1
|
Bhattacharjee N, Alonso-Cotchico L, Lucas MF. Enzyme immobilization studied through molecular dynamic simulations. Front Bioeng Biotechnol 2023; 11:1200293. [PMID: 37362217 PMCID: PMC10285225 DOI: 10.3389/fbioe.2023.1200293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 05/30/2023] [Indexed: 06/28/2023] Open
Abstract
In recent years, simulations have been used to great advantage to understand the structural and dynamic aspects of distinct enzyme immobilization strategies, as experimental techniques have limitations in establishing their impact at the molecular level. In this review, we discuss how molecular dynamic simulations have been employed to characterize the surface phenomenon in the enzyme immobilization procedure, in an attempt to decipher its impact on the enzyme features, such as activity and stability. In particular, computational studies on the immobilization of enzymes using i) nanoparticles, ii) self-assembled monolayers, iii) graphene and carbon nanotubes, and iv) other surfaces are covered. Importantly, this thorough literature survey reveals that, while simulations have been primarily performed to rationalize the molecular aspects of the immobilization event, their use to predict adequate protocols that can control its impact on the enzyme properties is, up to date, mostly missing.
Collapse
|
2
|
Angelici G, Bhattacharjee N, Pypec M, Jouffret L, Didierjean C, Jolibois F, Perrin L, Roy O, Taillefumier C. Unveiling the conformational landscape of achiral all- cis tert-butyl β-peptoids. Org Biomol Chem 2022; 20:7907-7915. [PMID: 36173021 DOI: 10.1039/d2ob01351g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The synthesis and conformational study of N-substituted β-alanines with tert-butyl side chains is described. The oligomers prepared by submonomer synthesis and block coupling methods are up to 15 residues long and are characterised by amide bonds in the cis-conformation. A conformational study comprising experimental solution NMR spectroscopy, X-ray crystallography and molecular modeling shows that despite their intrinsic higher conformational flexibility compared to their α-peptoid counterparts, this family of achiral oligomers adopt preferred secondary structures including a helical conformation close to that described with (1-naphthyl)ethyl side chains but also a novel ribbon-like conformation.
Collapse
Affiliation(s)
- Gaetano Angelici
- Université Clermont Auvergne, Clermont Auvergne INP, CNRS, ICCF, 63000 Clermont-Ferrand, France.
| | - Nicholus Bhattacharjee
- Université de Lyon, Université Claude Bernard Lyon I, CNRS, INSA, CPE, UMR 5246, ICBMS, 1 rue Victor Grignard, F-69622 Villeurbanne, France
| | - Maxime Pypec
- Université Clermont Auvergne, Clermont Auvergne INP, CNRS, ICCF, 63000 Clermont-Ferrand, France.
| | - Laurent Jouffret
- Université Clermont Auvergne, Clermont Auvergne INP, CNRS, ICCF, 63000 Clermont-Ferrand, France.
| | | | - Franck Jolibois
- Université de Toulouse-INSA-UPS, LPCNO, CNRS UMR 5215, 135 av. Rangueil, F-31077, Toulouse, France
| | - Lionel Perrin
- Université de Lyon, Université Claude Bernard Lyon I, CNRS, INSA, CPE, UMR 5246, ICBMS, 1 rue Victor Grignard, F-69622 Villeurbanne, France
| | - Olivier Roy
- Université Clermont Auvergne, Clermont Auvergne INP, CNRS, ICCF, 63000 Clermont-Ferrand, France.
| | - Claude Taillefumier
- Université Clermont Auvergne, Clermont Auvergne INP, CNRS, ICCF, 63000 Clermont-Ferrand, France.
| |
Collapse
|
3
|
Del Frate G, Macchiagodena M, Akhunzada MJ, D'Autilia F, Catte A, Bhattacharjee N, Barone V, Cardarelli F, Brancato G. Probing Liquid-Ordered and Disordered Phases in Lipid Model Membranes: A Combined Theoretical and Spectroscopic Study of a Fluorescent Molecular Rotor. J Phys Chem B 2022; 126:480-491. [PMID: 35001625 PMCID: PMC8785181 DOI: 10.1021/acs.jpcb.1c08324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
![]()
An integrated theoretical/experimental
strategy has been applied
to the study of environmental effects on the spectroscopic parameters
of 4-(diphenylamino)phtalonitrile (DPAP), a fluorescent molecular
rotor. The computational part starts from the development of an effective
force field for the first excited electronic state of DPAP and proceeds
through molecular dynamics simulations in solvents of different polarities
toward the evaluation of Stokes shifts by quantum mechanics/molecular
mechanics (QM/MM) approaches. The trends of the computed results closely
parallel the available experimental results thus giving confidence
to the interpretation of new experimental studies of the photophysics
of DPAP in lipid bilayers. In this context, results show unambiguously
that both flexible dihedral angles and global rotations are significantly
retarded in a cholesterol/DPPC lipid matrix with respect to the DOPC
matrix, thus confirming the sensitivity of DPAP to probe different
environments and, therefore, its applicability as a probe for detecting
different structures and levels of plasma membrane organization.
Collapse
Affiliation(s)
| | | | | | - Francesca D'Autilia
- Center for Nanotechnology Innovation@NEST (CNI@NEST), Piazza San Silvestro 12, I-56127 Pisa, Italy
| | - Andrea Catte
- Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa, Italy
| | | | - Vincenzo Barone
- Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa, Italy.,Istituto Nazionale di Fisica Nucleare(INFN), Largo Pontecorvo 3, I-56 127 Pisa, Italy.,Consorzio Interuniversitario per lo Sviluppo dei Sistemi a Grande Interfase (CSGI), Via della Lastruccia 3, I-50 019 Sesto Fiorentino, Florence, Italy
| | | | - Giuseppe Brancato
- Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa, Italy.,Istituto Nazionale di Fisica Nucleare(INFN), Largo Pontecorvo 3, I-56 127 Pisa, Italy.,Consorzio Interuniversitario per lo Sviluppo dei Sistemi a Grande Interfase (CSGI), Via della Lastruccia 3, I-50 019 Sesto Fiorentino, Florence, Italy
| |
Collapse
|
4
|
Lavarda G, Bhattacharjee N, Brancato G, Torres T, Bottari G. Enabling Racemization of Axially Chiral Subphthalocyanine‐Tetracyanobutadiene‐Aniline Enantiomers by Triplet State Photogeneration. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202010133] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Giulia Lavarda
- Departamento de Química Orgánica Universidad Autónoma de Madrid Campus de Cantoblanco 28049 Madrid Spain
| | - Nicholus Bhattacharjee
- Scuola Normale Superiore Piazza dei Cavalieri 7 56126 Pisa Italy
- Istituto Nazionale di Fisica Nucleare Largo Pontecorvo 3 56100 Pisa Italy
| | - Giuseppe Brancato
- Scuola Normale Superiore Piazza dei Cavalieri 7 56126 Pisa Italy
- Istituto Nazionale di Fisica Nucleare Largo Pontecorvo 3 56100 Pisa Italy
| | - Tomás Torres
- Departamento de Química Orgánica Universidad Autónoma de Madrid Campus de Cantoblanco 28049 Madrid Spain
- IMDEA-Nanociencia c/Faraday 9, Campus de Cantoblanco 28049 Madrid Spain
- Institute for Advanced Research in Chemical Sciences (IAdChem) Universidad Autónoma de Madrid 28049 Madrid Spain
| | - Giovanni Bottari
- Departamento de Química Orgánica Universidad Autónoma de Madrid Campus de Cantoblanco 28049 Madrid Spain
- IMDEA-Nanociencia c/Faraday 9, Campus de Cantoblanco 28049 Madrid Spain
- Institute for Advanced Research in Chemical Sciences (IAdChem) Universidad Autónoma de Madrid 28049 Madrid Spain
| |
Collapse
|
5
|
