SYNTHETIC FLAVO HEMO PROTEINS

我们已经成功地设计和建造了从头合成 具有光激活蛋白内电子的黄血黄蛋白 调职。我们使用我们传统的四螺旋捆绑框架来 将溴黄素共价连接到内部的半胱氨酸上， 束的几何中心。在相同的捆绑包中，内饰 组氨酸A与添加的亚铁血红素形成双-希氏配位 朝向束状物内部的任一端。我们已经证明了 蓝色黄素吸收带的照明产生了一个激发 一种能从一种方便的电子中提取一对电子的状态 含氮碱基供体(如EDTA)可产生还原的黄素 自发地将电子转移到附近连接的双组氨酸 亚铁血红素。我们目前正在使用RLBL纳秒染料激光器来捕获 激发黄素态的光谱，随后被约化 Flavin，并提供时间进程的初步描述 蛋白质内电子从还原的Fla vin转移到血红素。 很有可能会出现时间的异质性 与黄素/血红素距离的分布相对应的课程 氧化还原肽的不同构象。我们期待着一场竞争 黄素激发态与血红素之间的能量转移猝灭 黄素和亚铁血红素之间的电子转移。我们会的 将合成的黄血球蛋白加EDTA溶液流经 用于比较有和没有蓝色泵浦的区域的光谱的单元格 脉搏。我们可以很容易地通过暴露溶液来再生我们的材料 到分子氧，它能迅速氧化血红素成分。在……里面 此外，我们正在研究使用色氨酸的可行性 电子转移方案中的一部分。色氨酸残留物会 抽运波长为266 nm的四倍频激光。

We have succeeded in designing and constructing de novo synthetic flavo-hemo-proteins that exhibit light activated intraprotein electron transfer. We use our traditional four-helix bundle framework to covalently link a bromoflavin to an interior cysteine very close to the geometric center of the bundle. In the same bundle, interior histidines a positioned to form a bis-His ligation of added heme toward either end of the bundle interior. We have shown that illumination of the blue flavin absorption band creates an excited state which can extract a pair of electrons from a convenient nitrogenous base donor (such as EDTA) to create a reduced flavin that spontaneously transfers electrons to nearby bis-histidine ligated heme. We are presently using the RLBL nanosecond dye laser to capture the spectra of the excited flavin state, the subsequent reduced flavin, and to provide an initial description of the time course of intraprotein electron transfer from the reduced fla vin to the heme. It is quite possible that there will be a heterogeneity of the time course corresponding to a distribution of flavin/heme distances for different conformations of the redox peptide. We expect a competition between flavin excited state quenching by energy transfer to the heme and electron transfer between the flavin and the heme. We will be flowing the synthetic flavo-hemo-protein plus EDTA solution through a cell to compare the spectra of regions with and without the blue pump pulse. We can easily regenerate our material by exposing the solution to molecular oxygen, which rapidly oxidizes the heme component. In addition, we are investigating the viability of using a tryptophan moiety in this electron transfer scheme. The tryptophan residue will be pumped with the fourth harmonic of the Nd:YAG (266 nm).