Dr. Tiwari's research utilizes both computational approaches such as molecular docking, virtual screening, and molecular dynamics (MD) simulations and experimental techniques such as surface plasmon resonance (SPR) biophysical as well as other biochemical experiments to conduct different lines of research. Dr. Tiwari is also collaborating with researchers at Georgetown University (GU) and other institutions outside of GU. Dr. Tiwari is also interested in developing models/tools to investigate and analyze biomolecular interactions.

Drug Development:

DNA Topoisomerases as targets: DNA topoisomerase (topo) regulates DNA topology, which has special importance in key cellular processes, including replication, transcription, and recombination. Human topoisomerase I (HtopoI) forms a transient covalent complex with DNA and is a druggable target for novel topoisomerase poison inhibitors that represent a new class of anticancer drugs. 

  Human topos (Htopos) and other enzymes that have a functional relationship with Htopos can also be used as drug targets for the development of anticancer drugs. Dr. Tiwari's current research is focused on targeting these important biomolecules to discover new small molecule (SM) inhibitors that can be developed as anticancer agents. Bacterial DNA topoI forms a transient covalent complex with DNA and can be a druggable target for novel topoI poison inhibitors that represent a new class of antibacterial drugs. Besides Htopos and related targets, Dr. Tiwari's current research is focused on finding new SM inhibitors targeting EctopoI that can be developed as new antibacterial drugs to treat bacterial infections.

TDP1 and PARP1 as targets: Tyrosyl-phosphodiesterase 1 (TDP1) catalyzes the hydrolysis of the phosphodiester bond between an active site tyrosine in HtopoI and DNA 3’-phosphate making TDP1 functionally connected with HtopoI activity. TDP1 interacts with Poly [ADP-ribose] polymerase 1 (PARP1) and gets PARylated that enhances recruitment of TDP1 to DNA damage sites. Dr. Tiwari's research involves development of new inhibitors targeting these two functionally important proteins.

HDACs as targets: Histone deacetylases (HDACs) regulate the expression and activity of several proteins involved in both cancer initiation and cancer progression as well in neuronal cell death. HDACs also interact with other cellular proteins, which has implications in control of cell growth, differentiation, and apoptosis.  Dr. Tiwari's research has interest in targeting HDACs and blocking interactions of HDACs with other proteins that are related to certain disease conditions.

Biophysical Characterizations:

DNA Topoisomerases and their binding partners: Dr. Tiwari's research has interest in the biophysical characterization of complex formation between topos and their binding partners.

HDACs and their binding partners: Dr. Tiwari's is also interested in characterization of complex formations of HDACs with other binding partners, including other HDACs, LSD1, NCoR1, and MEF2.  

Heme proteins: Dr. Tiwari is also interested in  biophysical characterization of complex formation between heme proteins, including Neuroglobin (Ngb) and Cytochrome c (Cyt c). Neuroglobin (Ngb) is a six-coordinated heme protein and Cytochrome c (Cyt c) is another heme protein, a known binding partner of Ngb. The formation of a complex between Ngb and Cyt c has an important biological role in preventing apoptosis.

Kaiso binding proteins: Dr. Tiwari is also involved in collaborative research to characterize interactions of Kaiso binding proteins with their binding partners. 

Models/Tools Development:

  Besides interest in drug development and characterization of biomolecular interactions, Dr. Tiwari is interested in developing new models/tools to identify underlying biphasic binding mechanisms and to analyze the biomolecular interactions.