Title : Site-specific N-glycan characterization of human
complement factor H . Human
complement factor H (
CFH ) is a plasma
glycoprotein involved in the regulation of the alternative pathway of the complement system
Abstract :
- A deficiency in CFH is a cause of severe pathologies like atypical haemolytic uraemic syndrome (aHUS)
- CFH is a 155-kDa glycoprotein containing nine potential N-glycosylation sites
- In the current study, we present a quantitative glycosylation analysis of CFH using capillary electrophoresis and a complete site-specific N-glycan characterization using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) and liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESIMS/MS)
- A 17.9-kDa mass decrease, observed after glycosidase treatment, indicated that N-glycosylation is the major post-translational modification of CFH
- This mass difference is consistent with CFH glycosylation by diantennary disialylated glycans of 2204 Da on eight sites
- CFH was not sensitive to endoglycosidase H (Endo H) deglycosylation, indicating the absence of hybrid and oligomannose structures
- Quantitative analysis showed that CFH is mainly glycosylated by complex, diantennary disialylated, non-fucosylated glycans
- Disialylated fucosylated and monosialylated non-fucosylated oligosaccharides were also identified
- MS analysis allowed complete characterization of the protein backbone, verification of the glycosylation sites and site-specific N-glycan identification
- The absence of glycosylation at Asn199 of the NGSP sequence of CFH is shown
- Asn511, Asn700, Asn784, Asn804, Asn864, Asn893, Asn1011 and Asn1077 are glycosylated essentially by diantennary disialylated structures with a relative distribution varying between 45% for Asn804 and 75% for Asn864
- Diantennary monosialylated glycans and triantennary trisialylated fucosylated and non-fucosylated structures have also been identified
- Interestingly, the sialylation level along with the amount of triantennary structures decreases from the N- to the C-terminal side of the protein
Output (sent_index, trigger,
protein,
sugar,
site):
- 0. factor, , complement factor H, Site-specific N-glycan characterization, -
- 0. glycoprotein, , glycoprotein, Site-specific N-glycan characterization, -
- 11. disialylated, , -, diantennary disialylated structures, -
- 11. glycosylated, , -, -, Asn511, Asn700, Asn784, Asn804, Asn864, Asn893, Asn1011 and Asn1077
- 12. fucosylated, , -, triantennary trisialylated fucosylated and non-fucosylated structures, -
- 12. monosialylated, , -, Diantennary monosialylated glycans, -
- 12. non-fucosylated, , -, triantennary trisialylated fucosylated and non-fucosylated structures, -
- 12. trisialylated, , -, triantennary trisialylated fucosylated and non-fucosylated structures, -
- 2. N-glycosylation, , -, -, sites
- 2. glycoprotein, , CFH, -, -
- 2. glycoprotein, , glycoprotein, -, -
- 3. CFH, , CFH, a complete site-specific N-glycan characterization, -
- 3. glycosylation, , CFH, -, -
- 5. disialylated, , -, diantennary disialylated glycans, -
- 5. glycosylation, , -, -, sites
- 7. disialylated, , -, complex, diantennary disialylated, non-fucosylated glycans, -
- 7. glycosylated, , CFH, -, -
- 8. Disialylated, , -, Disialylated fucosylated and monosialylated non-fucosylated oligosaccharides, -
- 8. fucosylated, , -, Disialylated fucosylated and monosialylated non-fucosylated oligosaccharides, -
- 8. monosialylated, , -, Disialylated fucosylated and monosialylated non-fucosylated oligosaccharides, -
- 8. non-fucosylated, , -, Disialylated fucosylated and monosialylated non-fucosylated oligosaccharides, -
- 9. glycosylation, , -, -, sites
- 9. sites, , -, site-specific N-glycan identification, sites
Output(Part-Of) (sent_index,
protein,
site):
- 10. CFH, sequence
- 2. CFH, sites
- 2. glycoprotein, sites
*Output_Site_Fusion* (sent_index,
protein,
sugar,
site):
- 11. complement factor H, -, Asn511, Asn700, Asn784, Asn804, Asn864, Asn893, Asn1011 and Asn1077