Abstract:
:The functional diversity of gap junction intercellular channels arising from the large number of connexin isoforms is significantly increased by heterotypic interactions between members of this family. This is particularly evident in the rectifying behavior of Cx26/Cx32 heterotypic channels (. Proc. Natl. Acad. Sci. USA. 88:8410-8414). The channel properties responsible for producing the rectifying current observed for Cx26/Cx32 heterotypic gap junction channels were determined in transfected mouse neuroblastoma 2A (N2A) cells. Transfectants revealed maximum unitary conductances (gamma(j)) of 135 pS for Cx26 and 53 pS for Cx32 homotypic channels in 120 mM KCl. Anionic substitution of glutamate for Cl indicated that Cx26 channels favored cations by 2.6:1, whereas Cx32 channels were relatively nonselective with respect to charge. In Cx26/Cx32 heterotypic cell pairs, the macroscopic fast rectification of the current-voltage relationship was fully explained at the single-channel level by a rectifying gamma(j) that increased by a factor of 2.9 as the transjunctional voltage (V(j)) changed from -100 to +100 mV with the Cx26 cell as the positive pole. A model of electrodiffusion of ions through the gap junction pore based on Nernst-Planck equations for ion concentrations and the Poisson equation for the electrical potential within the junction is developed. Selectivity characteristics are ascribed to each hemichannel based on either pore features (treated as uniform along the length of the hemichannel) or entrance effects unique to each connexin. Both analytical GHK approximations and full numerical solutions predict rectifying characteristics for Cx32/Cx26 heterotypic channels, although not to the full extent seen empirically. The model predicts that asymmetries in the conductance/permeability properties of the hemichannels (also cast as Donnan potentials) will produce either an accumulation or a depletion of ions within the channel, depending on voltage polarity, that will result in rectification.
journal_name
Biophys Jjournal_title
Biophysical journalauthors
Suchyna TM,Nitsche JM,Chilton M,Harris AL,Veenstra RD,Nicholson BJdoi
10.1016/S0006-3495(99)77129-8subject
Has Abstractpub_date
1999-12-01 00:00:00pages
2968-87issue
6eissn
0006-3495issn
1542-0086pii
S0006-3495(99)77129-8journal_volume
77pub_type
杂志文章abstract::Formation of amyloid oligomers, the most toxic species of amyloids in degenerative diseases, is critically coupled to the interplay with surrounding water. The hydrophobic force driving the oligomerization causes water removal from interfaces, changing the surface-hydration properties. Here, we show that such effects ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2011.03.029
更新日期:2011-05-04 00:00:00
abstract::Myoglobin (Mb) is a model system for ligand binding and migration. The energy barriers (ΔG) for ligand migration in Mb have been studied in the past by experiment and theory and significant differences between different approaches were found. From experiment, it is known that Mb can assume a large number of conformati...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2011.10.058
更新日期:2012-01-18 00:00:00
abstract::TOK1 encodes the channel responsible for the prominent outward K(+) current of the yeast plasma membrane. It can dwell in several impermeable states, including a rapidly transiting, K(+)-electromotive-force-dependent "R" (rectifying) state, a voltage-independent "IB" (interburst) state, and a set of [K(+)](ext) and vo...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(02)75440-4
更新日期:2002-02-01 00:00:00
abstract::Amantadine is known to block the M2 proton channel of the Influenza A virus. Here, we present a structure of the M2 trans-membrane domain blocked with amantadine, built using orientational constraints obtained from solid-state NMR polarization-inversion-spin-exchange-at-the-magic-angle experiments. The data indicates ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.106.090183
更新日期:2007-06-15 00:00:00
abstract::The phenomena reported are part of a study about the effects of ionizing radiation on membrane transport. We found that the conductance of lipid membranes in the presence of the polyene-antibiotics nystatin or amphotericin B is reduced to virtually zero following irradiation. Ion channels formed by these substances se...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(93)81343-2
更新日期:1993-01-01 00:00:00
abstract::The widely used hydrophobic cannabinoid ligand CP-55,940 partitions with high efficiency into biomembranes. We studied the location, orientation, and dynamics of CP-55,940 in POPC bilayers by solid-state NMR. Chemical-shift perturbation of POPC protons from the aromatic ring-current effect, as well as 1H NMR cross-rel...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2009.03.033
更新日期:2009-06-17 00:00:00
