Japanese Source

Abstract

With recent progress in genetic engineering technologies, new fusion protein probes carrying genetically engineered photoproteins have been utilized for illuminating the bioactivity of a target substance. Recently, technologies for molecular imaging of a target substance in cell lines have been demonstrated in broad applications, such as the determination of bioactive small molecules, protein-protein interactions, and conformational changes of a target protein. In the present contribution, we introduce recent achievements in molecular imaging studies based on bioluminescence in our laboratory. This includes the molecular imaging of nuclear trafficking of transcription factors and nongenomic protein-protein interactions in the cytosol. In addition, we describe an integrated molecule-format bioluminescent probe, where all of the components for ligand sensing and light emission are integrated in a single molecule format. This probe was redesigned as a multicolor imaging measure for tracing multiple signal transduction pathways in response to exogenous stimulations. We also demonstrate new breakthroughs to improve ligand sensitivity through circular permutation and genetic manipulation of a small bioluminescent enzyme. We intend with this contribution that researchers in the field of analytical sciences will be able to recognize the joy of molecular imaging studies. © 2009 The Japan Society for Analytical Chemistry.