Abstract:
:Protein solubility in aqueous solutions depends in a complicated and not well understood way on pH, salt type, and salt concentration. Why for instance does the use of two different monovalent salts, potassium thiocyanate and potassium chloride, produce such different results? One important and previously neglected source of ion specificity is the ionic dispersion potential that acts between each ion and the protein. This attractive potential is found to be much stronger for SCN(-) than it is for Cl(-). We present model calculations, performed within a modified ion-specific double-layer theory, that demonstrate the large effect of including these ionic dispersion potentials. The results are consistent with experiments performed on hen egg-white lysozymes and on neutral black lipid membranes. The calculated surface pH and net lysozyme charge depend strongly on the choice of anion. We demonstrate that the lysozyme net charge is larger, and the corresponding Debye length shorter, in a thiocyanate salt solution than in a chloride salt solution. Recent experiments have suggested that pK(a) values of histidines depend on salt concentration and on ionic species. We finally demonstrate that once ionic dispersion potentials are included in the theory these results can quantitatively be reinterpreted in terms of a highly specific surface pH (and a salt-independent pK(a)).
journal_name
Biophys Jjournal_title
Biophysical journalauthors
Boström M,Williams DR,Ninham BWdoi
10.1016/S0006-3495(03)74512-3subject
Has Abstractpub_date
2003-08-01 00:00:00pages
686-94issue
2eissn
0006-3495issn
1542-0086pii
S0006-3495(03)74512-3journal_volume
85pub_type
杂志文章abstract::A dissipative system is approximated by a nonlinear rate equation: Z congruent to K1Z - K2Z3 (K2 greater than 0), in which the right side is derived from -delta G/delta Z of Taylor's series of the thermodynamic potential given by Gibbs' function G(Tc, Pc) (Z) at about the critical point C(Tc, Pc) of the control variab...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(90)82518-2
更新日期:1990-01-01 00:00:00
abstract::An analysis is presented of the complex anisotropy behavior of trans-parinaric acid in single component DEPC lipid bilayers. It is shown that a model involving two species with distinct lifetime and motional behavior is required, and is adequate, to explain the observed data. In particular, the observed increase in th...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(89)82909-1
更新日期:1989-06-01 00:00:00
abstract::We compared wild-type rat skeletal muscle NaChs (micro1) and a mutant NaCh (Y1586K) that has a single amino acid substitution, lysine (K) for tyrosine (Y), at position 1586 in the S6 transmembrane segment of domain 4. In Y1586K, macroscopic current decay is faster, the V(1/2) of the activation curve is shifted in the ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(00)76635-5
更新日期:2000-02-01 00:00:00
abstract::Membrane proteins diffuse within the membrane, form oligomers and supramolecular assemblies. Using high-speed atomic force microscopy, we present direct experimental measure of an in-membrane-plane interaction potential between membrane proteins. In purple membranes, ATP-synthase c-rings formed dimers that temporarily...
