ID   ITR2_MOMCH              Reviewed;          28 AA.
AC   P10295;
DT   01-JUL-1989, integrated into UniProtKB/Swiss-Prot.
DT   01-JUL-1989, sequence version 1.
DT   24-JAN-2024, entry version 108.
DE   RecName: Full=Trypsin inhibitor 2;
DE   AltName: Full=MCTI-A;
DE   AltName: Full=MCTI-II;
DE   AltName: Full=Trypsin inhibitor II;
OS   Momordica charantia (Bitter gourd) (Balsam pear).
OC   Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC   Spermatophyta; Magnoliopsida; eudicotyledons; Gunneridae; Pentapetalae;
OC   rosids; fabids; Cucurbitales; Cucurbitaceae; Momordiceae; Momordica.
OX   NCBI_TaxID=3673;
RN   [1]
RP   PROTEIN SEQUENCE, DOMAIN, AND DISULFIDE BONDS.
RC   TISSUE=Seed;
RX   PubMed=2738047; DOI=10.1093/oxfordjournals.jbchem.a122625;
RA   Hara S., Makino J., Ikenaka T.;
RT   "Amino acid sequences and disulfide bridges of serine proteinase inhibitors
RT   from bitter gourd (Momordica charantia LINN.) seeds.";
RL   J. Biochem. 105:88-92(1989).
RN   [2]
RP   X-RAY CRYSTALLOGRAPHY (1.6 ANGSTROMS).
RX   PubMed=8445634; DOI=10.1006/jmbi.1993.1102;
RA   Huang Q., Liu S., Tang Y.;
RT   "Refined 1.6-A resolution crystal structure of the complex formed between
RT   porcine beta-trypsin and MCTI-A, a trypsin inhibitor of the squash family.
RT   Detailed comparison with bovine beta-trypsin and its complex.";
RL   J. Mol. Biol. 229:1022-1036(1993).
RN   [3]
RP   X-RAY CRYSTALLOGRAPHY (1.6 ANGSTROMS).
RX   PubMed=1551419; DOI=10.1016/0014-5793(92)80346-i;
RA   Huang Q., Liu S., Tang Y., Zeng F., Qian R.;
RT   "Amino acid sequencing of a trypsin inhibitor by refined 1.6 A X-ray
RT   crystal structure of its complex with porcine beta-trypsin.";
RL   FEBS Lett. 297:143-146(1992).
CC   -!- FUNCTION: Inhibits trypsin.
CC   -!- SUBCELLULAR LOCATION: Secreted.
CC   -!- DOMAIN: The presence of a 'disulfide through disulfide knot'
CC       structurally defines this protein as a knottin.
CC       {ECO:0000269|PubMed:2738047}.
CC   -!- SIMILARITY: Belongs to the protease inhibitor I7 (squash-type serine
CC       protease inhibitor) family. {ECO:0000305}.
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DR   PIR; JC2507; JC2507.
DR   PIR; JX0058; JX0058.
DR   PDB; 1F2S; X-ray; 1.79 A; I=1-28.
DR   PDBsum; 1F2S; -.
DR   AlphaFoldDB; P10295; -.
DR   SMR; P10295; -.
DR   MINT; P10295; -.
DR   MEROPS; I07.008; -.
DR   EvolutionaryTrace; P10295; -.
DR   Proteomes; UP000504603; Unplaced.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0004867; F:serine-type endopeptidase inhibitor activity; IEA:UniProtKB-KW.
DR   CDD; cd00150; PlantTI; 1.
DR   Gene3D; 4.10.75.20; -; 1.
DR   InterPro; IPR000737; Prot_inh_squash.
DR   InterPro; IPR011052; Proteinase_amylase_inhib_sf.
DR   Pfam; PF00299; Squash; 1.
DR   PRINTS; PR00293; SQUASHINHBTR.
DR   SMART; SM00286; PTI; 1.
DR   SUPFAM; SSF57027; Plant inhibitors of proteinases and amylases; 1.
DR   PROSITE; PS00286; SQUASH_INHIBITOR; 1.
PE   1: Evidence at protein level;
KW   3D-structure; Direct protein sequencing; Disulfide bond; Knottin;
KW   Protease inhibitor; Reference proteome; Secreted;
KW   Serine protease inhibitor.
FT   PEPTIDE         1..28
FT                   /note="Trypsin inhibitor 2"
FT                   /id="PRO_0000044387"
FT   SITE            5..6
FT                   /note="Reactive bond"
FT   DISULFID        3..20
FT                   /evidence="ECO:0000269|PubMed:2738047"
FT   DISULFID        10..22
FT                   /evidence="ECO:0000269|PubMed:2738047"
FT   DISULFID        16..27
FT                   /evidence="ECO:0000269|PubMed:2738047"
FT   HELIX           13..15
FT                   /evidence="ECO:0007829|PDB:1F2S"
SQ   SEQUENCE   28 AA;  3230 MW;  67E263D36974FEDF CRC64;
     RICPRIWMEC KRDSDCMAQC ICVDGHCG
//