Lavarda G, Bhattacharjee N, Brancato G, Torres T, Bottari G. Enabling Racemization of Axially Chiral Subphthalocyanine‐Tetracyanobutadiene‐Aniline Enantiomers by Triplet State Photogeneration. Angew Chem Int Ed Engl 2020; 59:21224-21229. [DOI: 10.1002/anie.202010133] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Indexed: 12/24/2022]
Affiliation(s)
- Giulia Lavarda
- Departamento de Química Orgánica Universidad Autónoma de Madrid Campus de Cantoblanco 28049 Madrid Spain
| | - Nicholus Bhattacharjee
- Scuola Normale Superiore Piazza dei Cavalieri 7 56126 Pisa Italy
- Istituto Nazionale di Fisica Nucleare Largo Pontecorvo 3 56100 Pisa Italy
| | - Giuseppe Brancato
- Scuola Normale Superiore Piazza dei Cavalieri 7 56126 Pisa Italy
- Istituto Nazionale di Fisica Nucleare Largo Pontecorvo 3 56100 Pisa Italy
| | - Tomás Torres
- Departamento de Química Orgánica Universidad Autónoma de Madrid Campus de Cantoblanco 28049 Madrid Spain
- IMDEA-Nanociencia c/Faraday 9, Campus de Cantoblanco 28049 Madrid Spain
- Institute for Advanced Research in Chemical Sciences (IAdChem) Universidad Autónoma de Madrid 28049 Madrid Spain
| | - Giovanni Bottari
- Departamento de Química Orgánica Universidad Autónoma de Madrid Campus de Cantoblanco 28049 Madrid Spain
- IMDEA-Nanociencia c/Faraday 9, Campus de Cantoblanco 28049 Madrid Spain
- Institute for Advanced Research in Chemical Sciences (IAdChem) Universidad Autónoma de Madrid 28049 Madrid Spain
| |
Collapse
|
6
|
Rodriguez A, Horowitz L, Castro K, Kenerson H, Bhattacharjee N, Gandhe G, Raman A, Monnat RJ, Yeung R, Rostomily R, Folch A. A microfluidic platform for functional testing of cancer drugs on intact tumor slices. Lab Chip 2020; 20:1658-1675. [PMID: 32270149 PMCID: PMC7679198 DOI: 10.1039/c9lc00811j] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Present approaches to assess cancer treatments are often inaccurate, costly, and/or cumbersome. Functional testing platforms that use live tumor cells are a promising tool both for drug development and for identifying the optimal therapy for a given patient, i.e. precision oncology. However, current methods that utilize patient-derived cells from dissociated tissue typically lack the microenvironment of the tumor tissue and/or cannot inform on a timescale rapid enough to guide decisions for patient-specific therapy. We have developed a microfluidic platform that allows for multiplexed drug testing of intact tumor slices cultured on a porous membrane. The device is digitally-manufactured in a biocompatible thermoplastic by laser-cutting and solvent bonding. Here we describe the fabrication process in detail, we characterize the fluidic performance of the device, and demonstrate on-device drug-response testing with tumor slices from xenografts and from a patient colorectal tumor.
Collapse
Affiliation(s)
- A.D Rodriguez
- Department of Bioengineering, University of Washington, Seattle, WA, 98105, USA
- corresponding author:
| | - L.F Horowitz
- Department of Bioengineering, University of Washington, Seattle, WA, 98105, USA
- Department of Pathology, University of Washington, Seattle, WA 98195, USA
| | - K. Castro
- Department of Bioengineering, University of Washington, Seattle, WA, 98105, USA
| | - H. Kenerson
- Department of Surgery, University of Washington Seattle, WA 98105, USA
| | - N. Bhattacharjee
- Department of Bioengineering, University of Washington, Seattle, WA, 98105, USA
| | - G. Gandhe
- Department of Bioengineering, University of Washington, Seattle, WA, 98105, USA
| | - A. Raman
- Department of Bioengineering, University of Washington, Seattle, WA, 98105, USA
| | - R. J. Monnat
- Department of Pathology, University of Washington, Seattle, WA 98195, USA
| | - R. Yeung
- Department of Surgery, University of Washington Seattle, WA 98105, USA
| | - R.C. Rostomily
- Department of Neurosurgery, Houston Methodist Hospital and Research Institute, Houston, TX, USA
- Weill Cornell School of Medicine, Department of Neurosurgery
| | - A. Folch
- Department of Bioengineering, University of Washington, Seattle, WA, 98105, USA
| |
Collapse
|
7
|
Bhattacharjee N, Sapozhnik AA, Bodnar SY, Grigorev VY, Agustsson SY, Cao J, Dominko D, Obergfell M, Gomonay O, Sinova J, Kläui M, Elmers HJ, Jourdan M, Demsar J. Retraction: Néel Spin-Orbit Torque Driven Antiferromagnetic Resonance in Mn_{2}Au Probed by Time-Domain THz Spectroscopy [Phys. Rev. Lett. 120, 237201 (2018)]. Phys Rev Lett 2020; 124:039901. [PMID: 32031846 DOI: 10.1103/physrevlett.124.039901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Indexed: 06/10/2023]
Abstract
Retraction of DOI: 10.1103/PhysRevLett.120.237201.
Collapse
|
8
|
Bhattacharjee N, Perrin L, Jolibois F. Relating circular dichroism to atomic structure by means of MD simulations and computed CD spectra with α-peptoids as an example. Phys Chem Chem Phys 2020; 22:13192-13200. [DOI: 10.1039/d0cp01336f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Accurate TD-DFT calculations of electronic circular dichroism have been performed to characterise the 3D structure of α-peptoids.
Collapse
Affiliation(s)
| | - Lionel Perrin
- Université de Lyon
- Université Claude Bernard Lyon 1
- CPE Lyon
- INSA Lyon
- ICBMS
| | - Franck Jolibois
- Université de Toulouse-INSA-UPS
- LPCNO
- CNRS UMR 5215
- 135 av. Rangueil
- Toulouse
| |
Collapse
|
9
|
Catte A, Ferbel L, Bhattacharjee N, Jan Akhunzada M, D'Agostino T, Brancato G. In silico investigation of the interaction between the voltage-gated potassium channel Kv4.3 and its auxiliary protein KChIP1. Phys Chem Chem Phys 2019; 21:25290-25301. [PMID: 31701097 DOI: 10.1039/c9cp04082j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The voltage-gated potassium channel Kv4.3 plays a vital role in shaping the timing, frequency, and backpropagation of electrical signals in the brain and heart by generating fast transient currents at subthreshold membrane potentials in repetitive firing neurons. To achieve its physiological function, Kv4.3 is assisted by auxiliary β-subunits that become integral parts of the native A-type potassium channels, among which there are the Kv channel-interacting proteins (KChIPs). KChIPs are a family of cytosolic proteins that, when coexpressed with Kv4, lead to higher current density, modulation of channel inactivation and faster recovery from inactivation, while the loss of KChIP function may lead to severe pathological states. Recently, the structural basis of the KChIP1-Kv4.3 interaction was reported by using two similar X-ray crystallographic structures, which supported a crucial role for KChIP1 in enhancing the stability of the Kv4.3 tetrameric assembly, thus helping the trafficking of the channel to the plasma membrane. Here, we investigate through fully atomistic simulations the structure and stability of the human Kv4.3 tetramerization (T1) domain in complex with KChIP1 upon specific mutations located in the first and second interfaces of the complex, as compared to the wild-type (WT). Our results nicely complement the available structural and biophysical information collected so far on these complex variants. In particular, the degree of structural deviations and energetic instability, from small to substantial, observed in these variants with respect to the WT model seems to parallel well the level of channel dysfunction known from electrophysiology data. Our simulations provide an octameric structure of the WT KChIP1-Kv4.3 assembly very similar to the known crystal structures, and, at the same time, highlight the importance of a previously overlooked site of interaction between KChIP1 and the Kv4.3 T1 domain.
