Abstract:
:We have used optical tweezers to study the elasticity of red cell membranes; force was applied to a bead attached to a permeabilized spherical ghost and the force-extension relation was obtained from the response of a second bead bound at a diametrically opposite position. Interruption of the skeletal network by dissociation of spectrin tetramers or extraction of the actin junctions engendered a fourfold reduction in stiffness at low applied force, but only a twofold change at larger extensions. Proteolytic scission of the ankyrin, which links the membrane skeleton to the integral membrane protein, band 3, induced a similar effect. The modified, unlike the native membranes, showed plastic relaxation under a prolonged stretch. Flaccid giant liposomes showed no measurable elasticity. Our observations indicate that the elastic character is at least as much a consequence of the attachment of spectrin as of a continuous membrane-bound network, and they offer a rationale for formation of elliptocytes in genetic conditions associated with membrane-skeletal perturbations. The theory of Parker and Winlove for elastic deformation of axisymmetric shells (accompanying paper) allows us to determine the function BH(2) for the spherical saponin-permeabilized ghost membranes (where B is the bending modulus and H the shear modulus); taking the literature value of 2 x 10(-19) Nm for B, H then emerges as 2 x 10(-6) Nm(-1). This is an order of magnitude higher than the value reported for intact cells from micropipette aspiration. Reasons for the difference are discussed.
journal_name
Biophys Jjournal_title
Biophysical journalauthors
Sleep J,Wilson D,Simmons R,Gratzer Wdoi
10.1016/S0006-3495(99)77139-0subject
Has Abstractpub_date
1999-12-01 00:00:00pages
3085-95issue
6eissn
0006-3495issn
1542-0086pii
S0006-3495(99)77139-0journal_volume
77pub_type
杂志文章abstract::Moesin, a protein of the ezrin, radixin, and moesin family, which links the plasma membrane to the cytoskeleton, is involved in multiple physiological and pathological processes, including viral budding and infection. Its interaction with the plasma membrane occurs via a key phosphoinositide, the phosphatidyl(4,5)inos...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2017.10.041
更新日期:2018-01-09 00:00:00
abstract::The triplet state absorption and phosphorescence of Zn and Pd derivatives of myoglobin were compared. Both metal derivatives exhibit long triplet state lifetimes at room temperature, but whereas the Pd derivative showed exponential decay and an isosbestic point in the transient absorption spectra, the decay of the Zn ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(90)82363-8
更新日期:1990-07-01 00:00:00
abstract::A simple method of generating electric field-induced concentration gradients in planar supported bilayers has been developed. Gradients of charged, fluorescently labeled probes were visualized by epifluorescence microscopy and could be observed at field strengths as low as 1 V/cm. Steady-state concentration gradients ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(95)80067-6
更新日期:1995-11-01 00:00:00
abstract::The genetic map of T4 (and T2) bacteriophage is circular but the DNA molecule that is liberated by phenol extraction is a linear duplex of polynucleotide chains. If the genetic map is related to the physical structure of the DNA molecule, the problem arises as to how a linear molecule can give rise to a circular map. ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/s0006-3495(64)86771-0
更新日期:1964-03-01 00:00:00
abstract::We have formulated a kinetic model for the primary steps that occur at the cell membrane during receptor-mediated endocytosis. This model includes the diffusion of receptor molecules, the binding of receptors to coated pits, the loss of coated pits by invagination, and random reinsertion of receptors and coated pits. ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(85)83879-0
更新日期:1985-01-01 00:00:00
abstract::Recent NMR structural characterization studies showed that a seven-residue segment (FKKGERL) from the src SH3 domain adopts the nativelike diverging type II beta-turn in aqueous solution in support of the prediction based on the I-sites library of sequence structural motifs. We study the conformational variability and...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(03)74966-2
更新日期:2003-03-01 00:00:00
abstract::The crowded environment of cells poses a challenge for rapid protein-protein association. Yet, it has been established that the rates of association are similar in crowded and in dilute solutions. Here we probe the pathway leading to fast association between TEM1 β-lactamase and its inhibitor protein BLIP in crowded s...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2012.08.009
更新日期:2012-09-05 00:00:00
