Heme-Spin Label Studies of Hemoglobin

Heme-Spin Label Studies of Hemoglobin

In order to investigate the protein conformation in the vicinity of the heme and the spin states of the heme-iron in dissolved hemoglobins, a nitroxide spin label was covalently attached to one of the propionic acid groups of the porphyrin ring. The optical spectra of the heme-spin labeled ferrihemoglobins were identical to those of native hemoglobins indicating that the spin labeling did not a...

Sequence of oxygen binding by hemoglobin ( hemoglobin subunits / spin - labeling / electron paramagnetic resonance / heme - heme interactions ) TOSHio ASAKURA AND PUI

A nitroxide spin-label probe was attached directly to a propionic acid group of heme in either the a or the P chain of hemoglobin. The electron paramagnetic resonance (EPR) spectrum of the spin label is altered by the spin-state change of the heme iron to which the spin label is attached. These hybrid hemoglobins showed normal optical and functional properties, indicating that the attachment of...

Spin-label study of hemoglobin conformations in solution.

There is now a great deal of physical and chemical evidence that horse and human hemoglobins undergo a change of protein conformation on oxygenation.' 9 The molecular mechanism whereby these hemoglobins show cooperative or sigmoidal oxygen binding has remained obscure, however. In order to understand this "heme-heme" interaction, one must obtain structural information on partially oxygenated he...

Heme, Myoglobin, Hemoglobin

Spin label studies of erythrocytes during storage of blood.

The kinetic behavior of the spin label MAL-6 in the interaction with differently aged human erythrocyte membranes was evaluated by monitoring the rate of disappearance of the room temperature ESR signal due to the MAL-6 spin label added to blood after storage at 4 degrees C or after incubation of red cells at 37 degrees C in a protein-free medium. After 35 days of blood storage or 60 h of eryth...