The patent US 11,162,951 – Membrane-impermeant fluorogenic chromophores for non-permeant FAST fluorogens was just granted by the USPTO. The inventors, Arnaud Gautier, Ludovic Jullien, Chenge Li, and Franck Perez, indeed developed very special fluorogens for FAST and splitFAST. The EPO had already delivered a related patent one year ago.
non-permeant FAST fluorogens in human cells
Li et al. disclosed non-permeant fluorogens in Bioconjugate Chemistry 2018. In this paper they indeed introduced a new method to differentially label cell-surface and intracellular membrane proteins. Firstly, the protein of interest, here the human D2 dopamine receptor, is “genetically” labeled with the FAST tag. Secondly, mixing membrane-impermeant fluorogens and conventional permeant fluorogens, they were able to discriminate the proteins based on their location, inside the cell or at the surface. One key breakthrough in their workflow is the interrogation by flow cytometry, a basic feature of FAST. That is, without the need for imaging! As a result, it opens great prospects for high-throughput screening of small molecules able to correct genetic disorders of protein trafficking.
non-permeant FAST fluorogens in bacteria
More recently, a combined team of Institut Pasteur and ENS has adapted the method in Listeria. They indeed published FAST for visualizing the dynamics of bacterial proteins export in Scientific Reports 2020. Therefore, they used a combination of membrane-permeant (HBR-3,5DM) and non‐permeant (HBRAA-3E) fluorogens to reveal FAST tags. Moreover, one can specifically tag the external side of the bacterial envelop in both diderm and monoderm bacteria.
FAST patents belong to ENS and Institut Curie of PSL Research University, Sorbonne Université, and CNRS. Whereas The Twinkle Factory is the exclusive, worldwide, licensee. Besides non-permeant fluorogens, the fast expanding portfolio comprises of the princeps patent and the splitFAST patent. This comprehensive IP is the outcome of FLUOSWITCH, a multi-year project supported by ERC. Gautier is indeed a laureate of a multi-million ERC Consolidator grant.
The Twinkle Factory offers a catalog of commercial fluorogens for FAST and splitFAST. Of those, tfAmber-NP, a.k.a. HBRAA-3E. Furthermore, The Twinkle Factory is continuously expanding its fluorogen range. Keep posted!