Multicomponent Bioluminescence Imaging with Naphthylamino Luciferins

Bioluminescent tools have been used for decades to image processes in complex tissues and preclinical models. However, few distinct probes are available to probe multicellular interactions. We and others are addressing this limitation by engineering new luciferases that can selectively process synthetic luciferin analogues. In this work, we explored naphthylamino luciferins as orthogonal bioluminescent probes. Three analogues were prepared using an optimized synthetic route. The luciferins were found to be robust emitters with native luciferase in vitro and in cellulo. We further screened the analogues against libraries of luciferase mutants to identify unique enzyme-substrate pairs. The new probes can be used in conjunction with existing bioluminescent tools for multi-component imaging.     

基于GSO算法的最小连通支配集问题求解

经典的最小连通支配集(MCDS)计算是NP难问题。为此,提出一种利用萤火虫优化算法求解该难题的新方法。把网络中的每个节点当作一个萤火虫个体,以节点度为基础构成荧光素,通过概率选择和荧光素调节机制,使个体被吸引向邻接的高亮度个体,从而由所选出的个体组成网络的支配集。经连接和修剪处理后,得到MCDS的近似解。在无线传感器网络模型的单位圆盘图上进行模拟实验,结果表明,该算法得到的连通支配集规模较小,更接近集中式算法的结果。     

一种最大最小萤光素值人工萤火虫算法*

针对基本人工萤火虫算法存在着易陷入局部极小和进化后期收敛速度慢等缺点,提出了一种最大最小萤光素值人工萤火虫算法。该算法在萤光素值更新过程中,对荧光素的变化范围加以限定,给出最大最小萤光素值范围,从而避免算法陷入局部最优。通过八个典型函数测试,实验结果表明所提出的算法具有较强的全局搜索能力,且能有效地避免早熟现象,从而提高了人工萤火虫算法整体性能。     

萤火虫算法的研究进展

萤火虫算法是通过模拟萤火虫在觅食和求偶等生活习性中产生的因光而吸引移动的行为来解决最优问题的一种新型群体智能优化算法。萤火虫算法因具有较强的鲁棒性和随机搜索性,已广泛地应用于函数寻优、聚类问题、机器人协作等多个方面。本文阐述了萤火虫算法的基本原理,给出了现有的各种改进算法,并展望了萤火虫算法的发展方向。     

基于生物发光技术的细菌总数快速检测仪

针对细菌总数现场检测需求，设计了一种基于ATP（三磷酸腺苷）生物发光技术的细菌总数现场快速检测仪。传统方法检测细菌总数需要2-3天，而利用ATP生物发光技术可在30min之内完成检测，大大提高了检测速度。本检测仪选取H5773-02型光电倍增管作为光电转换器件以检测微弱光信号，该光电倍增管的工作波长范围为330-850nm，峰值检测波长为500nm，ATP生物发光波长为550nm，两者基本一致，使检测仪具有较高的测量灵敏度。采用流动注射技术，在加入被测样品后分别向样品池中加入检测试剂。由于样品池被密闭在检测腔中，因此可有效减小外界光对测量结果的影响，同时也减小了人为加样对检测重复性的影响，提高检测重复性。利用本检测仪对浓度在10^-6-10^-14mol/L内的ATP样品进行了检测。实验表明，测量结果具有明显梯度，测试时间小于400s时，与标准样品浓度间的线性相关系数达到0.986。设计的细菌总数快速检测仪具有检测速度快、重复性高、操作简单等优点，可适用于食品卫生与安全、环境检测等领域。     

Brominated Luciferins Are Versatile Bioluminescent Probes

We report a set of brominated luciferins for bioluminescence imaging. These regioisomeric scaffolds were accessed by using a common synthetic route. All analogues produced light with firefly luciferase, although varying levels of emission were observed. Differences in photon output were analyzed by computation and photophysical measurements. The brightest brominated luciferin was further evaluated in cell and animal models. At low doses, the analogue outperformed the native substrate in cells. The remaining luciferins, although weak emitters with firefly luciferase, were inherently capable of light production and thus potential substrates for orthogonal mutant enzymes.     

求解TSP的人工萤火虫群优化算法

人工萤火虫群优化算法是一种新型群体智能算法,已在复杂多目标函数优化方面得到了成功的应用,并表现出良好的性能.为了充分发挥人工萤火虫群优化算法的优点,将该算法与C2Opt算子相结合,设计了求解旅行商问题(TSP)的一个新的高效人工萤火虫群优化算法,并用其求解TSP这一经典的NP难问题.通过对比TSP实例测试,所得结果表明,所提出算法在种群规模较小、迭代次数较少的情况下可以收敛到已知的最优解.     

Pyridone Luciferins and Mutant Luciferases for Bioluminescence Imaging

New applications for bioluminescence imaging require an expanded set of luciferase enzymes and luciferin substrates. Here, we report two novel luciferins for use in vitro and in cells. These molecules comprise regioisomeric pyridone cores that can be accessed from a common synthetic route. The analogues exhibited unique emission spectra with firefly luciferase, although photon intensities remained weak. Enhanced light outputs were achieved by using mutant luciferase enzymes. One of the luciferin–luciferase pairs produced light on par with native probes in live cells. The pyridone analogues and complementary luciferases add to a growing set of designer probes for bioluminescence imaging.     

Identification of the luciferin-luciferase system and quantification of coelenterazine by mass spectrometry in the deep-sea luminous ostracod Conchoecia pseudodiscophora

The bioluminescence system of the ostracod Conchoecia pseudodiscophora, which is abundant in the Sea of Japan, has been characterized. The luminescence (lambda(max)=463 nm) is produced by a luciferin-luciferase reaction, and the luciferin has been identified as coelenterazine. Coelenterazine, coelenteramide, and coelenteramine from C. pseudodiscophora were quantified by LC-ESI-MS/MS analysis. The coelenterazine content was estimated to be approximately 230 pg per animal by using a calibration curve of synthetic coelenterazine. The reaction between homogenates of C. pseudodiscophora and synthetic coelenterazine showed luminescence activity; this suggests that a coelenterazine-type luciferase is present.