Speaker
Abhishek Singharoy, Ph.D.
Speaker's Institution
Arizona State University
Date
4/19/21
Time
4:00 PM
Location
Virtual Seminar
Additional Information

About the Seminar:

We report a 100-million atom-scale model of an entire cell organelle, a photosynthetic chromatophore vesicle from a purple bacterium, that reveals the cascade of energy conversion steps culminating in the generation of ATP from sunlight. Molecular dynamics simulations of this vesicle elucidate how the integral membrane complexes influence local curvature to tune photoexcitation of pigments. Brownian dynamics of small molecules within the chromatophore probe the mechanisms of directional charge transport under various pH and salinity conditions. Reproducing phenotypic properties from atomistic details, a kinetic model evinces that low-light adaptations of the bacterium emerge as a spontaneous outcome of optimizing the balance between the chromatophore’s structural integrity and robust energy conversion. Parallels are drawn with the more universal mitochondrial bioenergetic machinery, from whence molecular-scale insights into the mechanism of cellular aging are inferred. Together, our integrative method and spectroscopic experiments pave the way to first-principles modeling of whole living cells.

Sener, M.; Strumpher, J.; Singharoy, A.; Hunter, N.; Schulten, K. “Overall energy conversion efficiency of a photosynthetic vesicle” eLife 2016, 5, e09541.

Singharoy, A.*; Maffeo, C; Delgado-Magnero, K.H.; Swainsbury, D. J. K; Sener, M; Kleinekathöfer, U.; Isralewitz, B.; Teo, I.; Chandler, D.; Vant, J. W.; Stone, J. E.; Phillips, J.; Pogorelov, T.V.; Mallus, M. I.; Chipot, C.; Luthey-Schulten, Z.; Tieleman, P.; Hunter, C. N.; Tajkhorshid, E.; Aksimentiev, A.; Schulten, K.“Atoms to Phenotypes: Molecular Design Principles of Cellular Energy Metabolism” Cell 2019, 179, 1098.

 Gupta, C.; Khaniya, U.; Chan, C.K.; Dehez, F.; Shekhar, M.; Gunner, M. R.; Sazanov, L.; Chipot, C.; Singharoy, A.* “Charge Transfer and Chemo-Mechanical Coupling in Respiratory Complex I.” J. Am. Chem. Soc.  2020, 142, 9220.

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Meeting ID: 962 0472 0578

Ralf Sudlowe