Exposition of the N-glycan nomenclature system "ProGlycan"

Drafted by:Friedrich Altmann, Johannes Helm, Martin Pabst* and Johannes Stadlmann

University of Natural Resources and Life Sciences, Vienna. Austria.
* Delft University of Technology, Delft, The Netherlands.

Contact: friedrich.altmann@boku.ac.at


In Brief:

The Vienna ProGlycan Nomenclature provides a comprehensive system for the abbreviatated notation of N-glycan stuctures. For example Gal(b1-4)GlcNAc(b1-2)Man(a1-3)[Gal(b1-4)GlcNAc(b1-2)Man(a1-6)]Man(b1-4)GlcNAc(b1-4)[Fuc(a1-6)] GlcNAc is simplified to A4A4F6 by applying the following set of rules:

RULE 1: Monosaccharides are denoted by single capital letters. Modifications are specified by a subsequent small letter:

G glucoseGnN-acetylglucosamine
M mannoseNaN-acetylneuraminic acid
A galactoseNgN-glycolylneuraminic acid
F fucoseXxylose

RULE 2: Terminal residues are read from top to bottom & counterclockwise.

The first term describes the non-reducing terminal sugar of the 6-arm antenna
The second term describes the non-reducing terminal sugar of the 3-arm.

RULE 3: Linkage positions of substituents are indicated by superscript numbers and connected by a hyphen.

RULE 4: If more than one terminal residue occurs on one antenna, these residues are put in brackets. Round brackets are used for all branching, but not for antennae.

RULE 5: Bisected GlcNAc is indicated by 'bi' and is always listed as the last extension term

RULE 6: Antennae connected to the same core-mannose residue areput in square brackets. The order within brackets follows the 'counter-clockwise' notion in RULE 1.

RULE 7: Complex terminal structures comprising two or three monosaccharides may be expressed by two letters starting with an L followed by a specification letter:

Lx Lewis X (i.e. Galb4(Fuca3)GlcNAc-)LhBlood group H (i.e. Fuca2Galb-)
La Lewis A (i.e. Fuca4(Galb3)GlcNAc-) Ln LacNac repeat (i.e. Galb4GlcNAcb3-)

LacNAc repeats
The primary LacNAc disaccharide Galβ1-4GlcNAcβ1- that is linked to a mannose can be further elongated by the addition of GlcNAc (in β1-3 linkage to Gal), which usually is followed by the quick addition of Gal to arrive at another Galβ1-4GlcNAcβ1- , or LacNAc unit.

RULE 8: Non-sugar substituents are given by two lower-case characters. The position to which the substituent is linked is given immediately after the term followed by a hyphen.:

me methylacacetylsusulphate
ph phosphate pcphosphocholine pephosphoethanolamine