abstract::Fluorescence recovery after photobleaching (FRAP) is a powerful technique to study molecular dynamics inside living cells. During the past years, several laboratories have used FRAP to image the motion of RNA-protein and other macromolecular complexes in the nucleus and cytoplasm. In the case of mRNAs, there is growin...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.106.096693
更新日期:2007-04-15 00:00:00
abstract::Scaffold proteins are central players in regulating the spatial-temporal organization of many important signaling pathways in cells. They offer physical platforms to downstream signaling proteins so that their transient interactions in a crowded and heterogeneous environment of cytosol can be greatly facilitated. Howe...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2020.10.002
更新日期:2020-11-17 00:00:00
abstract::The fluorescein arsenical hairpin binder (FlAsH) shows much promise to determine the relative orientations of protein regions and structures even in living cells and in the plasma membrane. In this study, we characterized FlAsH's photophysical properties by steady-state anisotropy and time-resolved single photon count...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2010.08.080
更新日期:2011-02-16 00:00:00
abstract::Nisin is an antimicrobial peptide used as food preservative. To gain some insights into the hypothesis that its bactericidal activity is due to the perturbation of the lipid fraction of the bacterial plasmic membrane, we have investigated the effect of nisin on model phosphatidylcholine (PC) membranes. We show that ni...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(99)76936-5
更新日期:1999-08-01 00:00:00
abstract::The insertion of myelin basic protein into microemulsion droplets of sodium bis (2-ethylhexyl) sulfosuccinate (AOT) has been studied by quasi-elastic light scattering. Measurements were made at both low and high molar ratios of water to surfactant, as a function of protein occupancy. The hydrodynamic radii of filled a...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(85)83851-0
更新日期:1985-12-01 00:00:00
abstract::The piezoelectric properties of single collagen type I fibrils in fascia were imaged with sub-20 nm spatial resolution using piezoresponse force microscopy. A detailed analysis of the piezoresponse force microscopy signal in controlled tip-fibril geometry revealed shear piezoelectricity parallel to the fibril axis. Th...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2010.02.047
更新日期:2010-06-16 00:00:00
abstract::The relationship between calcium current and transmitter release was studied in squid giant synapse. It was found that the voltage-dependent calcium current triggers the release of synaptic transmitter in direct proportion to its magnitude and duration. Transmitter release occurs with a delay of approximately 200 mus ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(81)84899-0
更新日期:1981-03-01 00:00:00
abstract::Two different spin labels, N-(1-oxyl-2,2,5,5-tetramethyl-3-pyrrolidinyl)iodoacetamide (IPSL) and (1-oxyl-2,2,5,5-tetramethylpyrroline-3-methyl) methanethiosulfonate (MTSSL), and two different fluorescent labels 5-((((2-iodoacetyl)amino)-ethyl)amino)naphtalene-1-sulfonic acid (IAEDANS) and 6-bromoacetyl-2-dimetylaminon...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(01)76253-4
更新日期:2001-06-01 00:00:00
abstract::We have studied the combined effects of X-irradiation and nitrogen mustard treatment on the colony-forming ability of Chinese hamster cells. In contrast to X-irradiation, nitrogen mustard acting by itself yields an exponential dose-effect relationship. Moreover, whether delivered in immediate sequence or after varying...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(69)86439-8
更新日期:1969-09-01 00:00:00
abstract::One theory of freezing damage suggests that slowly cooled cells are killed by being exposed to increasing concentrations of electrolytes as the suspending medium freezes. A corollary to this view is that protective additives such as glycerol protect cells by acting colligatively to reduce the electrolyte concentration...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(78)85436-8
更新日期:1978-07-01 00:00:00
abstract::Functional RNAs can fold into intricate structures using a number of different secondary and tertiary structural motifs. Many factors contribute to the overall free energy of the target fold. This study aims at quantifying the entropic costs coming from the loss of conformational freedom when the sugar-phosphate backb...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2018.03.035
更新日期:2018-05-08 00:00:00
abstract::Emission spectra of the photolabile Ca2+ chelators DM-nitrophen, nitr-5, and diazo-2 were studied alone, and in the presence of indo-1, to investigate potential interactions that would make the simultaneous manipulation and ratiometric measurement of the intracellular Ca2+ concentration difficult. Neither diazo-2 nor ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(93)81328-6
