Live‐Cell Imaging with Water‐Soluble Aminophenoxazinone Dyes Synthesised through Laccase Biocatalysis

Aminophenoxazinone dyes with variable water solubilities were assayed for the first time in a live‐cell imaging application. Among a library of ten sulfonylated chromophores, one compound gave excellent results as an endocytic marker, showing a precise subcellular distribution. The compound was compared to four commercial vital tracers, including Lucifer Yellow. The first laccase‐mediated regioselective synthesis of a diphosphorylated 2‐aminophenoxazinone dye was also described. This compound, water‐soluble at 10^?2 M , displayed modest fluorescence properties and the ability to complex Mg²⁺ and Ca²⁺ cations, therefore giving fluorescence quenching.     

Selective Imaging of Lipids in Adipocytes by Using an Imidazolyl Derivative of Perylene Bisimide

A small molecule, perylene bisimide imidazolyl derivative (PBI‐ID), has been identified and developed as a specific marker for labelling multifunctional fat bodies in various organisms, including Drosophila and mammalian adipocytes. Interestingly, PBI‐ID neither labels the plasma membranes nor cell nuclei by trapping into it. A remarkable feature of unbound PBI‐ID is diminished fluorescence, which reduces the background emission noise, while contrasting the bound state effectively.     

Alkoxy Tetrazine Substitution at a Boron Center: A Strategy for Synthesizing Highly Fluorogenic Hydrophilic Probes

Strongly fluorogenic boron dipyrromethene (BODIPY)–tetrazine probes have been obtained by introducing an alkoxy tetrazine fragment at the boron center. The fluorescence signal from these probes strongly increases by up to 225‐fold after reaction with bioorthogonal coupling partners, and the hydrophilicity of probes is improved, such that they are suitable for live‐cell imaging.     

基于生命体系中氨基键合标记的荧光探针研究进展

氨基是生物分子化学结构中常见的基团。通常可利用荧光探针的静电吸引、疏水作用和化学键合的方式对其进行荧光标记。本文综述了基于化学键合作用的荧光探针及其常见的键合类型和染料母体结构。有48篇参考文献。     

生物标示用3H-吲哚菁染料

随着生物技术和荧光标示技术的飞速发展,3H-吲哚菁染料已成为在DNA、蛋白质及核酸等分析检测中使用的主要荧光探针。其中代表性化合物Cy3.、Cy5.作为新一代商品化荧光标示剂在生物芯片、分子信标等方面得到了重要应用。本文综述了该类碳菁染料在生物领域中取得的重大应用进展、并探讨了其结构与性能之间的关系。     

Genetic targeting of individual cells with a voltage-sensitive dye through enzymatic activation of membrane binding

Optical recording of the electrical activity of individual neurons in culture or in a tissue requires cell-selective staining with a fluorescent voltage-sensitive dye. In a proof-of-principle experiment, we implement a novel approach to genetically targeted staining. The method relies on a water-soluble precursor dye and an overexpressed cell-surface enzyme that transforms the precursor into a hydrophobic dye that binds to the targeted cell. We fused an alkaline phosphatase to a specifically designed general-purpose membrane anchor, and the fusion protein was expressed on the surface of HEK293 cells, as was corroborated by immuno- and histochemical staining. We next synthesised an amphiphilic hemicyanine dye containing two enzymatically cleavable phosphate groups at its hydrocarbon tails. When the phosphate groups were removed, the binding to membranes was enhanced by a factor of a thousand, as shown by titration with lipid vesicles. We observed selective staining of enzymatically active cells by fluorescence microscopy in a mixed population of phosphatase-transfected and untransfected HEK293 cells. The critical parameters of enzyme-induced cell-selective staining were elucidated by a simple kinetic model to guide further developments of the method.     

