Sequential unfolding of individual helices of bacterioopsin observed in molecular dynamics simulations of extraction from the purple membrane.

Abstract:

:Multiple molecular dynamics simulations of bacterioopsin pulling from its C-terminus show that its alpha-helices unfold individually. In the first metastable state observed in the simulations, helix G is unfolded at its C-terminal segment while the rest of helix G (residues 200-216) is folded and opposes resistance because of a salt-bridge network consisting of Asp-212 and Lys-216 on helix G and Arg-82 and Asp-85 on helix C. Helix G unfolds inside the bundle because the external force is applied to its C-terminal end in a direction perpendicular to the surface of the membrane. Inversely, helix F has to flip by 180 degrees to exit from the membrane because the applied force and the helical N-C axis point in opposite directions. At the highest peak of the force, which cannot be interpreted in single-molecule force spectroscopy experiments, helix F has a pronounced kink at Pro-186. Mutation of Pro-186 and/or the charged side chains mentioned above, which are involved in very favorable electrostatic interactions in the low-dielectric region of the membrane, are expected to reduce the highest peak of the force. Helices E and D unfold in a similar way to helices G and F, respectively. Hence, the force-distance profile and sequence of events during forced unfolding of bacterioopsin are influenced by the up-and-down topology of the seven-helix bundle. The sequential extraction of individual helices from the membrane suggests that the spontaneous (un)folding of bacterioopsin proceeds through metastable bundles of fewer than seven helices. The metastable states observed in the simulations provide atomic level evidence that corroborates the interpretation of very recent force spectroscopy experiments of bacteriorhodopsin refolding.

journal_name

Biophys J

journal_title

Biophysical journal

authors

Seeber M,Fanelli F,Paci E,Caflisch A

doi

10.1529/biophysj.106.088591

subject

Has Abstract

pub_date

2006-11-01 00:00:00

pages

3276-84

issue

9

eissn

0006-3495

issn

1542-0086

pii

S0006-3495(06)72040-9

journal_volume

91

pub_type

杂志文章
  • The effects of thermal disorder on the solution-scattering profiles of macromolecules.

    abstract::The solution-scattering profiles of macromolecules are significantly affected by the thermal motions of their atoms, especially at wide scattering angles, even when only a single conformational state is significantly populated in solution. Here it is shown that the impact thermal motions have on the molecular componen...

    journal_title:Biophysical journal

    pub_type: 杂志文章

    doi:10.1016/j.bpj.2014.02.016

    authors: Moore PB

    更新日期:2014-04-01 00:00:00

  • Electric-Induced Reversal of Morphogenesis in Hydra.

    abstract::Morphogenesis involves the dynamic interplay of biochemical, mechanical, and electrical processes. Here, we ask to what extent can the course of morphogenesis be modulated and controlled by an external electric field? We show that at a critical amplitude, an external electric field can halt morphogenesis in Hydra rege...

    journal_title:Biophysical journal

    pub_type: 杂志文章

    doi:10.1016/j.bpj.2019.09.007

    authors: Braun E,Ori H

    更新日期:2019-10-15 00:00:00

  • A theoretical analysis for the effect of focal contact formation on cell-substrate attachment strength.

    abstract::For many cell types, growth, differentiation, and motility are dependent on receptor-mediated adhesion to ligand-coated surfaces. Focal contacts are strong, specialized, adhesive connections between cell and substrate in which receptors aggregate and connect extracellular ligand to intracellular cytoskeletal molecules...

    journal_title:Biophysical journal

    pub_type: 杂志文章

    doi:10.1016/S0006-3495(93)81456-5

    authors: Ward MD,Hammer DA

    更新日期:1993-03-01 00:00:00

  • Photoselection in polarized photolysis experiments on heme proteins.

    abstract::Polarized photolysis experiments have been performed on the carbon monoxide complex of myoglobin to assess the effects of photoselection on the kinetics of ligand rebinding and to investigate the reorientational dynamics of the heme plane. The results are analyzed in terms of the optical theory developed in the preced...