更新日期:1993-12-01 00:00:00
abstract::The muscle nicotinic receptor (AChR) is a pentamer of four different subunits, each of which contains four transmembrane domains (M1-M4). We recently showed that channel opening and closing rates of the AChR depend on a hydrogen bond involving a threonine at position 14' of the M4 domain in the alpha-subunit. To deter...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(02)75541-0
更新日期:2002-04-01 00:00:00
abstract::A new electrophoresis model of charged components in a spherical phospholipid vesicle is proposed. In the new model the effective local tangential electric field is a result of the uniform external electric field modified by the electric field of redistributed charges. The modification is calculated on the basis of th...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/s0006-3495(97)78699-5
更新日期:1997-02-01 00:00:00
abstract::The photocycle of salinarum halorhodopsin was investigated in the presence of azide. The azide binds to the halorhodopsin with 150 mM binding constant in the absence of chloride and with 250 mM binding constant in the presence of 1 M chloride. We demonstrate that the azide-binding site is different from that of chlori...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(02)75521-5
更新日期:2002-04-01 00:00:00
abstract::We explore the means by which immobilization of a substrate on a surface can increase the rate of a diffusion-controlled enzymatic reaction. A quasichemical approach is developed and compared with Brownian dynamics simulations. We use these methods to show that restricting only the orientation of the enzyme by long-ra...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.105.072785
更新日期:2006-02-01 00:00:00
abstract::Open channel properties of canine cardiac Purkinje cell Na+ channels were studied with single channel cell-attached recording and with whole cell macroscopic current recording in internally perfused cells. Single channel currents and membrane currents increased with an increase in Na+ concentration, but showed evidenc...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(87)83183-1
更新日期:1987-07-01 00:00:00
abstract::Wiener kernels have been measured for the light growth response of a number of mutants of Phycomyces which show abnormal phototropism (mad mutants). Representative mutants were chosen from the six complementation groups (madA to madF) associated with the light response pathway. One group, madA, associated with the inp...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(75)85881-4
更新日期:1975-10-01 00:00:00
abstract::Competitive hybridization, at the surface and in the bulk, lowers the sensitivity of DNA chips. Competitive surface hybridization occurs when different targets can hybridize with the same probe. Competitive bulk hybridization takes place when the targets can hybridize with free complementary chains in the solution. Th...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(04)74150-8
更新日期:2004-02-01 00:00:00
abstract::It has been repeatedly noted that the change of conformation of the molecules that serve as the ion-selective channels for sodium and potassium conductance in the nerve membrane will be accompanied by a change in the dipole moment of the molecule. This time-dependent change of dipole moment will produce transient curr...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(77)85587-2
更新日期:1977-09-01 00:00:00
abstract::Endothelin-1 (ET-1) mediates physiological responses via endothelin A (ET(A)) and B (ET(B)) receptors, which may form homo- and heterodimers with unknown function. Here, we investigated ET-receptor dimerization using fluorescence resonance energy transfer (FRET) between receptors tagged with CFP (donor) and receptors ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.107.119206
更新日期:2008-07-01 00:00:00
abstract::Forces applied by intact mucus-propelling cilia were measured for the first time that we know of using a combined atomic force microscopy (AFM) and electrooptic system. The AFM probe was dipped into a field of beating cilia and its time-dependent deflection was recorded as it was struck by the cilia while the electroo...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.106.094698
更新日期:2007-03-01 00:00:00
abstract::Excised inside-out membrane patches are useful for studying the cGMP-activated ion channels that generate the electrical response to light in retinal rod cells. We show that strong ionic current across a patch changes the driving force on the current by altering the ionic concentration near the surface membrane, an ef...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(88)82966-7
更新日期:1988-08-01 00:00:00