Paschim, India
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Pal P.,Indian Association for The Cultivation of Science | Mahato M.,Indian Association for The Cultivation of Science | Kamilya T.,Narajole Raj College | Tah B.,Indian Association for The Cultivation of Science | And 2 more authors.
Journal of Physical Chemistry B | Year: 2011

Here we report the fibrillation of egg white ovalbumin (OVA) induced by the biomineralization of two alkali halides (KCl, NaCl) in the Langmuir-Blodgett (LB) film of OVA. The pressure-area isotherm of OVA shows the salt-induced increment of apparent area/monomer of OVA. Fibrillation of OVA in the LB film is monitored by FE-SEM imaging. Formation of fibrillar aggregates is concomitant with an increase of salt concentration. HR-TEM and EDX measurements allowed us to identify nanostructured crystals of salt, which are associated with this fibrillar structure. FTIR spectroscopic study of the amide band in LB films as well as CD spectroscopy in solution qualitatively indicates the increase in β-sheet to α-helix ratio in the presence of salt, indicating unfolding of protein. We suggest that the ion attachment to the peptide chain leads to unfolding and that subsequent recrystallization in the transferred monolayer leads to fibrillation of protein as well as biomineralization of alkali halide salts. This finding demonstrates that the fibrillation of OVA is induced by the biomineralization of alkali halides. © 2011 American Chemical Society.


Mahato M.,Indian Association for The Cultivation of Science | Pal P.,Indian Association for The Cultivation of Science | Kamilya T.,Indian Association for The Cultivation of Science | Kamilya T.,Narajole Raj College | And 2 more authors.
Journal of Physical Chemistry B | Year: 2010

In this Article, we report the surface activity of the human globular blood protein, hemoglobin (Hb), at the air/water interface. The Langmuir-Blodgett technique is used for monolayer characterization. The adsorption growth-kinetics study shows that the adsorption process at the air/water interface is involved with two mechanisms: one diffusion with adsorption and the other rearrangement with unfolding. The kinetics is found to be dependent on pH and protein concentration in the subphase. The CD and FTIR studies suggest larger intermolecular aggregate and β-sheet formation in the film lifted from the air/acidic water subphase. In alkaline pH and in isoelectric pH (6.8), not much variation is observed. The FE-SEM images support this observation. The acidic pH induced such conformational changes, and aggregation is explained with the argument of a-helix to β-sheet conversion as well as the competition between protonation and deprotonation of the aromaticamino acid residues at the air/water interface. © 2010 American Chemical Society.


Mahato M.,Indian Association for The Cultivation of Science | Pal P.,Indian Association for The Cultivation of Science | Kamilya T.,Indian Association for The Cultivation of Science | Kamilya T.,Narajole Raj College | And 3 more authors.
Journal of Physical Chemistry B | Year: 2010

In this article, we report the results of the extent of interaction as well as the formation of a bioconjugate of human hemoglobin (Hb) with silver (Ag). The complexation process and conformational changes are characterized using different spectroscopic and microscopic techniques. The UV-vis study demonstrates the perturbation of the soret/heme band and generates conformational heterogeneity within the heme group in the presence of silver. A fluorescence study suggests that the Tryptophan (Trp) residues of Hb are in a more polar environment after conjugation. Initial fluorescence enhancement with addition of silver is due to metal-enhanced fluorescence. Moreover, the fluorescence quenching after the formation of the Hb-Ag bioconjugate follows the modified Stern-Volmer (S-V) plot. The S-V plot along with the time-resolved fluorescence study indicates the presence of both static and dynamic types of quenching. In addition, the reduction potential values of the entities (Hb-heme, Ag+, and Trp) indicate the possible electron transfer. The secondary structure calculation from CD and FTIR spectra indicate α-helix to β-sheet conversion, and unfolding of Hb is also responsible for the bioconjugate formation. In addition, FE-SEM, phase contrast inverted microscopy (PCIM) images demonstrate the formation of the silver-protein bioconjugate. The overall data show that there is a change in the secondary as well as the tertiary structure of Hb after conjugation with silver. © 2010 American Chemical Society.


