Glycan structure and protein-glycosylation research using GlyGen's 5 ToolUniverse
tools: GlyGen_get_glycan, GlyGen_search_glycans, GlyGen_get_glycoprotein,
GlyGen_search_glycoproteins, GlyGen_get_site.
LOOK UP, DON'T GUESS: Glycan composition, mass, and site-level glycosylation data are highly specific and not reliably recalled from memory — always resolve through these tools rather than asserting a glycan's structure or a protein's glycosylation status from general knowledge.
When to Use This Skill
Apply when users ask about:
- A specific glycan's structure, mass, monosaccharide composition, or species
distribution (given a GlyTouCan accession, e.g.
G17689DH) - Finding glycans that match a mass range, monosaccharide-count range, or glycan type (N-linked / O-linked)
- A protein's overall glycosylation profile (site count, site positions, attached glycans, associated diseases/pathways) given a UniProt accession
- Finding glycosylated proteins in an organism, by gene name, or by glycosylation-evidence level
- Detailed information about one specific glycosylation site: exact position, flanking amino-acid sequence, the glycan attached there, and any SNVs co-located at that position
NOT for (route elsewhere):
- Resolving a gene/protein name to its UniProt accession in the first place ->
tooluniverse-sequence-retrievalortooluniverse-protein-structure-retrieval(GlyGen tools require a UniProt accession as input, not a gene symbol, exceptGlyGen_search_glycoproteins'sgene_namefilter) - 3D protein structure ->
tooluniverse-protein-structure-retrieval - Non-glycan post-translational modifications (phosphorylation as a topic in
its own right, ubiquitination, etc.) ->
tooluniverse-protein-modification-analysis - General small-molecule/chemical compound lookup ->
tooluniverse-chemical-compound-retrieval
Tool Chains for Common Questions
"What glycans are attached to protein X?"
- If you only have a gene symbol, resolve it to a UniProt accession first
(
tooluniverse-sequence-retrieval/tooluniverse-protein-structure-retrieval, or pass the gene name straight intoGlyGen_search_glycoproteins'sgene_namefilter if you just need to confirm the protein is glycosylated at all). GlyGen_get_glycoprotein(uniprot_ac=...)— returnsglycosylation_countand aglycosylation_siteslist, each entry givingposition,residue,type(N-linked/O-linked), and theglytoucan_acof the attached glycan.- For full structural detail on any glycan found in step 2, call
GlyGen_get_glycan(glytoucan_ac=...). - For full detail on one specific site (flanking sequence, co-located SNVs),
build a
site_idas<uniprot_ac>.<start_pos>.<end_pos>(the canonical isoform accession from step 2's response usually needs a-1suffix, e.g.P14210-1.294.294— confirm the exact accession format from the glycoprotein response rather than assuming) and callGlyGen_get_site.
"Find glycans matching a mass or composition range"
GlyGen_search_glycans(mass_min=..., mass_max=..., monosaccharide_min=..., monosaccharide_max=..., glycan_type=...)— all filters are optional and combine as AND; omit filters you don't need. Returns a ranked list withhit_score.GlyGen_get_glycan(glytoucan_ac=...)on any hit for full structural detail (composition breakdown, IUPAC/WURCS notation, species).
"Which proteins are glycosylated in organism X / by gene name?"
GlyGen_search_glycoproteins(organism_id=..., gene_name=..., glycosylation_type=..., glycosylation_evidence="reported")—organism_idis an NCBI taxonomy ID (9606 = human, 10090 = mouse, 10029 = Chinese hamster). Returns proteins ranked byhit_scorewith aglycosylation_countper protein.- Drill into any hit with
GlyGen_get_glycoproteinfor the full site list.
Response Shape Notes (observed from live calls, not assumed from schema)
- Every tool wraps its payload as
{"status": "success", "data": {...or [...]}, "metadata": {"source": "GlyGen", "query": ..., "endpoint": ...}}on success, or{"error": "..."}on failure — checkstatus/errorbefore readingdata. GlyGen_get_glycan'sdataincludes a monosaccharide-composition array (each entry hasname,residue,count, and a PubChemcid/url) and abyoniccomposition string (e.g.HexNAc(4)Hex(5)dHex(1)NeuAc(2) % 2368.84091476) in addition to the fields in the JSON schema.GlyGen_get_glycoprotein'sdataincludessequence_length,function,snv_count, andpublication_countalongside the documented fields. Each entry inglycosylation_siteshasposition,residue,type,glytoucan_ac, andsite_category(e.g."reported_with_glycan") — this is the richest per-site summary and is often enough without a follow-upGlyGen_get_sitecall unless you need flanking sequence or SNV detail.GlyGen_search_glycoproteins'smetadataincludestotal_results(may exceed the returned page) andlist_id— usetotal_resultsto know whether to page further withoffset.GlyGen_get_site'sdataincludes aspeciesarray withcommon_name/reference_species, anall_sites_count(other sites reported on the same protein), and acategoriesarray (e.g.["glycosylation_flag", "snv_flag"]) indicating what kinds of annotations exist at that position.
See references/glygen_tool_reference.md for the full parameter table and
captured example responses for all 5 tools.
Output
State the GlyTouCan/UniProt accessions used, the resolved values (mass, site positions, etc.), and cite GlyGen as the source. Do not report a glycan composition or site position that wasn't actually returned by a tool call.