Topic
IAEDANS
About: IAEDANS is a research topic. Over the lifetime, 136 publications have been published within this topic receiving 3814 citations. The topic is also known as: N-iodoacetyl-N'-(5-sulfonic-1-napthyl)ethylene-diamine & I-AED.
Papers published on a yearly basis
Papers
TL;DR: The results show that actin in the weakly bound complex with S1 assumes a new structural state in which the actin filament has microsecond rotational dynamics intermediate between that of free actin and the strongly bound complex and S1-induced changes are not propagated along theActin filament, in contrast to the highly cooperative changes due to the stronglybound complex.
Abstract: We have used optical spectroscopy (transient phosphorescence anisotropy, TPA, and fluorescence resonance energy transfer, FRET) to detect the effects of weakly bound myosin S1 on actin during the actomyosin ATPase cycle. The changes in actin were reported by (a) a phosphorescent probe (ErIA) attached to Cys 374 and (b) a FRET donor-acceptor pair, IAEDANS attached to Cys 374 and a nucleotide analogue (TNPADP) in the nucleotide-binding cleft. Strong interactions were detected in the absence of ATP, and weak interactions were detected in the presence of ATP or its slowly hydrolyzed analogue ATP-A-S, under conditions where a significant fraction of weakly bound acto-S1 complex was present and the rate of nucleotide hydrolysis was low enough to enable steady-state measurements. The results show that actin in the weakly bound complex with S1 assumes a new structural state in which (a) the actin filament has microsecond rotational dynamics intermediate between that of free actin and the strongly bound complex and (b) S1-induced changes are not propagated along the actin filament, in contrast to the highly cooperative changes due to the strongly bound complex. We propose that the transition on the acto-myosin interface from weak to strong binding is accompanied by transitions in the structural dynamics of actin parallel to transitions in the dynamics of interacting myosin heads.
83 citations
TL;DR: The ensemble of results shows that the amphipathic helices of the C-terminal fragment open out on the surface of the lipid bilayer during the initial phase of membrane insertion, showing that intermolecular transfer reduces the distance estimated in samples containing only labelled protein.
81 citations
TL;DR: It has been unequivocally demonstrated by gel electrophoresis that the fast-reacting thiol is located on the myosin heavy chain.
71 citations
TL;DR: This study continued a previously initiated mapping of the intermediate structure of human carbonic anhydrase II by engineering Cys residues into various regions of the protein structure to obtain chemically reactive probes and handles for spectroscopic probes to report on conformational changes accompanying the folding process.
Abstract: Several conformation-sensitive parameters have shown that human carbonic anhydrase II exists as a stable and compact equilibrium folding intermediate of molten globule type. In this study we have continued a previously initiated mapping of the intermediate structure. Cys residues were engineered, one at a time, into various regions of the protein structure, so as to obtain chemically reactive probes and handles for spectroscopic probes. These probes were used to specifically report on conformational changes accompanying the folding process. Thus, the accessibility of the introduced Cys residues to specific chemical labeling by radioactive iodoacetate was used to monitor the stability and compactness of the substructure surrounding each Cys residue. In addition, a spin-label (nitroxide radical) and a fluorescent probe (IAEDANS) were attached to the inserted SH-groups to give complementary information. The mobility of the spin-label was used to indicate local changes in structure, and the fluorophore was used to probe local changes in polarity at various stages of unfolding. Much of the predominant beta-structure, consisting of 10 beta-strands extending throughout the entire molecule, appears to be compact and largely intact in the intermediate. Thus, beta-strands 3-7, probed at positions 68, 97, 118, 123, 206, and 245, seem to have a native-like structure in the folding intermediate. In contrast, a more flexible structure is found around positions 56, 176, and 256 in the peripheral beta-strands 1, 2, and 9, showing that the stability of the secondary structure in the intermediate state is less in the outer parts of the protein. A hydrophobic region, containing beta-strands 3-5, seems to be remarkably stable and is not ruptured until strong denaturing conditions (5 M GuHCl) are applied. The stability of this hydrophobic beta-core appears to increase toward the center. This stable region is contained in the middle of a sequentially continuous antiparallel structure that spans beta-strands 2-6, suggesting that this part might represent a site where folding is initiated.
68 citations
TL;DR: In this paper, the chaperone activity of α-crystallins toward βLOW- and various γ-crystins at the onset of their denaturation, 60 and 66 °C, respectively, was studied at high and low crystallin concentrations using small angle x-ray scattering (SAXS) and fluorescence energy transfer (FRET).
68 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2021 | 1 |
| 2020 | 1 |
| 2017 | 1 |
| 2016 | 2 |
| 2015 | 1 |
| 2014 | 1 |