Dynamics Imaging of Biomolecular Assemblies

 

Single cells are the building blocks for all biological systems; yet they are inherently complex with intricate networks of dynamic biomolecular assemblies made up of proteins, coenzymes, ligands, DNA, RNA and lipids. In addition, these molecular assemblies are dynamically changing their sizes, conformations and intermolecular interactions in response to specific chemical, environmental or biological cues. In Heikal laboratory, we are using fluorescence microscopy (confocal, two-photon, TIRF, and wide-field) and spectroscopy (time-resolved fluorescence, time-resolved anisotropy, FLIM, and FCS) to investigate molecular and cellular biophysics. These noninvasive and quantitative approaches complement traditional biochemical techniques on purified biomolecules from cell lysates.

Our interdisciplinary research interests are focused on understanding the molecular underpinning of cellular processes such as energy metabolism in living cells, mitochondrial dysfunction, biomimetic membranes, and immunoglobulin E receptor signaling. We are also interested in studying protein & molecular dynamics, protein-protein interactions, macromolecular crowding, and spectroscopy. In addition, we are developing fluorescence-based micro-spectroscopic tools, image processing algorithm and modeling.

Students in Heikal laboratory (both undergraduates and graduates) are trained on a number of analytical, biophysical, and biochemical methods that include cell culture, model membrane assemblies, molecular dynamics, optical microscopy and ultrafast laser spectroscopy. Different aspects of scientific research (e.g., experimental design, data and image analysis, critical thinking, scientific writing, communication and teamwork skills) are also emphasized. The students in Heikal laboratory also gain an appreciation of interdisciplinary research at the interface of traditional disciplines of chemistry, biochemistry, biology, physics, and mathematics.

 

News

 

 

 

 

Jacob Schwarz, Hannah Leopold, Ryan Leighton, Robert C. Miller, Cody P. Aplin, Arnold J. Boersma, Ahmed A. Heikal, and Erin D. Sheets. “Macromolecula Crowding Effects on Energy Transfer Efficiency and Donor-Acceptor Distance of Hetero-FRET Sensors using Time-Resolved Fluorescence.” Methods and Applications in Fluorescence, 7(2): 025002 (2019). DOI: 10.1088/2050-6120/ab0242.

 

Hannah Leopold, Ryan Leighton, Jacob Schwarz, Arnold J. Boersma, Erin D. Sheets, and Ahmed A Heikal. "Crowding Effects on Energy Transfer Efficiencies of hetero-FRET Probes as Measured using Time-Resolved Fluorescence Anisotropy". J. Phys. Chem. (B), 2019, 123, 379 - 393. DOI: 10.1021/acs.jpcb.8b09829.

 

Anh Cong, Rafaela M. L. Pimenta, Hong Bok Lee, Venkatram Mereddy, Jon Holy, Ahmed A. Heikal. "Two-Photon Fluorescence Lifetime Imaging of Intrinsic NAD(P)H in Three-Dimensional Tumor Models". Cytometry (Part A), 95A, 80-92, 2019. DOI: 10.1002-cyto.a.23632.

 

Hong Bok Lee, Anh Cong, Hannah Leopold, Megan Currie, Arnold J. Boersma, Erin D. Sheets,  and Ahmed A. Heikal. "Rotational and Translational Diffusion of Size-Dependent Fluorescent Probes in Homogeneous and Heterogeneous Environments". Phys. Chem. Chem. Phys., 2018, 20, 24045 – 24057. DOI: 10.1039/c8cp03873b.

 

Congratulation to Rowna Simonet for her Outstanding Poster Presentation at the Summer Undergraduate Research Program (SURP) Symposium (August 03, 2018).

 

Ahmed Heikal was an invited speaker at the upcoming SPIE 2018 (Session: Optical Engineering and Applications), which will be held in San Diego, CA (August 19-23, 2018).

 

Congratulations to Hong Bok Lee for successfully defending his M.S. Thesis (May 27, 2018). Hong Bok will attend the Graduate Ph.D. Chemistry Program at the University of Iowa.

 

Congratulation to Rowna Simonet for her POLYED Award for Achievement in Organic Chemistry (Spring-2018).


Congratulations to Ryan Leighton, the reciepient of Honors from both Chemistry & Biochemistry and Physics, the Physics and Astronomy Research Award, the Lake Superior Section of the ACS Award, and FB Moore Award (Spring-2018).

 

Ahmed Heikal was nominated by students for the "Outstanding Academic Advisor Award" for the academic year of 2017-18.

 

Congratulations to Shane Wilson for successfully defending his M.S. thesis (August 23, 2017).

 

Congratulations to Hannah Leopold and Jacob Schwarz for successfully defending their M.S. thesis (August 10, 2017).

 

Congratulations to Megan Currie for successfully defending her M.S. thesis (May 9, 2017).

 

On Thursday, October 5th (2017), Ahmed A. Heikal was an invited speaker at the Biophysical Seminar Series at the School of Physics and Astronomy, University of Minnesota, Twin Cities.

 

Jacob Schwarz, Ryan Leighton, Hannah J. Leopold, Megan Currie, Arnold J. Boersma, Erin D. Sheets, and Ahmed A. Heikal. 2017.“Kinetics Model for the Wavelength-Dependence of Excited-State Dynamics of Hetero-FRET Sensors.”  Proc. SPIE 10380, Ultrafast Nonlinear Imaging and Spectroscopy V, 103800S; doi: 10.1117/12.2274793.

 

Hannah Leopold, Megan Currie, Jacob Schwarz, Erin D. Sheets, and Ahmed A. Heikal. "Molecular spectroscopy and dynamics of novel FRET Sensors in crowded environments". SPIE Optical Engineering and Applications, Ultrafast Nonlinear Imaging and Spectroscopy IV, San Diego, CA, August 6 – 10, 2017, “Invited Talk”.

 

Megan Currie, Hannah Leopold, Jacob Schwarz, Arnold J. Boersma, Erin D. Sheets, and Ahmed A. Heikal. 2017. "Fluorescence Dynamics of a FRET Probe Designed for Crowding Studies". The Journal of Physical Chemistry (B), 121 (23), 5688-5698. DOI: 10.1021/acs.jpcb.7b01306.