Collapse
Affiliation(s)
- Andrea Catte
- Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa, Italy. and Istituto Nazionale di Fisica Nucleare, Largo Pontecorvo 3, I-56100 Pisa, Italy
| | - Letizia Ferbel
- Università di Pisa, Dipartimento di Ingegneria Civile ed Industriale, Largo Lucio Lazzarino 2, I-56124 Pisa, Italy
| | - Nicholus Bhattacharjee
- Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa, Italy. and Istituto Nazionale di Fisica Nucleare, Largo Pontecorvo 3, I-56100 Pisa, Italy
| | - Muhammad Jan Akhunzada
- Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa, Italy. and Istituto Nazionale di Fisica Nucleare, Largo Pontecorvo 3, I-56100 Pisa, Italy
| | - Tommaso D'Agostino
- Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa, Italy. and Istituto Nazionale di Fisica Nucleare, Largo Pontecorvo 3, I-56100 Pisa, Italy
| | - Giuseppe Brancato
- Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa, Italy. and Istituto Nazionale di Fisica Nucleare, Largo Pontecorvo 3, I-56100 Pisa, Italy
| |
Collapse
|
10
|
Jan Akhunzada M, D'Autilia F, Chandramouli B, Bhattacharjee N, Catte A, Di Rienzo R, Cardarelli F, Brancato G. Interplay between lipid lateral diffusion, dye concentration and membrane permeability unveiled by a combined spectroscopic and computational study of a model lipid bilayer. Sci Rep 2019; 9:1508. [PMID: 30728410 PMCID: PMC6365552 DOI: 10.1038/s41598-018-37814-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Accepted: 12/10/2018] [Indexed: 01/08/2023] Open
Abstract
Lipid lateral diffusion in membrane bilayers is a fundamental process exploited by cells to enable complex protein structural and dynamic reorganizations. For its importance, lipid mobility in both cellular and model bilayers has been extensively investigated in recent years, especially through the application of time-resolved, fluorescence-based, optical microscopy techniques. However, one caveat of fluorescence techniques is the need to use dye-labeled variants of the lipid of interest, thus potentially perturbing the structural and dynamic properties of the native species. Generally, the effect of the dye/tracer molecule is implicitly assumed to be negligible. Nevertheless, in view of the widespread use of optically modified lipids for studying lipid bilayer dynamics, it is highly desirable to well assess this point. Here, fluorescence correlation spectroscopy (FCS) and molecular dynamics (MD) simulations have been combined together to uncover subtle structural and dynamic effects in DOPC planar membranes enriched with a standard Rhodamine-labeled lipid. Our findings support a non-neutral role of the dye-labeled lipids in diffusion experiments, quantitatively estimating a decrease in lipid mobility of up to 20% with respect to the unlabeled species. Moreover, results highlight the existing interplay between dye concentration, lipid lateral diffusion and membrane permeability, thus suggesting possible implications for future optical microscopy studies of biophysical processes occurring at the membrane level.
Collapse
Affiliation(s)
- Muhammad Jan Akhunzada
- Scuola Normale Superiore, piazza dei Cavalieri 7, I-56126, Pisa, Italy.,Istituto Nazionale di Fisica Nucleare, Largo Pontecorvo 3, I-56100, Pisa, Italy
| | | | - Balasubramanian Chandramouli
- Scuola Normale Superiore, piazza dei Cavalieri 7, I-56126, Pisa, Italy.,Compunet, Istituto Italiano di Tecnologia (IIT), Via Morego 30, I-16163, Genova, Italy
| | - Nicholus Bhattacharjee
- Scuola Normale Superiore, piazza dei Cavalieri 7, I-56126, Pisa, Italy.,Istituto Nazionale di Fisica Nucleare, Largo Pontecorvo 3, I-56100, Pisa, Italy
| | - Andrea Catte
- Scuola Normale Superiore, piazza dei Cavalieri 7, I-56126, Pisa, Italy.,Istituto Nazionale di Fisica Nucleare, Largo Pontecorvo 3, I-56100, Pisa, Italy
| | - Roberto Di Rienzo
- Dipartimento di Ingegneria dell'Informazione, Università di Pisa, Via Girolamo Caruso 16, I-56122 Pisa, Italy
| | - Francesco Cardarelli
- NEST, Scuola Normale Superiore and Istituto Nanoscienze-CNR, Piazza San Silvestro 12, 56127, Pisa, Italy
| | - Giuseppe Brancato
- Scuola Normale Superiore, piazza dei Cavalieri 7, I-56126, Pisa, Italy. .,Istituto Nazionale di Fisica Nucleare, Largo Pontecorvo 3, I-56100, Pisa, Italy.
| |
Collapse
|
11
|
Bhattacharjee N, Sapozhnik AA, Bodnar SY, Grigorev VY, Agustsson SY, Cao J, Dominko D, Obergfell M, Gomonay O, Sinova J, Kläui M, Elmers HJ, Jourdan M, Demsar J. Néel Spin-Orbit Torque Driven Antiferromagnetic Resonance in Mn_{2}Au Probed by Time-Domain THz Spectroscopy. Phys Rev Lett 2018; 120:237201. [PMID: 29932703 DOI: 10.1103/physrevlett.120.237201] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Indexed: 06/08/2023]
Abstract
We observe the excitation of collective modes in the terahertz (THz) range driven by the recently discovered Néel spin-orbit torques (NSOTs) in the metallic antiferromagnet Mn_{2}Au. Temperature-dependent THz spectroscopy reveals a strong absorption mode centered near 1 THz, which upon heating from 4 to 450 K softens and loses intensity. A comparison with the estimated eigenmode frequencies implies that the observed mode is an in-plane antiferromagnetic resonance (AFMR). The AFMR absorption strength exceeds those found in antiferromagnetic insulators, driven by the magnetic field of the THz radiation, by 3 orders of magnitude. Based on this and the agreement with our theory modeling, we infer that the driving mechanism for the observed mode is the current-induced NSOT. Here the electric field component of the THz pulse drives an ac current in the metal, which subsequently drives the AFMR. This electric manipulation of the Néel order parameter at high frequencies makes Mn_{2}Au a prime candidate for antiferromagnetic ultrafast memory applications.
Collapse
Affiliation(s)
- N Bhattacharjee
- Institute of Physics, Johannes Gutenberg-University Mainz, 55099 Mainz, Germany
| | - A A Sapozhnik
- Institute of Physics, Johannes Gutenberg-University Mainz, 55099 Mainz, Germany
- Graduate School of Excellence, Materials Science in Mainz (MAINZ), 55099 Mainz, Germany
| | - S Yu Bodnar
- Institute of Physics, Johannes Gutenberg-University Mainz, 55099 Mainz, Germany
| | - V Yu Grigorev
- Institute of Physics, Johannes Gutenberg-University Mainz, 55099 Mainz, Germany
- Graduate School of Excellence, Materials Science in Mainz (MAINZ), 55099 Mainz, Germany
| | - S Y Agustsson
- Institute of Physics, Johannes Gutenberg-University Mainz, 55099 Mainz, Germany
| | - J Cao
- Institute of Physics, Johannes Gutenberg-University Mainz, 55099 Mainz, Germany
| | - D Dominko
- Institute of Physics, Johannes Gutenberg-University Mainz, 55099 Mainz, Germany
- Institute of Physics, Bijenička c. 46, 10000 Zagreb, Croatia
| | - M Obergfell
- Institute of Physics, Johannes Gutenberg-University Mainz, 55099 Mainz, Germany
| | - O Gomonay
- Institute of Physics, Johannes Gutenberg-University Mainz, 55099 Mainz, Germany
| | - J Sinova
- Institute of Physics, Johannes Gutenberg-University Mainz, 55099 Mainz, Germany
- Graduate School of Excellence, Materials Science in Mainz (MAINZ), 55099 Mainz, Germany
- Institute of Physics ASCR, v.v.i., Cukrovarnicka 10, 162 53 Praha 6, Czech Republic
| | - M Kläui
- Institute of Physics, Johannes Gutenberg-University Mainz, 55099 Mainz, Germany
- Graduate School of Excellence, Materials Science in Mainz (MAINZ), 55099 Mainz, Germany
| | - H-J Elmers
- Institute of Physics, Johannes Gutenberg-University Mainz, 55099 Mainz, Germany
- Graduate School of Excellence, Materials Science in Mainz (MAINZ), 55099 Mainz, Germany
| | - M Jourdan
- Institute of Physics, Johannes Gutenberg-University Mainz, 55099 Mainz, Germany
- Graduate School of Excellence, Materials Science in Mainz (MAINZ), 55099 Mainz, Germany
| | - J Demsar
- Institute of Physics, Johannes Gutenberg-University Mainz, 55099 Mainz, Germany
