Laizhong Chen

Bioluminescent Probe for Hydrogen Peroxide Imaging in Vitro and in Vivo

Reactive oxygen species (ROS) often have significant roles in mediating redox modifications and other essential physiological processes, such as biological process regulation and signal transduction. Considering that H2O2 is a substantial member of ROS, detection and quantitation of H2O2 undertakes important but urgent responsibility. In this report, a bioluminescent probe for detecting H2O2 was well designed, synthesized, and evaluated. This probe was designed into three parts: a H2O2-sensitive aryl boronic acid, a bioluminescent aminoluciferin moiety, and a self-immolative linker. After extensive evaluation, this probe can selectively and sensitively react with H2O2 to release aminoluciferin. It should be pointed out that this probe is a potential bioluminescent sensor for H2O2 since it can provide a promising toolkit for real-time detection of the H2O2 level in vitro, in cellulo, and in vivo.

Discovery of Bioluminogenic Probes for Aminopeptidase N Imaging

To find an approach that can image the hydrolysis activity of aminopeptidase N (APN) both in vitro and in vivo, three bioluminescent probes have been well designed and synthesized herein. All of them can be recognized and hydrolyzed by APN to produce bioluminescence emission in the presence of firefly luciferase. To the best of our knowledge, they are the first bioluminescent probes for imaging APN in deep tissues and living animals.

A novel pH “off–on” fluorescent probe for lysosome imaging

In the present paper, a new pH sensitive fluorescent probe based on a 4-acylated naphthalimide fluorophore was well designed and synthesized. It has a high specificity for lysosomes over other cell organelles. The intrinsic high signal to noise ratio in cell imaging, broad Stokes shift and practical fluorescence quantum yield of this probe will ensure its prominent position in the intracellular lysosome targeting and imaging toolbox.

Strategies in the design of small-molecule fluorescent probes for peptidases.

Peptidases, which can cleave specific peptide bonds in innumerable categories of substrates, usually present pivotal positions in protein activation, cell signaling and regulation as well as in the origination of amino acids for protein generation or application in other metabolic pathways. They are also involved in many pathological conditions, such as cancer, atherosclerosis, arthritis, and neurodegenerative disorders. This review article aims to conduct a wide‐ranging survey on the development of small‐molecule fluorescent probes for peptidases, as well as to realize the state of the art in the tailor‐made probes for diverse types of peptidases.

Discovery of Quinazoline-Based Fluorescent Probes to α1-Adrenergic Receptors.

α1-Adrenergic receptors (α1-ARs), as the essential members of G protein-coupled receptors (GPCRs), can mediate numerous physiological responses in the sympathetic nervous system. In the current research, a series of quinazoline-based small-molecule fluorescent probes to α1-ARs (1a-1e), including two parts, a pharmacophore for α1-AR recognition and a fluorophore for visualization, were well designed and synthesized. The biological evaluation results displayed that these probes held reasonable fluorescent properties, high affinity, accepted cell toxicity, and excellent subcellular localization imaging potential for α1-ARs.

The first ratiometric fluorescent probe for aminopeptidase N

The current work describes the design and synthesis of the first ratiometric fluorescent probe, Ala-PABA-7HC, for the detection of aminopeptidase N (APN) at both the enzymatic and the cellular level. Upon addition of APN to the solution of Ala-PABA-7HC in PBS or culture medium, the maximum emission peak experienced a red shift from 390 nm to 450 nm, and the ratio of fluorescence intensity (I450/I390) (λex = 330 nm) significantly increased from 0.26 to 3.05 (R = 11.7-fold) in 15 min.

Bioluminogenic Imaging of AminopeptidaseN In Vitro and In Vivo

Bioluminescence is a process that converts biochemical energy to visible light. Bioluminescence-based imaging technology has been widely applicable in the imaging of process envisioned in life sciences. As one of the most popular bioluminescence system, the firefly luciferin-luciferase system is exceptionally suitable for deep tissue imaging in living animals owing to its long wavelength emission light. Herein, we report the experimental detail of bioluminogenic imaging of aminopeptidase N activity both in vitro and in vivo.