Home > Academics > Academic Units > Faculty of Sciences (FoS) > Chemistry > Nirmalya Bag
Assistant Professor Grade-I
Chemistry
We employ a multidisciplinary approach combining advanced chemical biology tools with high-resolution fluorescence microscopy and spectroscopy to establish functional relationship between biophysical organization of plasma membranes - driven collectively by protein-protein, protein-lipid, and lipid-lipid interactions - and cellular signaling in both healthy and disease (cancer and neurodegenerative) contexts. We specially focus on the physico-chemical and functional roles of membrane lipids in biological functions. We are currently investiigating he plasma membrane signaling systems such as those mediated through cell surface immunoreceptors and growth factor receptors.
The biological processes of our interest occur at millisecods to minutes time-scale and nanoscopic spatial-scale. We use confocal and total internal reflection fluorescence (TIRF) microscopy for live cell imaging to generate seconds to minutes time-scale data. We extract ultrahigh temporal resolution by implementing novel spectrosopic analysis procedures such fluorescence correlation spectroscopy (FCS), camera-based Imaging FCS using TIRF illumination, and fluorescence lifetime imaging (FLIM). We further employ super-resolution microscopy and FRET to gather nanoscale information from our experimental systems. Quantitative physiological parameters (such as lipid diffusion, membrane order and viscosity, and clustering) obtained from our high resolution (both temporal and spatial) experiments in live specimen can be further used by computational biologists to develop realistic models. This synergy will result a holistic picture of cellular signaling across the scales of time and space and ultimately help develop novel drug desing strategies targeing lipid dyamics and organization as well as novel precision medicine tools such as lipid-coated drug delivery systems. Finally, the current textbook level models of biochemical reactions at the plasma membrane, which are largely focussed on specific protein-based interactions, will be refined by incorporating more elaborate descriptions of membrane physical chemistry and their essential role in highly orchestrated signal processing.
Lipid-based and protein-based interactions synergize transmembrane signaling stimulated by antigen-clustering of IgE receptors. by Bag N., Wagenknecht-wiesner A. , Lee A. , Shi S. M., Holowka D. A., Baird B. A. Proc. Natl. Acad. Sci., USA 118 e2026583118- (2021)
Temperature Dependence of Diffusion in Model and Live Cell Membranes Characterized by Imaging Fluorescence Correlation Spectroscopy by Bag N., Yap D. , Wohland T. Biochimica et Biophysica Acta Biomembranes 1838 802-813 (2014)
Calibration and Limits of Camera-Based Fluorescence Correlation Spectroscopy: A Supported Lipid Bilayer Study by Bag N., Sankaran J. , Paul A. , Kraut R. , Wohland T. ChemPhysChem 108 2784-2794 (2012)
Plasma Membrane Organization of Epidermal Growth Factor Receptor in Resting and Ligand-Bound States by Bag N., Huang S. , Wohland T. Biophysical Journal 109 1925-1936 (2015)
Membrane Destabilization by Monomeric hIAPP Observed by Imaging Fluorescence Correlation Spectroscopy by Bag N., Ali A. , Chauhan V. , Wohland T. , Mishra A. Chemical Communications 49 9155-9157 (2013)
Imaging FCS Delineates Subtle Heterogeneity in Plasma Membranes of Resting Mast Cells by Bag N., Holowka D. A., Baird B. A. Molecular Biology of Cell 31 709-723 (2020)
High Resolution Characterization of Plasma Membrane Biophysics and its Impact on Cellular Signaling by Fluorescence Techniques SRIC, IIT KHARAGPUR
High Resolution Characterization of Plasma Membrane Biophysics and Its Impact on Cellular Signaling by Fluorescence Techniques Science and Engineering Research Board (SERB)
Arpita Tripathy
Area of Research: Biophysical Chemistry
Dishari Medda
Area of Research: Biophysical Chemistry
Arijit Maity
Area of Research: Chemical Dynamics in Confined Media
