Pradip K. Biswas

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In order to understand the role of metabolic regulation in environmental stress tolerance, a comprehensive analysis of demand-side effects (i.e. changes in energy demands for basal maintenance) and supply-side effects (i.e. metabolic capacity to provide ATP to cover the energy demand) of environmental stressors is required. We have studied the effects of(More)
Resveratrol, a naturally occurring stilbene, has been categorized as a phytoestrogen due to its ability to compete with natural estrogens for binding to estrogen receptor alpha (ERα) and modulate the biological responses exerted by the receptor. Biological effects of resveratrol (RES) on estrogen receptor alpha (ERα) remain highly controversial, since both(More)
(6R)-5,6,7,8-Tetrahydrobiopterin (BH(4)) is a key cofactor involved in the electron transfer to the P(450) heme of nitric oxide synthase. We calculated the electronic structure of the neutral, cationic, and anionic forms of BH(4) in the gas phase, in solution (both dielectric and explicit water), and in the protein environment using density functional(More)
Correspondence between time-evolution dynamics of a tumor and an attractively interacting Bose-Einstein Condensate with feeding and dissipation. The morphology and time-evolution dynamics of tumors are expected to depend heavily on the detailed balance of the overall physics of the cell assembly (e.g., the kinetic pressure, the cell-cell interaction, and(More)
We describe a regularized and renormalized electrostatic coupling Hamiltonian for hybrid quantum-mechanical (QM)-molecular-mechanical (MM) calculations. To remedy the nonphysical QM/MM Coulomb interaction at short distances arising from a point electrostatic potential (ESP) charge of the MM atom and also to accommodate the effect of polarized MM atom in the(More)
Understanding the damage of DNA bases from hydrogen abstraction by free OH radicals is of particular importance to understanding the indirect effect of ionizing radiation. Previous studies address the problem with truncated DNA bases as ab initio quantum simulations required to study such electronic-spin-dependent processes are computationally expensive.(More)
Biological effects of estrogenic ligands are transduced by two estrogen receptors, ERα and ERβ; they transactivate as dimers. Since ERββ and ERαβ homo- and heterodimers are known to exhibit anti-proliferative effects, we characterized their dimerization interface in atomic details and explored their ligand induced conformational dynamics. ERαβ heterodimer(More)
Human estrogen receptor alpha (ERα), which acts as a biomarker and as a therapeutic target for breast cancers, is activated by agonist ligands and co-activator proteins. Selective estrogen receptor modulators (SERM) act as antagonists in specific tissues and tamoxifen, a SERM, has served as a drug for decades for ERα-positive breast cancers. However, the(More)
Tamoxifen-an anti-estrogenic ligand in breast tissues used as a first-line treatment in estrogen receptor (ER)-positive breast cancers-is associated with the development of resistance followed by resumption of tumor growth in about 30 % of cases. Whether tamoxifen assists in proliferation in such cases or whether any ligand-independent pathway to(More)
We show that the observed oscillatory pattern in the growth dynamics of a multicel-lular tumor may be successfully simulated with a classical field limit nonlinear matter wave equation given by the mean-field Gross-Pitacvskii model. Constructing and scaling the many-body Hamilto-nian we account for the overall physics of the cell aggregate (e.g., the(More)