    journal_title:Biophysical journal

    pub_type: 杂志文章

    doi:10.1016/S0006-3495(93)81446-2

    authors: Ansari A,Jones CM,Henry ER,Hofrichter J,Eaton WA

    更新日期:1993-03-01 00:00:00

  • Switch II mutants reveal coupling between the nucleotide- and actin-binding regions in myosin V.

    abstract::Conserved active-site elements in myosins and other P-loop NTPases play critical roles in nucleotide binding and hydrolysis; however, the mechanisms of allosteric communication among these mechanoenzymes remain unresolved. In this work we introduced the E442A mutation, which abrogates a salt-bridge between switch I an...

    journal_title:Biophysical journal

    pub_type: 杂志文章

    doi:10.1016/j.bpj.2012.04.025

    authors: Trivedi DV,David C,Jacobs DJ,Yengo CM

    更新日期:2012-06-06 00:00:00

  • Properties of gap junction channels formed by Cx46 alone and in combination with Cx50.

    abstract::Gap junctions formed of connexin46 (Cx46) and connexin50 (Cx50) in lens fiber cells are crucial for maintaining lens transparency. We determined the functional properties of homotypic Cx46, heterotypic Cx46/Cx50, and heteromeric Cx46/Cx50 channels in a communication-deficient neuroblastoma (N2A) cell line, using dual ...

    journal_title:Biophysical journal

    pub_type: 杂志文章

    doi:10.1016/S0006-3495(00)76444-7

    authors: Hopperstad MG,Srinivas M,Spray DC

    更新日期:2000-10-01 00:00:00

  • A Model for the Hippo Pathway in the Drosophila Wing Disc.

    abstract::Although significant progress has been made toward understanding morphogen-mediated patterning in development, control of the size and shape of tissues via local and global signaling is poorly understood. In particular, little is known about how cell-cell interactions are involved in the control of tissue size. The Hi...

    journal_title:Biophysical journal

    pub_type: 杂志文章

    doi:10.1016/j.bpj.2018.07.002

    authors: Gou J,Lin L,Othmer HG

    更新日期:2018-08-21 00:00:00

  • Design Parameters for Granzyme-Mediated Cytotoxic Lymphocyte Target-Cell Killing and Specificity.

    abstract::Cytotoxic lymphocytes are key elements of the immune system that are primarily responsible for targeting cells infected with intracellular pathogens, or cells that have become malignantly transformed. Target cells are killed mainly via lymphocyte exocytosis of specialized lysosomes containing perforin, a pore-forming ...

    journal_title:Biophysical journal

    pub_type: 杂志文章

    doi:10.1016/j.bpj.2015.06.045

    authors: Woodsworth DJ,Dunsing V,Coombs D

    更新日期:2015-08-04 00:00:00

  • Tuning passive mechanics through differential splicing of titin during skeletal muscle development.

    abstract::During postnatal development, major changes in mechanical properties of skeletal muscle occur. We investigated passive properties of skeletal muscle in mice and rabbits that varied in age from 1 day to approximately 1 year. Neonatal skeletal muscle expressed large titin isoforms directly after birth, followed by a gra...

    journal_title:Biophysical journal

    pub_type: 杂志文章

    doi:10.1016/j.bpj.2009.07.041

    authors: Ottenheijm CA,Knottnerus AM,Buck D,Luo X,Greer K,Hoying A,Labeit S,Granzier H

    更新日期:2009-10-21 00:00:00

  • A new technique for calculating individual dermal fibroblast contractile forces generated within collagen-GAG scaffolds.

    abstract::Cell-mediated contraction plays a critical role in many physiological and pathological processes, notably organized contraction during wound healing. Implantation of an appropriately formulated (i.e., mean pore size, chemical composition, degradation rate) three-dimensional scaffold into an in vivo wound site effectiv...

    journal_title:Biophysical journal

    pub_type: 杂志文章

    doi:10.1529/biophysj.106.095471

    authors: Harley BA,Freyman TM,Wong MQ,Gibson LJ

    更新日期:2007-10-15 00:00:00

  • Molecular models need to be tested: the case of a solar flares discoidal HDL model.

