An Extended Spectrum of Target Proteins and Modification Sites in the General O-Linked Protein Glycosylation System in Neisseria gonorrhoeae
An Extended Spectrum of Target Proteins and Modification Sites in the General O-Linked Protein Glycosylation System in Neisseria gonorrhoeae
复制标题
DOI：
10.1021/pr300584x
复制
发表时间：
2012-12-01
影响因子：
4.4
通讯作者：
Koomey, Michael
中科院分区：
文献类型：
--
作者：
Anonsen, Jan Haug;Vik, Ashild;Koomey, Michael
人类病原体淋球菌表达一个通用的O-连接蛋白糖基化(PGL)系统，已知以至少12种膜相关蛋白为靶标。为了更好地了解这个糖基化系统的机制、意义和功能，我们试图进一步描绘PGL系统的靶蛋白质组。为此，我们使用针对糖链部分的单抗对糖蛋白进行免疫亲和富集法。随后用MS分析酶产生的多肽，以鉴定糖肽和糖基化位点。通过这种方式，我们将淋球菌中已知的糖蛋白总数增加到19个。这些新的糖蛋白参与了广泛的细胞质外功能。通过碰撞碎裂，我们绘制了9个新的糖基化位点，它们都是丝氨酸。没有明显的靶标亮片，尽管附着位置通常定位于序列复杂性较低的区域。此外，我们还发现其中5种蛋白质被不止一种糖链修饰。因此，这项工作证实并推广了先前对结构特征的观察。奈瑟氏菌的糖蛋白。
The bacterial human pathogen Neisseria gonorrhoeae expresses a general O-linked protein glycosylation (Pgl) system known to target at least 12 membrane-associated proteins. To facilitate a better understanding of the mechanisms, significance and function of this glycosylation system, we sought to further delineate the target proteome of the Pgl system. To this end, we employed immunoaffinity enrichment of glycoproteins using a monoclonal antibody against the glycan moiety. Enzymatically generated peptides were subsequently analyzed by MS to identify glycopeptides and glycosylation sites. In this way, we increase the total number of known glycoproteins in N. gonorrhoeae to 19. These new glycoproteins are involved in a wide variety of extracytoplasmic functions. By employing collision fragmentation, we mapped nine new glycosylation sites, all of which were serine. No target sequon was readily apparent, although attachment sites were most often localized with regions of low sequence complexity. Moreover, we found that 5 of the proteins were modified with more than one glycan. This work thus confirms and extends earlier observations on the structural features. of Neisseria glycoproteins.