- Graduate School of Excellence, Materials Science in Mainz (MAINZ), 55099 Mainz, Germany
| |
Collapse
|
12
|
Dumonteil G, Bhattacharjee N, Angelici G, Roy O, Faure S, Jouffret L, Jolibois F, Perrin L, Taillefumier C. Exploring the Conformation of Mixed Cis–Trans α,β-Oligopeptoids: A Joint Experimental and Computational Study. J Org Chem 2018; 83:6382-6396. [DOI: 10.1021/acs.joc.8b00606] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Geoffrey Dumonteil
- Université Clermont Auvergne, CNRS, SIGMA Clermont, ICCF, F-63000 Clermont-Ferrand, France
| | - Nicholus Bhattacharjee
- Université de Toulouse-INSA-UPS, LPCNO, CNRS UMR 5215, 135 av Rangueil, F-31077, Toulouse, France
- Université de Lyon, Université Claude Bernard Lyon 1, CPE Lyon, INSA Lyon, ICBMS, CNRS UMR 5246, Equipe ITEMM, Bât Curien, 43 Boulevard du 11 Novembre 1918, 69622 Villeurbanne, France
| | - Gaetano Angelici
- Université Clermont Auvergne, CNRS, SIGMA Clermont, ICCF, F-63000 Clermont-Ferrand, France
| | - Olivier Roy
- Université Clermont Auvergne, CNRS, SIGMA Clermont, ICCF, F-63000 Clermont-Ferrand, France
| | - Sophie Faure
- Université Clermont Auvergne, CNRS, SIGMA Clermont, ICCF, F-63000 Clermont-Ferrand, France
| | - Laurent Jouffret
- Université Clermont Auvergne, CNRS, SIGMA Clermont, ICCF, F-63000 Clermont-Ferrand, France
| | - Franck Jolibois
- Université de Toulouse-INSA-UPS, LPCNO, CNRS UMR 5215, 135 av Rangueil, F-31077, Toulouse, France
| | - Lionel Perrin
- Université de Lyon, Université Claude Bernard Lyon 1, CPE Lyon, INSA Lyon, ICBMS, CNRS UMR 5246, Equipe ITEMM, Bât Curien, 43 Boulevard du 11 Novembre 1918, 69622 Villeurbanne, France
| | - Claude Taillefumier
- Université Clermont Auvergne, CNRS, SIGMA Clermont, ICCF, F-63000 Clermont-Ferrand, France
| |
Collapse
|
13
|
Shaik MM, Bhattacharjee N, Feliks M, Ng KKS, Field MJ. Norovirus RNA-dependent RNA polymerase: A computational study of metal-binding preferences. Proteins 2017; 85:1435-1445. [PMID: 28383118 DOI: 10.1002/prot.25304] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Revised: 03/31/2017] [Accepted: 04/04/2017] [Indexed: 12/21/2022]
Abstract
Norovirus (NV) RNA-dependent RNA polymerase (RdRP) is essential for replicating the genome of the virus, which makes this enzyme a key target for the development of antiviral agents against NV gastroenteritis. In this work, a complex of NV RdRP bound to manganese ions and an RNA primer-template duplex was investigated using X-ray crystallography and hybrid quantum chemical/molecular mechanical simulations. Experimentally, the complex crystallized in a tetragonal crystal form. The nature of the primer/template duplex binding in the resulting structure indicates that the complex is a closed back-tracked state of the enzyme, in which the 3'-end of the primer occupies the position expected for the post-incorporated nucleotide before translocation. Computationally, it is found that the complex can accept a range of divalent metal cations without marked distortions in the active site structure. The highest binding energy is for copper, followed closely by manganese and iron, and then by zinc, nickel, and cobalt. Proteins 2017; 85:1435-1445. © 2017 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Md Munan Shaik
- Division of Molecular Medicine, Boston Children's Hospital, Boston, Massachusetts, 02115.,Department of Pediatrics, Harvard Medical School, 3 Blackfan Street, Boston, Massachusetts, 02115
| | - Nicholus Bhattacharjee
- Dynamo Team/DYNAMOP Group, UMR5075, Université Grenoble I, CEA, CNRS, Institut de Biologie Structurale, 71 Avenue des Martyrs, CS 10090, Grenoble Cedex 9, 38044, France
| | - Mikolaj Feliks
- Dynamo Team/DYNAMOP Group, UMR5075, Université Grenoble I, CEA, CNRS, Institut de Biologie Structurale, 71 Avenue des Martyrs, CS 10090, Grenoble Cedex 9, 38044, France
| | - Kenneth K-S Ng
- Department of Biological Sciences and Alberta Glycomics Centre, University of Calgary, Calgary, Alberta, Canada
| | - Martin J Field
- Dynamo Team/DYNAMOP Group, UMR5075, Université Grenoble I, CEA, CNRS, Institut de Biologie Structurale, 71 Avenue des Martyrs, CS 10090, Grenoble Cedex 9, 38044, France
| |
Collapse
|
14
|
Jan Akhunzada M, Chandramouli B, Bhattacharjee N, Macchi S, Cardarelli F, Brancato G. The role of Tat peptide self-aggregation in membrane pore stabilization: insights from a computational study. Phys Chem Chem Phys 2017; 19:27603-27610. [DOI: 10.1039/c7cp05103d] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Role of Tat peptide self-aggregation to direct transduction in cells is highlighted in a computational study of dimer versus monomer.
Collapse
Affiliation(s)
| | | | | | - Sara Macchi
- NEST
- Scuola Normale Superiore and Istituto Nanoscienze-CNR
- 56127 Pisa
- Italy
| | | | - Giuseppe Brancato
- Scuola Normale Superiore
- Italy
- Istituto Nazionale di Fisica Nucleare
- I-56100 Pisa
- Italy
| |
Collapse
|
15
|
Affiliation(s)
- Nicholus Bhattacharjee
- Dynamo
Team/DYNAMOP Group, UMR5075, Université Grenoble I, CEA, CNRS, Institut de Biologie Structurale, 71 Avenue des Martyrs, CS 10090, 38044 Grenoble Cedex 9, France
| | - Mikolaj Feliks
- Dynamo
Team/DYNAMOP Group, UMR5075, Université Grenoble I, CEA, CNRS, Institut de Biologie Structurale, 71 Avenue des Martyrs, CS 10090, 38044 Grenoble Cedex 9, France
| | - Md Munan Shaik
- Division
of Molecular Medicine, Boston Children’s Hospital, Boston, Massachusetts 02115, United States
- Department
of Pediatrics, Harvard Medical School, 3 Blackfan Street, Boston, Massachusetts 02115, United States
| | - Martin J. Field
- Dynamo
Team/DYNAMOP Group, UMR5075, Université Grenoble I, CEA, CNRS, Institut de Biologie Structurale, 71 Avenue des Martyrs, CS 10090, 38044 Grenoble Cedex 9, France
| |
Collapse
|
16
|
Bhattacharjee N, Horowitz LF, Folch A. Continuous-flow multi-pulse electroporation at low DC voltages by microfluidic flipping of the voltage space topology. Appl Phys Lett 2016; 109:163702. [PMID: 27821874 PMCID: PMC5075000 DOI: 10.1063/1.4963316] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Accepted: 09/12/2016] [Indexed: 05/13/2023]
Abstract
Concerns over biosafety, cost, and carrying capacity of viral vectors have accelerated research into physical techniques for gene delivery such as electroporation and mechanoporation. Advances in microfabrication have made it possible to create high electric fields over microscales, resulting in more efficient DNA delivery and higher cell viability. Continuous-flow microfluidic methods are typically more suitable for cellular therapies where a large number of cells need to be transfected under sterile conditions. However, the existing continuous-flow designs used to generate multiple pulses either require expensive peripherals such as high-voltage (>400 V) sources or function generators, or result in reduced cell viability due to the proximity of the cells to the electrodes. In this paper, we report a continuous-flow microfluidic device whose channel geometry reduces instrumentation demands and minimizes cellular toxicity. Our design can generate multiple pulses of high DC electric field strength using significantly lower voltages (15-60 V) than previous designs. The cells flow along a serpentine channel that repeatedly flips the cells between a cathode and an anode at high throughput. The cells must flow through a constriction each time they pass from an anode to a cathode, exposing them to high electric field strength for short durations of time (the "pulse-width"). A conductive biocompatible poly-aniline hydrogel network formed in situ is used to apply the DC voltage without bringing the metal electrodes close to the cells, further sheltering cells from the already low voltage electrodes. The device was used to electroporate multiple cell lines using electric field strengths between 700 and 800 V/cm with transfection efficiencies superior than previous flow-through designs.