Pal P.,Indian Association for The Cultivation of Science | Mahato M.,Indian Association for The Cultivation of Science | Kamilya T.,Indian Association for The Cultivation of Science | Kamilya T.,Narajole Raj College | Talapatra G.B.,Indian Association for The Cultivation of Science
Physical Chemistry Chemical Physics | Year: 2011

Here, we report the glycosylation of human adult hemoglobin (Hb) studied in aqueous solution and at the air-water interface by the Langmuir-Blodgett (LB) technique. Pressure-area (π-A) and pressure-time (π-t) measurements show that the concentration of glucose (GLC) and interaction time have an effect on Hb molecular area as well as on surface activity. Solution studies by UV-vis absorption and emission spectroscopy show that the GLC can alter the local conformation of Hb to some extent at the tryptophan and heme residues. CD spectroscopic studies in solution indicate that the α-helix content increases in the presence of GLC at the secondary structure level, which may be the cause of an increased adsorption rate of Hb. Also, secondary structure calculation using FTIR technique in the LB film follows the decrease in α-helix and increase in β-sheet structure as well as the formation of intermolecular aggregates. AFM images of Hb in the LB film indicate the transition from globular to an ellipsoid-like structure of Hb in the presence of GLC. FTIR studies of the LB film support the AFM imaging and the analysis of π-t kinetics. The molecular docking study revealed that Val 1 and Lys 132 are the most favorable docked sites along with some other sites such as Hem 147, Trp 37, Asp 94, Tyr 145, Leu 91, His 143, Glu 43 etc. The overall study may predict the processes of interactions with the increased concentration of GLC on Hb as well as on other long lived proteins. © 2011 the Owner Societies.


Ghosh S.K.,Narajole Raj College | Beg O.A.,Sheffield Hallam University | Zueco J.,Technical University of Cartagena | Prasad V.R.,Madanapalle Institute of Technology and Science
Zeitschrift fur Angewandte Mathematik und Physik | Year: 2010

Closed-form solutions are presented for the transient hydromagnetic flow in a rotating channel with inclined applied magnetic field under the influence of a forced oscillation. Magnetic Reynolds number is large enough to permit the inclusion of magnetic induction effects. The Maxwell displacement current effect is also included and simulated via a dielectric strength parameter. The governing momentum and magnetic induction conservation equations are normalized with appropriate transformations and the resulting quartet of partial differential equations are solved exactly. A parametric study is performed of the influence of oscillation frequency parameter (ω), time (T), inverse Ekman number, i.e. rotation parameter (K2), square of the Hartmann magnetohydrodynamic (MHD) parameter (M2), and magnetic field inclination (θ) on the primary and secondary induced magnetic field components (bx, by) and velocity components (u, v) across the channel. Network solutions are also obtained to validate the exact solutions and shown to be in excellent agreement. Applications of the study arise in planetary plasma physics and rotating MHD induction power generators and also astronautical flows. © 2009 Birkhäuser Verlag Basel/Switzerland.


Shit S.,Jalpaiguri Government Engineering College | Kamilya T.,Narajole Raj College | Samanta P.K.,Ghatal Rabindra Satabarsiki Mahavidyalaya
Materials Letters | Year: 2014

A simple chemical reduction method has been successfully employed to synthesize ZnO nanocrystals. The nanocrystals are spherical having a dimension of ~100 nm as revealed from scanning electron microscopy and transmission electron microcopy. The growth of the nanocrystals follows a bottom-up approach via the formation of ZnO nuclei and successive growth. The ZnO nanocrystals exhibit strong absorption at ~378 nm. The synthesized ZnO exhibits strong UV emission at ~387 nm owing to the band to band transition. © 2013 Elsevier B.V.


