glycoengineering

name	glycoengineering
description	Analyze and engineer protein glycosylation. Scan sequences for N-glycosylation sequons (N-X-S/T), predict O-glycosylation hotspots, and access curated glycoengineering tools (NetOGlyc, GlycoShield, GlycoWorkbench). For glycoprotein engineering, therapeutic antibody optimization, and vaccine design.
license	Unknown
tags	["scientific-skills","glycoengineering","experimental-design","performance"]
metadata	{"skill-author":"Kuan-lin Huang"}

|----------|-------| | Enhance ADCC | Defucosylation at Fc Asn297 | Afucosylated IgG1 has ~50× better FcγRIIIa binding | | Reduce immunogenicity | Remove non-human glycans | Eliminate α-Gal, NGNA epitopes | | Improve PK half-life | Sialylation | Sialylated glycans extend half-life | | Reduce inflammation | Hypersialylation | IVIG anti-inflammatory mechanism | | Create glycan shield | Add N-glycosites to surface | Masks vulnerable epitopes (vaccine design) |

Common Mutations Used

Mutation	Effect
N297A/Q (IgG1)	Removes Fc glycosylation (aglycosyl)
N297D (IgG1)	Removes Fc glycosylation
S298A/E333A/K334A	Increases FcγRIIIa binding
F243L (IgG1)	Increases defucosylation
T299A	Removes Fc glycosylation

Glycan Notation

IUPAC Condensed Notation (Monosaccharide abbreviations)

Symbol	Full Name	Type
Glc	Glucose	Hexose
GlcNAc	N-Acetylglucosamine	HexNAc
Man	Mannose	Hexose
Gal	Galactose	Hexose
Fuc	Fucose	Deoxyhexose
Neu5Ac	N-Acetylneuraminic acid (Sialic acid)	Sialic acid
GalNAc	N-Acetylgalactosamine	HexNAc

Complex N-Glycan Structure

Typical complex biantennary N-glycan:
Neu5Ac-Gal-GlcNAc-Man\
                       Man-GlcNAc-GlcNAc-[Asn]
Neu5Ac-Gal-GlcNAc-Man/
(±Core Fuc at innermost GlcNAc)

Best Practices

• Start with NetNGlyc/NetOGlyc for computational prediction before experimental validation
• Verify with mass spectrometry: Glycoproteomics (Byonic, Mascot) for site-specific glycan profiling
• Consider site context: Not all predicted sequons are actually glycosylated (accessibility, cell type, protein conformation)
• For antibodies: Fc N297 glycan is critical — always characterize this site first
• Use GlyConnect to check if your protein of interest has experimentally verified glycosylation data

Additional Resources

• GlyTouCan (glycan structure repository): https://glytoucan.org/
• GlyConnect: https://glyconnect.expasy.org/
• CFG Functional Glycomics: http://www.functionalglycomics.org/
• DTU Health Tech servers (NetNGlyc, NetOGlyc): https://services.healthtech.dtu.dk/
• GlycoWorkbench: https://glycoworkbench.software.informer.com/
• Review: Apweiler R et al. (1999) Biochim Biophys Acta. PMID: 10564035
• Therapeutic glycoengineering review: Jefferis R (2009) Nature Reviews Drug Discovery. PMID: 19448661