Collapse
Affiliation(s)
- N Bhattacharjee
- Department of Bioengineering, University of Washington , Seattle, Washington 98195, USA
| | - L F Horowitz
- Department of Bioengineering, University of Washington , Seattle, Washington 98195, USA
| | - A Folch
- Department of Bioengineering, University of Washington , Seattle, Washington 98195, USA
| |
Collapse
|
17
|
Bhattacharjee N, Field MJ, Simorre JP, Arthur M, Bougault CM. Hybrid Potential Simulation of the Acylation of Enterococcus faecium l,d-Transpeptidase by Carbapenems. J Phys Chem B 2016; 120:4767-81. [DOI: 10.1021/acs.jpcb.6b02836] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Nicholus Bhattacharjee
- DYNAMO/DYNAMOP,
UMR 5075, Université Grenoble 1, CNRS, CEA, Institut de Biologie
Structurale, 71 Avenue des Martyrs,
CS 10090, 38044 Grenoble Cedex 9, France
| | - Martin J. Field
- DYNAMO/DYNAMOP,
UMR 5075, Université Grenoble 1, CNRS, CEA, Institut de Biologie
Structurale, 71 Avenue des Martyrs,
CS 10090, 38044 Grenoble Cedex 9, France
| | - Jean-Pierre Simorre
- RMN, UMR 5075,
Université Grenoble 1, CNRS, CEA, Institut de Biologie Structurale, 71 Avenue des Martyrs, CS 10090, 38044 Grenoble Cedex 9, France
| | - Michel Arthur
- Centre de Recherche
des Cordeliers, Equipe 12, UMR S 872, Université Pierre et
Marie Curie-Paris 6, INSERM, Université Paris Descartes, Sorbonne
Paris Cité, 15 rue de l’Ecole
de Médecine, 75006 Paris, France
| | - Catherine M. Bougault
- RMN, UMR 5075,
Université Grenoble 1, CNRS, CEA, Institut de Biologie Structurale, 71 Avenue des Martyrs, CS 10090, 38044 Grenoble Cedex 9, France
| |
Collapse
|
18
|
Angelici G, Bhattacharjee N, Roy O, Faure S, Didierjean C, Jouffret L, Jolibois F, Perrin L, Taillefumier C. Correction: Weak backbone CH⋯OC and side chain tBu⋯tBu London interactions help promote helix folding of achiral NtBu peptoids. Chem Commun (Camb) 2016; 52:6625. [DOI: 10.1039/c6cc90163h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Correction for ‘Weak backbone CH⋯OC and side chain tBu⋯tBu London interactions help promote helix folding of achiral NtBu peptoids’ by G. Angelici et al., Chem. Commun., 2016, 52, 4573–4576.
Collapse
Affiliation(s)
- G. Angelici
- Université Clermont Auvergne
- Université Blaise Pascal
- Institut de Chimie de Clermont-Ferrand
- F-63000 Clermont-Ferrand
- France
| | | | - O. Roy
- Université Clermont Auvergne
- Université Blaise Pascal
- Institut de Chimie de Clermont-Ferrand
- F-63000 Clermont-Ferrand
- France
| | - S. Faure
- Université Clermont Auvergne
- Université Blaise Pascal
- Institut de Chimie de Clermont-Ferrand
- F-63000 Clermont-Ferrand
- France
| | - C. Didierjean
- LCM3B
- Université de Lorraine
- UMR CNRS 7036 CRM2
- F-54506 Vandoeuvre-lès-Nancy
- France
| | - L. Jouffret
- Université Clermont Auvergne
- Université Blaise Pascal
- Institut de Chimie de Clermont-Ferrand
- F-63000 Clermont-Ferrand
- France
| | - F. Jolibois
- Université de Toulouse-INSA-UPS
- LPCNO
- CNRS UMR 5215
- Toulouse
- France
| | - L. Perrin
- ICBMS UMR 5246
- Université de Lyon
- 69622 Villeurbanne cedex
- France
| | - C. Taillefumier
- Université Clermont Auvergne
- Université Blaise Pascal
- Institut de Chimie de Clermont-Ferrand
- F-63000 Clermont-Ferrand
- France
| |
Collapse
|
19
|
Angelici G, Bhattacharjee N, Roy O, Faure S, Didierjean C, Jouffret L, Jolibois F, Perrin L, Taillefumier C. Weak backbone CH⋯OC and side chain tBu⋯tBu London interactions help promote helix folding of achiral NtBu peptoids. Chem Commun (Camb) 2016; 52:4573-6. [DOI: 10.1039/c6cc00375c] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The synthesis and helix folding propensity of achiral all-cis amide (NtBu)-glycine oligomers is reported.
Collapse
Affiliation(s)
- G. Angelici
- Université Clermont Auvergne
- Université Blaise Pascal
- Institut de Chimie de Clermont-Ferrand
- F-63000 Clermont-Ferrand
- France
| | | | - O. Roy
- Université Clermont Auvergne
- Université Blaise Pascal
- Institut de Chimie de Clermont-Ferrand
- F-63000 Clermont-Ferrand
- France
| | - S. Faure
- Université Clermont Auvergne
- Université Blaise Pascal
- Institut de Chimie de Clermont-Ferrand
- F-63000 Clermont-Ferrand
- France
| | - C. Didierjean
- LCM3B
- Université de Lorraine
- UMR CNRS 7036 CRM2
- F-54506 Vandoeuvre-lès-Nancy
- France
| | - L. Jouffret
- Université Clermont Auvergne
- Université Blaise Pascal
- Institut de Chimie de Clermont-Ferrand
- F-63000 Clermont-Ferrand
- France
| | - F. Jolibois
- Université de Toulouse-INSA-UPS
- LPCNO
- CNRS UMR 5215
- Toulouse
- France
| | - L. Perrin
- ICBMS UMR 5246
- Université de Lyon
- Bât. Curien
- 69622 Villeurbanne cedex
- France
| | - C. Taillefumier
- Université Clermont Auvergne
- Université Blaise Pascal
- Institut de Chimie de Clermont-Ferrand
- F-63000 Clermont-Ferrand
- France
| |
Collapse
|
20
|
Munan Shaik M, Bhattacharjee N, Bhattacharjee A, Field MJ, Zanotti G. Characterization of the divalent metal binding site of bacterial polysaccharide deacetylase using crystallography and quantum chemical calculations. Proteins 2014; 82:1311-8. [DOI: 10.1002/prot.24497] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2013] [Revised: 11/18/2013] [Accepted: 12/09/2013] [Indexed: 12/20/2022]
Affiliation(s)
- Md Munan Shaik
- PATBAC, Institut de Biologie Structurale-Jean-Pierre Ebel; Grenoble France
| | | | | | - Martin J. Field
- DYNAMOP, Institut de Biologie Structurale-Jean-Pierre Ebel; Grenoble France
| | - Giuseppe Zanotti
- Department of Biomedical Sciences; University of Padua; Padua Italy
| |
Collapse
|
21
|
Bhattacharjee N, Rani P, Biswas P. Capturing molten globule state of α-lactalbumin through constant pH molecular dynamics simulations. J Chem Phys 2013; 138:095101. [PMID: 23485328 DOI: 10.1063/1.4793470] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The recently developed methods of constant pH molecular dynamics directly captures the correlation between protonation and conformation to probe protein structure, function, and dynamics. In this work, we investigate the effect of pH on the conformational properties of the protein human α-lactalbumin. Constant pH simulations at both acidic and alkaline medium indicate the formation of the molten globule state, which is in accordance with the previous experimental observations (especially, in acidic medium). The size of the protein measured by its radius of gyration (RG) exhibits a marked increase in both acidic and alkaline medium, which matches with the corresponding experimentally observed value of RG found in the molten globule. The probability of native contacts is also considerably reduced at acidic and basic pH as compared to that of native structure crystallized at neutral pH. The mean fractal dimension D2 of the protein records a sharp increase in basic medium as compared to those in neutral and acidic solutions implying a significant pH induced conformational change. The mean square fluctuations of all residues of the entire protein are found to increase by several folds in both acidic and basic medium, which may be correlated with the normalized solvent accessibility of the residues indicating role of solvent accessible surface area on protein internal dynamics. The helices comprising the α-domain of the protein are moderately preserved in the acidic and alkaline pH. However, the β-sheet structures present in the β-domain are completely disrupted in both acidic as well as basic pH.