    abstract::In the absence of atomic structures of high-density lipoproteins in their lipid-bound states, many molecular models have been produced based on experimental data. Using molecular dynamics, we show that a recently proposed "solar-flares" model of discoidal high-density lipoprotein is implausible. Our simulations show a...

    journal_title:Biophysical journal

    pub_type: 信件

    doi:10.1529/biophysj.108.131581

    authors: Shih AY,Sligar SG,Schulten K

    更新日期:2008-06-01 00:00:00

  • Inhibition of lactoperoxidase by its own catalytic product: crystal structure of the hypothiocyanate-inhibited bovine lactoperoxidase at 2.3-A resolution.

    abstract::To the best of our knowledge, this is the first report on the structure of product-inhibited mammalian peroxidase. Lactoperoxidase is a heme containing an enzyme that catalyzes the inactivation of a wide range of microorganisms. In the presence of hydrogen peroxide, it preferentially converts thiocyanate ion into a to...

    journal_title:Biophysical journal

    pub_type: 杂志文章

    doi:10.1016/j.bpj.2008.09.019

    authors: Singh AK,Singh N,Sharma S,Shin K,Takase M,Kaur P,Srinivasan A,Singh TP

    更新日期:2009-01-01 00:00:00

  • Patch electrode glass composition affects ion channel currents.

    abstract::The influence of patch electrode glass composition on macroscopic IV relations in inside-out patches of the cGMP-activated ion channel from rod photoreceptors was examined for a soda lime glass, a Kovar sealing glass, a borosilicate glass, and several soft lead glasses. In several glasses the shape or magnitude of the...

    journal_title:Biophysical journal

    pub_type: 杂志文章

    doi:10.1016/S0006-3495(88)83091-1

    authors: Furman RE,Tanaka JC

    更新日期:1988-02-01 00:00:00

  • Oleoylethanolamide-based lyotropic liquid crystals as vehicles for delivery of amino acids in aqueous environment.

    abstract::We have investigated the phase behavior of self-assembled lyotropic liquid crystals (LC) formed by ternary mixtures of oleoylethanolamide (OEA), water and arginine. OEA, a natural analog of the endogenous cannabinoid anandamide involved in the peripheral regulation of feeding, was selected as a main component due to i...

    journal_title:Biophysical journal

    pub_type: 杂志文章

    doi:10.1016/j.bpj.2008.10.057

    authors: Mohammady SZ,Pouzot M,Mezzenga R

    更新日期:2009-02-18 00:00:00

  • Toward the understanding of MNEI sweetness from hydration map surfaces.

    abstract::The binding mechanism of sweet proteins to their receptor, a G-protein-coupled receptor, is not supported by direct structural information. In principle, the key groups responsible for biological activity (glucophores) can be localized on a small structural unit (sweet finger) or spread on a larger surface area. A rec...

    journal_title:Biophysical journal

    pub_type: 杂志文章

    doi:10.1529/biophysj.105.073171

    authors: De Simone A,Spadaccini R,Temussi PA,Fraternali F

    更新日期:2006-05-01 00:00:00

  • The hill coefficient for the Ca2+-activation of striated muscle contraction.

    abstract::The following arguments are presented for the observation that curves relating free Ca2+ and force development of thin filament regulated myofilaments of skinned muscle fibers have Hill coefficient (n) greater than 4, which is the number of Ca2+ binding sites on troponin: Activation of the myofilaments is a process re...

    journal_title:Biophysical journal

    pub_type: 杂志文章

    doi:10.1016/S0006-3495(84)84051-5

    authors: Shiner JS,Solaro RJ

    更新日期:1984-10-01 00:00:00

  • Diffraction rings obtained from a suspension of skeletal myofibrils by laser light illumination. Study of internal structure of sarcomeres.

    abstract::Diffraction rings corresponding to the first, second, and third order were obtained by laser light illumination from a suspension of rabbit glycerinated psoas myofibrils (diameter, 1-2 microns; average length of the straight region, 44 microns; average sarcomere length, 2.2-2.6 microns) of which the optical thickness ...

