On the state of iron in biological systems

Magnetometric diagnostics of ferritin in living matter

“…As can be seen from these data, the samples behave in the magnetic field like diamagnetics (χ ∞ < 0 at 1/H 0), whereas the saturation magnetization is σ s > 0 (see table). The presence of regions possessing positive σ s can be explained based on the notions about plant physiology [2,3,6]. The hypothesis that the samples contain ferrihydrite particles is confirmed by the results of magnetic measurements on the samples upon a hydrothermal treatment [1,3], after which almost all samples exhibited a growth in the σ s value (see table).…”

“…The presence of regions possessing positive σ s can be explained based on the notions about plant physiology [2,3,6]. The hypothesis that the samples contain ferrihydrite particles is confirmed by the results of magnetic measurements on the samples upon a hydrothermal treatment [1,3], after which almost all samples exhibited a growth in the σ s value (see table). Therefore, it is necessary to identify iron containing compounds that account for the σ s values observed before and after the hydrothermal treatment.…”

“…Since Fe 3+ cations form nuclei of the globular protein ferritin (ferrihydrite) with micelle sizes ≤10 nm [1,5,6], the numbers of internal and sur face Fe atoms are close [2][3][4]. Therefore, one doublet (with smaller Δ) can be assigned to Fe atoms in a less distorted environment, while the other doublet (with greater Δ) can be attributed to the surface Fe atoms.…”

“…Determining ferritin in the blood is used for the monitoring of iron metabolism in the organism and the differential diagnostics of anemia and tumor development [1][2][3]. Previously, ferritin preparations have been studied using magnetic and Mössbauer spectroscopy measurements at temperatures from 300 to 0.8 K [1][2][3][4][5][6].…”

“…Determination of the specific magnetic suscepti bility χ was based on the well known interpolation for mula [3,6] (1) The values of χ ∞ and saturation magnetization σ s at T = 293 K for some typical samples are presented in the table. Figure 2 shows plots of the room temperature (T = 293 K) specific magnetic susceptibility χ versus inverse magnetic field 1/H for various native samples.…”