Collapse
|
22
|
Abstract
Background Mutation of amino acid sequences in a protein may have diverse effects on its structure and function. Point mutations of even a single amino acid residue in the helices of the non-redundant database may lead to sequentially identical peptides which adopt different secondary structures in different proteins. However, various physico-chemical factors which govern the formation of these ambivalent helices generated by point mutations of a sequence are not clearly known. Results Sequences generated by point mutations of helices are mapped on to their non-helical counterparts in the SCOP database. The results show that short helices are prone to transform into non-helical conformations upon point mutations. Mutation of amino acid residues by helix breakers preferentially yield non-helical conformations, while mutation with residues of intermediate helix propensity display least preferences for non-helical conformations. Differences in the solvent accessibility of the mutating/mutated residues are found to be a major criteria for these sequences to conform to non-helical conformations. Even with minimal differences in the amino acid distributions of the sequences flanking the helical and non-helical conformations, helix-flanking sequences are found be more solvent accessible. Conclusions All types of mutations from helical to non-helical conformations are investigated. The primary factors attributing such changes in conformation can be: i) type/propensity of the mutating and mutant residues ii) solvent accessibility of the residue at the mutation site iii) context/environment dependence of the flanking sequences. The results from the present study may be used to design de novo proteins via point mutations.
Collapse
|
23
|
Abstract
This work is a first attempt to characterise the conformational preference of structurally ambivalent helices in terms of their backbone conformational entropy. Ambivalent sequences conform to two different secondary structures (helix-sheet or helix-random coil or sheet-random coil, etc.) in two different proteins. For variable ambivalent helices, the helical conformations are found to possess less conformational entropy as compared with their non-helical counterparts when the ϕ-ψ dihedral angle range of the entire peptide segment is used to calculate the backbone conformational entropy. The favourable number of native contacts is a primary stabilising factor for these helical conformations. However, an opposite trend is observed when the ϕ-ψ angles of the individual amino acids are used to calculate the backbone conformational entropy. The results show that these peptide segments are rather reluctant to form helices, but are driven to form helices due to the favourable number of native contacts and optimum range of ϕ-ψ angle of the segments. Both procedures are validated by applying on conserved helices in the non-redundant database and their corresponding counterparts in the Structural Classification of Proteins database. Although context is a major determinant in deciding conformations of ambivalent sequences, no significant difference in the conformational entropy of sequences flanking ambivalent helical sequences in helical and non-helical forms is observed in this study. The results may be useful in understanding the structural context and environmental factors which leads to the formation of ambivalent helices and designing de novo proteins.
Collapse
|
24
|
Abstract
Water on a protein surface plays a key role in determining the structure and dynamics of proteins. Compared to the properties of bulk water, many aspects of the structure and dynamics of the water surrounding the proteins are less understood. It is interesting therefore to explore how the properties of the water within the solvation shell around the peptide molecule depend on its specific secondary structure. In this work we investigate the orientational order and residence times of the water molecules to characterize the structure, energetics, and dynamics of the hydration shell water around ambivalent peptides. Ambivalent sequences are identical sequences which display multiple secondary structures in different proteins. Molecular dynamics simulations of representative proteins containing variable helix, variable nonhelix, and conserved helix are also used to explore the local structure and mobility of water molecules in their vicinity. The results, for the first time, depict a different water distribution pattern around the conserved and variable helices. The water molecules surrounding the helical segments in variable helices are found to possess a less locally ordered structure compared to those around their corresponding nonhelical counterparts and conserved helices. The long conserved helices exhibit extremely high local residence times compared to the helical conformations of the variable helices, whereas the residence times of the nonhelical conformations of the variable helices are comparable to those of the short conserved helices. This differential pattern of the structure and dynamics of water molecules in the vicinity of conserved/variable helices may lend valuable insights for understanding the role of solvent effects in determining sequence ambivalency and help in improving the accuracy of water models used in the simulations of proteins.
Collapse
|
25
|
Bhattacharjee N, Biswas P. Structure of hydration water in proteins: a comparison of molecular dynamics simulations and database analysis. Biophys Chem 2011; 158:73-80. [PMID: 21665349 DOI: 10.1016/j.bpc.2011.05.009] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2011] [Revised: 05/07/2011] [Accepted: 05/08/2011] [Indexed: 11/15/2022]
Abstract
Hydration layer water molecules play important structural and functional roles in proteins. Despite being a critical component in biomolecular systems, characterizing the properties of hydration water poses a challenge for both experiments and simulations. In this context we investigate the local structure of hydration water molecules as a function of the distance from the protein and water molecules respectively in 188 high resolution protein structures and compare it with those obtained from molecular dynamics simulations. Tetrahedral order parameter of water in proteins calculated from previous and present simulation studies show that the potential of bulk water overestimates the average tetrahedral order parameter compared to those calculated from crystal structures. Hydration waters are found to be more ordered at a distance between the first and second solvation shell from the protein surface. The values of the order parameter decrease sharply when the water molecules are located very near or far away from the protein surface. At small water-water distance, the values of order parameter of water are very low. The average order parameter records a maximum value at a distance equivalent to the first solvation layer with respect to the water-water radial distribution and asymptotically approaches a constant value at large distances. Results from present analysis will help to get a better insight into structure of hydration water around proteins. The analysis will also help to improve the accuracy of water models on the protein surface.
Collapse
|
26
|
Bhattacharjee N, Saha SP, Ganguly RP, Patra KK, Dhali B, Das N, Barui G. A randomised comparative study between low-dose intravenous magnesium sulphate and standard intramuscular regimen for treatment of eclampsia. J OBSTET GYNAECOL 2011; 31:298-303. [DOI: 10.3109/01443615.2010.549972] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
27
|
Bhattacharjee N, Biswas P. Statistical analysis and molecular dynamics simulations of ambivalent α-helices. BMC Bioinformatics 2010; 11:519. [PMID: 20955581 PMCID: PMC2973962 DOI: 10.1186/1471-2105-11-519] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2010] [Accepted: 10/18/2010] [Indexed: 11/17/2022] Open
Abstract
Background Analysis of known protein structures reveals that identical sequence fragments in proteins can adopt different secondary structure conformations. The extent of this conformational diversity is influenced by various factors like the intrinsic sequence propensity, sequence context and other environmental factors such as pH, site directed mutations or alteration of the binding ligands. Understanding the mechanism by which the environment affects the structural ambivalence of these peptides has potential implications for protein design and reliable local structure prediction algorithms. Identification of the structurally ambivalent sequence fragments and determining the rules which dictate their conformational preferences play an important role in understanding the conformational changes observed in misfolding diseases. However, a systematic classification of their intrinsic sequence patterns or a statistical analysis of their properties and sequence context in relation to the origin of their structural diversity have largely remained unexplored. Results In this work, the conformational variability of α-helices is studied by mapping sequences from the non-redundant database to identical sequences across all classes of the SCOP (Structural Classification of Proteins) database. Some helices retain their conformations when mapped in the SCOP database while others exhibit a complete/partial switch to non-helical conformations. The results clearly depict the differences in the propensities of amino acids for the variable and conserved helices. Sequences flanking these ambivalent sequence fragments have anisotropic propensities at the N- and C-termini. This structural variability is depicted by molecular dynamics simulations in explicit solvent, which show that the short conserved helices retain their conformations while their longer counterparts fray into two or more shorter helices. Variable helices in the non-redundant database exhibit a trend of retaining helical conformations while their corresponding non-helical conformations in SCOP database show large deviations from their respective initial structures by adopting partial or full helical conformations. Partially ambivalent helices are also found to retain their respective conformations. Conclusions All sequence fragments which show structural diversity in different proteins of the non-redundant database are investigated. The final conformation of these ambivalent sequences are dictated by a fine tuning of their intrinsic sequence propensity and the anisotropic amino acid propensity of the flanking sequences. This analysis may unravel the connection between diverse secondary structures, which conserve the overall structural fold of the protein thus determining its function.