Progress and Prospects of Pyrrole‐Imidazole Polyamide–Fluorophore Conjugates as Sequence‐Selective DNA Probes

Recently, the versatility of N‐methylpyrrole (Py)‐N‐methylimidazole (Im) polyamide conjugates, which have been developed from the DNA‐binding antibiotics distamycin A and netropsin, has been shown. These synthetic small molecules can permeate cells to bind with duplex DNA in a sequence‐specific manner, and hence can influence gene expression in vivo. Accordingly, several reports demonstrating the sequence specificity and biological activity of Py‐Im polyamides have accumulated. However, the benefits of Py‐Im polyamides, in particular those conjugated with fluorophores, has been overlooked. Moreover, clear directions for the employment of these attractive artificial small molecules have not yet been shown. Here, we present a detailed overview of the current and prospective applications of Py‐Im polyamide–fluorophore conjugates, including sequence‐specific recognition with fluorescence emission properties, and their potential roles in biological imaging.     

菁染料在荧光探针及光动力疗法中的应用

菁染料的研究及应用已有100多年的历史，近年来，它们在生物方面的应用研究已取得一定的成果．本就近几年菁染料及其衍生物在生物医疗方面的研究及进展情况加以综述，特别阐述了这类染料用作荧光探针在生物大分子标识以及作为光敏剂在光动力疗法(PDT)中用于恶性肿瘤的诊断与治疗这两方面的研究进展．     

Versatile Interacting Peptide (VIP) Tags for Labeling Proteins with Bright Chemical Reporters

Fluorescence microscopy is an essential tool for the biosciences, enabling the direct observation of proteins in their cellular environment. New methods that facilitate attachment of photostable synthetic fluorophores with genetic specificity are needed to advance the frontiers of biological imaging. Here, we describe a new set of small, selective, genetically encoded tags for proteins based on a heterodimeric coiled‐coil interaction between two peptides: CoilY and CoilZ. Proteins expressed as a fusion to CoilZ were selectively labeled with the complementary CoilY fluorescent probe peptide. Fluorophore‐labeled target proteins were readily detected in cell lysates with high specificity and sensitivity. We found that these versatile interacting peptide (VIP) tags allowed rapid and specific delivery of bright organic dyes or quantum dots to proteins displayed on living cells. Additionally, we validated that either CoilY or CoilZ could serve as the VIP tag, which enabled us to observe two distinct cell‐surface protein targets with this one heterodimeric pair.     

荧光免疫分析用染料及其研究进展

介绍了染料在荧光免疫分析中的应用原理及所用的荧光染料的研究进展。并且提出了近红外吸收染料在这一领域的应用前景。     

A Fluorescent Probe for Imaging Sirtuin Activity in Living Cells,Based on One‐Step Cleavage of the Dabcyl Quencher

Sirtuins (SIRTs) are a family of NAD⁺‐dependent histone deacetylases. In mammals, dysfunction of SIRTs is associated with age‐related metabolic diseases and cancers, so SIRT modulators are considered attractive therapeutic targets. However, current screening methodologies are problematic, and no tools for imaging endogenous SIRT activity in living cells have been available until now. In this work we present a series of simple and highly sensitive new SIRT activity probes. Fluorescence of these probes is activated by SIRT‐mediated hydrolytic release of a 4‐(4‐dimethylaminophenylazo)benzoyl (Dabcyl)‐based FRET quencher moiety from the ?‐amino group of lysine in a nonapeptide derived from histone H3K9 and bearing a C‐terminal fluorophore. The probe SFP3 detected activities of SIRT1, ‐2, ‐3, and ‐6, which exhibit deacylase activities towards long‐chain fatty acyl groups. We then truncated the molecular structure of SFP3 in order to improve both its stability to peptidases and its membrane permeability, and developed probe KST‐F, which showed specificity for SIRT1 over SIRT2 and SIRT3. We show that KST‐F can visualize endogenous SIRT1 activity in living cells.     

Controllable preparation of a soluble trapezoidal polyacetylene with broadband absorption by a one‐step strategy

A new trapezoidal functional polyacetylene with broadband absorption from the visible to the near infrared and excellent thermal stability was effectively prepared by molecular design and a controllable strategy. It is completely soluble in common organic solvents because the 6‐ethynyl‐2‐methylquinoline copolymerized with phenylacetylene. The absorption spectrum can be effectively adjusted by controlling the ratio of semi‐squaraine and squaraine in the process of preparation. Interestingly, it was found that the improvement of thermal stability of the target product may originate from the synergy of the shielding effect of the quinoline ring to the main chain and the strong interactions between squaraine groups. The formation mechanism of the broadband absorbance properties was studied through an online spectrum tracking method. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44096.