Abstract:
:In a pure fluid-phase lipid, the dependence of the lateral diffusion coefficient on the size of the diffusing particle may be obtained from the Saffman-Delbrück equation or the free-volume model. When diffusion is obstructed by immobile proteins or domains of gel-phase lipids, the obstacles yield an additional contribution to the size dependence. Here this contribution is examined using Monte Carlo calculations. For random point and hexagonal obstacles, the diffusion coefficient depends strongly on the size of the diffusing particle, but for fractal obstacles--cluster-cluster aggregates and multicenter diffusion-limited aggregates--the diffusion coefficient is independent of the size of the diffusing particle. The reason is that fractals have no characteristic length scale, so a tracer sees on average the same obstructions, regardless of its size. The fractal geometry of the excluded area for tracers of various sizes is examined. Percolation thresholds are evaluated for a variety of obstacles to determine how the threshold depends on tracer size and to compare the thresholds for compact and extended obstacles.
journal_name
Biophys Jjournal_title
Biophysical journalauthors
Saxton MJdoi
10.1016/S0006-3495(93)81471-1subject
Has Abstractpub_date
1993-04-01 00:00:00pages
1053-62issue
4eissn
0006-3495issn
1542-0086pii
S0006-3495(93)81471-1journal_volume
64pub_type
杂志文章abstract::Mechanical properties of living cells can be determined using atomic force microscopy (AFM). In this study, a novel analysis was developed to determine the mechanical properties of adherent monolayers of pulmonary microvascular endothelial cells (ECs) using AFM and finite element modeling, which considers both the fin...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.106.099333
更新日期:2008-04-15 00:00:00
abstract::We have measured the fluorescence spectra of a single fluorophore attached to a single protein molecule in aqueous solution using a total internal reflection fluorescence microscope. The most reactive cysteine residue of myosin subfragment-1 (S1) was labeled with tetramethylrhodamine. The spectral shift induced by a c...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(00)76708-7
更新日期:2000-03-01 00:00:00
abstract::A mean-field statistical mechanical theory has been developed to describe molecular distributions in interphases. The excluded volume interaction has been modeled in terms of a reversible work that is required to create a cavity of the solute size against a pressure tensor exerted by the surrounding interphase molecul...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/s0006-3495(94)80833-1
更新日期:1994-03-01 00:00:00
abstract::The 77-K resonance Raman vibrational spectrum of intact goldfish rod photoreceptors containing 3,4-dehydro (A2) retinal is dominated by scattering from the 9-cis component of the steady state at all excitation wavelengths. Intact goldfish photoreceptors were regenerated with an A1-retinal chromophore to determine whet...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(87)83250-2
更新日期:1987-10-01 00:00:00
abstract::The steady-state stimulus-response curve of the Limulus ventral photoreceptor comprises a linear portion followed by a less-than-unity power law dependence, which is maintained over at least 4 decades of intensity. This progressive desensitization corresponds to light adaptation. For flash stimulation of dark-adapted ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(88)83111-4
更新日期:1988-03-01 00:00:00
abstract::Fluorescent probes in biological systems are sensitive to environmental polarity by virtue of their response to the reaction field created by polarization of the dielectric medium. Classically, fluorophore solvatochromism is analyzed in terms of the Lippert equation and later variants, all of which rely upon the origi...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2009.01.006
更新日期:2009-04-08 00:00:00
abstract::Distinct lipid environments, including lipid rafts, are increasingly recognized as a crucial factor affecting membrane protein function in plasma membranes. Unfortunately, an understanding of their role in membrane protein activation and oligomerization has remained elusive due to the challenge of characterizing these...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2011.08.040
更新日期:2011-10-05 00:00:00
abstract::Alamethicin is a 19-residue hydrophobic peptide, which is extended by a C-terminal phenylalaninol but lacks residues that might anchor the ends of the peptide at the lipid-water interface. Voltage-dependent ion channels formed by alamethicin depend strongly in their characteristics on chain length of the host lipid me...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.107.104026
更新日期:2007-06-01 00:00:00
abstract::We have developed a saturation transfer EPR (ST-EPR) method to measure selectively the rotational dynamics of those lipids that are motionally restricted by integral membrane proteins and have applied this methodology to measure lipid-protein interactions in native sarcoplasmic reticulum (SR) membranes. This analysis ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(89)82721-3
更新日期:1989-10-01 00:00:00
abstract::Binding features of heroin in whole blood and in blood fractions were delineated by measuring the selective spin-lattice relaxation rates of heroin protons in physiologic conditions. Interaction with some receptor located in the whole human blood or in the human plasma was detected and the apparent binding constant ca...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(85)83778-4
更新日期:1985-08-01 00:00:00
abstract::A method for fabricating biomimetic surfaces from intact cell membranes is described. A monolayer of alkanethiol on gold is covered by a second layer derived from the components of erythrocyte membranes either by self-assembly or by Langmuir-Blodgett methods. The resulting asymmetric hybrid layer was characterized by ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(97)78334-6
更新日期:1997-12-01 00:00:00
abstract::The channels present on the surface membrane of isolated rat flexor digitorum brevis muscle fibers were surveyed using the patch clamp technique. 85 out of 139 fibers had a novel channel which excluded the anions chloride, sulfate, and isethionate with a permeability ratio of chloride to sodium of less than 0.05. The ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(91)82340-2
更新日期:1991-06-01 00:00:00
abstract::Nerve growth factor (NGF) mimics play an important role for therapies that target the receptor tyrosine kinase A (trkA). The N-terminal fragment of the NGF (N-term@NGF) was previously demonstrated to be an important determinant for affinity and specificity in the binding to trkA. Here we use a variety of computational...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.106.083519
更新日期:2006-09-15 00:00:00
abstract::hbAP0 is a model membrane protein designed to possess an anesthetic-binding cavity in its hydrophilic domain and a cation channel in its hydrophobic domain. Grazing incidence x-ray diffraction shows that hbAP0 forms four-helix bundles that are vectorially oriented within Langmuir monolayers at the air-water interface....