abstract::Two independent methods, induced osmosis and solvent drag, were used to determine the reflection coefficients for NaCl (sigma NaCl) in brush border and basolateral membrane vesicles isolated from rabbit proximal tubule. In the induced osmosis method, vesicles loaded with sucrose were subjected to varying inward NaCl g...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(89)82920-0
更新日期:1989-06-01 00:00:00
abstract::Bax and Bid are proapoptotic proteins of the Bcl-2 family that regulate the release of apoptogenic factors from mitochondria. Although they localize constitutively in the cytoplasm, their apoptotic function is exerted at the mitochondrial outer membrane, and is related to their ability to form transbilayer pores. Here...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.104.058008
更新日期:2005-06-01 00:00:00
abstract::Sharing of positive or negative regulators between multiple targets is frequently observed in cellular signaling cascades. For instance, phosphatase sharing between multiple kinases is ubiquitous within the MAPK pathway. Here we investigate how such phosphatase sharing could shape robustness and evolvability of the ph...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2017.10.037
更新日期:2018-01-09 00:00:00
abstract::An experimental method and analysis are introduced which provide direct quantitation of the strength of adhesive contact for large agglutinin-bonded regions between macroscopically smooth membrane capsules (e.g., red blood cells). The approach yields intrinsic properties for separation of adherent regions independent ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(91)82298-6
更新日期:1991-04-01 00:00:00
abstract::Previously, we discussed the calculation of the dipole moments of small proteins using the three-dimensional protein data-base. Our results demonstrate that the calculated dipole moments are in acceptable agreement with measured values. We, however, noted the difficulty of the calculation with larger proteins, in part...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(93)81524-8
更新日期:1993-05-01 00:00:00
abstract::Photosystem II catalyzes photosynthetic water oxidation in plants, green algae, and cyanobacteria. The manganese-containing active site cycles through a series of five oxidation states, S(n), where n refers to the number of oxidizing equivalents stored. In this report, reaction-induced Fourier transform infrared and e...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(03)74680-3
更新日期:2003-10-01 00:00:00
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
更新日期:2007-10-15 00:00:00
abstract::In recent experimental reports, robust circadian oscillation of the phosphorylation level of KaiC has been reconstituted by incubating three cyanobacterial proteins, KaiA, KaiB, and KaiC, with ATP in vitro. This reconstitution indicates that protein-protein interactions and the associated ATP hydrolysis suffice to gen...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2010.02.036
更新日期:2010-06-02 00:00:00
abstract::Many traditional approaches to the analysis of sedimentation velocity data work poorly with data for low-molecular-weight solutes, which have sedimentation boundaries that are severely broadened by diffusion. An approach that has previously had some success is to directly fit these broad boundaries to approximate solu...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(97)78684-3
更新日期:1997-01-01 00:00:00
abstract::During inflammation, flowing leukocytes tether to and roll on vascular surfaces through the association and dissociation of selectin/ligand bonds. The interactions of P- and L- selectins with their respective ligands exhibit catch-slip bonds, such that increasing force initially prolongs and then shortens bond lifetim...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2010.05.040
更新日期:2010-08-09 00:00:00
abstract::Receptor activity modifying proteins (RAMPs) are a family of single-pass transmembrane proteins that dimerize with G-protein-coupled receptors. They may alter the ligand recognition properties of the receptors (particularly for the calcitonin receptor-like receptor, CLR). Very little structural information is availabl...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.106.084582
更新日期:2006-07-15 00:00:00
abstract::Large and rapid changes in light scattering accompany secretion from nerve terminals of the mammalian neurohypophysis (posterior pituitary). In the mouse, these intrinsic optical signals are intimately related to the arrival of the action potential E-wave and the release of arginine vasopressin and oxytocin (S-wave). ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.106.103754
更新日期:2007-05-01 00:00:00
