Primary structure of the heterosaccharide of the surface glycoprotein of Methanothermus fervidus

• Published in: The Journal of biological chemistry 1993-12, Vol.268 (36), p.26821-26826
• Main Authors: Kärcher, U, Schröder, H, Haslinger, E, Allmaier, G, Schreiner, R, Wieland, F, Haselbeck, A, König, H
• Format: Article
• Language: English
• Subjects: Analytical, structural and metabolic biochemistry; Biological and medical sciences; Carbohydrate Sequence; Chromatography, Gel; Chromatography, High Pressure Liquid; Chromatography, Thin Layer; Fundamental and applied biological sciences. Psychology; Glycoproteins; Magnetic Resonance Spectroscopy; Methanobacteriales - chemistry; Methanothermus fervidus; Molecular Sequence Data; Oligosaccharides - chemistry; Oligosaccharides - isolation & purification; Polysaccharides - analysis; Proteins
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1016/S0021-9258(19)74185-4

The outer surface of the cells of the hyperthermophile Methanothermus fervidus is covered by crystalline glycoprotein subunits (S-layer). From the purified S-layer glycoprotein, a heterosaccharide was isolated. The heterosaccharide consists of D-3-O-methylmannose, D-mannose, and D-N-acetylgalactosamine in a molar ratio of 2:3:1 corresponding to a relative molecular mass of 1061.83 Da. 3-O-methylmannose could be partly replaced by 3-O-methylglucose. The primary structure of the glycan was revealed by methylation analysis, by plasma desorption mass spectrometry, and by high field NMR spectroscopy. The purified heterosaccharide is linked via N-acetylgalactosamine to an asparagine residue of the peptide moiety. The following structure is proposed for the heterosaccharide: alpha-D-3-O-MetManp-(1-->6)-alpha-D-3-O-MetManp-((1-->2)-alp ha-D-Manp)3-(1-->4) - D-GalNAc.