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 dynamics, protein-protein interactions, and macromolecular crowding in controlled environments. 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, 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.




Professor Yves Mély, Biophotonics and Pharmacology laboratory, Université de Strasbourg, France, will be visiting UMD as an invited speaker in the weekly seminar series of the Department of Chemistry & Biochemistry. The seminar is entitled "Advanced Fluorescent Amino-Acid and Nucleotide Analogues for Monitoring Protein-Nucleic Acid and Protein-Membrane Interactions" and will take place on Friday, February 13, 2015, 3 - 4 PM, Kobilka Lecture Hall (200 Chem). Please join us.

Spencer Gardeen, Joseph L. Johnson, and Ahmed A. Heikal. "Fluorescence microspectroscopy assessment of the in vitro dimerization of BACE1-GFP fusion protein in cultured cells", The 249th American Chemical Society Meeting, Symposium: Current Topics in Biological Chemistry, Division of Biological Chemistry, Denever, CO, March 22 - 26, 2015.

Rochelle Warner, Tyler Floden, Ahmed A. Heikal, and Erin Sheets. "Molecular and Mechanical Manipulation of Membrane Domains in Planar Supported Bilayers". The 59th Biophysical Society Meeting, Baltimore, MD, February 7 - 11, 2015.

Vladimir V. Ghukasyan and Ahmed A. Heikal have co-edited a book entitled, "Natural Biomarkers for Cellular Metabolism: Biology, Techniques, and Applications", which was published by Taylor & Francis, CRC Press (October 7, 2014, 408 Pages), ISBN: 9781466509986), Series in Cellular and Clinical Imaging (Senior Editor: Ammasi Periasamy).

Vishwasrao, H.D., Q. Yu, K. Hewawasam, Ahmed A. Heikal. “Polarization Imaging of Cellular Autofluorescence”. In “Natural Biomarkers for Cellular Metabolism: Biology, Techniques, and Applications, Ghukasyan, V. and A.A Heikal (Editors), Series in Cellular and Clinical Imaging, Dr. Ammasi Periasamy (Senior Editor), Taylor & Francis Books, (October 2014).

Wickramasinghe, D., R. Timerman, J. Bartusek, and Ahmed A. Heikal. “Partitioning and Diffusion Dynamics of Fluorescently Labeled FTY720 in Resting Epithelial Cells”. In “Advanced Time-Correlated Single-Photon Counting Applications”, Wolfgang Becker (Editor), Springer (In Press; Scheduled for May 2015).

John Alfveby, Randi Timerman, Monica P. Soto Velasquez, Dhanushka W.P.M. Wickramasinghe, Jillian Bartusek, and Ahmed A. Heikal. 2014. "Time- and Polarization-Resolved Cellular Autofluorescence Towards Quantitative Biochemistry on Living Cells". Ultrafast Nonlinear Imaging and Spectroscopy II, Zhiwen Liu, Iam Choon Khoo, Demetri Psaltis (Editors), Proc. of SPIE Vol. 9198 91980U, Pages 1-15 (invited paper).

Ahmed A. Heikal. 2014. "Natural Bioluminescence in Living Cells for Biomedical Diagnostics". SPIE Newsroom, DOI: 10.1117/2.1201410.005615, October 10, 2014.

- Ahmed A. Heikal will be an invited speaker at the Ultrafast Imaging and Spectroscopy conference in the 2015 SPIE Optics and Photonics, San Diego, CA, August 9 - 13, 2015.

Ahmed A. Heikal will be an invited spkeaker at the Department of Chemistry, St. Olaf College, on March 5th, 2015.

John Alfveby defended his MS Thesis successfully on July 21, 2014. The final thesis was accepted by the Graduate School, University of Minnesota, on August 29, 2014. John will be applying for a PhD program for Fall-2015 following a year of job experience. Congratulations John and Best Wishes.

Ahmed Heikal was an invited speaker at the Ultrafast Imaging and Spectroscopy conference in the 2014 SPIE Optics and Photonics, San Diego, CA, August 17 - 21, 2014.

Ahmed Heikal, "Searching for Self in a Diverse World", Duluth News Tribune (Thursday, July 24, 2014).

Ahmed Heikal, "Egyptian Women are the Forgotten Heroes", Duluth News Tribune (Sunday, June 1, 2014).

Ahmed Heikal has participated in a session on "Spectroscopy in Kinetics and Dynamics" in the upcoming "69th International Symposium on Molecular Spectroscopy", June 16 - 20, 2014, at the University of Illinois at Urbana-Champain. He also chaired a Mini-symposium on "Spectroscopy in Kinetics and Dynamics."

Paul Yager, Corey Geehan, and Chang Thao were named the winners of the "Ilenda Award for Outstanding Undergraduate Research" during the "2014 Undergraduate Research Symposium" at UMD Department of Chemistry and Biochemistry. The symposium took place on May 1st, 2014 and the Keynote Speaker was Professor Nils Petersen, Department of Chemistry, University of Alberta, Canada. Congratulations to Paul, Corey and Chang.

Ahmed Heikal has just published a peer-reviewed paper entitled, "Time-resolved fluorescence anisotropy and fluctuation correlation analysis of major histocompatibility complex class I proteins in fibroblast cells", Methods, (66) 283-291 (2014). This paper was published in a special issue of Methods, entitled "Advanced Light Microscopy Imaging in Biological Sciences."

Randi Timerman (undergraduate) and John Alfveby (MS candidate) from Heikal Group have presented their research (two posters) at the 58th Biophysical Society Meeting, San Francisco, CA (February 15 - 19, 2014). Chang Thao, Holly Israelson, Jillian Bartusek, Dhanushka Wickramasinghe, and Robb Welty were also co-authors.

Ahmed Heikal was an invited speaker at the 11th Annual Advanced Imaging Techniques Workshop, University of California-Berkeley, Berkeley, CA, January 29 - 31, 2014. His talk was entitled, "Bioenergetics and Diffusion in the Crowded Milieu of Living Cells". The workshop was sponsored by Molecular Imaging Center / Cancer Research Laboratory at UC Berkeley, Becker & Hickl GmbH (Berlin, Germany), and Boston Electronics.

Ahmed Heikal served as an external examiner of a PhD thesis at The Institute of Biomaterials and Biomedical Engineering (IBBME), University of Toronto, Canada, on July 25th, 2013.