abstract::Bistability is a major mechanism for cellular decision making and usually results from positive feedback in biochemical control systems. Here we show theoretically that bistability between unbound and bound states of adhesion clusters results from positive feedback mediated by structural rather than biochemical proces...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.106.090209
更新日期:2006-09-15 00:00:00
abstract::We have previously studied single, voltage-dependent, saxitoxin-(STX) blockable sodium channels from rat brain in planar lipid bilayers, and found that channel block by STX was voltage-dependent. Here we describe the effect of voltage on the degree of block and on the kinetics of the blocking reaction. From their volt...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(84)84156-9
更新日期:1984-01-01 00:00:00
abstract::We have attempted to link the solution actomyosin ATPase with the mechanical properties of in vitro actin filament sliding over heavy meromyosin. To accomplish this we perturbed the system by altering the substrate with various NTPs and divalent cations, and by altering ionic strength. A wide variety of enzymatic and ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(01)76022-5
更新日期:2001-01-01 00:00:00
abstract::Films of O-phospho-L-serine-P-ethylester (PSE) were studied by infrared spectroscopy. PSE films were studied pure and as 1:1 mixture with LiOH, NaOH, KOH, and Ca(OH)2 as a function of the degree of hydration. The same investigations were performed if (L-glu)n was added to the system (ratio 1:1, PSE/glu residue). In th...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(89)82861-9
更新日期:1989-04-01 00:00:00
abstract::Trains of nerve impulses from the crayfish stretch receptor under steady conditions are found to be extremely regular with a standard deviation of S = 0.7 x 10(-2)tau when tau, the mean interval, is in the 15 to 80 msec range. Such a small fluctuation increases the problems of film recording, accurate measurement of i...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(66)86651-1
更新日期:1966-03-01 00:00:00
abstract::In the budding yeast nucleus, transfer RNA (tRNA) genes are considered to localize in the vicinity of the nucleolus; however, the use of Hi-C and fluorescent repressor-operator system techniques has clearly indicated that the tRNA genes are distributed not only around the nucleolus but also at other nuclear locations....
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2019.12.029
更新日期:2020-05-05 00:00:00
abstract::Internally perfused squid giant axons with intact sodium inactivation gating were prepared for gating current experiments. Gating current records were obtained in sinusoidally driven dynamic steady states and as dynamic transients as functions of the mean membrane potential and the frequency of the command sinusoid. C...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(86)83486-5
更新日期:1986-09-01 00:00:00
abstract::We analyzed the microstructure in the first-order laser diffraction line from both resting and tetanically contracting single twitch fibers from frog anterior tibial muscle to see if the distribution of sarcomere lengths is continuous or discrete. Measuring the distance between adjacent microstructural elements lying ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(82)84695-X
更新日期:1982-02-01 00:00:00
abstract::Kinetic measurements of the self-assembly of proteins into amyloid fibrils are often used to make inferences about molecular mechanisms. In particular, the lag time--the quiescent period before aggregates are detected--is often found to scale with the protein concentration as a power law, whose exponent has been used ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2014.11.3465
更新日期:2015-02-03 00:00:00
abstract::Integrin-mediated adhesion of circulating neutrophils to endothelium during inflammation involves multiple adhesion molecules on both neutrophils and endothelium. Most studies of neutrophil adhesion have focused on adhesion to ICAM-1 (mediated by beta(2) integrins), but interaction with the endothelial ligand vascular...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2008.10.001
更新日期:2009-01-01 00:00:00
abstract::Detection algorithms are widely used for the analysis of single-channel data because they remove the background noise from the measured current signal and reconstruct the noise-free time series. Standard detection algorithms assume channels switching only between zero and full conductance. Many types of channels, howe...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(94)80614-9
更新日期:1994-10-01 00:00:00
abstract::Synchronous neurotransmitter release is mediated by the opening of voltage-gated Ca(2+) channels and the build-up of submembrane Ca(2+) microdomains. Previous models of Ca(2+) microdomains have neglected possible electrostatic interactions between Ca(2+) ions and negative surface charges on the inner leaflet of the pl...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.107.124909
更新日期:2008-09-01 00:00:00