scholarly journals Time-resolved detection of SDS-induced conformational changes in α-synuclein by a micro-stopped-flow system

RSC Advances ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 1086-1097
Author(s):  
Shunki Takaramoto ◽  
Yusuke Nakasone ◽  
Kei Sadakane ◽  
Shinsaku Maruta ◽  
Masahide Terazima
Keyword(s):  
Conformational Changes ◽  
Flow System ◽  
Stopped Flow ◽  
Time Resolved ◽  
Sds Micelles ◽  
Conformation Changes ◽  
System P

Dynamics of conformation changes of α-synuclein induced by the presence of SDS micelles are revealed using time-resolved diffusion, CD, and FRET measurements combined with a micro-stopped flow system.

Study of polymer chain dynamics in solution by time-resolved spectrofluorometry

1989 ◽  
Vol 54 (11) ◽  
pp. 3011-3024 ◽  
Author(s):  
Vlastimil Fidler ◽  
Stefan Vajda ◽  
Zuzana Limpouchová ◽  
Jiří Dvořák ◽  
Karel Procházka ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Conformational Changes ◽  
Methacrylic Acid ◽  
Correlation Time ◽  
General Level ◽  
Polymeric Chain ◽  
Relative Molecular Mass ◽  
Chain Dynamics ◽  
Time Resolved ◽  
Covalently Bonded

The methodology of polarization time-resolved fluorometry and interpretation of its results are outlined at a general level, and the measurement on and use of facilities of the Edinburgh Instruments Model 299T apparatus are discussed in detail. The dynamics of conformational changes in chains of poly(methacrylic acid) containing covalently bonded dansyl labels are studied in aqueous solutions at various pH. It is shown that at pH > 6, the shorter effective rational correlation time τr < 2 ns corresponds to the rotation of the free dansyl label about bonds by which it is attached to the polymeric chain; at pH < 4 the longer effective rational correlation time τr = 20-26 ns corresponds to the rotation of the compact spherical formation constituted by a part of the collapsed polymeric chain in which the label is fixed and whose relative molecular mass is approx. 15 000-20 000.

scholarly journals PSVIII-17 Assessment of conformational changes across three parities in sows

2020 ◽  
Vol 98 (Supplement_3) ◽  
pp. 221-222
Author(s):  
Melanie D Trenhaile-Grannemann ◽  
Ronald M Lewis ◽  
Stephen D Kachman ◽  
Kenneth J Stalder ◽  
Benny E Mote
Keyword(s):  
Body Size ◽  
Body Length ◽  
Conformational Changes ◽  
Repeated Measures ◽  
Fixed Effects ◽  
Random Effect ◽  
Joint Angles ◽  
Body Depth ◽  
Conformation Changes ◽  
Over Time

Abstract Conformation-based sow selection is performed prior to reaching mature size, yet little is known about how conformation changes as growth continues. To assess conformation changes, 9 conformational traits were objectively measured at 12 discrete time points between 112 d of age and parity 3 weaning on 622 sows in 5 cohorts. The 9 traits included 5 body size traits (body length, body depth at the shoulder and flank, and height at the shoulder and flank) and 4 joint angles (knee, hock, and front and rear pastern). Data were analyzed with a repeated measures model (SAS V 9.4) including cohort and time point as fixed effects, sire as a random effect, and heterogeneous compound symmetry as the covariance structure. Sire variance ranged from 0.16 (body depth shoulder) to 2.00 (body length) cm2 for body size traits and 2.28 (rear pastern) to 4.22 (front pastern) degrees2 for joint angles. Cohort had an effect on all traits (P &lt; 0.05). All traits displayed changes over time (P &lt; 0.001). Size traits increased between 112 d of age and parity 3 weaning (64.16 vs. 107.57 cm, 26.62 vs. 44.14 cm, 23.32 vs. 36.92 cm, 46.10 vs. 73.55 cm, 49.36 vs. 77.47 cm for body length, body depth shoulder and flank, and height shoulder and flank, respectively); however, they fluctuated within parity by increasing during gestation and decreasing at weaning. Knee angle decreased (164.12 vs. 150.72 degrees) while fluctuating within parity by decreasing in the second half of gestation and increasing after weaning. Front and rear pastern angles decreased over time (60.89 vs. 53.74 degrees and 64.64 vs. 55.50 degrees for front and rear pastern, respectively), while biologically negligible change was observed in hock angle (148.63 vs. 147.48 degrees). Sow conformation changes throughout life, and these changes may require consideration when making selection decisions.

Heteropoly acid-catalyzed three-component aza-Diels–Alder reaction in a continuous micro-flow system

RSC Advances ◽  
2015 ◽  
Vol 5 (72) ◽  
pp. 58798-58803 ◽  
Author(s):  
Wei He ◽  
Zheng Fang ◽  
Zhao Yang ◽  
Dong Ji ◽  
Kai Guo
Keyword(s):  
Water Absorption ◽  
Heteropoly Acid ◽  
Phosphotungstic Acid ◽  
Flow System ◽  
Alder Reaction ◽  
Diels Alder ◽  
Diels Alder Reaction ◽  
System P ◽  
Micro Flow ◽  
Acid Catalyzed

The first direct aza-Diels–Alder reaction catalyzed using phosphotungstic acid combined with a water absorption device in a micro-flow system was reported.

scholarly journals Conformational Changes Generated in GroEL during ATP Hydrolysis as Seen by Time-resolved Infrared Spectroscopy

