Expertise
I am currently working as a postdoctoral researcher at the Department of Chemistry & Chemical Biology, Indiana University Purdue University Indianapolis (IUPUI) with Dr. Ian K. Webb (since January 2020). My current research is focused on the use of gas-phase ion/ion reactions to increase Ion Mobility (IM) resolution for various compound classes. As a part of my postdoctoral research, I am employing gas-phase derivatization chemistry to increase the separation power, sensitivity, and selectivity of Ion Mobility Mass Spectrometry (IM-MS) methods. This research can be extrapolated to limit/eliminate the chromatographic step during the analysis of peptides during bottom-up proteomic analysis. I believe that this technique will particularly help in the structural analysis of proteins using HDX, where back-exchange during the chromatographic step is a major setback (Structural Mass Spectrometry).
I did my Ph.D. at the Department of Chemistry & Chemical Biology, Indiana University Purdue University Indianapolis (IUPUI) with Dr. Eric C. Long (August 2015-December 2019). My Ph.D. research focused on exploring the alkaline reactivity of Cyclobutane Pyrimidine Dimer (CPD) lesions that are frequently produced in living tissues on UV-exposure, with an eye towards understanding their complete reactivity, and as a possible means to detect and quantify their presence in the genome. We found that CPD is generally inert under alkaline conditions. However, a re-evaluation of the same reaction in presence of O18 labelled water (ESI-MS and C13 NMR-based quantification) demonstrated that, similar to other sunlight-induced DNA lesions, CPD undergoes a water addition at the C4=O group of the nucleobase leading to the formation of a hemiaminal intermediate. However, this intermediate is refractory to hydrolysis and completely reverts to starting material under alkaline conditions. Moreover, the two C4=O groups present on 3’ and 5’-thymines in a CPD molecule show different chemical reactivities, a fact reflected in different rates of exchange with the incoming nucleophile leading to the hemiaminal intermediate. In addition, during the course of our investigation of the nucleophilic reactivity of CPD, we observed a chemical reaction leading to what appears to be the rapid and total chemical reversal of CPD lesions to TpT (thymine-thymine dinucleotide) (manuscript under preparation) (DNA damage and repair).
Prior to accepting the Ph.D. position at IUPUI, I worked as a Research Associate at Indian Institute of Technology (IIT) Kanpur, India (January 2011-July 2015) in order to get a hands-on experience in biomolecular chemistry. During this time, I achieved the first-ever preparation of non-fluorescent variants of Green Fluorescent Protein (GFP) by single-point mutations in the amino-acid sequence of the protein chromophore. These non-fluorescent variants were eventually ‘reconstituted’ by encapsulation with synthetic imidazolidone derivatives, and were tested for applications in photo-voltaic systems (Protein chemistry).
I have expertise in multi-step organic synthesis (evidenced by the synthesis of sunlight-induced DNA lesions at dinucleotide and oligonucleotide levels), including the manual synthesis of oligonucleotides (of various lengths) using controlled pore glass (CPG) beads. I have successfully conducted the multi-step synthesis and analysis of dinucleotides and oligonucleotides with a selective N15 label as part of their chemical analyses. I am proficient in the use of UV-Visible absorption spectroscopy, high performance liquid chromatography (HPLC) (analytical and preparative scale), NMR spectroscopy, ESI-MS and IM-MS for the characterization and quantification of small molecules and oligonucleotides. My contributions to the subfield of DNA photochemistry have been singled-out through a number of award-recognized scientific contributions. These recognitions include the Grand Poster Award at the Think Like a Molecule poster session (April 2018) and an IUPUI Dean's Award (honourable mention) at the Think Like a Molecule poster session (April 2019), both conferred by the American Chemical Society (ACS) Indiana section. My Ph.D. research is disseminated in 3 full papers (manuscripts under preparation).
Past Affiliations

Graduate Student, College of Science, Purdue University (past)

Research Assistant, Department of Chemistry, Sciences, Indian Institute of Technology Kanpur (past)

Communities
Biochemistry, Chemistry
Degrees
PhD, Purdue University, Chemistry, 2020
MSc, University of Delhi, Chemistry, 2010
Keywords
deoxyribonucleic acid, dna dna repair mass spectrometry
Languages
English, Hindi
Honors

Lead panelist for 'Being a TA: What's in it for you and your students?' at 2019 IUPUI TA Orientation, Center for Teaching and Learning (CTL), IUPUI, August, 2019

IUPUI Dean's Award- 2019, Think Like a Molecule poster session, American Chemical Society, April, 2019

Grand Poster Award- 2018, Think Like a Molecule poster session, American Chemical Society, April, 2018

Teaching Assistant (TA) of the month (Feb 2017), Department of Chemistry, Indiana University- Purdue University Indianapolis (IUPUI), February, 2017

Research Fellowship (JRF and SRF), Council for Scienti c and Industrial Research (CSIR), Government of India, INDIA, January 2011-July 2015

Associations
American Society for Mass Spectrometry (ASMS)