Spectroscopic and protein chemical analyses demonstrate the presence of C-mannosylated tryptophan in intact human RNase 2 and its isoforms.

Détails

ID Serval
serval:BIB_975D6CEF14DC
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Spectroscopic and protein chemical analyses demonstrate the presence of C-mannosylated tryptophan in intact human RNase 2 and its isoforms.
Périodique
Biochemistry
Auteur⸱e⸱s
Löffler A., Doucey M.A., Jansson A.M., Müller D.R., de Beer T., Hess D., Meldal M., Richter W.J., Vliegenthart J.F., Hofsteenge J.
ISSN
0006-2960 (Print)
ISSN-L
0006-2960
Statut éditorial
Publié
Date de publication
1996
Volume
35
Numéro
37
Pages
12005-12014
Langue
anglais
Résumé
Recently, the C-mannosylation of a specific tryptophan residue in RNase 2 from human urine has been reported [Hofsteenge, J., et al. (1994) Biochemistry 33, 13524-13530; de Beer, T., et al. (1995) Biochemistry 34, 11785-11789]. In those studies, identification of this unusual modification was accomplished by mass spectrometric and NMR spectroscopic analysis of peptide fragments. The evidence for the occurrence of C2-alpha-mannosyltryptophan [(C2-Man-)Trp] in the intact protein relied exclusively on the detection of the same phenylthiohydantoin derivatives during Edman degradation. In this paper, we have (1) excluded the possibility that (C2-Man-)Trp arose artificially under the acidic conditions previously employed for protein and peptide isolation and analysis, by maintaining the pH > 5 throughout these procedures, (2) demonstrated the occurrence of (C2-Man-)Trp in the intact protein, by NMR spectroscopy, (3) showed that (C2-Man-)Trp is not unique for RNase 2 from urine but that it is also present in the enzyme isolated from erythrocytes, and (4) found also that high-molecular mass isoforms of urinary RNase 2 are C-mannosylated. These observations firmly establish C-mannosylation as a novel way of post-translationally attaching carbohydrate to protein, in addition to the well-known N- and O-glycosylations. Furthermore, the NMR data, in combination with molecular dynamics calculations, indicate that in the native protein the mannopyranosyl residue is in a different conformation than in the glycopeptide or denatured protein, due to protein-carbohydrate interactions.
Mots-clé
Amino Acid Sequence, Blotting, Western, Endoribonucleases/chemistry, Endoribonucleases/isolation & purification, Female, Glycosylation, Humans, Isoenzymes/chemistry, Isoenzymes/isolation & purification, Magnetic Resonance Spectroscopy, Mannose/analysis, Mass Spectrometry, Menopause, Models, Molecular, Molecular Sequence Data, Molecular Weight, Peptide Fragments/chemistry, Peptide Fragments/isolation & purification, Pregnancy, Protein Conformation, Tryptophan/analogs & derivatives, Tryptophan/analysis
Pubmed
Web of science
Création de la notice
28/01/2008 8:28
Dernière modification de la notice
20/08/2019 14:59
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