黑素转铁蛋白在家兔网织红细胞膜上的表达及其在铁摄取中的作用

THE EXPRESSION OF P97 ON THE MEMBRANE OF THE RETICULOCYTE AND THE ROLE IN IRON UPTAKE IN RABBIT

目的 :研究黑素转铁蛋白 (p97)在家兔网织红细胞膜上的表达及其在非转铁蛋白结合铁摄取中的作用。方法 :聚丙烯酰胺凝胶电泳 (SDS =PAGE)和放射性同位素法 (59Fe)。结果 :①网织红细胞孵育液浓缩后 ,经SDS PAGE测定 ,在分子量 97kD位置上可见一条明显的蛋白带 ;用磷脂酚肌醇磷脂酶C(PI PLC) 30 0mu/ml预处理网织红细胞后 ,孵育液浓缩再经SDS PAGE测定 ,在分子量 97kD处仍有一条明显的蛋白带 ,且其平均OD值高于未经处理的网织红细胞 ;而成熟的红细胞在此处却没有明显的蛋白带。②单纯用PI PLC作用于网织红细胞 ,其铁摄取无明显变化 (P >0 .0 5 )。③去除内源性转铁蛋白后 ,再用PI PLC作用网织红细胞 ,则胞浆内铁及整合到血红素中的铁均较未经处理的网织红细胞明显降低 (P <0 .0 5 )。结论 :p97可能存在于家兔网织红细胞膜上 。

Aim: To investigate the expression of p97 on the membrane of the reticulocyte and the possible role in non transferrin bound iron uptake. Methods: The SDS PAGE and the radioisotope ( 59 Fe) was used in this investigation. Results: ①The protein of the supernatant of reticulocytes was separated on SDS PAGE.There was one band near 97kDa. The same result was obtained with reticulocytes treated with PI PLC and the Mean OD of the band was higher than that of untreated reticulocytes. But for the mature erythrocytes,there wasn't apparent band near 97kD. ②No apparent effect of only PI PLC treatment on iron uptake by reticulocytes ( P > 0.05 ). ③Reticulocytes, depleted endogenoustransferrin and then treated by PI PLC, gave a significant decrease in iron uptake in cytosol and in heme ( P <0.05). Conclusion: The results support the possibility that p97 might be able to be expressed on the membrane of reticulocytes and plays a role in non transferrin bound iron uptake by this type of cells in rabbit.