Electron paramagnetic resonance probe

It is worth recalling that other types of probes are used in practice for example, radioactive tracers, with their well-known drawback of their radioactivity, and EPR (electronic paramagnetic resonance) probes that provide information mainly on molecular mobility. In contrast to these probes, which are used in rather limited fields of applications, fluorescent probes can offer a wealth of information in various fields, as shown in Table 1.4. The various examples described in this book will demonstrate their outstanding versatility. 

R.V. Stahelin, 2003) with the C2 domain of CPLA2 preferring a phosphatidylcholine-rich interface. C2 domains that have been labeled with electron paramagnetic resonance probes have been used to analyze membrane docking on the phospholipid surface [10]. 

The electron paramagnetic resonance probe technique described by Valglimigli et al. (2001) provides a versatile way of gaining rapid and reproducible quantitative measurements of reactive oxygen species in biological systems, ranging from subcel-lular fractions to whole animals and human liver. 

Electron spin resonance (or electron paramagnetic resonance) is now a well-established analytical technique, which also offers a unique probe into the details of molecular structure. The energy levels involved are very close together and reflect essentially the properties of a single electronic state split by a small perturbation. 

Local Structure of the Eu2+ Impurity. From the experimental perspective, the doping of lanthanide ions into solid state materials can be probed by different instrumental technics such as nuclear magnetic resonance (NMR),44 extended X-ray absorption fine structure (EXAFS),45,46 or electron paramagnetic resonance (EPR),47 which instead of giving a direct clue of the local geometry offers only data that can be corroborated to it. From the theoretical point of view,... 

Kochelaev BI, Teitel baum GB (2005) Nanoscale Properties of Superconducting Cuprates Probed by the Electron Paramagnetic Resonance 114 205-266 Kochi JK, see RosokhaSV (2007) 126 137-160 Kohler J, see Deng (2005) 114 103-141 van Koningsbruggen, see Giitlich P (2004) 107 27-76... 

The crystallographic structure of rubredoxin from Clostridium pasteurianum at 2.5 A, a resolution sufficient to reveal the sequence of several of the bulky amino acid side chains, shows the iron coordinated to two pairs of cysteine residues located rather near the termini of the polypeptide chain (Fig. 1). A related rubredoxin, with a three times larger molecular weight, from Pseudomonas oleovorans is believed to bind iron in a similar fashion. This conclusion is based on physical probes, especially electron paramagnetic resonance spectroscopy, all of which indicate that the iron is in each case situated in a highly similar environment however, the proteins display some specificity in catalytic function. 

Rakowsky, M. H., K. M. More et al. (1995). Time-domain electron paramagnetic resonance as a probe of electron-electron spin-spin interaction in spin-labeled low-spin iron porphyrins. J. Am. Chem. Soc. 117 2049-2057. 

Amine-terminated, full-generation PAMAM and PPI dendrimers, as well as carboxylate-terminated half-generation PAMAM dendrimers, can directly bind metal ions to their surfaces via coordination to the amine or acid functionality. A partial hst of metal ions that have been bound to these dendrimers in this way includes Na+, K+, Cs+, Rb+, Fe +, Fe +, Gd +, Cu+, Cu +, Ag+, Mn +, Pd, Zn, Co, Rh+,Ru +,andPt + [18,19,27,36,54,82-96]. Tuxro et al.have also shown that the metal ion complexes, such as tris(2,2 -bipyridine)ruthenium (Rulbpylj), can be attached to PAMAM dendrimer surfaces by electrostatic attraction [97]. A wide variety of other famihes of dendrimers have also been prepared that bind metal ions to their periphery. These have recently been reviewed [3]. Such surface-bound metal ions can be used to probe dendrimer structure using optical spectroscopy, mass spectrometry, and electron paramagnetic resonance (EPR) [86-88,90,97-99]. 

Before the availability of a high-resolution structure of P. aeruginosa CCP, the properties and environments of the two hemes had been probed using a range of solution spectroscopies. These include electron paramagnetic resonance (EPR) (51, 57, 58, 61), resonance Raman (59), circular dichroism (CD) 71, 72), MCD 58, 61, 73, 74). Until the demonstration by Ellfolk and colleagues that it is the mixed-valence form of the... 

Nanoscale Properties of Superconducting Cuprates Probed by the Electron Paramagnetic Resonance... 

When one looks for methods to detect OH, one always has two keep in mind that these radicals are very reactive, and in the presence of substrates their steady-state concentrations are extremely low even at a high rate of OH production. The fact that OH only absorbs far out in the UV region (Hug 1981) is thus not the reason why an optical detection of OH is not feasible. Electron paramagnetic resonance (EPR) must also fail because of the extremely low steady-state concentrations that prevail in the presence of scavengers. The only possibility to detect their presence is by competition of a suitable OH probe that allows the identification of a characteristic product [probe product, reaction (41)]. When this reaction is carried out in a cellular environment, the reaction with the probe is in competition with all other cellular components which also readily react with OH [reaction (42)]. The concentration of the probe product is then given by Eq. (43), where [ OH ] is the total OH concentration that has been formed in this cellular environment and q is the yield of the probe product per OH that has reacted with the probe. 

SIMS (61,64,86), microscopy (65), XPS (56), electron microprobe techniques (14,66), electron paramagnetic resonance (EPR) (67) and luminescence experiments (68) have been successfully employed to probe and study V mobility and reactivity on a catalyst surface. TEM, STEM and energy dispersive X-ray emission (EDX) measurements have indicated that V interaction with REY-crystals induced vanadate clusters formation (65). Vanadium was also found capable of reacting with rare-earths outside the zeolite cavities to form LaVQ4... 

---