journal_title:Biophysical journal
pub_type: 信件
doi:10.1016/j.bpj.2010.07.028
更新日期:2010-10-06 00:00:00
abstract::The kinetics of porin incorporation into black lipid membranes (BLM) made of phosphatidylinositol (PI) or oxidized cholesterol (Ox Ch) were studied by means of alternating current; the set-up was able to acquire resistance and capacitance simultaneously by means of a mixed double-frequency approach at 1 Hz and 1 KHz, ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(96)79283-4
更新日期:1996-08-01 00:00:00
abstract::Articular cartilage is the connective tissue that lines joints and provides a smooth surface for joint motion. Because cartilage is avascular, molecular transport occurs primarily via diffusion or convection, and cartilage matrix structure and composition may affect diffusive transport. Because of the inhomogeneous co...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.108.137752
更新日期:2008-11-15 00:00:00
abstract::Molecular chaperone Hsp70 plays important roles in the pathology of amyloid diseases by inhibiting aberrant aggregation of proteins. However, the biophysical mechanism of the interaction of Hsp70 with the intrinsically disordered proteins (IDPs) is unclear. Here, we report that Hsp70 inhibits aggregation of islet amyl...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2020.12.019
更新日期:2021-01-06 00:00:00
abstract::We have used fluorescence-quenching measurements to characterize the partitioning of a variety of indolyl-labeled phospho- and sphingolipids between gel or liquid-ordered and liquid-disordered lipid domains in several types of lipid bilayers where such domains coexist. In both cholesterol-free and cholesterol-containi...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(03)74857-7
更新日期:2003-01-01 00:00:00
abstract::Here we present a model for maltodextrin translocation through maltoporin channels. In a first step, our theoretical analysis does consider the case of a single binding site for a given substrate in a structurally unaffected channel with a possibly different entrance barrier on either side. It is shown how by means of...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(03)70025-3
更新日期:2003-05-01 00:00:00
abstract::The study of mechanotransduction relies on tools that are capable of applying mechanical forces to elicit and assess cellular responses. Here we report a new (to our knowledge) technique, called two-bubble acoustic tweezing cytometry (TB-ATC), for generating spatiotemporally controlled subcellular mechanical forces on...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2014.11.050
更新日期:2015-01-06 00:00:00
abstract::Properties of filamentous acetamidofluorescein-labeled actin and acetamidotetramethylrhodamine-labeled actin (AF and ATR-actin, respectively) were examined to resolve discrepancies in the reported translational diffusion coefficients of F-actin measured in vitro by FPR and other techniques. Using falling-ball viscomet...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(88)83018-2
更新日期:1988-11-01 00:00:00
abstract::Reversible blockage of the voltage-dependent anion channel (VDAC) of the mitochondrial outer membrane by dimeric tubulin is being recognized as a potent regulator of mitochondrial respiration. The tubulin-blocked state of VDAC is impermeant for ATP but only partially closed for small ions. This residual conductance al...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2012.03.058
更新日期:2012-05-02 00:00:00
abstract::We have measured, using infrared spectroscopy, the hydrogen/deuterium exchange rates of the amide protons in the photosynthetic antenna of Rhodospirillum rubrum. These measurements were made not only on the intact protein in detergent solution but also on two dissociated forms (B820 and B777). We have, on the basis of...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(98)74022-6
更新日期:1998-02-01 00:00:00
abstract::The kinetics of J-aggregate formation has been studied for two chromophores, tetrakis-4-sulfonatophenylporphine in an acid medium and pseudoisocyanine on a polyvinylsulfonate template. The assembly processes differ both in their sensitivity to initiation protocols and in the reaction profiles they produce. The porphyr...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(00)76316-8
更新日期:2000-07-01 00:00:00
abstract::We have used chemical synthesis, electron paramagnetic resonance (EPR), and circular dichroism to detect and analyze the structural dynamics of a ryanodine receptor (RyR) peptide bound to calmodulin (CaM). The skeletal muscle calcium release channel RyR1 is activated by Ca2+-free CaM and inhibited by Ca2+-bound CaM. T...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2016.10.025
更新日期:2016-12-06 00:00:00
abstract::We have performed molecular dynamics simulations of multiple copies of the lung-surfactant peptide SP-B1-25 in a palmitic acid (PA) monolayer. SP-B1-25 is a shorter version of lung-surfactant protein B, an important component of lung surfactant. Up to 30 ns simulations of 20 wt % SP-B1-25 in the PA monolayers were per...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.105.066241
更新日期:2005-12-01 00:00:00
