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.

 

News

 

Vladimir V. Ghukasyan and Ahmed A. Heikal have co-edited a book entitled, "Natural Biomarkers for Cellular Metabolism: Biology, Techniques, and Applications", which will be 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, A.A. Heikal. “Polarization Imaging of Cellular Autofluorescence”. InNatural Biomarkers for Cellular Metabolism: Biology, Techniques, and Applications, Editors: V. Ghukasyan and A.A. Heikal, Series in Cellular and Clinical Imaging, Dr. Ammasi Periasamy (Senior Editor), Taylor & Francis Books, Pages: 107 - 135 (October 7, 2014).

Ahmed Heikal will be an invited speaker at the "Eighth Fall Workshop on Advanced TCSPC Techniques in Biomedical Sciences", Bethesda, MD, October 20-21, 2014. The wokshop is organized by Becker & Hickl GmbH, National Institutes of Health, and Boston Electronics Corporation.

John Alfveby defended his MS Thesis successfully on July 21, 2014. John and his collaborators (Randi Timermana, Monica Soto Velasquezb, Dhanushka Wickramasinghea, Jillian Bartuseka, and Ahmed A. Heikal) have just published a paper in the SPIE Proceedings (2014) based on his thesis project, entitled "Time- and Polarization-Resolved Cellular Autofluorescence Towards Quantitative Biochemistry on Living Cells", Proce. of SPIE, Vol. 9198, Ultrafast Nonlinear Imaging and Spectroscopy II, 91980U: 1 - 15. DOI:10.1117/12.2062045.

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. His contribution was highlighted in SPIE Newsroom under the title, "Natural Bioluminescence in Living Cells for Biomedical Diagnostics"; 10 October 2014; DOI: 10.1117/2.1201410.005615.

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

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.