A magnetic study of acidic ferric hemoglobin

Nakano, Norihito; Nakano, K; Tasaki, Akira

doi:10.1016/0005-2795(71)90116-4

Cited by 6 publications

(3 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The e.p.r. spectrum of acid-methaemoglobin below 77K exhibits low-spin signals at g = 1.70, 2.20 and 2.80 (Nakano et al, 1971). Acid-metmyoglobin, however, is entirely highspin at < 77K (lizuka & Kotani, 1969).…”

Section: Acid-metleghaemoglobin Derivativementioning

confidence: 95%

Electron-paramagnetic-resonance studies of leghaemoglobins from soya-bean and cowpea root nodules. Identification of nitrosyl-leghaemoglobin in crude leghaemoglobin preparations

Maskall

Gibson

Dart

1977

Biochemical Journal

View full text Add to dashboard Cite

1. Leghaemoglobins from soya-bean (Glycine max) and cowpea (Vigna unguiculata) root nodules were purified by chromatography on DEAE-cellulose phosphate columns at pH8.0 and pH5.8, to avoid the relatively low pH (5.2) commonly used to purify these proteins. 2. E.p.r. (electron-paramagnetic-resonance) spectra of the fluoride, azide, hydroxide and cyanide complexes of these ferric leghaemoglobins were very similar to the spectra of the corresponding myoglobin derivatives, indicating that the immediate environment of the iron in leghaemoglobin and myoglobin is similar, an imidazole moiety of histidine being the proximal ligand to the haem iron [cf. Appleby, Blumberg, Peisach, Wittenberg & Wittenberg (1976) J. Biol. Chem.251, 6090-6096]. 3. E.p.r. spectra of the acid-metleghaemoglobins showed prominent high-spin features very near g=6 and g=2 and, unlike myoglobin, small low-spin absorptions near g=2.26, 2.72 and 3.14. The width of the g=6 absorption derivative at 10-20K was about 4-4.5mT, similar to the value for acid-methaemoglobin. In contrast, a recently published (Appleby et al., 1976) spectrum of acid-metleghaemoglobin a had less high-spin character and a much broader absorption derivative around g=6. 4. E.p.r. spectra of ferric leghaemoglobin nicotinate and imidazole complexes suggest that the low-spin absorption near g=3.14 can be attributed to a trace of ferric leghaemoglobin nicotinate, and those near g=2.26 and 2.72 are from an endogenous dihistidyl haemichrome. 5. A large e.p.r. signal at g=2 in all samples of crude leghaemoglobin was shown to be from nitrosyl-leghaemoglobin. A soya-bean sample contained 27+/-3% of the latter. A previously unidentified form of soya-bean ferrous leghaemoglobin a was shown to be its nitrosyl derivative. If this is not an artifact, and occurs in the root nodule, the nitrosyl radical may interfere with the function of leghaemoglobin.

show abstract

Section: Acid-metleghaemoglobin Derivativementioning

confidence: 95%

Electron-paramagnetic-resonance studies of leghaemoglobins from soya-bean and cowpea root nodules. Identification of nitrosyl-leghaemoglobin in crude leghaemoglobin preparations

Maskall

Gibson

Dart

1977

Biochemical Journal

View full text Add to dashboard Cite

show abstract

“…supramolecular systems 3 as well as in human hemoglobin 13 . Some of these materials have found promising applications as sensors, or displaying and recording devices.…”

mentioning

confidence: 99%

Spin transition in a four-coordinate iron oxide

et al. 2009

View full text Add to dashboard Cite

Spin transition has attracted the interest of researchers in various fields since the early 1930s, with thousands of examples now recognized, including those in minerals and biomolecules. However, so far the metal centres in which it has been found to occur are almost always octahedral six-coordinate 3d(4) to 3d(7) metals, such as Fe(II). A five-coordinate centre is only rarely seen. Here we report that under pressure SrFe(II)O(2), which features a four-fold square-planar coordination, exhibits a transition from high spin (S = 2) to intermediate spin (S = 1). This is accompanied by a transition from an antiferromagnetic insulating state to a ferromagnetic so-called half-metallic state: only half of the spin-down (d(xz),d(yz)) states are filled. These results highlight the square-planar coordinated iron oxides as a new class of magnetic and electric materials.

show abstract

“…5 The external perturbations are heat, light, magnetic and electronical fields, chemical substitution, gas adsorptions, and so on. [6][7][8][9][10][11] The phase transitions can happen in a wide range of materials, as supramolecular system, 7 porous materials, 10 metalorganic complexes, 12 human haemoglobin, 13 as well as in perovskite oxides. [1][2][3] Some of these materials have been found promising applications as sensors, information storage, optical switches, phase-change memory, or as displaying and recording devices.…”

Section: Introductionmentioning

confidence: 99%

Effect of high-pressure on the electronic and magnetic properties in double perovskite oxide Sr2FeMoO6

Qian

et al. 2012

Journal of Applied Physics

View full text Add to dashboard Cite

The high-pressure effect on the physical properties in double perovskite Sr2FeMoO6 is explored theoretically. The structure of Sr2FeMoO6 exhibits I4/mmm symmetry in the whole external hydrostatic pressure applied. A spin crossover of Fe ion from high-spin to low-spin state is found at the pressure of about 33–36 GPa, accompanied by a transition from ferrimagnetic half-metallic to nonmagnetic semiconductor state. When the pressure is above 45 GPa, the nonmagnetic compound behaves as full metal. By the mean-field theory, the estimated Curie temperature of the ferrimagnetic Sr2FeMoO6 increases from 472 to 639 K when the pressure increases from 0 to 30 GPa.

show abstract

A magnetic study of acidic ferric hemoglobin

Cited by 6 publications

References 11 publications

Electron-paramagnetic-resonance studies of leghaemoglobins from soya-bean and cowpea root nodules. Identification of nitrosyl-leghaemoglobin in crude leghaemoglobin preparations

Electron-paramagnetic-resonance studies of leghaemoglobins from soya-bean and cowpea root nodules. Identification of nitrosyl-leghaemoglobin in crude leghaemoglobin preparations

Spin transition in a four-coordinate iron oxide

Effect of high-pressure on the electronic and magnetic properties in double perovskite oxide Sr2FeMoO6

Contact Info

Product

Resources

About