Reversible Michael Addition of an Engineered Cysteine Residue to a Light Activated Ligand, a New Design Strategy for a Synthetic Photoswitchable Fluorescent Protein

Abstract

Reversible photoswitchable fluorescent probes can transit between two different optical states when triggered by light. Because of the ability to switch, they become useful in live cell super-resolution microscopy (e.g. RESOLFT, psSIM, STORM, PALM), information storage, and optical control of protein activity. Currently, only a handful of fluorescent proteins and synthetic dyes exhibit reversible photoswitchability. Hence, there is a growing interest for new systems with enhanced functionality. We are currently focused on utilizing a synthetic ligand capable of reversible Michael addition of an active cysteine residue, within the binding pocket of human cellular retinoid binding protein (hCRBPII).