ID   VKTTI_NAJNA             Reviewed;          57 AA.
AC   P20229;
DT   01-FEB-1991, integrated into UniProtKB/Swiss-Prot.
DT   01-FEB-1991, sequence version 1.
DT   03-AUG-2022, entry version 83.
DE   RecName: Full=Kunitz-type serine protease inhibitor;
DE   AltName: Full=Venom trypsin inhibitor;
OS   Naja naja (Indian cobra).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC   Lepidosauria; Squamata; Bifurcata; Unidentata; Episquamata; Toxicofera;
OC   Serpentes; Colubroidea; Elapidae; Elapinae; Naja.
OX   NCBI_TaxID=35670;
RN   [1]
RP   PROTEIN SEQUENCE, AND FUNCTION.
RC   TISSUE=Venom;
RX   PubMed=1702708; DOI=10.1111/j.1432-1033.1990.tb15622.x;
RA   Shafqat J., Beg O.U., Yin S.-J., Zaidi Z.H., Joernvall H.;
RT   "Primary structure and functional properties of cobra (Naja naja naja)
RT   venom Kunitz-type trypsin inhibitor.";
RL   Eur. J. Biochem. 194:337-341(1990).
CC   -!- FUNCTION: Serine protease inhibitor that inhibits trypsin (Ki=0.0035
CC       nM). {ECO:0000269|PubMed:1702708}.
CC   -!- SUBCELLULAR LOCATION: Secreted.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC   -!- SIMILARITY: Belongs to the venom Kunitz-type family. {ECO:0000305}.
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DR   PIR; S13846; S13846.
DR   AlphaFoldDB; P20229; -.
DR   SMR; P20229; -.
DR   MEROPS; I02.055; -.
DR   Proteomes; UP000694559; 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; 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;
KW   Reference proteome; Secreted; Serine protease inhibitor.
FT   CHAIN           1..57
FT                   /note="Kunitz-type serine protease inhibitor"
FT                   /id="PRO_0000155439"
FT   DOMAIN          5..55
FT                   /note="BPTI/Kunitz inhibitor"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00031"
FT   SITE            15..16
FT                   /note="Reactive bond for trypsin"
FT                   /evidence="ECO:0000250"
FT   DISULFID        5..55
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00031"
FT   DISULFID        14..38
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00031"
FT   DISULFID        30..51
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00031"
SQ   SEQUENCE   57 AA;  6371 MW;  AABFD72949ADC12A CRC64;
     RPGFCELPAA KGLCKAHKPA FYYNKDSHRC QKFIYGGCGG NANRFRTIDE CNRTCVG