    journal_title:Biophysical journal

    pub_type: 杂志文章

    doi:10.1016/S0006-3495(89)82759-6

    authors: Ishiwata S,Okamura N

    更新日期:1989-12-01 00:00:00

  • Interactions of the M2delta segment of the acetylcholine receptor with lipid bilayers: a continuum-solvent model study.

    abstract::M2delta, one of the transmembrane segments of the nicotinic acetylcholine receptor, is a 23-amino-acid peptide, frequently used as a model for peptide-membrane interactions. In this and the companion article we describe studies of M2delta-membrane interactions, using two different computational approaches. In the pres...

    journal_title:Biophysical journal

    pub_type: 杂志文章

    doi:10.1016/S0006-3495(03)74785-7

    authors: Kessel A,Haliloglu T,Ben-Tal N

    更新日期:2003-12-01 00:00:00

  • Donnan potentials from the A- and I-bands of glycerinated and chemically skinned muscles, relaxed and in rigor.

    abstract::Using a combination of microelectrode measurements and high-power microscopy we have demonstrated that different Donnan potentials can be recorded from the A- and I-bands of glycerinated and chemically skinned muscles in rigor, so that the A-band fixed charge concentration exceeds the I-band fixed charge concentration...

    journal_title:Biophysical journal

    pub_type: 杂志文章

    doi:10.1016/S0006-3495(85)83760-7

    authors: Bartels EM,Elliott GF

    更新日期:1985-07-01 00:00:00

  • Intramolecular fluorescence correlation spectroscopy in a feedback tracking microscope.

    abstract::We derive the statistics of the signals generated by shape fluctuations of large molecules studied by feedback tracking microscopy. We account for the influence of intramolecular dynamics on the response of the tracking system and derive a general expression for the fluorescence autocorrelation function that applies w...

    journal_title:Biophysical journal

    pub_type: 杂志文章

    doi:10.1016/j.bpj.2010.03.045

    authors: McHale K,Mabuchi H

    更新日期:2010-07-07 00:00:00

  • Saturation behavior of single, amiloride-sensitive Na+ channels in planar lipid bilayers.

    abstract::Single epithelial Na+ channels incorporated into planar lipid bilayers were studied to determine the effects of Na concentration on its own conductance. Amiloride-sensitive Na+ channels were obtained from apical membrane vesicles made from A6 cells, a continuous epithelial cell-line derived from amphibian kidney. Sing...

    journal_title:Biophysical journal

    pub_type: 杂志文章

    doi:10.1016/S0006-3495(84)84082-5

    authors: Olans L,Sariban-Sohraby S,Benos DJ

    更新日期:1984-12-01 00:00:00

  • Process noise: an explanation for the fluctuations in the immune response during acute viral infection.

    abstract::The parameters of the immune response dynamics are usually estimated by the use of deterministic ordinary differential equations that relate data trends to parameter values. Since the physical basis of the response is stochastic, we are investigating the intensity of the data fluctuations resulting from the intrinsic ...

    journal_title:Biophysical journal

    pub_type: 杂志文章

    doi:10.1529/biophysj.106.094508

    authors: Milutinovic D,De Boer RJ

    更新日期:2007-05-15 00:00:00

  • 19F nuclear magnetic resonance investigation of stereoselective binding of isoflurane to bovine serum albumin.

    abstract::Whether proteins or lipids are the primary target sites for general anesthetic action has engendered considerable debate. Recent in vivo studies have shown that the S(+) and R(-) enantiomers of isoflurane are not equipotent, implying involvement of proteins. Bovine serum albumin (BSA), a soluble protein devoid of lipi...

    journal_title:Biophysical journal

    pub_type: 杂志文章

    doi:10.1016/S0006-3495(96)79599-1

    authors: Xu Y,Tang P,Firestone L,Zhang TT

    更新日期:1996-01-01 00:00:00

  • Comparison between orientational and conformational orders in fluid lipid bilayers.

