Isolated erythrocyte membranes of transfusion-dependent and non-transfused thalassemia patients in Jakarta, investigated by electron paramagnetic resonance spectroscopy

Issue title: Proceedings of the Second International Symposium on Antioxidants in Nutrition and Therapy, Bali, Indonesia, 2–4 October 2002

Article type: Research Article

Authors: Udyaningsih-Freisleben, Seruni K.^; | Kurniati, Vita | Prasetyo, Pamulih B. | Handayani, Sri | Adhiyanto, Chris | Soegianto, Rondang R. | Pudiantari, Ratna | Munthe, Bulan G. | Ramelan, Wahyuning | Freisleben, Hans-Joachim

Affiliations: Department of Physics, Faculty of Mathematics and Natural Science, University of Indonesia, Depok, Indonesia | Thalassemia Center, Cipto Mangunkusumo General Hospital, Indonesia | Study Program Biomedical Science, Faculty of Medicine, Salemba, Jakarta, Indonesia

Note: [] Address for correspondence: Seruni K. Udyaningsih-Freisleben, Ludwig-Ruppel-Str. 45, D-60437 Frankfurt am Main, Germany. Tel.: +49 69 5068 5866; Fax: +49 69 5068 5867 or 5068 5868; E-mail: [email protected] or: [email protected]

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Abstract: Erythrocyte membrane structural parameters were studied in transfusion-dependent β-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.

Keywords: thalassemia major, thalassemia intermedia, transfusion, erythrocyte membrane, EPR spectroscopy

Journal: BioFactors, vol. 19, no. 1-2, pp. 87-100, 2003