Collapse
|
28
|
Abstract
Background Despite the importance of β-strands as main building blocks in proteins, the propensity of amino acid in β-strands is not well-understood as it has been more difficult to determine experimentally compared to α-helices. Recent studies have shown that most of the amino acids have significantly high or low propensity towards both ends of β-strands. However, a comprehensive analysis of the sequence dependent amino acid propensities at positions between the ends of the β-strand has not been investigated. Results The propensities of the amino acids calculated from a large non-redundant database of proteins are found to be highly position-specific and vary continuously throughout the length of the β-strand. They follow an unexpected characteristic periodic pattern in inner positions with respect to the cap residues in both termini of β-strands; this periodic nature is markedly different from that of the α-helices with respect to the strength and pattern in periodicity. This periodicity is not only different for different amino acids but it also varies considerably for the amino acids belonging to the same physico-chemical group. Average hydrophobicity is also found to be periodic with respect to the positions from both termini of β-strands. Conclusions The results contradict the earlier perception of isotropic nature of amino acid propensities in the middle region of β-strands. These position-specific propensities should be of immense help in understanding the factors responsible for β-strand design and efficient prediction of β-strand structure in unknown proteins.
Collapse
|
29
|
Saha SP, Bhattacharjee N, Ganguli RP, Sil S, Patra KK, Sengupta M, Barui G, Goswami BK. Prevalence and significance of antiphospholipid antibodies in selected at-risk obstetrics cases: a comparative prospective study. J OBSTET GYNAECOL 2009; 29:614-8. [PMID: 19757265 DOI: 10.1080/01443610903052073] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
In a prospective comparative study we screened 112 women with a past history either of pre-eclampsia, eclampsia, recurrent abortion, IUGR, IUFD or abruptio placentae, with no apparent aetiology and a demographically matched cohort of 106 women having a past history of uncomplicated pregnancy outcome for the presence of antiphospholipid antibodies (aPL) and their significance. In the former group, the prevalence of aPL ranged from 10-46.87% compared with 8.49% in the later group. In women with the presence of aPL, the incidence of pre-eclampsia, early onset pre-eclampsia and abruptio placentae were 25%, 14.58% and 18.75%, respectively. In the same group, the abortion rate was 25% and live-birth rate was 64.58% with IUFD rate of 10.42%. Fetal morbidity rates were also higher in the mothers with aPL positivity, the incidence of IUGR was 27.08% and oligohydramnios was 33.33% in them. All these complications were statistically significant when compared with those of aPL negative mothers.
Collapse
Affiliation(s)
- S P Saha
- Department of Obstetrics and Gynaecology, North Bengal Medical College, Sushrutanagar, West Bengal, Darjeeling, India.
| | | | | | | | | | | | | | | |
Collapse
|
30
|
|
31
|
Biswas SJ, Bhattacharjee N, Khuda-Bukhsh AR. Efficacy of a plant extract (Chelidonium majus L.) in combating induced hepatocarcinogenesis in mice. Food Chem Toxicol 2007; 46:1474-87. [PMID: 18215450 DOI: 10.1016/j.fct.2007.12.009] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2007] [Revised: 10/29/2007] [Accepted: 12/06/2007] [Indexed: 11/18/2022]
Abstract
Ethanolic whole plant extract of Chelidonium majus, extensively used in traditional systems of medicine against various liver ailments, has been tested for its possible anti-tumor, hepato-protective and anti-genotoxic effects in p-dimethylaminoazobenzene (p-DAB) induced hepatocarcinogenesis in mice through multiple assays: cytogenetical, biochemical, histological and electron microscopical. Different sets of mice, 5 (for 7, 15 and 30 days' treatment) or 10 (for 60, 90 and 120 days) each, were chronically fed a diet suitably mixed with p-DAB and phenobarbital to develop liver tumors. One sub-group of carcinogen fed mice was also fed C. majus extract; 0.1 ml daily (drug-treated) while the other equal amount of dilute ethyl alcohol ("vehicle" of plant extract) (positive control). A separate group of mice was maintained with normal diet without any carcinogen treatment (negative control). Data of several cytogenetical endpoints and biochemical assay of some toxicity marker enzymes at all fixation intervals and histology of liver sections through ordinary, scanning and transmission electron microscopy at 60 and 120 days and that of spleen and kidney at 90 days were critically analyzed in the treated lots vis-a-vis controls. The results suggest anti-tumor, anti-genotoxic and hepato-protective effects of the plant extract, showing potentials for use in cancer therapy.
Collapse
Affiliation(s)
- S J Biswas
- Cytogenetics Laboratory, University of Kalyani, Kalyani, Nadia, West Bengal, India
| | | | | |
Collapse
|
32
|
Shah AJ, Bhattacharjee N, Joshi M, Sitapara A. Colostomy shift en masse--a new procedure. Pediatr Surg Int 2003; 19:693-4. [PMID: 14608470 DOI: 10.1007/s00383-003-1043-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/28/2002] [Indexed: 10/26/2022]
Abstract
Colostomy shift en masse is a novel technique in which the colostomy is shifted along with a rim of skin and abdominal wall tissue. This provides additional length of distal bowel if needed during pull-through anastomosis. We have treated three cases (two Hirschsprung's disease and one anorectal malformation) with colostomy shift en masse, and have achieved good results.
Collapse
Affiliation(s)
- Ashok J Shah
- Naranpura Nursing Home, Sanghavi High School, Naranpura, 380 013 Ahmedabad, India.
| | | | | | | |
Collapse
|
33
|
Abstract
BACKGROUND/PURPOSE Perineal ectopic anus in female infants is not a very uncommon congenital anomaly. The close proximity of the ectopic anus with the vulva and the stenosed opening seen in large majority of cases necessitate some form of surgical correction. A variety of surgical procedures like cutback, posterior anal transposition, PSARP, or ASAPR, with or without diverting colostomy have been described in the literature. However, in dealing with a case of ectopic anus, the authors thought a much simpler surgical correction would suffice giving an aesthetically and functionally acceptable perineum. This new and simple surgical procedure developed by Ashok Shah, Anal Shift is described in this report. METHODS Twelve female infants with anterior ectopic anus, between 3 and 18 months of age who had undergone surgical correction by this new method (Anal Shift) is reported. Five of these children had severe and 2 had mild anal stenosis. The new technique described in detail includes shifting and creation of a new anus in the anatomically normal site and construction of the perineal body. Colostomy was not done in any of them. RESULTS The cases had been followed up for 12 to 24 months. Anal function was normal with satisfactory vulvo-anal distance without any stenosis. One patient had superficial anterior wound dehiscence; she underwent reoperation with good results. CONCLUSIONS Anal Shift is a simple surgical procedure. It does not necessitate lateral dissection, therefore, the rectal support and the neurovascular supply to the rectum remains undisturbed, eliminating any chance of retraction. The anterior half of the neoanus does not have a suture line, thereby minimizing the chances of stricture formation. Anal Shift appears to be a safe, simple and satisfactory surgical procedure to correct anterior ectopic anus in girls without a colostomy.
Collapse
Affiliation(s)
- Ashok J Shah
- Department of Pediatric Surgery, Sheth K.M. School of P.G. Medicine & Research and V.S. General Hospital, Ahmedabad, India
| | | | | | | |
Collapse
|
34
|
Majumder SM, Ibrahim MF, Huda QK, Bhattacharjee N, Amin MN. Recurrent respiratory papillomatosis: a study of 24 cases. Bangladesh Med Res Counc Bull 1999; 25:46-50. [PMID: 11026935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
24 cases of recurrent respiratory papillomatosis (RRP) in children were treated by surgical removal with cup forceps and followed up for variable periods between 1990-95. Most of the patients required multiple operations due to recurrence. No anaesthetic death or complication was recorded. Voice changes of different degrees were noted. Four patients has glottic web formation. The findings suggest that recurrence of RRP is very common & needs multiple session of surgery. For children with persistent and progressive voice change/cry, the necessity of precise & comprehensive endoscopic examination of the upper aerodigestive tract under general anesthesia (GA) is emphasized.
