Abstract:
:Ultrasonic relaxation of multilamellar liposomes formed from dipalmitoylphosphatidylcholine was measured near the gel-to-liquid crystal transition by a differential ultrasonic resonator. The relaxation time and strength increased remarkably near the transition temperature, indicating a pseudocritical phenomenon. A quantitative analysis of the relaxation in terms of thermodynamic relationships between specific heat, thermal-expansion coefficient, and compressibility showed that more than 90% of the total endothermic heat of the transition arises from the latent heat. The temperature dependence of the ultrasonic relaxation parameters was also analyzed by the Landau theory; we obtain a small but finite difference, 0.6 degree C, between the pseudocritical temperature and the transition temperature. These results provide a quantitative description of both the first-order and second-order characters of the gel-to-liquid crystal transition.
journal_name
Biophys Jjournal_title
Biophysical journalauthors
Mitaku S,Jippo T,Kataoka Rdoi
10.1016/S0006-3495(83)84379-3subject
Has Abstractpub_date
1983-05-01 00:00:00pages
137-44issue
2eissn
0006-3495issn
1542-0086pii
S0006-3495(83)84379-3journal_volume
42pub_type
杂志文章abstract::A method for generating angular forces around sigma-bonded transition metal ions is generalized to treat pi-bonded configurations. The theoretical approach is based on an analysis of ligand-field and small-cluster Hamiltonians based on the moments of the electron state distribution. The functional forms that are obtai...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(01)75675-5
更新日期:2001-07-01 00:00:00
abstract::In biology, molecular linkages at, within, and beneath cell interfaces arise mainly from weak noncovalent interactions. These bonds will fail under any level of pulling force if held for sufficient time. Thus, when tested with ultrasensitive force probes, we expect cohesive material strength and strength of adhesion a...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(97)78802-7
更新日期:1997-04-01 00:00:00
abstract::In this study stereochemically pure d-erythro-sphingomyelins (SMs) with either 16:0 or 18:1(cisDelta9) as the N-linked acyl-chain were synthesized. Our purpose was to examine the properties of these sphingomyelins and acyl-chain matched racemic (d-erythro/l-threo) sphingomyelins in model membranes. Liquid-expanded d-e...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(99)76997-3
更新日期:1999-09-01 00:00:00
abstract::The stoichiometric matrix, S, represents a mapping of reaction rate vectors into a space of concentration time derivatives. The left null space of the stoichiometric matrix contains the dynamic invariants: a combination of concentration variables, referred to as metabolic pools, whose total concentration does not chan...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(03)74450-6
更新日期:2003-07-01 00:00:00
abstract::In most studied microbial rhodopsins two conserved carboxylic acid residues (the homologs of Asp-85 and Asp-212 in bacteriorhodopsin) and an arginine residue (the homolog of Arg-82) form a complex counterion to the protonated retinylidene Schiff base, and neutralization of the negatively charged carboxylates causes re...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2014.03.002
更新日期:2014-04-15 00:00:00
abstract::The lateral mobility of the lipid analog N-4-nitrobenzo-2-oxa-1,3 diazole phosphatidylethanolamine and of the integral protein glycophorin in giant dimyristoylphosphatidylcholine vesicles was studied by the photobleaching technique. Above the temperature of the chain-melting transition (Tm = 23 degrees C), the diffusi...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(84)84195-8
更新日期:1984-03-01 00:00:00
abstract::Diffusion of the chloride salts of Li, Na, K, Rb, and Cs from water into 1-butanol and from 1-butanol into water was examined at temperatures from 13-40 degrees C. Distribution coefficients, interfacial transfer coefficients, Arrhenius activation energy, free energy of activation, enthalpy, and entropy of activation w...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(66)86697-3
更新日期:1966-11-01 00:00:00
abstract::The distal side of the heme pocket, known to regulate ligand affinity, is shown to be directly involved in subunit interactions. Valency hybrids with oxygen or carbon monoxide bound to the reduced chain are used to model R-state hemoglobin with different distal perturbations. Electron paramagnetic resonance of the oxi...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(92)81879-9
更新日期:1992-03-01 00:00:00
abstract::The harmonic mode analysis method was used to characterize the conformational deformability of regular Watson-Crick paired, mismatch- and bulge-containing RNA. Good agreement between atomic Debye-Waller factors derived from x-ray crystallography of a regular RNA oligonucleotide and calculated atomic fluctuations was o...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(00)76798-1
更新日期:2000-05-01 00:00:00
abstract::13C alpha chemical shifts and site-specific unfolding curves are reported for 12 sites on a 33-residue, GCN4-like leucine zipper peptide (GCN4-lzK), ranging over most of the chain and sampling most heptad positions. Data were derived from NMR spectra of nine synthetic, isosequential peptides bearing 99% 13C alpha at s...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(97)78136-0
更新日期:1997-08-01 00:00:00
abstract::A novel system for measuring, simultaneously, ciliary beating and intracellular free calcium is presented. The advantages and dynamic nature of the system are demonstrated by measuring the effects of the calcium ionophore lonomycin and of extracellular ATP on ciliated rabbit trachea. The results are discussed with reg...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(94)80492-8
更新日期:1994-07-01 00:00:00
abstract::Morphine spin labeled on the phenolic hydroxy group has been prepared using commercially available reagents and characterized by thin layer chromatography, mass spectroscopy, and electron spin resonance spectroscopy. It has been shown that morphine modified in this way retains some opiate activity, does not pass throu...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(75)85889-9