    abstract::The orientational order as determined by 2H NMR and the infrared frequencies of the C--H stretching modes of the methylene groups have been measured for several systems (POPC, POPC/cholesterol and POPE), all in the fluid phase, and then were compared; this work reveals an unexpected linear correlation between them. Th...

    journal_title:Biophysical journal

    pub_type: 杂志文章

    doi:10.1016/S0006-3495(93)81351-1

    authors: Kodati VR,Lafleur M

    更新日期:1993-01-01 00:00:00

  • Molecular dynamics simulations of lipid vesicle fusion in atomic detail.

    abstract::The fusion of a membrane-bounded vesicle with a target membrane is a key step in intracellular trafficking, exocytosis, and drug delivery. Molecular dynamics simulations have been used to study the fusion of small unilamellar vesicles composed of a dipalmitoyl-phosphatidylcholine (DPPC)/palmitic acid 1:2 mixture in at...

    journal_title:Biophysical journal

    pub_type: 杂志文章

    doi:10.1529/biophysj.106.103572

    authors: Knecht V,Marrink SJ

    更新日期:2007-06-15 00:00:00

  • A physical model of ATP-induced actin-myosin movement in vitro.

    abstract::The nature of the mechanism limiting the velocity of ATP-induced unidirectional movements of actin-myosin filaments in vitro is considered. In the sliding process two types of "cyclic" interactions between myosin heads and actin are involved, i.e., productive and nonproductive. In the productive interaction, myosin he...

    journal_title:Biophysical journal

    pub_type: 杂志文章

    doi:10.1016/S0006-3495(91)82228-7

    authors: Tawada K,Sekimoto K

    更新日期:1991-02-01 00:00:00

  • Relaxation kinetics and the glassiness of native proteins: coupling of timescales.

    abstract::We provide evidence that the onset of functional dynamics of folded proteins with elevated temperatures is associated with the effective sampling of its energy landscape under physiological conditions. The analysis is based on data describing the relaxation phenomena governing the backbone dynamics of bovine pancreati...

    journal_title:Biophysical journal

    pub_type: 杂志文章

    doi:10.1529/biophysj.104.050252

    authors: Baysal C,Atilgan AR

    更新日期:2005-03-01 00:00:00

  • In situ mechanical analysis of myofibrillar perturbation and aging on soft, bilayered Drosophila myocardium.

    abstract::Drosophila melanogaster is a genetically malleable organism with a short life span, making it a tractable system in which to study mechanical effects of genetic perturbation and aging on tissues, e.g., impaired heart function. However, Drosophila heart-tube studies can be hampered by its bilayered structure: a ventral...

    journal_title:Biophysical journal

    pub_type: 杂志文章

    doi:10.1016/j.bpj.2011.10.042

    authors: Kaushik G,Fuhrmann A,Cammarato A,Engler AJ

    更新日期:2011-12-07 00:00:00

  • Laser flow measurements of scattering and fluorescence from cell nuclei in the presence of increasing Mg++ concentrations.

    abstract::The effects of Mg++ on the spatial organization of nuclei from rat hepatocytes are analyzed in the range 0-60 mM, in the presence of suitable concentrations of KCl to reproduce physiological conditions. It is shown that the scatter-signal distribution measured by means of a flow microfluorimeter is greatly affected by...

    journal_title:Biophysical journal

    pub_type: 杂志文章

    doi:10.1016/S0006-3495(85)83938-2

    authors: Grattarola M,Carlo P,Giannetti G,Finollo R,Viviani R,Chiabrera A

    更新日期:1985-04-01 00:00:00

  • Lipid Binding Controls Dimerization of the Coat Protein p24 Transmembrane Helix.

    abstract::Coat protein (COP) I and COP II complexes are involved in the transport of proteins between the endoplasmic reticulum and the Golgi apparatus in eukaryotic cells. The formation of COP I/II complexes at membrane surfaces is an early step in vesicle formation and is mastered by p24, a type I transmembrane protein. Oligo...

    journal_title:Biophysical journal

    pub_type: 杂志文章

    doi:10.1016/j.bpj.2019.09.021

    authors: Pannwitt S,Stangl M,Schneider D

    更新日期:2019-11-05 00:00:00