Abstract:
:In order to verify the "radiation protection" effect of prosthetic groups in irradiated conjugated proteins and the influence of their electronic structure on intramolecular excitation transfer, two series of substances were examined. The first was composed of ferrihemoglobin and its constituents and the second was composed of similar hemoproteins with heme groups with major differences in electronic structure. The results point to a strong radiation protection effect of the heme groups and a dependence of radical yield of hemoproteins on the electronic structure of the heme. A possible interpretation of this latter effect is discussed.
journal_name
Biophys Jjournal_title
Biophysical journalauthors
Crippa PR,Vecli Adoi
10.1016/S0006-3495(70)86299-3subject
Has Abstractpub_date
1970-03-01 00:00:00pages
269-76issue
3eissn
0006-3495issn
1542-0086pii
S0006-3495(70)86299-3journal_volume
10pub_type
杂志文章abstract::Cardiac contraction and relaxation dynamics result from a set of simultaneously interacting Ca(2+) regulatory mechanisms. In this study, cardiocyte Ca(2+) dynamics were modeled using a set of six differential equations that were based on theories, equations, and parameters described in previous studies. Among the uniq...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(00)76276-X
更新日期:2000-07-01 00:00:00
abstract::Phosphatidylinositol phospholipase Cγ (PLCγ) is an intracellular membrane-associated second-messenger signaling protein activated by tyrosine kinases such as fibroblast growth factor receptor 1. PLCγ contains the regulatory γ-specific array (γSA) comprising a tandem Src homology 2 (SH2) pair, an SH3 domain, and a spli...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2018.05.031
更新日期:2018-07-03 00:00:00
abstract::The observation of biological processes at the molecular scale in real time requires high spatial and temporal resolution. Magnetic tweezers are straightforward to implement, free of radiation or photodamage, and provide ample multiplexing capability, but their spatiotemporal resolution has lagged behind that of other...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2015.10.018
更新日期:2015-11-17 00:00:00
abstract::EmrE is a small multidrug resistance transporter that has been well studied as a model for secondary active transport. Because transport requires the protein to convert between at least two states open to opposite sides of the membrane, it is expected that blocking these conformational transitions will prevent transpo...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2014.06.030
更新日期:2014-08-05 00:00:00
abstract::Fluorescence recovery after photobleaching (FRAP) has been used previously to investigate the kinetics of binding to biological surfaces. The present study adapts and further develops this technique for the quantification of mass transport and reaction parameters in bulk media. The technique's ability to obtain the bu...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(91)82089-6
更新日期:1991-09-01 00:00:00
abstract::The theoretical relationships between the fluorescence and photochemical yields of PS II and the fraction of open reaction centers are examined in a general model endowed with the following features: i) a homogeneous, infinite PS II domain; ii) exciton-radical-pair equilibrium; and iii) different rates of exciton tran...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(95)80429-7
更新日期:1995-06-01 00:00:00
abstract::Despite the recognition that actin filaments are important for numerous cellular processes, and decades of investigation, the dynamics of in vitro actin filaments are still not completely understood. Here, we follow the time evolution of the length distribution of labeled actin reporter filaments in an unlabeled F-act...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2011.07.009
更新日期:2011-08-17 00:00:00
abstract::We report the first time-resolved study of the two-dimensional x-ray diffraction pattern during active contraction in insect flight muscle (IFM). Activation of demembranated Lethocerus IFM was triggered by 1.5-2.5% step stretches (risetime 10 ms; held for 1.5 s) giving delayed active tension that peaked at 100-200 ms....
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(98)77856-7
更新日期:1998-03-01 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::Kinesin-1 is an ATP-driven molecular motor that transports cellular cargo along microtubules. At low loads, kinesin-1 almost always steps forward, toward microtubule plus ends, but at higher loads, it can also step backward. Backsteps are usually 8 nm but can be larger. These larger backward events of 16 nm, 24 nm, or...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2020.09.034
更新日期:2020-11-17 00:00:00
abstract::The relationship between epithelial fluid transport, standing osmotic gradients, and standing hydrostatic pressure gradients has been investigated using a perturbation expansion of the governing equations. The assumptions used in the expansion are: (a) the volume of lateral intercellular space per unit volume of epith...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(85)83986-2
更新日期:1985-06-01 00:00:00
abstract::Phytochromes sense red/far-red light and control many biological processes in plants, fungi, and bacteria. Although the crystal structures of dark- and light-adapted states have been determined, the molecular mechanisms underlying photoactivation remain elusive. Here, we demonstrate that the conserved tongue region of...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2019.11.025
更新日期:2020-01-21 00:00:00
abstract::The biological influence of radiation on living matter has been studied for years; however, several questions about the detailed mechanism of radiation damage formation remain largely unanswered. Among all biomolecules exposed to radiation, DNA plays an important role because any damage to its molecular structure can ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2016.01.031
更新日期:2016-03-29 00:00:00
abstract::The use of the long-lived fluorescence probe coronene (mean value of tau(FL) approximately 200 ns) is described for investigating submicrosecond lipid dynamics in DPPC model bilayer systems occurring below the lipid phase transition. Time-resolved fluorescence emission anisotropy decay profiles, measures as a function...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(96)79384-0
更新日期:1996-10-01 00:00:00