更新日期:1975-11-01 00:00:00
abstract::Dipole moment, enthalpy, and entropy changes were calculated for hypothetical structural units which control the opening and closing of ionic channels in axon membranes. The changes of these thermodynamic functions were calculated both for activation (transition to intermediate complex) and for the structural transfor...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(75)85815-2
更新日期:1975-03-01 00:00:00
abstract::Structure-function studies of the Cys loop family of ionotropic neurotransmitter receptors (GABA, nACh, 5-HT(3), and glycine receptors) have resulted in a six-loop (A-F) model of the agonist-binding site. Key amino acids have been identified in these loops that associate with, and stabilize, bound ligand. The next ste...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2008.09.011
更新日期:2009-01-01 00:00:00
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
更新日期:2009-10-21 00:00:00
abstract::Muscle contraction is governed by tropomyosin (Tpm) shifting azimuthally between three states on F-actin (B-, C-, and M-states) in response to calcium binding to troponin and actomyosin cross-bridge formation. The Tpm coiled coil polymerizes head to tail along the long-pitch helix of F-actin to form continuous superhe...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2019.11.3396
更新日期:2020-01-21 00:00:00
abstract::The dependence of phospholipid vesicle size on lipid composition is investigated by photon correlation spectroscopy. For each lipid composition prolonged ultracentrifugation was used to isolate a nearly uniform population of minimum-sized vesicles. The residual size variations in the samples were sufficient to cause p...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(82)84524-4
更新日期:1982-04-01 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::In contrast with most inhalational anesthetics, the anesthetic gases xenon (Xe) and nitrous oxide (N(2)O) act by blocking the N-methyl-d-aspartate (NMDA) receptor. Using x-ray crystallography, we examined the binding characteristics of these two gases on two soluble proteins as structural models: urate oxidase, which ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.106.093807
更新日期:2007-01-01 00:00:00
abstract::Quantitative analysis of DNA microarray data is complicated by uncertainties inherent to the experimental setup. Using computer simulations and real-time experimental results, we have previously demonstrated effects of multiplex reactions on a single sensing zone of an array, which may be a leading factor in erroneous...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.107.121459
更新日期:2008-03-01 00:00:00
abstract::The E5 oncoprotein is the major transforming protein of bovine papillomavirus type 1. This 44-residue transmembrane protein can interact with the platelet-derived growth factor receptor β, leading to ligand-independent activation and cell transformation. For productive interaction, E5 needs to dimerize via a C-termina...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2010.06.073
更新日期:2010-09-22 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::This paper is concerned with the nature of the transmembrane potential induced in an inactive nerve fiber lying in an impressed potential field within a nerve trunk. The impressed potential field is assumed to be produced by the synchronous activity of other fibers within the trunk; an expression for the induced trans...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(71)86214-8
更新日期:1971-03-01 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::A ternary lipid mixture of palmitoyl-oleoyl-phosphatidylcholine (POPC), palmitoyl-erythro-sphingosylphosphorylcholine (PSM), and cholesterol at a mixing ratio of 37.5:37.5:25 mol/mol/mol was characterized using fluorescence microscopy, (2)H NMR, and electron paramagnetic resonance spectroscopy. The synthetic PSM provi...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.107.112904
更新日期:2008-04-01 00:00:00
abstract::Association of transmembrane (TM) helices is facilitated by the close packing of small residues present along the amino-acid sequence. Extensive studies have established the role of such small residue motifs (GxxxG) in the dimerization of Glycophorin A (GpA) and helped to elucidate the association of TM domains in the...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2010.10.023
更新日期:2010-12-01 00:00:00
abstract::The electrophysiological properties of the cation channel of the purified nicotinic acetylcholine receptor (AChR) reconstituted in planar lipid bilayers were characterized. Single-channel currents were activated by acetylcholine, carbamylcholine and suberyldicholine. The single channel conductance (28 pS in 0.3 M NaCl...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(84)84145-4
更新日期:1984-01-01 00:00:00
abstract::The mechanism for transport of divalent cations across phospholipid bilayers by the ionophore A23187 was investigated. The intrinsic fluorescence of the ionophore was used in equilibrium and rapid-mixing experiments as an indicator of ionophore environment and complexation with divalent cations. The neutral (protonate...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(81)84738-8
更新日期:1981-11-01 00:00:00
abstract::Transient receptor potential (TRP) channels are members of a large family of ion channels located in membranes rich in cholesterol, some of whose functions are affected by the cholesterol content of the membrane. Here, cholesterol binding to TRPs is studied using a docking procedure that allows the transmembrane surfa...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2019.10.011
更新日期:2019-11-19 00:00:00
abstract::Ca2+ entry under resting conditions may be important for contraction of vascular smooth muscle, but little is known about the mechanisms involved. Ca2+ leakage was studied in the A7r5 smooth muscle-derived cell line by patch-clamp techniques. Two channels that could mediate calcium influx at resting membrane potential...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(98)74047-0
更新日期:1998-09-01 00:00:00