Reversal by insulin of concanavalin A inhibition of myotube formation and evidence for common binding sites.
Reversal by insulin of concanavalin A inhibition of myotube formation and evidence for common binding sites.
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胰岛素逆转伴刀豆球蛋白 A 对肌管形成的抑制以及常见结合位点的证据。
DOI：
10.1210/endo-105-2-391
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发表时间：
1979
期刊：
影响因子：
4.8
通讯作者：
R. Przybylski
中科院分区：
文献类型：
--
作者：
A. Sandra;M. Leon;R. Przybylski
刀豆蛋白A （cona）抑制胰蛋白酶处理的成肌细胞融合。这种抑制作用可以通过在培养物持续存在期间添加超生理浓度（4微克/毫升）的胰岛素或在培养36和48小时（未使用Con A处理的培养物进行成肌细胞融合之前）脉冲添加来逆转。这种逆转不是由于胰岛素的有丝分裂作用。在逆转条件下，没有检测到结合的[125I]碘- con A的特定位移，也没有胰岛素刺激代谢物的摄取。血青素标记的Con A的细胞表面复制表明，胰岛素逆转对肌管形成的抑制与Con A结合位点的改变有关，Con A结合位点从被抑制细胞中的聚集配置转变为与正常肌管形成相关的分散状态。虽然因果关系尚未表明,冲突的数据表明insulin-mediated逆转成肌细胞融合的抑制可能与胰岛素的能力在supraphysiological水平改变细胞表面的平移移动组件含有葡萄糖和/或甘露糖残基能绑定Con a提出的研究的证据表明,胰岛素和反面共同绑定网站,因为在生理范围内的胰岛素浓度(1 ng / ml),Con A预处理导致特异性[125I]碘-胰岛素结合的抑制，胰岛素和Con A对代谢物摄取和细胞增殖产生拮抗作用。因此，似乎发育中的骨骼肌的胰岛素受体是含有甘黄苷的糖蛋白。
Concanavalin A (Con A) inhibits fusion of trypsin-treated myoblasts. This inhibition is reversed by the addition of supraphysiological concentrations (4 micrograms/ml) of insulin either during continuous presence in culture or by pulse additions at 36 and 48 h of culture, just before the time that cultures not treated with Con A undergo myoblast fusion. This reversal is not due to the mitogenic effects of insulin. Under reversal conditions, no specific displacement of bound [125I]iodo-Con A was detected nor did insulin stimulate metabolite uptake. Cell surface replicas of hemocyanin-tagged Con A showed that insulin reversal of the inhibition of myotube formation correlated with the alteration of Con A-binding sites from a clustered configuration present in the inhibited cells to a dispersed state correlated with normal myotube formation. Although a causal relationship has yet to be shown, the data suggest that insulin-mediated reversal of Con A inhibition of myoblast fusion may be related to the ability of insulin at supraphysiological levels to alter the translational mobility of cell surface components containing glucose and/or mannose residues capable of binding Con A. Evidence is presented which suggests that insulin and Con A share common binding sites, since in the physiological range of insulin concentrations (1 ng/ml), Con A pretreatments results in an inhibition of specific [125I]iodo-insulin binding, and antagonistic interactions of insulin and Con A on metabolite uptake and cell proliferation occur. Thus, it appears that the insulin receptors of developing skeletal muscle are glycoproteins containing glycopyranosides.