abstract::Cytosolic calcium oscillations occur in a wide variety of cells and are involved in different cellular functions. We describe these calcium oscillations by a mathematical model based on the putative electrophysiological properties of the endoplasmic reticulum (ER) membrane. The salient features of our membrane model a...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(92)81583-7
更新日期:1992-07-01 00:00:00
abstract::A new Fourier series representation of supercoiled DNA is employed in Langevin dynamics simulations to study large-scale configurational motions of intermediate-length chains. The polymer is modeled as an ideal elastic rod subject to long-range van der Waals' interactions. The van der Waals' term prevents the self-con...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(97)78205-5
更新日期:1997-10-01 00:00:00
abstract::The time correlation function of the shape fluctuations of large (greater than 10 micron), cylindrical, hydrated, phospholipid-membrane vesicles consisting of one bimolecular layer was measured. The restoring force of the membrane was due to the excess curvature of a membrane element. A value for the curvature elastic...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(84)84235-6
更新日期:1984-05-01 00:00:00
abstract::Calculations based on the known dimensions of bull spermatozoa show that the scattered light intensity is strongly dependent upon the relative orientation of the particle to the incident beam. The magnitude of this effect of apparently much greater than for other systems where motility has been investigated by dynamic...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(80)85046-6
更新日期:1980-07-01 00:00:00
abstract::The prion protein (PrP), widely recognized to misfold into the causative agent of the transmissible spongiform encephalopathies, has previously been shown to bind to lipid membranes with binding influenced by both membrane composition and pH. Aside from the misfolding events associated with prion pathogenesis, PrP can...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2014.09.027
更新日期:2014-11-18 00:00:00
abstract::The effects of different cations on the hydrodynamic radius (RH) of a 48-bp synthetic DNA are measured by time-resolved fluorescence polarization anisotropy of intercalated ethidium. Relative statistical errors in RH are only approximately 1%. With increasing cation concentration, Na+ causes a small decrease in RH, Cs...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(94)80481-3
更新日期:1994-07-01 00:00:00
abstract::We examined the effect of temperature (12-40°C) on local and global Ca2+ signals mediated by inositol trisphosphate receptor/channels (IP3R) in human neuroblastoma (SH-SY5Y) cells. The amplitudes and spatial spread of local signals arising from single IP3R (blips) and clusters of IP3R (puffs) showed little temperature...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2012.12.024
更新日期:2013-01-22 00:00:00
abstract::The increasingly widespread use of parametric mathematical models to describe biological systems means that the ability to infer model parameters is of great importance. In this study, we consider parameter inferability in nonlinear ordinary differential equation models that undergo a bifurcation, focusing on a simple...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.107.126086
更新日期:2008-07-01 00:00:00
abstract::Omega-3 polyunsaturated fatty acids (n-3 PUFA), enriched in fish oils, are increasingly recognized to have potential benefits for treating many human afflictions. Despite the importance of PUFA, their molecular mechanism of action remains unclear. One emerging hypothesis is that phospholipids containing n-3 PUFA acyl ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2012.06.016
更新日期:2012-07-18 00:00:00
abstract::Large-conductance Ca(2+)-activated K(+) channels (BK) play a fundamental role in modulating membrane potential in many cell types. The gating of BK channels and its modulation by Ca(2+) and voltage has been the subject of intensive research over almost three decades, yielding several of the most complicated kinetic me...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2009.02.042
更新日期:2009-05-20 00:00:00
abstract::The suprachiasmatic nucleus governs daily variations of physiology and behavior in mammals. Within single neurons, interlocked transcriptional/translational feedback loops generate circadian rhythms on the molecular level. We present a mathematical model that reflects the essential features of the mammalian circadian ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.104.040824
更新日期:2004-11-01 00:00:00
abstract::The interaction of cells in a tissue depends on the nature of the extracellular matrix. The electrical properties of the narrow extracellular space are unknown. Here we consider cell adhesion mediated by extracellular matrix protein on a solid substrate as a model system. We culture human embryonic kidney (HEK293) cel...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.105.072587
更新日期:2006-04-01 00:00:00
abstract::Neal and Cunningham (Neal, M. J., and J. R. Cunningham. 1995. J. Physiol. (Lond.). 482:363-372) showed that GABA(B) agonists and glycinergic antagonists enhance the light-evoked release of retinal acetylcholine. They proposed that glycinergic cells inhibit the cholinergic Starburst amacrine cells and are in turn inhib...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.105.072256
更新日期:2006-07-15 00:00:00
abstract::Characterizing the ionic distribution around chromatin is important for understanding the electrostatic forces governing chromatin structure and function. Here we develop an electrostatic model to handle multivalent ions and compute the ionic distribution around a mesoscale chromatin model as a function of conformatio...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2010.08.023
更新日期:2010-10-20 00:00:00
abstract::Cytochrome c3 (cyt c3) can mediate electron transport across phosphatidylcholine (PC)/cardiolipin (CL) and PC/phosphatidylglycerol (PG) membranes. A two-molecule process is involved in the electron transport across PC/CL membranes in the liquid-crystalline state. In contrast, a single-molecule process dominates the el...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.105.065359
更新日期:2006-01-15 00:00:00
abstract::It was shown previously that a significant fraction of the myosin crossbridges is attached to actin in the skinned rabbit psoas fibers under relaxed conditions at low ionic strength and low temperature (Brenner, B., M. Schoenberg, J. M. Chalovich, L. E. Greene, and E. Eisenberg. 1982. Proc. Natl. Acad. Sci. USA. 79:72...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(89)82838-3
更新日期:1989-03-01 00:00:00