July 17, 2017 at 4.00 pm in AG-69
Modulation of emission signaling pathway through allosteric control on the conformational rigidity of coumarin-imidazole conjugate
The allosteric regulation in the biological system is controlled at the molecular level by recognition events that are triggered by subtle conformational changes of the proteins.1 Although it is very challenging to mimic such complex communication pathways, one can still be inspired by these systems and design prototype that can give into fundamentals of molecular recognition2 in physiological environments. There seems to be a significant lag in the area of chemically controlled conformational switches that modulate new fluorescence signaling pathway through allostery; bridging this gap may lead to novel molecular systems. The design of such molecular systems represents a promising avenue for finding and manipulating allosteric networks3 in the biology.
In this presentation, I will discuss about a prototype based on coumarin-imidazole conjugate which undergo conformational changes through distal intramolecular H-bonding interactions.4 The key factor behind this conformational switching is a cooperative effect that involves coumarin side arm, solvents, and leads to a conformational or dynamic changes in the distal coumarin sidearm through intramolecular H-bonds, affecting its emission output function. So we hypothesized that the combination of distal intramolecular H-bond interactions and allostery results in the observed effects on the fluorescence output signaling pathway. The concept of new emission signaling pathways caused by conformational switching between two states offers a new paradigm to introduce functional allostery in macromolecular backbones.
1. (a) Monod, J.; Changeux, J.; Jacob, F. J. Mol. Biol. 1963, 6, 306-329. (b) Changeux, J. P. Ann. Rev.
Biophys. 2012, 41, 103-133.
2. (a) Mechanisms of cooperativity and allosteric regulation in proteins; University Press: Cambridge,
UK, 1990. (b) Laskowski, R. A.; Luscombe, N. M.; Swindells, M. B.; Thornton, J. M.
Protein Sci. 1996, 5, 2438-2452. (c) Faulkner, A.; Leeuwen, T. V.; Feringa, B. L.; Wezenberg, S. J. J.
Am. Chem. Soc. 2016, 138, 13597-13603.
3. Dokholyan, N. V. Chem. Rev. 2016, 116, 6463-6487.
4. Bhattacharjee, I.; Ghosh, N.; Raina, A.; Dasgupta, J.; Ray, D.- Manuscript under communication