Intrinsic tryptophan fluorescence measurements suggest that polylactosaminyl glycosylation affects the protein conformation of the gelatin-binding domain from human placental fibronectin.
Intrinsic tryptophan fluorescence measurements suggest that polylactosaminyl glycosylation affects the protein conformation of the gelatin-binding domain from human placental fibronectin.
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内在色氨酸荧光测量表明，聚乳糖胺基糖基化影响人胎盘纤连蛋白明胶结合结构域的蛋白质构象。
DOI：
10.1111/j.1432-1033.1990.tb15516.x
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发表时间：
1990
期刊：
影响因子：
--
通讯作者：
Barkley,MD
中科院分区：
文献类型：
--
作者：
Zhu,BC;Laine,RA;Barkley,MD
糖基化可以影响糖蛋白中多肽链的物理和生化性质。来自人胎盘纤连蛋白的胰凝乳蛋白酶44-kDa明胶结合结构域的天冬酰胺-N-连接的聚乳糖胺基糖基化赋予蛋白酶抗性[Zhu，B. C. R.，Fisher，S. F.、潘达，H.，Calaycay，J.，Shively，J.E. & Laine，R. A.（1984）J.Biol.Chem.259，3962-3970]并减弱与明胶的结合[Zhu，B. C. R. & Laine，R. A.（1985）J.Biol.Chem.260，4041-4045]。明胶结合结构域的固有色氨酸荧光用于探测糖基化依赖性蛋白质构象变化。在含有逐渐变小的聚乳糖胺寡糖的明胶结合片段中，荧光强度逐渐降低，发射光谱向蓝色移动约7 nm。用来自弗氏大肠杆菌的内切-β-半乳糖苷酶从高度糖基化的片段中去除聚乳糖胺链也淬灭了蛋白质荧光。荧光寿命似乎没有受到糖基化程度的影响，这表明在低糖基化片段中色氨酸发射的静态淬灭。丙烯酰胺淬灭的研究表明，无障碍的小溶质的糖基化没有改变。稳态发射各向异性随着聚乳糖胺链长的减小而增加。结果表明，聚乳糖胺链改变了明胶结合结构域中的色氨酸环境，可能是通过改变多肽构象。这些推定的蛋白质构象变化可能是部分负责改变明胶结合，蛋白酶抗性，和细胞粘附功能的胎儿组织纤连蛋白。
Glycosylation can affect the physical and biochemical properties of the polypeptide chain in glycoproteins. Asparagine‐N‐linked polylactosaminyl glycosylation of the chymotryptic 44‐kDa gelatin‐binding domain from human placental fibronectin confers protease resistance [Zhu, B. C. R., Fisher, S. F., Panda, H., Calaycay, J., Shively, J. E. & Laine, R. A. (1984)J. Biol. Chem. 259, 3962–3970] and weakens the binding to gelatin [Zhu, B. C. R. & Laine, R. A. (1985)J. Biol. Chem. 260, 4041–4045]. Intrinsic tryptophan fluorescence of the gelatinbinding domain was used to probe glycosylation‐dependent protein conformation changes. In gelatin‐binding fragments containing incrementally smaller polylactosamine oligosaccharides, the fluorescence intensity progressively decreased and the emission spectrum shifted about 7 nm to the blue. Removal of the polylactosamine chains from a highly glycosylated fragment with endo‐β‐galactosidase fromEscherichia freundiialso quenched the protein fluorescence. The fluorescence lifetimes did not appear to be affected by the extent of glycosylation, suggesting static quenching of the tryptophan emission in the low glycosylated fragments. Acrylamide quenching studies showed that the accessibility of the tryptophans to small solutes was not altered by glycosylation. The steadystate emission anisotropy increased with decreasing polylactosamine chain length. The results indicate that the polylactosamine chains alter the tryptophan environments in the gelatin‐binding domain, probably by changing the polypeptide conformation. These putative protein conformation changes may be partially responsible for the altered gelatin binding, protease resistance, and cell adhesion functions of fetal tissue fibronectin.