Krishanu Ray, PhD

K. Ray, S.P. Ananthavel, D.H. Waldeck, R. Naaman, Asymmetric scattering of polarized electrons by organized organic films of chiral molecules, Science, 1999, 283,814.

M.D. Mason, Krishanu Ray, R.D. Grober, G. Pohlers, J. Cameron, Single molecule acid/base kinetics and thermodynamics, Physical Review Letters, 2004, 93, 073004. Selected for the August 15, 2004 issue of Virtual Journal of Biological Physics Research, covering a focused area of frontier research.

Krishanu Ray, R. Badugu, J. R. Lakowicz, Metal-enhanced fluorescence from CdTe nanocrystals: A single-molecule fluorescence study, J. Am. Chem. Soc.  2006, 128, 8998-8999.

Krishanu Ray, H. Szmacinski, J. Enderlein, J.R. Lakowicz, Distance-dependence of surface plasmon-coupled emission observed using Langmuir-Blodgett films, Appl. Phys. Lett. 2007, 90, 251116.

Krishanu Ray*, M.H. Chowdhury, J.R. Lakowicz, Single molecule spectroscopic study of enhanced intrinsic phycoerythrin fluorescence on silver nanostructured surfaces, Anal. Chem. 2008, 80, 6942-6948. (Cover Article)

Krishanu Ray*, J. Zhang, J.R. Lakowicz, Fluorescence lifetime correlation spectroscopic study of fluorophore-labeled silver nanoparticles, Anal. Chem. 2008, 80, 7313 – 7318.

Krishanu Ray*, H. Szmacinski, J.R. Lakowicz, Enhanced fluorescence of proteins and label-free bioassays using aluminum nanostructures, Anal. Chem. 2009, 80, 7313 - 7318.

Krishanu Ray, J. Ma, M. Oram, J. R. Lakowicz, L. W. Black, Single Molecule- and Fluorescence Correlation Spectroscopy-FRET Analysis of Phage DNA Packaging: Co-localization of the Packaged Phage T4 DNA Ends within the Capsid. J. Mol. Biol., 2010 395, 1102-1113.

Krishanu Ray, C. Sabanayagam, J.R. Lakowicz, L.W. Black, DNA crunching by a viral packaging motor: Compression of a procapsid-portal stalled Y-DNA substrate, Virology, 2010, 398, 224-32.

M. Chowdhury, N. Lindquist, A. Lesuffleur, S. Oh, J. R. Lakowicz, Krishanu Ray*,Effect of Nanohole Spacing on the Self-Imaging Phenomenon Created by the Three-Dimensional Propagation of Light through Periodic Nanohole Arrays, J. Phys. Chem. C, 2012, 116, 19958–19967.

A. Dixit, Krishanu Ray, L. Black, Compression of the DNA substrate by a viral packaging motor is supported by removal of intercalating dye during translocation, Proc Natl Acad Sci U S A. 2012,109, 20419-24.

 Krishanu Ray*, J.R. Lakowicz Metal-enhanced fluorescence lifetime imaging and spectroscopy on a modified SERS substrate, J. Phys. Chem C, 2013, 117, 15790–15797.

D. Fixler, T. Nayhoz, Krishanu Ray^*, Diffusion reflection and fluorescence lifetime imaging microscopy study of fluorophore-conjugated gold nanoparticles or nanorods in solid phantoms, ACS Photonics, 2014, 1, 900–905.

N. Gohain, W. Tolbert, P. Acharya, L. Yu, T. Liu, P. Zhao, C. Orlandi, M. Visciano, R. Kamin-Lewis, M. Sajadi, L. Martin, J. Robinson, P. Kwong, A. DeVico, Krishanu Ray, G. Lewis, M. Pazgier, Co-crystal structures of antibody N60-i3 and antibody JR4 in complex with gp120 define more Cluster A epitopes involved in effective antibody-dependent effector function against HIV-1, J. Virology, 2015, 89, 8840-54.

N. Gohain, WD Tolbert, C. Orlandi, J. Richard, S. Ding, X. Chen, D. Bonsor, E. Sundberg, W. Lu, Krishanu Ray, A. Finzi, G. Lewis, M. Pazgier, Molecular basis for epitope recognition by non-neutralizing anti-gp41 antibody F240. Scientific Reports 2016, 6, 36685. 

W. Tolbert, N. Gohain, N. Alsahafi, V. Van, C. Orlandi, S. Ding, L. Martin, A. Finzi, G. Lewis, Krishanu Ray, M. Pazgier Targeting the Late Stage of HIV-1 Entry for Antibody-dependent Cellular Cytotoxicity: Structural Basis for Env Epitopes in the C11 Region, Structure, 2017, 25, 1719.

C. Orlandi, D. Deredge, Krishanu Ray, N. Gohain, W. Tolbert, A. DeVico, P. Wintrode, M. Pazgier, G. Lewis Antigen-Induced Allosteric Changes in a Human IgG1 Fc Increase Low-Affinity Fcγ Receptor Binding, Structure, 2020, 28, 516.

K. Hegde, Krishanu Ray, H. Szmacinski, S. Sorto, A. Puche, I. Lengyel, R. Thompson Two-Photon Excited Fluorescence Lifetime Imaging of Tetracycline-Labeled Retinal Calcification. Sensors, 2023, 23, 6626.

L. Liang, L. Wu, P. Zheng, T. Ding, Krishanu Ray, I. Barman DNA-Patched Nanoparticles for the Self-Assembly of Colloidal Metamaterials, JACS Au, 2023, 3, 1176.