1999 ◽  
Vol 274 (9) ◽  
pp. 5508-5513 ◽  
Author(s):  
Frithjof von Germar ◽  
Asier Galán ◽  
Oscar Llorca ◽  
Jose L. Carrascosa ◽  
Jose M. Valpuesta ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Conformational Changes ◽  
Atp Hydrolysis ◽  
Time Resolved ◽  
Time Resolved Infrared Spectroscopy

scholarly journals Positive co-operative binding at two weak lysine-binding sites governs the Glu-plasminogen conformational change

1992 ◽  
Vol 285 (2) ◽  
pp. 419-425 ◽  
Author(s):  
U Christensen ◽  
L Mølgaard
Keyword(s):  
Ligand Binding ◽  
Binding Site ◽  
Conformational Change ◽  
Conformational Changes ◽  
Binding Sites ◽  
High Specificity ◽  
Stopped Flow ◽  
Protein Fluorescence ◽  
Lysine Residues ◽  
Kinetics Of

The kinetics of a series of Glu-plasminogen ligand-binding processes were investigated at pH 7.8 and 25 degrees C (in 0.1 M-NaCl). The ligands include compounds analogous to C-terminal lysine residues and to normal lysine residues. Changes of the Glu-plasminogen protein fluorescence were measured in a stopped-flow instrument as a function of time after rapid mixing of Glu-plasminogen and ligand at various concentrations. Large positive fluorescence changes (approximately 10%) accompany the ligand-induced conformational changes of Glu-plasminogen resulting from binding at weak lysine-binding sites. Detailed studies of the concentration-dependencies of the equilibrium signals and the rate constants of the process induced by various ligands showed the conformational change to involve two sites in a concerted positive co-operative process with three steps: (i) binding of a ligand at a very weak lysine-binding site that preferentially, but not exclusively, binds C-terminal-type lysine ligands, (ii) the rate-determining actual-conformational-change step and (iii) binding of one more lysine ligand at a second weak lysine-binding site that then binds the ligand more tightly. Further, totally independent initial small negative fluorescence changes (approximately 2-4%) corresponding to binding at the strong lysine-binding site of kringle 1 [Sottrup-Jensen, Claeys, Zajdel, Petersen & Magnusson (1978) Prog. Chem. Fibrinolysis Thrombolysis 3, 191-209] were observed for the C-terminal-type ligands. The finding that the conformational change in Glu-plasminogen involves two weak lysine-binding sites indicates that the effect cannot be assigned to any single kringle and that the problem of whether kringle 4 or kringle 5 is responsible for the process resolves itself. Probably kringle 4 and 5 are both participating. The involvement of two lysine binding-sites further makes the high specificity of Glu-plasminogen effectors more conceivable.

The kinetics of conformational changes of α2 -macroglobulin determined by time resolved X-ray solution scattering

FEBS Letters ◽  
1994 ◽  
Vol 337 (2) ◽  
pp. 171-174 ◽  
Author(s):  
Hideo Arakawa ◽  
Takuji Urisaka ◽  
Hirotsugu Tsuruta ◽  
Yoshiyuki Amemiya ◽  
Hiroshi Kihara ◽  
...  
Keyword(s):  
Conformational Changes ◽  
Time Resolved ◽  
X Ray ◽  
Α2 Macroglobulin ◽  
Kinetics Of

scholarly journals Predicting data quality in biological X-ray solution scattering

2018 ◽  
Vol 74 (8) ◽  
pp. 727-738
Author(s):  
Chenzheng Wang ◽  
Yuexia Lin ◽  
Devin Bougie ◽  
Richard E. Gillilan
Keyword(s):  
Conformational Changes ◽  
Sample Path ◽  
Flow Time ◽  
Photon Flux ◽  
Detector Efficiency ◽  
Time Resolved ◽  
Short Sample ◽  
X Ray ◽  
Path Lengths ◽  
Flux Energy

Biological small-angle X-ray solution scattering (BioSAXS) is now widely used to gain information on biomolecules in the solution state. Often, however, it is not obvious in advance whether a particular sample will scatter strongly enough to give useful data to draw conclusions under practically achievable solution conditions. Conformational changes that appear to be large may not always produce scattering curves that are distinguishable from each other at realistic concentrations and exposure times. Emerging technologies such as time-resolved SAXS (TR-SAXS) pose additional challenges owing to small beams and short sample path lengths. Beamline optics vary in brilliance and degree of background scatter, and major upgrades and improvements to sources promise to expand the reach of these methods. Computations are developed to estimate BioSAXS sample intensity at a more detailed level than previous approaches, taking into account flux, energy, sample thickness, window material, instrumental background, detector efficiency, solution conditions and other parameters. The results are validated with calibrated experiments using standard proteins on four different beamlines with various fluxes, energies and configurations. The ability of BioSAXS to statistically distinguish a variety of conformational movements under continuous-flow time-resolved conditions is then computed on a set of matched structure pairs drawn from the Database of Macromolecular Motions (http://molmovdb.org). The feasibility of experiments is ranked according to sample consumption, a quantity that varies by over two orders of magnitude for the set of structures. In addition to photon flux, the calculations suggest that window scattering and choice of wavelength are also important factors given the short sample path lengths common in such setups.

scholarly journals Stopped-flow microscopy for time resolved shape change observation of floating erythrocyte

1996 ◽  
Vol 36 (6) ◽  
pp. 293-296
Author(s):  
Takayuki SANO ◽  
Kenji SATO ◽  
Katsumasa INOUE
Keyword(s):  
Shape Change ◽  
Stopped Flow ◽  
Time Resolved
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