Isolated erythrocyte membranes of transfusion-dependent and non-transfused thalassemia patients in Jakarta, investigated by electron paramagnetic resonance spectroscopy.
Erythrocyte membrane structural parameters were studied in transfusion-dependent beta-thalassemia patients, in long-term transfused patients (regularly transfused < 15 years), and in those who had not yet obtained transfusions. Controls were voluntary students up to 30 years of age without diagnosis or clinical signs of thalassemia. Membranes were isolated and investigated by sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE) and electron paramagnetic resonance (EPR) spectroscopy. Data obtained from the thiol-reactive spin label N-ethyl-maleimidoproxyl reveal immobilization of protein environment in erythrocyte membranes from thalassemic patients. SDS-PAGE shows both degradation and aggregation of membrane proteins. Thalassemic erythrocyte membranes exert higher order parameters in the hydrophobic region as determined by 16-doxyl-stearic acid. Rotational correlation times of this spin label increase only in transfused patients. Polarity is higher in membranes of all patients than in controls. In the polar interface, order parameters obtained from 5-doxyl-stearic acid increase in non-transfused and decrease in transfusion-dependent patients as compared with controls. Transfused patients exert increasing membrane order in the hydrophobic region and counter-currently decreasing order in the polar interface indicating loss of membrane integrity along with the loss of fluidity and polarity gradients and the loss the energetic barrier function of the membrane.
Udyaningsih-Freisleben
Seruni K
SK
Department of Physics, Faculty of Mathematics and Natural Science, University of Indonesia, Depok, Indonesia. seruni@chem.usyd.edu.au
Kurniati
Vita
V
Prasetyo
Pamulih B
PB
Handayani
Sri
S
Adhiyanto
Chris
C
Soegianto
Rondang R
RR
Pudiantari
Ratna
R
Munthe
Bulan G
BG
Ramelan
Wahyuning
W
Freisleben
Hans-Joachim
HJ
D000293:Adolescent; D000328:Adult; D001803:Blood Transfusion; D002648:Child; D004578:Electron Spin Resonance Spectroscopy; D004591:Electrophoresis, Polyacrylamide Gel; D004910:Erythrocyte Membrane / Q000737:chemistry* / Q000378:metabolism; D005260:Female; D006801:Humans; D007214:Indonesia; D008297:Male; D008560:Membrane Fluidity; D012016:Reference Values; D013113:Spin Labels; D013995:Time; D017086:beta-Thalassemia / Q000097:blood* / Q000628:therapy
D013113:Spin Labels