Some EPR spin probe and spin label studies of polymer systems

1996 ◽  
Vol 10 (1-3) ◽  
pp. 413-429 ◽  
Author(s):  
A. M. Wasserman ◽  
T. N. Khazanovich ◽  
V. A. Kasaikin
Keyword(s):  
Spin Label ◽  
Spin Probe ◽  
Polymer Systems

SPIN-PROBE—SPIN-LABEL INVESTIGATIONS OF MODEL MEMBRANES

1978 ◽  
pp. 1253-1261 ◽  
Author(s):  
James S. Hyde ◽  
Carol A. Popp ◽  
S. Schreier
Keyword(s):  
Spin Label ◽  
Spin Probe ◽  
Model Membranes ◽  
Probe Spin

scholarly journals Binding of two spin-labelled derivatives of chlorpromazine to human erythrocytes

1989 ◽  
Vol 264 (3) ◽  
pp. 633-641 ◽  
Author(s):  
J L Olivier ◽  
C Chachaty ◽  
C Wolf ◽  
D Daveloose ◽  
G Bereziat
Keyword(s):  
Spin Label ◽  
Binding Sites ◽  
Spin Probe ◽  
Slow Motion ◽  
Water Soluble ◽  
Spin Labels ◽  
Exponential Dependence ◽  
Exchange Frequency ◽  
Derivatives Of ◽  
Positively Charged

The binding to human intact erythrocytes of two different spin-labelled derivatives of chlorpromazine has been studied. The influence of the positively charged side chain of the drug has been the focus of our attention. The positively charged amphiphilic compound (spin derivative I) is water-soluble up to 80 microM at pH values below 5.9. The apolar analogue (spin derivative II) aggregates in aqueous buffer from the lowest concentration tested. Both spin derivatives undergo a slow reduction inside the erythrocyte. The reduced nitroxides are readily reoxidized by adding a low, non-quenching, concentration of potassium ferricyanide to the intact erythrocytes. The fractions of spin label I and II bound to the erythrocyte membrane or to the erythrocyte-extracted lipids remain constant as a function of the temperature (3-42 degrees C) and as a function of the concentration of the spin label up to 150 microM. E.s.r. spectra of both spin labels show a two-component lineshape when they are bound to intact erythrocytes. Below 35 degrees C for the positively charged spin probe, and below 32 degrees C for the apolar spin probe, the simulation of the lineshape shows that more than 50% of the spectrum originates from a slow-motion component. This slow-motion component is also found in erythrocyte-extracted lipids probed by the positively charged spin label below 25 degrees C. In contrast, no slow-motion component is detected in the range 4-40 degrees C for the apolar spin label in erythrocyte-extracted lipids. In this environment the apolar probe experiences a single fast anisotropic motion with an exponential dependence on 1/temperature. Detailed lineshape simulations take into account the exchange frequency between binding sites where the probe experiences a fast motion and binding sites where it experiences a slow motion. The exchange frequency is strongly temperature-dependent. Characterization of the different motions experienced inside the different locations has been achieved and compared for whole erythrocytes and for the extracted lipids. The biochemical nature of the binding sites (membrane protein/acidic phospholipid) giving rise to the slow-motion component is discussed as a function of the polarity of the spin-labelled drug and as a function of the temperature controlling the fluidity of the lipid bulk and influencing the distribution of the drug inside the membrane.

Thiol-reactive Clenbuterol Analogues Conjugated to Bovine Serum Albumin

2004 ◽  
Vol 59 (11-12) ◽  
pp. 880-886 ◽  
Author(s):  
Marko Oblak ◽  
Andrej Preželj ◽  
Slavko Pečar ◽  
Tom Solmajer
Keyword(s):  
Molecular Dynamics ◽  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Spin Label ◽  
Bovine Serum ◽  
Spin Probe ◽  
Coupling Reaction ◽  
High Yield ◽  
Paramagnetic Resonance ◽  
Electron Paramagnetic

Several novel thiol-reactive clenbuterol analogues were coupled in high yield with bovine serum albumin (BSA). After labelling of unreacted cysteines with maleimide spin label (MiSL), the yield of the coupling reaction was determined by electron paramagnetic resonance (EPR) spectroscopy and spectral analysis. Two spin-probe populations with different mobility states were quantitatively determined. Molecular dynamics was used to model the structure of clenbuterol analogues and spin label conjugated to BSA and recognition of conjugates by anti-clenbuterol antibodies was demonstrated. The recognition of BSA-A, BSA-C and BSAS conjugates with monoclonal and polyclonal anti-clenbuterol (mCLB-Ab and rCLB-Ab) antibodies was an indication, that chlorine substituents on the aromatic ring of clenbuterol derivatives are not necessary for the binding of antibodies to the conjugates. These results confirmed the importance of the tert-butylamino group as a part of the epitope and contribute to the understanding of the recognition process with anti-clenbuterol antibodies.

Use of spin label and spin probe methods in medical research

1991 ◽  
Vol 25 (6) ◽  
pp. 289-291
Author(s):  
A. G. Maksina ◽  
B. A. Dainyak
Keyword(s):  
Medical Research ◽  
Spin Label ◽  
Spin Probe

scholarly journals Exploring the Interactions of Ruthenium (II) Carbosilane Metallodendrimers and Precursors with Model Cell Membranes through a Dual Spin-Label Spin-Probe Technique Using EPR

Biomolecules ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 540 ◽  
Author(s):  
Riccardo Carloni ◽  
Natalia Sanz del Olmo ◽  
Paula Ortega ◽  
Alberto Fattori ◽  
Rafael Gómez ◽  
...  
Keyword(s):  
Spin Label ◽  
Spin Probe ◽  
Cell Membranes ◽  
Antitumor Agents ◽  
Hydrophobic Interactions ◽  
High Surface ◽  
High Surface Area ◽  
Surface Groups ◽  
Model Cell

Dendrimers exhibit unique interactions with cell membranes, arising from their nanometric size and high surface area. To a great extent, these interactions define their biological activity and can be reported in situ by spin-labelling techniques. Schiff-base carbosilane ruthenium (II) metallodendrimers are promising antitumor agents with a mechanism of action yet to explore. In order to study their in situ interactions with model cell membranes occurring at a molecular level, namely cetyltrimethylammonium bromide micelles (CTAB) and lecithin liposomes (LEC), electron paramagnetic resonance (EPR) was selected. Both a spin probe, 4-(N,N-dimethyl-N-dodecyl)ammonium-2,2,6,6-tetramethylpiperidine-1-oxyl bromide (CAT12), able to enter the model membranes, and a spin label, 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) covalently attached at newly synthesized heterofunctional dendrimers, were used to provide complementary information on the dendrimer–membrane interactions. The computer-aided EPR analysis demonstrated a good agreement between the results obtained for the spin probe and spin label experiments. Both points of view suggested the partial insertion of the dendrimer surface groups into the surfactant aggregates, mainly CTAB micelles, and the occurrence of both polar and hydrophobic interactions, while dendrimer–LEC interactions involved more polar interactions between surface groups. We found out that subtle changes in the dendrimer structure greatly modified their interacting abilities and, subsequently, their anticancer activity.

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