S. Dasgupta, Krishanu Ray* Plasmon Enhanced Fluorescence for Biophotonics and Bio-analytical Applications, Frontiers in Chemistry, 2024, 12, 1407561.

Single molecule imaging spectroscopy, Fluorescence correlation spectroscopy, Fluorescence lifetime imaging microscopy, Two-photon fluorescence, Metal enhance fluorescence, Surface plasmon coupled emission, Plasmon-controlled fluorescence, Radiative decay engineering, Fluorescence spectroscopy, Chemically amplified photoresists, Langmuir-Blodgett films, Layer-by-layer assembly, Nanotechnology, Plasmonic Nanostructures, Application of single molecule spectroscopy in biomedical research, Viral nucleic acid packaging, Single molecule studies of HIV proteins, HIV virions, Broadly neutralizing antibodies, Fc-receptors, SARS-CoV-2, Metabolic imaging.

My long-term research goal is to develop fluorescence, nanotechnology and imaging-based approaches for application in biomedical research. Present research focus is on the application of high-end imaging and spectroscopy methods to the study of HIV and SARS-CoV-2 related proteins, virions and development of a novel detection assay that can directly measure qualitative and quantitative aspects of multiple broadly neutralizing antibody classes binding to virus populations in plasma and culture fluids. At my lab, we investigate the nature of envelope/spike interactions with receptors, anti-envelope antibodies and Fc receptors using fluorescence correlation spectroscopy (FCS), single molecule detection (SMD), time-resolved fluorescence and super-resolution microscopy as novel tools. Through applications of FCS, my work has provided a unique view of HIV virion-antibody interactions. I have developed a novel FRET-FCS based assay to identify how neutralizing and non-neutralizing epitopes are expressed on single virions.

Single molecule fluorescence approaches enable interrogations of individual virions and virion trimers, providing a level of detail not achievable with standard analytical methods. These methods can interrogate fully native virions and do not require genetic and/or chemical modifications of Env/spike proteins. Recently, I developed a quantitative, intrinsic, label-free, and minimally invasive method based on two-photon fluorescence lifetime imaging microscopy (2p-FLIM) for imaging NADH metabolism of virally infected cells and tissue sections which revealed increased fluorescence lifetime and higher enzyme-bound NADH fraction suggesting oxidative phosphorylation (OxPhos) in HIV-1 infected cells and tissues. Steady-state, time-resolved single molecule fluorescence and super-resolution microscopy (STORM) approaches are being employed towards investigating allosteric interactions that couple antigen binding information in the Fab region with conformational changes in the Fc region.

I have successfully obtained NIH funding, published over 100 peer-reviewed manuscripts in excellent and outstanding journals (H index = 37, ~5600 citations), filed six US patent applications, developed a successful program to provide imaging, spectroscopy expertise on campus, and developed new and novel technologies.  Three research contributions are of particular importance:

1) Single molecule studies of the HIV envelope and Fc gamma receptors   

 Research in this area is focused on the biophysical properties of HIV proteins.  Fluorescence correlation spectroscopy (FCS) and single molecule detection (SMD) are used as novel tools to probe the nature of HIV-1 envelope interactions with cell surface receptors and/or anti-envelope antibodies at the molecular level to understand the initial step of HIV infection.

2) DNA packaging motor dynamics

 The primary objective is to directly probe the mechanism of the viral DNA packaging motor using single molecule fluorescence-based approaches.  Fluorescence measurements have the most potential to establish motor dynamics and structural changes to the DNA substrate that accompany translocation.

 3) Plasmon-controlled fluorescence applications in biomedical science

The goal of the research in this area is focused on understanding the correlation between plasmonic nanostructures, excitation light and enhanced fluorescence.  He has developed new techniques and methodology to apply this technology in biology.

NIH Career Grant Award, 2011

Japan Society for the Promotion of Science (JSPS) Fellowship, 2000.

ISCA Young Scientists’ Award 1997-98 in Physics from Indian Science Congress Association.

NIH/NIAID R01AI172487 (PI) Broadly neutralizing antibody combinations with single virions in HIV+ plasma

NIH/NIAID R61-AI176561 (PI) Detection assays for virion susceptibility to HIV broadly neutralizing antibodies in plasma and culture fluids

NIH/NIAID P01-AI162242 (Co-I) Impact of antibody effector function diversity on antiviral activity in situ

Completed

NIH/NIGMS R01GM117836 (PI) Conformational Dynamics of HIV Envelope by Single Molecule Spectroscopy

NIH/NIGMS R01GM117836-S1/S2 (PI) Conformational Dynamics of HIV Envelope by Single Molecule Spectroscopy

NIH/NIAID R56AI172487 (PI)

NIH/NIAID P01 AI120756 (Co-I) Bridging Antibody Fc-mediated Antiviral Functions across Humans and Non-human Primates

NIH/NIAID R01-AI155150 (Co-I) Novel bNAB-based Treatment and Prevention of HIV-1

NIH/ NIAID R01-AI129769 (Co-I) Unlocking Env: a new strategy for a functional cure through antibody-dependent cell-mediated cytotoxicity

NIH/NIGMS R01 GM118766 (Co-I) Mechanism of Bacteriophage DNA Packaging Initiation and DNA Translocation

NIH/NIAID K25 AI087968 (PI) Single Molecule Studies of HIV Envelope Properties

Single Molecule Imaging, Fluorescence Correlation Spectroscopy, FRET, Time-resolved Fluorescence, Confocal Microscopy, TIRF, Fluorescence Lifetime Imaging Microscopy, Multi-photon Fluorescence Imaging, Metabolic Imaging, Super-resolution Microscopy.