identifier: traitmech:000158
label: trypsin activity
definition: A physiological enzyme-activity phenotype in which a cell exhibits trypsin-like
  serine endopeptidase activity, preferentially cleaving peptide bonds on the carboxyl
  side of arginine or lysine residues.
definition_source: https://iubmb.qmul.ac.uk/enzyme/EC3/4/21/4.html
trait_category: PHYSIOLOGY
term_kind: CLASS
mapping_status: PROPOSED
parent_traits:
- METPO:1000059
synonyms:
- synonym_text: trypsin
  synonym_type: RELATED_SYNONYM
  source: https://iubmb.qmul.ac.uk/enzyme/EC3/4/21/4.html
evidence:
- reference: https://iubmb.qmul.ac.uk/enzyme/EC3/4/21/4.html
  snippet: '<b>Reaction:</b> Preferential cleavage: Arg<img src="../../../EZgif/FISS.GIF"
    align=top>, Lys<img src="../../../EZgif/FISS.GIF" align=top>'
  notes: The NC-IUBMB EC 3.4.21.4 entry accepts the name trypsin and its reaction
    line places the scissile-bond FISS.GIF image immediately after Arg and Lys.
- reference: https://iubmb.qmul.ac.uk/enzyme/EC3/4/21/4.html
  snippet: Isolated as multiple cationic and anionic trypsins [5] from the pancreas
    of many vertebrates and from lower species including crayfish, insects (cocoonase)
    and microorganisms
  notes: The NC-IUBMB EC 3.4.21.4 comments note that trypsins have also been isolated
    from microorganisms.
- reference: DOI:10.1371/journal.pone.0322500
  snippet: Enzyme activities of acid- and alkaline-phosphatases, esterase, esterase
    lipase, leucine arylamidase, trypsin, naphthol-AS-BI phosphohydrolase, and alpha-glucosidase
    are present when assayed with API ZYM system.
  notes: Park et al. treated trypsin as a positive API ZYM enzyme-activity phenotype
    in the Flexibacterium corallicola type species description.
canonical_examples:
- taxon_id: NCBITaxon:3037259
  taxon_label: Flexibacterium corallicola
  note: Park et al. reported Flexibacterium corallicola as positive for trypsin activity
    in the API ZYM enzyme activity panel.
  reference: DOI:10.1371/journal.pone.0322500
discussions:
- discussion_id: trypsin-activity-xref-gap
  prompt: Resolve an exact external ontology class for trypsin activity before adding
    a TraitRecord xref.
  kind: CURATION_TODO
  status: OPEN
  rationale: GO:0004295 trypsin activity is obsolete, and its replacement GO:0004252
    denotes broader serine-type endopeptidase molecular function rather than the organism-level
    trypsin-like serine endopeptidase phenotype. GO:0004252 is appropriate as a causal-node
    grounding for generic serine endopeptidase activity, not as an equivalent TraitRecord
    xref.
  posed_by: codex
  posed_date: '2026-09-12'
curation_history:
- timestamp: '2026-09-12T04:36:25Z'
  curator: codex
  action: MINTED_TRAITMECH_ID
  changes: Minted trypsin activity as a URL/DOI-backed TraitRecord after a repository-wide
    duplicate review covering ignored and hidden files; METPO has no exact trypsin
    activity class yet.
  llm_assisted: true
- timestamp: '2026-09-12T05:47:58Z'
  curator: codex
  action: CORRECTED_EVIDENCE_SNIPPET
  changes: Corrected the IUBMB reaction-line snippet for trypsin activity so it preserves
    the scissile-bond image tags from the source HTML (#819).
  llm_assisted: true
- timestamp: '2026-09-12T06:00:57Z'
  curator: codex
  action: TIGHTENED_DEFINITION_WORDING
  changes: Tightened the trypsin activity definition to describe a trypsin-like organismal
    phenotype instead of over-specifying production of the named vertebrate enzyme
    (#820).
  llm_assisted: true