Protein and Site Specificity of Fucosylation in Liver-Secreted Glycoproteins
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- 作者：Petr Pompach ; David J. Ashline ; Zuzana Brnakova ; Julius Benicky ; Miloslav Sanda ; Radoslav Goldman
- 刊名：Journal of Proteome Research
- 出版年：2014
- 出版时间：December 5, 2014
- 年：2014
- 卷：13
- 期：12
- 页码：5561-5569
- 全文大小：568K
- ISSN：1535-3907
文摘
Chronic liver diseases are a serious health problem worldwide. One of the frequently reported glycan alterations in liver disease is aberrant fucosylation, which was suggested as a marker for noninvasive serologic monitoring. We present a case study that compares site specific glycoforms of four proteins including haptoglobin, complement factor H, kininogen-1, and hemopexin isolated from the same patient. Our exoglycosidase-assisted LC鈥揗S/MS analysis confirms the high degree of fucosylation of some of the proteins but shows that microheterogeneity is protein- and site-specific. MSn analysis of permethylated detached glycans confirms the presence of LeY glycoforms on haptoglobin, which cannot be detected in hemopexin or complement factor H; all three proteins carry Lewis and H epitopes. Core fucosylation is detectable in only trace amounts in haptoglobin but with confidence on hemopexin and complement factor H, where core fucosylation of the bi-antennary glycans on select glycopeptides reaches 15鈥?0% intensity. These protein-specific differences in fucosylation, observed in proteins isolated from the same patient source, suggest that factors other than up-regulation of enzymatic activity regulate the microheterogeneity of glycoforms. This has implications for selection of candidate proteins for disease monitoring and suggests that site-specific glycoforms have structural determinants, which could lead to functional consequences for specific subsets of proteins or their domains.