ID   IBPI_TACTR              Reviewed;          61 AA.
AC   P16044;
DT   01-APR-1990, integrated into UniProtKB/Swiss-Prot.
DT   01-APR-1990, sequence version 1.
DT   03-AUG-2022, entry version 81.
DE   RecName: Full=Proteinase inhibitor;
DE   AltName: Full=BPI-type;
OS   Tachypleus tridentatus (Japanese horseshoe crab).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Merostomata;
OC   Xiphosura; Limulidae; Tachypleus.
OX   NCBI_TaxID=6853;
RN   [1]
RP   PROTEIN SEQUENCE.
RC   TISSUE=Hemocyte;
RX   PubMed=3308864; DOI=10.1093/oxfordjournals.jbchem.a121994;
RA   Nakamura T., Hirai T., Tokunaga F., Kawabata S., Iwanaga S.;
RT   "Purification and amino acid sequence of Kunitz-type protease inhibitor
RT   found in the hemocytes of horseshoe crab (Tachypleus tridentatus).";
RL   J. Biochem. 101:1297-1306(1987).
CC   -!- FUNCTION: Inhibitor of trypsin and chymotrypsin.
CC   -!- SUBCELLULAR LOCATION: Secreted.
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DR   PIR; A26923; TIHCBP.
DR   AlphaFoldDB; P16044; -.
DR   SMR; P16044; -.
DR   MEROPS; I02.017; -.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0004867; F:serine-type endopeptidase inhibitor activity; IEA:UniProtKB-KW.
DR   GO; GO:0044562; P:envenomation resulting in negative regulation of voltage-gated potassium channel activity in another organism; IEA:UniProt.
DR   CDD; cd00109; KU; 1.
DR   Gene3D; 4.10.410.10; -; 1.
DR   InterPro; IPR002223; Kunitz_BPTI.
DR   InterPro; IPR036880; Kunitz_BPTI_sf.
DR   InterPro; IPR020901; Prtase_inh_Kunz-CS.
DR   Pfam; PF00014; Kunitz_BPTI; 1.
DR   PRINTS; PR00759; BASICPTASE.
DR   SMART; SM00131; KU; 1.
DR   SUPFAM; SSF57362; SSF57362; 1.
DR   PROSITE; PS00280; BPTI_KUNITZ_1; 1.
DR   PROSITE; PS50279; BPTI_KUNITZ_2; 1.
PE   1: Evidence at protein level;
KW   Direct protein sequencing; Disulfide bond; Protease inhibitor; Secreted;
KW   Serine protease inhibitor.
FT   CHAIN           1..61
FT                   /note="Proteinase inhibitor"
FT                   /id="PRO_0000155411"
FT   DOMAIN          8..58
FT                   /note="BPTI/Kunitz inhibitor"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00031"
FT   SITE            18..19
FT                   /note="Reactive bond"
FT                   /evidence="ECO:0000250"
FT   DISULFID        8..58
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00031"
FT   DISULFID        17..41
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00031"
FT   DISULFID        33..54
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00031"
SQ   SEQUENCE   61 AA;  6825 MW;  730E82CDD0653E48 CRC64;
     TERGFLDCTS PPVTGPCRAG FKRYNYNTRT KQCEPFKYGG CKGNGNRYKS EQDCLDACSG
     F