NMR characterization of immunoglobulin G Fc glycan motion on enzymatic sialylation.
NMR characterization of immunoglobulin G Fc glycan motion on enzymatic sialylation.
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DOI：
10.1021/bi300319q
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发表时间：
2012-06-05
期刊：
影响因子：
2.9
通讯作者：
Prestegard JH
中科院分区：
文献类型：
--
作者：
Barb AW;Meng L;Gao Z;Johnson RW;Moremen KW;Prestegard JH
免疫球蛋白G（IgG）可结晶片段（Fc）上N-聚糖的末端碳水化合物残基决定IgG激活促炎或抗炎受体。在将α2-6连接的N-乙酰神经氨酸残基添加至N-聚糖后，单独的IgG Fc变得有效抗炎，从而激发了在用于自身免疫性疾病的新疗法中使用该实体的兴趣（Kaneko等人（2006）Science 313：670-3）。然而，由于分支特异性和通过聚糖-蛋白质相互作用的感知保护的组合，完全Fc唾液酸化被认为具有挑战性。在本文中，我们报告了通过使用足量的在瞬时转化的人细胞培养物中表达的高活性α2-6唾液酸转移酶（ST 6 Gal 1）制备物制备高水平的二唾液酸化Fc。令人惊讶的是，ST 6 Gal 1以与对游离N-聚糖观察到的显著相似的方式唾液酸化复合型双触角聚糖的两个末端，表明Fc多肽不会极大地影响ST 6 Gal 1特异性。此外，通过溶液NMR光谱判断，任一分支末端的唾液酸化似乎不会显著改变N-聚糖的运动行为。总之，这些数据表明N-聚糖占据两种不同的状态，一种是两个聚糖末端通过与多肽表面的α1- 6 Man分支相互作用而与酶促修饰隔离，另一种是两个聚糖末端暴露于本体溶剂且不存在聚糖-多肽相互作用。结果表明，新的模式，其中二唾液酸化的Fc可以作为一种抗炎效应。
The terminal carbohydrate residues of the N-glycan on the immunoglobulin G (IgG) Fragment crystalizable (Fc) determine whether IgG activates pro- or anti-inflammatory receptors. The IgG Fc alone becomes potently anti-inflammatory upon addition of α2–6 linked N-acetylneuraminic acid residues to the N-glycan, stimulating interest in use of this entity in novel therapies for autoimmune disease (Kaneko et al. (2006) Science 313:670-3). Complete Fc sialylation has, however, been deemed challenging, due to a combination of branch specificity and perceived protection by glycan-protein interactions. Here we report the preparation of high levels of disialylated Fc by using sufficient amounts of a highly active α2–6 sialyltransferase (ST6Gal1) preparation expressed in a transiently-transformed human cell culture. Surprisingly, ST6Gal1 sialylated the two termini of the complex-type binantennary glycan in a manner remarkably similar to that observed for the free N-glycan, suggesting the Fc polypeptide does not greatly influence ST6Gal1 specificity. In addition, sialylation of either branch terminus does not appear to dramatically alter the motional behavior of the N-glycan as judged by solution NMR spectroscopy. Together these data suggest the N-glycan occupies two distinct states, one with both glycan termini sequestered from enzymatic modification by an α1–6Man-branch interaction with the polypeptide surface, and the other with both glycan termini exposed to the bulk solvent and free from glycan-polypeptide interactions. The results suggest new modes by which disialylated Fc can act as an anti-inflammatory effector.
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影响因子：
46.9
作者：
Pédelacq, JD;Cabantous, S;Waldo, GS
通讯作者：
Waldo, GS
影响因子：
2.9
作者：
Liu, Shan;Meng, Lu;Prestegard, James H.
通讯作者：
Prestegard, James H.
影响因子：
15
作者：
Macnaughtan, Megan A.;Tian, Fang;Prestegard, James H.
通讯作者：
Prestegard, James H.
影响因子：
3.3
作者：
Nacher, J.;Guirado, R.;Hildebrandt, H.
通讯作者：
Hildebrandt, H.
影响因子：
3.7
作者：
MORGAN, EL;SPIEGELBERG, HL;WEIGLE, WO
通讯作者：
WEIGLE, WO