Grigor M R, Wilde C J, Flint D J
Department of Biochemistry, University of Otago, Dunedin, New Zealand.
Biochem Int. 1988 Oct;17(4):747-54.
The binding of 125I-transferrin to rat mammary cells isolated by collagenase and hyaluronidase digestion has been investigated. Surface binding was determined at 4 degrees C and total binding also at 4 degrees C but in the presence of 0.1% w/v saponin. KD values between 20 and 25 nM were obtained. Binding assays at 37 degrees C showed the internalisation of the receptor and the bound transferrin was occurring but also provided evidence for an impaired recycling of the receptors to the cell surface in the freshly isolated cells. No differences in total binding were observed in cells prepared at different stages of lactation with a mean value of 29 fmol transferrin bound/micrograms cellular DNA, equivalent to 180,000 receptors per cell.
研究了经胶原酶和透明质酸酶消化分离得到的大鼠乳腺细胞对125I-转铁蛋白的结合情况。在4℃测定表面结合，同样在4℃但存在0.1% （w/v）皂角苷的条件下测定总结合。得到的解离常数（KD）值在20至25 nM之间。37℃下的结合试验表明受体和结合的转铁蛋白发生了内化，但也提供了证据表明在新鲜分离的细胞中，受体向细胞表面的再循环受损。在不同泌乳阶段制备的细胞中，未观察到总结合的差异，平均结合量为29 fmol转铁蛋白/微克细胞DNA，相当于每个细胞有180,000个受体。
