Duo-Chol: A Photoconvertible Live Cell Imaging Tool for Tracking Cholesterol.

Investigating cholesterol trafficking pathways continues to be of significant scientific interest owing to its homeostasis being associated with several debilitating cardiovascular and neurodegenerative diseases including atherosclerosis, Niemann-Pick's disease, Alzheimer's disease, and Parkinson's disease. To further our understanding of cholesterol trafficking, it is imperative to develop new fluorescent probes that possess improved photostability, low efflux, and high spatial and temporal resolution for live-cell imaging. In this study, we developed a photoconvertible fluorescent cholesterol analog, Duo-Chol, enabling the improved spatiotemporal fluorescence imaging of the dynamic localization of cholesterol in live cells. This tool provides a unique and powerful approach to interrogating cholesterol dynamics, addressing the limitations of existing methods, and expanding our ability to probe the biological role of sterols in living cells.

Versatile Synthetic Route to Cycloheximide and Analogues That Potently Inhibit Translation Elongation.

Cycloheximide (CHX) is an inhibitor of eukaryotic translation elongation that has played an essential role in the study of protein synthesis. Despite its ubiquity, few studies have been directed towards accessing synthetic CHX derivatives, even though such efforts may lead to protein synthesis inhibitors with improved or alternate properties. Described here is the total synthesis of CHX and analogues, and the establishment of structure-activity relationships (SAR) responsible for translation inhibition. The SAR studies aided the design of more potent compounds, one of which irreversibly blocks ribosomal elongation, preserves polysome profiles, and may be a broadly useful tool for investigating protein synthesis.

Photoconvertible diazaxanthilidene dyes for live cell imaging.

Within the past two decades, photoconvertible fluorescent proteins (PC-FPs) have emerged as a class of useful proteins for the visualization and tracking of individual cells, complex cellular mechanisms, protein-protein interactions, and other dynamic processes. Despite the utility of these proteins, they are inherently limited by a number of factors including large size and inflexibility of tag location within a protein of interest. The following chapter describes the discovery and use of a small molecule photoconvertible dye based on the novel diazaxanthilidene scaffold. The diazaxanthilidene dye presented in this chapter is shown to be an effective alternative to well-known PC-FPs for spatiotemporally controlled cell labeling experiments.