The Magnetic Properties and Structure of Ferrihemoglobin (Methemoglobin) and Some of its Compounds

Abstract

not give data at 40 but at 38'; these values of K: are assumed to hold at 40'.Corrections were then applied by means of the relation x 2 / ( C -x ) = K'/KL for each value of "C" listed in Tables I and I1 and for each value of p"'.The resulting values of (C -x ) , the true [CO,-], were then related to the ionic strength by plotting l / m against GI2. Extrapolation of these curves to zero value of pl/' yielded the following values. Act. coeff. at 25' in Act. coeff. at 40° in summary 1. The solubilities at 25 and 40' of barium and strontium carbonates have been determined in pure water and in solutions of lithium, sodium and potassium chlorides. The solubilities in solutions of the alkali chlorides are presented tabularly. 2. The activity coefficients of these carbonates in the alkali chloride solutions have been calculated and recorded. 3. The average heats of solution of these carbonates into their saturated solutions have been calculated for the temperature range 25-40'. AUSTIN, TEXAS RECEIVED DECEMBER 7, 1930 [CONTRIBUTION FROM THE GATES AND CRELLIN LABORATOFSES OF No. 5801 CHEMISTRY,

Bioinorganic transformations of liver iron deposits observed by tissue magnetic characterisation in a rat model

“…This variation indicates a progressive decrease of the number of low-l eff species, consistent with the degradation of the iron dextran akaganéite particles, together with an increase of high-l eff species, most likely associated to the synthesis of ferritin or some paramagnetic iron containing molecules. At this point, we must remind that previous magnetic experiments on deoxyhaemoglobin and methemoglobin, which contain Fe 2+ and Fe 3+ , respectively, resulted in paramagnetic effective moments 5.46 l B and 5.80 l B , which are very close to the corresponding single ion values, while oxyhaemoglobin appears to be diamagnetic [3,48].…”

Hemoglobin stability: observations on the denaturation of normal and abnormal hemoglobins by oxidant dyes, heat, and alkali

“…The structural basis for the stabilization of methemoglobin by cyanide is not certain. Binding of cyanide is associated with a decrease in the ionic character and an increase in the covalent nature of the bond between histidine and the heme iron and between the iron atom and the four pyrrole rings of the porphyrin group (40,41). The porphyrin group is drawn closer to the protein portion of the molecule and the iron atom moves to a position closer to the plane of the porphyrin (41).…”

Sulfide-hemoglobin interactions in the sulfide-tolerant salt marsh resident, the California killifish Fundulus parvipinnis

“…SHb formation is a form of immobilization, where sulfide adds across a pyrrole double bond in the porphyrin as an episulfide (Morel1 et al 1967;Nichol et al 1968;Berzofsky et al 1972;Brittain et al 1982). Formation of ferric hemoglobin-sulfide complex likewise immobilizes sulfide, but the complex is unstable and eventually yields an oxidized sulfur product (Coryell et al 1937).…”