Bhunia A.K.,Vidyasagar University | Samanta P.K.,Ghatal R.S. Mahavidyalaya | Saha S.,Vidyasagar University | Kamilya T.,Narajole Raj College
Applied Physics Letters | Year: 2013

The interaction as well as the formation of bioconjugate of Bovine Serum Albumin (BSA) and Zinc Oxide nanoparticles (ZnO NPs) is investigated. The surface binding along with reorganization of BSA on the surface of ZnO NPs forms stable hard corona. The time constants for surface binding and reorganization are found to be 1.10 min and 70.68 min, respectively. The close proximity binding of BSA with ZnO NPs via tryptophan is responsible for bioconjugate formation. Fibrillar aggregated structure of BSA is observed due to conformational change of BSA in interaction with ZnO NPs. © 2013 AIP Publishing LLC.


Kumar Bhunia A.,Vidyasagar University | Kanti Samanta P.,Ghatal R.S. Mahavidyalaya | Saha S.,Vidyasagar University | Kamilya T.,Narajole Raj College
Applied Physics Letters | Year: 2014

Semiconductor nanoparticles (NPs) with near-infrared (NIR) fluorescence has achieved great interest for early detection of colon tumors/cancer. We have synthesized lead sulphide (PbS) NPs (5-7 nm) having emission in NIR region and investigated its interaction with bovine serum albumin (BSA) to determine the bio-safety of PbS NPs. The interaction of PbS NPs with BSA occurs through formation of "hard" and "soft" protein NPs corona and follows exponential association. The hard corona represents that the core PbS NPs are fully covered by BSA with shell thickness of ∼8 nm, i.e., the dimension of BSA monomer. A large number of PbS NPs with hard corona of BSA forms "colony" with diameters in the range of 200-400 nm. The soft corona grows surrounding this colony. The quenching of fluorescence BSA in the presence of PbS NPs follows dynamic quenching process with tryptophan as major binding sites. Nearest to human body temperature, positive cooperative association between PbS NPs and BSA are found, and affinity of BSA to the PbS NPs gradually increases in superlinear fashion. The electrostatic interaction is the key force in binding of PbS NPs with BSA, and hydrophobic interaction between PbS NPs and BSA is responsible for conformational change of BSA. © 2014 AIP Publishing LLC.


Bhunia A.K.,Vidyasagar University | Kamilya T.,Narajole Raj College | Saha S.,Vidyasagar University
Materials Today: Proceedings | Year: 2016

A simple wet chemical method has been successfully used to grow zinc oxide nanorods (ZnO NRs). The structural characteristics were investigated through XRD and TEM. The crystal unit cell of the NRs was found to be hexagonal and the size of the ZnO NR ≈27 nm. The interaction as well as the formation of bio-conjugate of Bovine Serum Albumin (BSA) and ZnO NRs is investigated using optical spectroscopy, zeta potential, TEM analysis. UV-VIS and fluorescence spectra show that a spontaneous binding process occurred between BSA and ZnO NRs. The binding constant and the number of binding sites were also calculated. © 2016 Elsevier Ltd.


Patra R.R.,Vidyasagar University | Das S.,Vidyasagar University | Jana R.N.,Vidyasagar University | Ghosh S.K.,Narajole Raj College
Journal of Applied Fluid Mechanics | Year: 2012

The effect of radiation on natural convection incompressible viscous fluid near a vertical flat plate with ramped wall temperature has been studied. An analytical solution of the governing equation has been obtained by employing Laplace transform technique. It is examined that two different solutions for the fluid velocities, one valid for fluids of Prandtl number (Pr) different from 1 + Ra, Ra being the radiation parameter and the other for which the Prandtl number equal to 1 + Ra. The variations of velocities and fluid temperature are presented graphically. Furthermore, the radiative heat transfer on natural convection flow near a ramped plate temperature has been compared with the flow near a plate with the constant wall temperature. It is found that an increase in radiation parameter leads to rise the fluid velocity as well as temperature.

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