Spin Label Studies of the Hemoglobin–Membrane Interaction During Sickle Hemoglobin Polymerization

JOSÉ E. FALCÓN DIEGUEZ; PABLO M. RODI; MANUEL A. LORES GUEVARA; ANA MARÍA GENNARO

APPLIED MAGNETIC RESONANCE

SPRINGER WIEN

Año: 2010 vol. 38 p. 443 - 453

0937-9347

An enhanced hemoglobin-membrane association has been previously documented in sickle cell anemia. However, it is not known how this interaction is modified during the hemoglobin S polymerization process. In this work, we use a model of reconstituted erythrocytes from ghost membranes whose cytoskeleton proteins had been previously labeled with the 4-maleimido Tempo spin label, and that were subsequently resealed with hemoglobin S or A solutions. Using electron paramagnetic resonance spectroscopy, we studied the time dependence of the spectral W/S parameter, indicative of the conformational state of cytoskeleton proteins (mainly spectrin) under spontaneous deoxygenation, with the aim of detecting the eventual effects due to hemoglobin S polymerization. The differences observed in the temporal behavior of W/S in erythrocytes reconstituted with both hemoglobins were considered as experimental evidence of an increment in hemoglobin S-membrane interaction as a result of the polymerization process of hemoglobin S under spontaneous deoxygenation. © 2010 Springer.