Der p 23, a major house dust mite allergen associated with the peritrophic matrix of mite faecal pellets. It contains a peritrophin-A-type (ChtBD2) chitin-binding domain fold, but direct assays found no chitin binding in vitro, so its molecular function is unresolved. Despite its small size and minor abundance it is a major allergen, recognized by IgE in a large fraction of dust-mite-allergic patients.
The preferred accession for this review is L7N6F8. These relationships are manually assessed.
REFERENCE PROTEOME CANDIDATE · Reviewed 2026-10-19
Reference proteome: UP000887458
Retain L7N6F8 as the primary Swiss-Prot accession. The leading small chitin-binding protein is a plausible Der p 23 counterpart, but global identity is 75.51% with substitutions and indels. Other chitin-binding proteins are present, and no shared source/target locus cross-reference establishes identity. Retain a candidate pending genomic mapping and gene-model assessment.
MMseqs2 searched 14,675 sequences across UP000887458 at E <= 1e-5 and sensitivity 7.5, returning 4 hits. Every returned sequence was globally aligned using BLOSUM62 with gap-open -10 and extension -0.5. Scores and sequences for all 4 returned candidates are retained, with 4 detailed alignment files. The heuristic search does not establish genomic absence or unique locus identity.
file:DERPT/Derp23/Derp23-record-evidence.yaml
target_sequence_count: 14675
file:DERPT/Derp23/Derp23-record-evidence.yaml
candidate_count: 4
A0ABQ8JBE4: 74 identities across 98 global-alignment columns (75.5102% identity including gaps), 9 substitutions and 15 gap columns. Query coverage is 92.2222%; target coverage is 91.2088%. Sequence similarity is interpreted in the manual rationale. Identity over paired residues is 89.1566% (74/83); gap columns are excluded from this denominator.
file:DERPT/Derp23/Derp23-record-evidence.yaml
query_length: 90 target_length: 91 alignment_columns: 98 identities: 74 mismatches: 9 gap_columns: 15 identity_percent: 75.5102 query_coverage_percent: 92.2222 target_coverage_percent: 91.2088
The primary accession is outside every searched exact-taxon reference proteome. Current UniProt records place A0ABQ8JBE4 in UP000887458 and give it the same taxon as the primary.
file:DERPT/Derp23/Derp23-record-evidence.yaml
primary_in_any_reference_proteome: false
file:DERPT/Derp23/Derp23-record-evidence.yaml
alternative_in_reference_proteome: true
file:DERPT/Derp23/Derp23-record-evidence.yaml
same_taxon: true
Sampled UniSave observations: 09-DEC-2015, entry version 10.: no Proteomes cross-reference; 17-JUN-2020, entry version 26.: no Proteomes cross-reference; 24-JUL-2024, entry version 33.: UP000515146. These dated observations do not establish uninterrupted membership/absence, the exact change date, or UniProt's motivation.
file:DERPT/Derp23/Derp23-record-evidence.yaml
entry_date: 09-DEC-2015, entry version 10. proteomes: []
file:DERPT/Derp23/Derp23-record-evidence.yaml
entry_date: 17-JUN-2020, entry version 26. proteomes: []
file:DERPT/Derp23/Derp23-record-evidence.yaml
entry_date: 24-JUL-2024, entry version 33. proteomes: - UP000515146
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0005576 extracellular region | IEA GO_REF:0000120 | ACCEPT | Summary: Der p 23 is secreted/excreted with mite faecal pellets (peritrophic matrix); extracellular localization is correct. Reason: Excreted allergen of the faecal-pellet peritrophic matrix. |
| GO:0005783 endoplasmic reticulum | IEA GO_REF:0000044 | KEEP AS NON CORE | Summary: ER localization reflects the secretory route in mite gut cells. Reason: Biosynthetic/secretory-route compartment; not the functional site. |
| GO:0031410 cytoplasmic vesicle | IEA GO_REF:0000044 | KEEP AS NON CORE | Summary: Vesicular localization reflects the secretory route. Reason: Secretory-route compartment; not the functional site. |
| GO:0005576 extracellular region | IDA PMID:23460742 Identification of Der p 23, a peritrophin-like protein, as a... | ACCEPT | Summary: Der p 23 was experimentally localized to the peritrophic matrix of mite faecal pellets (excreted). Reason: Experimental support for extracellular/excreted localization. Supporting Evidence: PMID:23460742 peritrophic matrix of mite fecal pellets |
| GO:0008061 chitin binding | IDA NOT PMID:26602749 Serological, genomic and structural analyses of the major mi... | ACCEPT | Summary: This is a NOT (negated) annotation: GOA records that Der p 23 does NOT bind chitin. Despite its peritrophin-A (ChtBD2) chitin-binding-domain fold, direct assays (PMID:26602749) found no chitin binding in vitro, as also stated in UniProt. The negation is correct and informative. Reason: The negated annotation accurately captures the experimental finding that Der p 23 lacks chitin-binding activity in vitro; it correctly prevents domain-based over-annotation of chitin binding. Supporting Evidence: file:DERPT/Derp23/Derp23-uniprot.txt Does not bind chitin in vitro. |
| GO:0019863 IgE binding | IMP PMID:24733847 Conversion of Der p 23, a new major house dust mite allergen... | KEEP AS NON CORE | Summary: Der p 23 binds IgE (basis of its allergenicity and hypoallergen-vaccine design); this reflects allergenicity toward humans, not its endogenous mite function. Reason: Allergen/IgE-reactivity property, not the protein's endogenous molecular function. |
| GO:0031410 cytoplasmic vesicle | IDA PMID:23460742 Identification of Der p 23, a peritrophin-like protein, as a... | KEEP AS NON CORE | Summary: Experimental vesicular localization consistent with the secretory route. Reason: Secretory-route compartment; not the functional site. |
| GO:0005783 endoplasmic reticulum | IDA PMID:23460742 Identification of Der p 23, a peritrophin-like protein, as a... | KEEP AS NON CORE | Summary: Experimental ER localization consistent with the secretory route. Reason: Biosynthetic/secretory-route compartment; not the functional site. |
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Download this section (compressed HTML)Q: If Der p 23 does not bind chitin, what is the endogenous ligand/function of its peritrophin-A domain in the mite peritrophic matrix?
Experiment: Screen recombinant Der p 23 for binding to peritrophic-matrix glycans/glycoproteins by pull-down and glycan-array assays.
Hypothesis: Der p 23's peritrophin domain binds a peritrophic-matrix component other than chitin (e.g. a glycoprotein or glycan).
Type: ligand identification / binding assay
Der p 23, major mite allergen of faecal-pellet peritrophic matrix. Chitin binding is a NOT (negated) GOA annotation -> ACCEPT negation (does NOT bind chitin in vitro PMID:26602749) despite peritrophin-A domain. IgE binding KEEP_AS_NON_CORE. Function gap: true ligand/activity unknown.
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