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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. 

Ghukasyan and Heikal_Edited Book (2014)

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

Anh T. Q. Cong, Rafaela M. L. Pimenta, Jon Holy  and Ahmed A. Heikal. 2021. Associated anisotropy of intrinsic NAD(P)H for monitoring changes in the metabolic activities of breast cancer cells (4T1) in three-dimensional collagen matrix. Phys. Chem. Chem. Phys., 2021, 23, 12692. DOI: https://doi.org/10.1039/D0CP06635D

Cody P. Aplin, Robert C. Miller, Taryn M. Kay, Ahmed A. Heikal, Arnold J. Boersma, and Erin D. Sheets. 2021. Fluorescence depolarization dynamics of ionic strength sensors using time-resolved anisotropy. Biophys. J., 120, 1417–1430. https://doi.org/10.1016/j.bpj.2021.01.035

Ahmed Heikal is an invited speaker at the SPIE-2021 conference (San Diego, CA) during August 1-5, 2021.

R. C. Miller, C. P. Aplin, T. M. Kay, R. Leighton, C. Libal, R. Simonet, A. Cembran, A. A. Heikal, A. J. Boersma, and E. D. Sheets. 2020. FRET Analysis of Ionic Strength Sensors in the Hofmeister Series of Salt Solutions Using Fluorescence Lifetime Measurements. J. Phys. Chem. B, 124, 3447−3458. https://dx.doi.org/10.1021/acs.jpcb.9b10498

Cody Aplin and Taryn Kay have defended their M.S. thesis successfully (summer 2020) and joined Cornell University for their Ph.D. degrees. Congratulations to both Cody and Taryn, we are very proud of you and your achievements.

Julie Beenken has successfully earned her BS Degree in Biochemistry and was accepted in a PhD program at the University of Minnesota, Twin Cities campus (summer 2020). Congratulations Julie.

Ahmed Heikal was an invited speaker at the SPIE-2020 conference (San Diego, CA), Remote Participation, 2020.

Anh Cong, Rafaela Pimenta, Jon Holy, and Ahmed Heikal. 2020. Effects of tumor-like 3D culture on the metabolic activities of murine breast cancer cells using two-photon fluorescence lifetime imaging microscopy of intrinsic NAD(P)H. ACS Fall 2020 Virtual Meeting, Physical Chemistry, Addressing Chemical Complexity with Nonlinear Optical Microscopy, Applications in Biology I, August 17 -20, 2020. Platform Presentation.

Cody Aplin, Robert Miller, Taryn Kay, Erin Sheets, and Ahmed Heikal. 2020. Intrinsically fluorescent protein constructs for sensing environmental ionic strength using time-resolved fluorescence. ACS Fall 2020 Virtual Meeting, Physical Chemistry, Biophysical Chemistry in Complex Environments, August 17 -20, 2020. Platform Presentation.

Congratulations to Elsie Johnson for her UROP Award in order to continue her undergraduate research during the spring-2020. Well deserved, Elsie.

Taryn Kay (graduate student in the UMD Department of Physics and Astronomy), Cody Aplin (graduate student in the UMD Department of Chemistry and Biochemistry), and Julie Beenken (undergraduate student in UMD Chemistry and Biochemistry) will be presenting their research projects in the upcoming Annual Biophysical Society Meeting (February 15-19, 2020, San Diego, CA). Taryn, Cody, and Julie are also the recipients for the Biophysical Society Travel Award to cover (in part) theirtravel expenses to the meeting. Congratulations!!!

Ahmed Heikal, Dr. Jon Holy (Duluth Medical School), Dr. Erin Sheets (UMD Chemistry and Biochemistry) are the recipients of the Grant-in-Aid of Research, Artistry, and Scholarship award from the Office of the Vice President for Research, the University of Minnesota, for the period of January 2020-January 2021. We are grateful for the university support of our collaborative, interdisciplinary research project.

Cody P. Aplin, Taryn M. Kay, Robert C. Miller, Arnold J. Boersma, Erin D. Sheets, Ahmed A. Heikal. Integrated fluorescence approach for FRET analysis of environmental sensors, Proc. SPIE 11122, Ultrafast Nonlinear Imaging and Spectroscopy VII, 111220E (9 September 2019). DOI: 10.1117/12.2531656.

Taryn Kay, a graduate student in the Department of Physics and Astronomy, UMD, was awarded the Mylan Radulovich Graduate Fellowship for 2019-20 acamademic year. Taryn is a memeber of the Heikal Research Group and is working on single-molecules studies of genetically encoded FRET constructs for environmental ionic-strength sensing. Congratulations to Taryn.

Ahmed Heikal was an invited speaker at the 13th Annual FLIM Workshop in the Biomedical Sciences (Bethesda, MD, October 31, 2019).

Congratulations to Anh Cong for successfully defending her MS thesis on August 06, 2019. Anh has secured a job in the Department of Biochemistry and Molecular Biology at the Mayo Clinc. Congratulations, Anh.

Congratulations to Robert Miller for successfully defending his MS thesis on July 19, 2019. Robert is admitted to Graduate PhD Chemistry Program at Cornell university, Ithaca, NY.

Ahmed Heikal was an invited speaker at the SPIE-2019 conference (San Diego, CA) during August 11-15, 2019.

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, 2019DOI: 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 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.