A new trisaccharide sugar chain linked to a serine residue in the first EGF-like domain of clotting factors VII and IX and protein Z.
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Iwanaga S, Nishimura H, Kawabata S, Kisiel W, Hase S, Ikenaka T
A new trisaccharide sugar chain linked to a serine residue in the first EGF-like domain of clotting factors VII and IX and protein Z.
Adv Exp Med Biol. 1990;281:121-31.
- PubMed ID
- 2129367 [ View in PubMed]
- Abstract
Recently, we determined the complete amino acid sequence of bovine factor VII (Takeya, H. et al. (1988) J. Biol. Chem. 263, 14868-14877). In the course of the studies, we found an unknown serine derivative at position 52 in the first epidermal growth factor-like domain of factor VII. A pentapeptide isolated from the S-aminoethylated factor VII contained Ser-52, which could not be identified with a gas-phase sequencer. The same results were also obtained for a pentapeptide containing Ser-53 of factor IX and protein Z. Component sugar analysis revealed that the peptide contained 1 mol of glucose and 2 mol of xylose. This sugar component was also confirmed by high-resolution fast atom bombardment mass spectrometric analysis of the pentapeptide. The trisaccharide was released from the peptides by means of beta-elimination reaction and its reducing end was identified as pyridylamino-glucose. These results indicate the existence of a (Xyl2)Glc-Ser structure in factors VII, IX and protein Z. Similar results were obtained for human factors VII, IX and protein Z. This is the first report of a (Xyl2)-Glc-Ser structure in glycoproteins to our knowledge. The presence of the unique trisaccharide structure in factors VII, IX and protein Z leads us to anticipate its biological role in the tissue factor pathway.