Collapse
Affiliation(s)
- S M Majumder
- Deptt. of ENT, Mymensingh Medical College Hospital
| | | | | | | | | |
Collapse
|
35
|
Bova JG, Bhattacharjee N, Jurdi R, Bennett WF. Comparison of no medication, placebo, and hyoscyamine for reducing pain during a barium enema. AJR Am J Roentgenol 1999; 172:1285-7. [PMID: 10227503 DOI: 10.2214/ajr.172.5.10227503] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE We carried out a prospective, randomized study to evaluate the usefulness of premedication with an oral anticholinergic for relief of pain during and after a barium enema of the colon. SUBJECTS AND METHODS Patients were randomized into three groups: no medication, placebo, and sublingual 1-hyoscyamine sulfate. The placebo or hyoscyamine tablet was placed under the tongue 15-30 min before the examination. After the procedure the patients were interviewed. An analog scale (0-10) was used to score the level of pain that the patients experienced during the examination. Forty-eight hours after the examination, the patients returned by mail a survey that used the same scale and asked about delayed pain. RESULTS Data from 110 patients were studied. Sixty-nine patients were women, and 41 were men. They ranged from 24 to 82 years old (mean, 55 years). For the no-medication group (n = 36), the mean pain score was 4.1; for the placebo group (n = 34), 3.8; and for the hyoscyamine group (n = 40), 4.2. No statistically significant difference in pain scores was found between any groups (p = .72). Six patients from each group reported minor side effects. The mean scores from the returned surveys (n = 79) were 3.8 for the no-medication group (n = 26) and placebo group (n = 22) and 3.1 for the hyoscyamine group (n = 31). No statistically significant difference was found between any of these groups (p = .48) or between delayed pain responses and initial pain responses (p = .27). CONCLUSION Although safe, hyoscyamine seems to provide no benefit over no drug or a placebo when used as a pain premedication for patients undergoing a barium enema.
Collapse
Affiliation(s)
- J G Bova
- Department of Radiology, The Ohio State University Medical Center, Columbus 43210, USA
| | | | | | | |
Collapse
|
36
|
Bhattacharjee N, Quader MA, Haque M. Dystrophic calcification in the neck--a case report. Bangladesh Med Res Counc Bull 1998; 24:20-2. [PMID: 9776871] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
One 55 years aged male person was admitted with progressive painless neck swelling with multiple discharging sinuses. His X-ray of the neck showed a dense radio-opaque shadow & serum calcium level was 2 mmol/l. On neck exploration, an irregular calculus was revealed; hooking around the left carotid sheath. Histopathology confirmed the clinical diagnosis of tuberculosis. Anti-TB chemotherapy for six months cured him.
Collapse
|
37
|
Hossain MM, Bhattacharjee N, Haroon AA, Chowdhury RK, Islam MS, Akhter N. Multiple papilloma of the larynx in an adult--a case report. Bangladesh Med Res Counc Bull 1997; 23:91-94. [PMID: 9621479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Multiple papilloma of the larynx commonly affects the juvenile subjects. Only a few adult cases have been reported. Such a rare case in Bangladesh, is reported here. Twenty five years old one male patient was admitted into Sir Salimullah Medical College & Mitford Hospital with the complaints of hoarseness of voice & dysponea. He was diagnosed as papilloma clinically and histopathologically, and treated with tracheostomy & microlaryngoscopic excision of the masses. The patient was readmitted after 3 months with recurrence of papilloma at the same site and the growth was excised under anaesthesia. The past history of his illness revealed that he underwent to more surgeries for the same condition. The patient was lost to follow up.
Collapse
Affiliation(s)
- M M Hossain
- Department of ENT, Mymensingh Medical College Hospital
| | | | | | | | | | | |
Collapse
|
38
|
Bhattacharjee N, Arefin SM, Mazumder SM, Khan MK. Cut throat injury: a retrospective study of 26 cases. Bangladesh Med Res Counc Bull 1997; 23:87-90. [PMID: 9621478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Cut throat injuries and associated deaths are common in our society. Majority succumb to their injuries. In this study, the hospital records of twenty six such cases (13 M & 13 F) were reviewed. Eleven victims were in their third decade. Eighteen cases came from poor socio-economic class. Eleven had suicidal, eleven homicidal and four accidental injuries. Familial troubles, psychiatric illness and poverty were the triggering factors in suicidal attempts. The motives of homicide included political conflict, sex related crimes, dacoity, familial, land related disputes, etc. All had their hypopharynx and/or larynx exposed. Tracheostomy was done in fifteen cases. All but two had uneventful recovery. One died in the hospital due to hemorrhage, shock and asphyxia from aspirated blood. It was observed that appropriate measures could save lives in vast majority.
Collapse
|
39
|
Bhattacharjee N, Hossain MM, Mazumder SM, Khan MK. A wooden foreign body in the neck. Bangladesh Med Res Counc Bull 1997; 23:63-5. [PMID: 9465439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Foreign bodies in the throat and/or neck are uncommon and transpharyngeal impaction of a wooden foreign body in the neck without vascular injury is very rare. The patient presented in this communication, reported to our center five days after severe physical assault with a pharyngocutaneous fistula in the left side of the neck. Clinical examination and X-rays were unremarkable. Conservative treatment led to healing of the fistula and he was discharged. Two weeks later he was readmitted with an abscess in the right supraclavicular region. Exploration under general anaesthesia revealed a 7 cm long wooden fragment of a spear in the abscess cavity. The fragment was removed. After several days' antibiotic treatment, he recovered fully and was discharged.
Collapse
|
40
|
Bhattacharjee N, De PM, Chakravarti SK, Chakraborty MS, Neogi DK, Mukherjee KK. Febrile episode among a floating population of C.R.P.F. Jawans stationed at Calcutta. J Commun Dis 1995; 27:70-6. [PMID: 7499775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
A virological investigation was carried out to establish the etiologic agent of a febrile outbreak amongst a floating population of C.R.P.F. Jawans, stationed at Calcutta during May-July, 1993. The illness was associated with fever, severe headache, bodyache and arthralgia which lasted for 2-4 days in most of the cases. Fifty cases were examined clinically and blood samples (both acute and convalescent) were subjected to virological study. One mouse-pathogenic agent could be isolated in suckling mice and identified as DEN-3. Sero-investigation of 50 single sera by HI & CF method revealed evidence of presumptive dengue infection in 33, while sero-conversion could be noted in 10 out of 25 available paired sera tested. Results of MAC ELISA revealed evidence of primary dengue infection in 6 out of 12 acute phase sera examined. Thus, the study shows that the episode is strongly suggestive of primary dengue infection.
Collapse
Affiliation(s)
- N Bhattacharjee
- Department of Virology, School of Tropical Medicine, Calcutta, India
| | | | | | | | | | | |
Collapse
|
41
|
Bhattacharjee N. Fractured tracheostomy tubes: 3 case reports. Bangladesh Med Res Counc Bull 1994; 20:8-11. [PMID: 7880154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Although tracheobronchial foreign bodies are not rare, fractured tracheostomy tubes presenting as such, is rare indeed. Three such cases (one metallic and two Polyvenyl Chloride (P.V.C. tubes) are reported here. These foreign bodies were removed bronchoscopically with uneventful recovery.
Collapse
|
42
|
Bhattacharjee N, Mukherjee KK, Chakravarti SK, Mukherjee MK, De PN, Sengupta M, Banik GB, Bhowmick P, Sinha SK, Chakraborty MS. Dengue haemorrhagic fever (DHF) outbreak in Calcutta--1990. J Commun Dis 1993; 25:10-4. [PMID: 8014433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
An outbreak of Dengue Haemorrhagic Fever (DHF) occurred in Calcutta between September and December, 1990. Children and young adults were the major victims. Haemorrhagic manifestations and shocks were the main features in most of the hospitalised cases. Five mouse pathogenic agents were isolated from 105 acute cases and all were identified as DEN-3. HI and CF test with 55 paired sera revealed evidence of dengue infection in 33 (60 per cent) and flavivirus group reaction including dengue in 17 (30.9 per cent). It was for the first time, that DEN-3 was considered to be the etiologic agent for DHF in Calcutta.
Collapse
|
43
|
Mallick BK, Bhattacharjee N, Tripathi P, Choudhuri D. Choledochus cyst. J Assoc Physicians India 1987; 35:457-8. [PMID: 3654558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
|
44
|
Pathak IC, Datta BN, Aikat BK, Reddy MM, Bhattacharjee N. Pattern of neoplastic disease in children with special reference to malignant tumours. Indian J Cancer 1975; 12:46-55. [PMID: 1184068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
|
45
|
Bhattacharjee N, Sharma BK, Kataria PN, Perkash I, Chugh KS, Bansal VK. Blood glucose changes and hazard of hyperosmolar coma during and after peritoneal dialysis. J Assoc Physicians India 1973; 21:505-10. [PMID: 4792724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
|