET) efficiency, which is dependent on the donor-to-acceptor (D-A) ratio, by using a new type of microchannel device called a "lipid-flow chip". The chip comprises two supported lipid bilayers (SLBs) that self-spread from either side of 10 microm wide straight lines and carry molecules embedded in them. We first show that the diffusion process that occurs when the two SLBs collide with each other in the channel and form a unified SLB can be expressed by a one-dimensional diffusion equation. Next we describe a method for determining the FRET efficiency between NBD (donor) and Texas Red (acceptor) from observations using the lipid-flow chip by employing a one-dimensional diffusion model. The advantages of our method are that all the D-A ratios are achieved in one chip, and a large number of data are recorded in one chip. The FRET efficiency varies depending on the D-A ratio under conditions whereby the concentration of the sum of the donors and acceptors is constant. The Förster radius is also estimated from our results using a known model describing two-dimensional FRET systems, which yields a radius consistent with the previously reported value for NBD and Texas Red.
我们报告了通过使用一种名为“脂质流芯片”的新型微通道装置来测定荧光共振能量转移（FRET）效率的方法，该效率取决于供体与受体（D - A）的比例。该芯片由两个支撑脂质双层（SLB）组成，它们从10微米宽的直线两侧自扩展，并携带嵌入其中的分子。我们首先表明，当两个SLB在通道中相互碰撞并形成一个统一的SLB时发生的扩散过程可以用一维扩散方程来表示。接下来，我们描述了一种通过使用脂质流芯片进行观察，采用一维扩散模型来确定NBD（供体）和Texas Red（受体）之间FRET效率的方法。我们方法的优点是所有的D - A比例都能在一个芯片中实现，并且在一个芯片中可以记录大量数据。在供体和受体总和浓度恒定的条件下，FRET效率随D - A比例而变化。还使用描述二维FRET系统的已知模型从我们的结果中估计了Förster半径，得到的半径与先前报道的NBD和Texas Red的值一致。
