Chemistry Departmental Seminar – Prof. H. Peter Lu, Bowling Green State University
2023-04-10 16:10 - 17:00 (Pacific Time (US & Canada)) | Fulmer Hall
Speaker: Prof. H. Peter Lu, Bowling Green State University, Department of Chemistry, Center for Photochemical Sciences

Title: Single-Molecule Spectroscopy and Force Manipulation Studies of Protein Dynamics and Signaling

Abstract: Single-molecule conformational manipulation provides unique methods for studying the relationship between function and structure of biomolecules, and for exploring novel properties of biomolecules under complex local environments. Enzymatic reactions are traditionally studied at the ensemble level, despite significant static and dynamic inhomogeneities. We have developed and applied AFM/Magnetic Tweezers force manipulation combined single-molecule spectroscopy to study the mechanisms and dynamics of enzymatic reactions involved with kinase and lysozyme proteins. Enzymatic reaction turnovers and the associated structure changes of individual protein molecules under pico-Newton force manipulations were observed simultaneously in real-time by single-molecule FRET detections. By a repetitive pulling-releasing manipulation of a Cy3-Cy5 dye labeled kinase molecules under the conditions with and without enzymatic substrates, we observed and analyzed the enzymatic conformational dynamics. We demonstrated that the enzyme conformational flexibility can be regulated by enzymesubstrate interaction, an experimental evidence of protein-substrate folding-binding interaction mechanism. Our new approach is applicable to a wide range of single-molecule AFM-FRET measurements for protein conformational changes under enzymatic reactions, including controls of enzymatic reactivity by mechanical-force manipulating protein conformations.

Reference:

1. S. Roy Chowdhury, H. Peter Lu, "Unraveling the Mechanism of Tau Protein Aggregation in Presence of Zinc Ion: The Earliest Step of Tau Aggregation," Chem. Phys. Impact, 4, 100060 (2022).

2. Meiling Wu, H. Peter Lu, "Ultra-Sensitive Lock-in Amplifier Coupled Oscillatory Magnetic Tweezers for PicoNewton Force Manipulation Applications," Feature Article, J. Applied Physics, 130, 014504 (2021).

3. S. Roy Chowdhury, Sunidhi Jaiswal, H. Peter Lu, "Compressive-force induced activation of apocalmodulin in protein signaling," Physical Chemistry Chemical Physics, 22, 1092-1096 (2020).

4. S. Roy Chowdhury, H. Peter Lu, "Spontaneous Rupture and Entanglement of Human Neuronal Tau Protein Induced by Piconewton Compressive Force," ACS Chemical Neuroscience, 10, 4061-4067 (2019).

5. Meiling Wu, H. Peter Lu, "Oscillating picoNewton Force Manipulation on Single-Molecule Enzymatic Conformational and Reaction Dynamics" J. Phys. Chem. B, 122, 12312-12321 (2018).

6. Zijiang Wang, H. Peter Lu, "Single-Molecule Spectroscopy Study of Crowding-Induced Protein Spontaneous Denature and Crowding-Perturbed Unfolding-Folding Conformational Fluctuation Dynamics," J. Phys. Chem. B, 122, 6724-6732 (2018).

7. S. Roy Chowdhury, H. Peter Lu, "Probing Activated and Non-Activated Single Calmodulin Molecule under a picoNewton Compressive Force," Biochemistry, 57, 1945-1948 (2018).

8. S. Roy Chowdhury, Jin Cao, Yufan He, and H. Peter Lu, "Revealing Abrupt and Spontaneous Ruptures of Protein Native Structure under Pico-Newton Compressive Stress Force Manipulation," ACS Nano, 12, 2448-2454 (2018).

9. Qing Guo, Yufan He, H. Peter Lu, "Repetitive Force Pulling-Releasing Manipulation of Enzymatic Conformational Fluctuations and Enzyme-Substrate Interactions by Single-Molecule FRET-Magnetic Tweezers Microscopy," Phys. Chem. Chem. Phys., 16, 13052 -13058 (2014).

10. H. Peter Lu, “Sizing up single-molecule enzymatic conformational dynamics,” Chem. Soc. Rev., Invited Review Article, 43, 1118-1143 (2014).
