Feugeas J P, Néel D, Goussault Y, Derappe C
INSERM U180, UFR Biomédicale, Paris, France.
Biochim Biophys Acta. 1991 Jul 1;1066(1):59-62. doi: 10.1016/0005-2736(91)90250-c.
The involvement of the carbohydrate moiety of the human erythrocyte glucose transporter in glucose transport activity was previously demonstrated (Feugeas et al. (1990) Biochim. Biophys. Acta 1030, 60-64): N-glycanase treatment of the transport glycoprotein reconstituted in proteoliposomes resulted in a dramatic decrease of the Vmax. In this study, kinetic measurements of glucose equilibrium influx confirm our previous results. In order to investigate that a minimum glycosidic structure is required to maintain glucose transport activity, proteoliposomes were respectively treated with either sialidase, or sialidase and endo-beta-galactosidase, or a pool of exo-glycosidases which allows the release of all the sugar residues, except the proximal N-acetylglucosamine. Kinetic measurements of zero-trans influx made on sialidase- and (sialidase + endo-beta-galactosidase)-treated proteoliposomes did not reveal any significant changes in the glucose transport activity. On the contrary, treatment of the same proteoliposomes by a pool of exoglycosidases led to a complete abolition of activity, suggesting that a minimum glycosidic structure is required for glucose transport activity.
人类红细胞葡萄糖转运蛋白的碳水化合物部分参与葡萄糖转运活性这一点先前已得到证实（Feugeas等人，（1990年）《生物化学与生物物理学报》1030卷，60 - 64页）：用N - 糖苷酶处理在蛋白脂质体中重组的转运糖蛋白会导致Vmax显著降低。在本研究中，葡萄糖平衡流入的动力学测量证实了我们先前的结果。为了研究维持葡萄糖转运活性是否需要最小糖苷结构，分别用唾液酸酶、唾液酸酶和内切β - 半乳糖苷酶或一组外切糖苷酶处理蛋白脂质体，该组外切糖苷酶可释放除近端N - 乙酰葡糖胺之外的所有糖残基。对经唾液酸酶和（唾液酸酶 + 内切β - 半乳糖苷酶）处理的蛋白脂质体进行的零转运流入动力学测量未显示葡萄糖转运活性有任何显著变化。相反，用一组外切糖苷酶处理相同的蛋白脂质体导致活性完全丧失，这表明葡萄糖转运活性需要最小糖苷结构。