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.105.072348
更新日期:2006-05-01 00:00:00
abstract::Biophysical understanding of membrane domains requires accurate knowledge of their structural details and elasticity. We report on a global small angle x-ray scattering data analysis technique for coexisting liquid-ordered (Lo) and liquid-disordered (Ld) domains in fully hydrated multilamellar vesicles. This enabled t...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2014.11.3488
更新日期:2015-02-17 00:00:00
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
更新日期:2006-05-01 00:00:00
abstract::Pre-mRNA processing protein 40 (Prp40) is a nuclear protein that has a role in pre-mRNA splicing. Prp40 possesses two leucine-rich nuclear export signals, but little is known about the function of Prp40 in the export process. Another protein that has a role in protein export is centrin, a member of the EF-hand superfa...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2017.03.042
更新日期:2017-06-20 00:00:00
abstract::We examined the state-, voltage-, and time dependences of interaction between 4-AP and a mammalian A-type K channel clone (rKv1.4) expressed in Xenopus oocytes using whole-cell and single-channel recordings. 4-AP blocked rKv1.4 from the cytoplasmic side of the membrane. The development of block required channel openin...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(94)80462-X
更新日期:1994-07-01 00:00:00
abstract::Bathorhodopsins were prepared by partially (10--15%) photoconverting bovine rhodopsin (11-cis chromophore) or isorhodopsin I (9-cis chromophore) at 77 degrees K; care was taken to avoid establishing photostationary states. The absorption spectra calculated for the bathorhodopsins derived from the two parent pigments a...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(80)85129-0
更新日期:1980-02-01 00:00:00
abstract::The structure of polymer-decorated phospholipid monolayers at the solid-solution interface was investigated using neutron reflectometry. The monolayers were composed of distearoylphosphatidylethanolamine (DSPE) matrixed with varying amounts of DSPE-PEG (DSPE with polyethylene glycol covalently grafted to its headgroup...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(98)77679-9
更新日期:1998-11-01 00:00:00
abstract::The quantitation of human granulocyte movement using a stochastic differential equation is described. The method has the potential to distinguish both positive and negative chemotaxis. Analysis and information concerning cell movements can be obtained for any point in time and distance for the duration of the experime...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(76)85685-8
更新日期:1976-03-01 00:00:00
abstract::A number of models proposed to account for the sodium conductance changes are shown to fall into two classes. The Hodgkin-Huxley (HH) model falls into a class (I) in which the conductance depends on two or more independent variables controlled by independent processes. The Mullins, Hoyt, and Goldman models fall into c...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(68)86540-3
更新日期:1968-10-01 00:00:00
abstract::Nanodiscs that hold a lipid bilayer surrounded by a boundary of scaffold proteins have emerged as a powerful tool for membrane protein solubilization and analysis. By combining nanodiscs and cell-free expression technologies, even completely detergent-free membrane protein characterization protocols can be designed. N...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2017.03.026
更新日期:2017-09-19 00:00:00
abstract::We investigated whether the cysteine residues in Shaker potassium (K+) channels are essential for activation and inactivation gating or for modulation of activation gating by external zinc (Zn2+). Mutants of the Shaker K+ channel were prepared in which all seven cysteine residues were replaced (C-less). These changes ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/s0006-3495(94)80843-4
更新日期:1994-03-01 00:00:00
abstract::Cellular sensory systems often respond not to the absolute levels of inputs but to the fold-changes in inputs. Such a property is called fold-change detection (FCD) and is important for accurately sensing dynamic changes in environmental signals in the presence of fluctuations in their absolute levels. Previous studie...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2013.10.039
更新日期:2014-01-07 00:00:00
abstract::Epigenetic modifications can extend over long genomic regions to form domain-level chromatin states that play critical roles in gene regulation. The molecular mechanism for the establishment and maintenance of these states is not fully understood and remains challenging to study with existing experimental techniques. ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2019.04.006
更新日期:2019-05-21 00:00:00
abstract::We have studied tubules formed from a polymerizable lipid in aqueous dispersion using freeze-fracture replication and transmission electron microscopy. The polymerizable diacetylenic lecithin 1,2-bis(10,12-tricosadiynoyl)-sn-glycero-3-phosphocholine converts from liposomes to hollow cylinders, which we call tubules, o...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(85)83852-2
更新日期:1985-12-01 00:00:00
abstract::We have constructed a theory for diffusion through the pore of a single-ion channel by taking a limit of a random walk around a cycle of states. Similar to Levitt's theory of single-ion diffusion, one obtains boundary conditions for the Nernst-Planck equation that guarantee that the pore is occupied by at most one ion...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(96)79374-8
更新日期:1996-10-01 00:00:00
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::We studied the effects of permeant ions on the gating of the large conductance Ca(2+)-activated K+ channel from rat skeletal muscle. Rb+ blockade of inward K+ current caused an increase in the open probability as though Rb+ occupancy of the pore interferes with channel closing. In support of this hypothesis, we direct...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(92)81869-6
更新日期:1992-03-01 00:00:00