abstract::The solubility of aqueous solutions of lysozyme in the presence of polyethylene glycol and various alkaline salts was studied experimentally. The protein-electrolyte mixture was titrated with polyethylene glycol, and when precipitation of the protein occurred, a strong increase of the absorbance at 340 nm was observed...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.108.128694
更新日期:2008-08-01 00:00:00
abstract::Protein/lipid coassembly is an understudied phenomenon that is important to the function of antimicrobial peptides as well as the pathological effects of amyloid. Here, we study the coassembly process of PAP248-286, a seminal peptide that displays both amyloid-forming and antimicrobial activity. PAP248-286 is a peptid...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2020.07.029
更新日期:2020-09-01 00:00:00
abstract::Investigations into the spatiotemporal dynamics of DNA repair using live-cell imaging are aided by the ability to generate well defined regions of ultravioletlike photolesions in an optical microscope. We demonstrate that multiphoton excitation of DNA in live cells with visible femtosecond pulses produces thymine cycl...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2011.09.031
更新日期:2011-11-02 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::Cyclic nucleotide-gated (CNG) channels, which were initially studied in retina and olfactory neurons, are activated by cytoplasmic cGMP or cAMP. Detailed comparisons of nucleotide-activated currents using nucleotide analogs and mutagenesis revealed channel-specific residues in the nucleotide-binding domain that regula...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(00)76778-6
更新日期:2000-05-01 00:00:00
abstract::Experimental approaches such as fiber diffraction and cryo-electron microscopy reconstruction have defined regulatory positions of tropomyosin on actin but have not, as yet, succeeded at determining key atomic-level contacts between these proteins or fully substantiated the dynamics of their interactions at a structur...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2020.05.017
更新日期:2020-07-07 00:00:00
abstract::The classical cable equation, in which membrane conductance is considered constant, is modified by including the linearized effect of membrane potential on sodium and potassium ionic currents, as formulated in the Hodgkin-Huxley equations for the squid giant axon. The resulting partial differential equation is solved ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(69)86446-5
更新日期:1969-10-01 00:00:00
abstract::We have examined the distribution of ryanodine receptors, L-type Ca(2+) channels, calsequestrin, Na(+)/Ca(2+) exchangers, and voltage-gated Na(+) channels in adult rat ventricular myocytes. Enzymatically dissociated cells were fixed and dual-labeled with specific antibodies using standard immunocytochemistry protocols...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(00)76506-4
更新日期:2000-11-01 00:00:00
abstract::A theory based on the Smolukowski analysis of colloid stability shows that the presence of charged, surface-active serum proteins at the alveolar air-liquid interface can severely reduce or eliminate the adsorption of lung surfactant from the subphase to the interface, consistent with the observations reported in the ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.105.062646
更新日期:2005-09-01 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 interactions between vitamin-A and beta-lactoglobulin have been investigated. We have found that two different complexes can be formed: one involving vitamin-A, and one involving a derivative of vitamin-A that most probably has a retro-beta-ionylidene structure. Room temperature absorption spectra for these comple...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(79)85192-9
更新日期:1979-12-01 00:00:00
abstract::Benjamin Franklin, mostly known for his participation in writing The Declaration of Independence and work on electricity, was also one of the first scientists to seek to understand the properties of oil monolayers on water surfaces. During one of his many voyages across the Atlantic Ocean, Franklin observed that oil h...
journal_title:Biophysical journal
pub_type: 传,历史文章,杂志文章
doi:10.1016/j.bpj.2012.12.028
更新日期:2013-01-22 00:00:00
abstract::The influence of mass transport on ligand binding to receptor immobilized in a polymer matrix, as detected with an evanescent wave biosensor, was investigated. A one-dimensional computer model for the mass transport of ligand between the bulk solution and the polymer gel and within the gel was employed, and the influe...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(96)79681-9
更新日期:1996-03-01 00:00:00
abstract::By exploring a recent model in which DNA bending elasticity, described by the wormlike chain model, is coupled to basepair denaturation, we demonstrate that small denaturation bubbles lead to anomalies in the flexibility of DNA at the nanometric scale, when confined in two dimensions (2D), as reported in atomic-force ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2009.03.035
更新日期:2009-06-03 00:00:00