Feugeas J P, Néel D, Pavia A A, Laham A, Goussault Y, Derappe C
INSERM U180, UFR Biomédicale, Paris, France.
Biochim Biophys Acta. 1990 Nov 30;1030(1):60-4. doi: 10.1016/0005-2736(90)90238-j.
The human erythrocyte glucose transporter is a fully integrated membrane glycoprotein having only one N-linked carbohydrate chain on the extracellular part of the molecule. Several authors have suggested the involvement of the carbohydrate moiety in glucose transport, but not definitive results have been published to date. Using transport glycoproteins reconstituted in proteoliposomes, kinetic studies of zero-trans influx were performed before and after N-glycanase treatment of the proteoliposomes: this enzymatic treatment results in a 50% decrease of the Vmax. The orientation of transport glycoproteins in the lipid bilayer of liposomes was investigated and it appears that about half of the reconstituted transporter molecules are oriented properly. Finally, it could be concluded that the release of the carbohydrate moiety from the transport glycoproteins leads to the loss of their transport activity.
人类红细胞葡萄糖转运蛋白是一种完全整合的膜糖蛋白，在分子的细胞外部分仅有一条N-连接碳水化合物链。几位作者曾提出碳水化合物部分参与葡萄糖转运，但迄今为止尚未发表确凿的结果。利用重组在蛋白脂质体中的转运糖蛋白，在对蛋白脂质体进行N-糖苷酶处理前后进行了零转运流入的动力学研究：这种酶处理导致Vmax降低50%。研究了转运糖蛋白在脂质体脂质双层中的取向，结果表明大约一半重组的转运蛋白分子取向正确。最后，可以得出结论，从转运糖蛋白上释放碳水化合物部分会导致其转运活性丧失。
