PMID: 15536627

 

    Legend: Gene, Sites

Title : Site-specific carbohydrate profiling of human transferrin by nano-flow liquid chromatography/electrospray ionization mass spectrometry

Abstract :
  1. Glycopeptides derived from a lysylendopeptidase digest of commercially available human transferrin were analyzed by nano-flow liquid chromatography/electrospray ionization mass spectrometry (LC/ ESI-MS), which permitted the carbohydrate profiles at Asn432 and Asn630 to be determined
  2. Both are located in a well-known motif for N-glycosylation, Asn-Xaa-Ser/Thr
  3. The contents of the carbohydrates at each site were significantly different from each other, and consisted of a variety of minor types of oligosaccharides in addition to the major one, a biantennary complex-type oligosaccharide
  4. Nano-flow ESI tandem mass spectrometry (MS/MS) of the glycopeptides (Cys421-Lys433 and Ile619-Lys646) containing these two sites yielded predominantly ions originating from the non-reducing termini (oxonium ions) and reducing terminus , resulting from cleavage of the glycosidic bonds of the carbohydrate moieties; this permitted the structural read-out of a small minority of the carbohydrate moieties
  5. In particular, the observation of oxonium ions at m/z 512.2 and 803.2 is useful for probing outer non-reducing terminal fucosylation, which represented carbohydrate structures consisting of Hex, dHex, and HexNAc, and NeuNAc, Hex, dHex, and HexNAc, respectively, from which the Lewis X structure (Galbeta1-4(Fucalpha1-3)GlcNAc) was readily deduced
  6. Moreover, fucosylation at the reducing-terminal GlcNAc (Fucalpha1-6GlcNAc) specifically occurred at Asn630 , as demonstrated by treatment of the glycopeptides with alpha1-3/4-L-fucosidase
Output (sent_index, trigger, protein, sugar, site):
  • 0. transferrin, , transferrin, Site-specific carbohydrate profiling, -
  • 1. Asn432, , -, the carbohydrate profiles, Asn432 and Asn630
  • 1. Asn630, , -, the carbohydrate profiles, Asn432 and Asn630
  • 1. carbohydrate, , -, -, Asn432 and Asn630
  • 3. site, , -, the carbohydrates, site
  • 4. glycopeptides, , -, -, glycopeptides
  • 6. fucosylation, , -, Fucalpha1-6GlcNAc, Asn630
  • 6. fucosylation, , -, the reducing-terminal GlcNAc, Asn630
  • 6. glycopeptides, , -, -, glycopeptides
Output(Part-Of) (sent_index, protein, site):
*Output_Site_Fusion* (sent_index, protein, sugar, site):
  • 1. transferrin, -, Asn432 and Asn630
  • 1. transferrin, the carbohydrate profiles, Asn432 and Asn630
  • 6. transferrin, Fucalpha1-6GlcNAc, Asn630
  • 6. transferrin, the reducing-terminal GlcNAc, Asn630

 

 

Protein NCBI ID SENTENCE INDEX
transferrin 7018 0,1