ID   API8_SOLTU              Reviewed;         220 AA.
AC   P17979;
DT   01-NOV-1990, integrated into UniProtKB/Swiss-Prot.
DT   01-NOV-1990, sequence version 1.
DT   03-AUG-2022, entry version 93.
DE   RecName: Full=Aspartic protease inhibitor 8;
DE            Short=API;
DE            Short=API-8;
DE            Short=PI-8;
DE            Short=pi8;
DE   AltName: Full=Cathepsin D inhibitor;
DE   Flags: Precursor;
OS   Solanum tuberosum (Potato).
OC   Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC   Spermatophyta; Magnoliopsida; eudicotyledons; Gunneridae; Pentapetalae;
OC   asterids; lamiids; Solanales; Solanaceae; Solanoideae; Solaneae; Solanum.
OX   NCBI_TaxID=4113;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RC   STRAIN=cv. Ulster Prince; TISSUE=Tuber;
RX   PubMed=2201952; DOI=10.1093/nar/18.15.4605;
RA   Strukelj B., Pungercar J., Ritonja A., Krizaj I., Gubensek F., Kregar I.,
RA   Turk V.;
RT   "Nucleotide and deduced amino acid sequence of an aspartic proteinase
RT   inhibitor homologue from potato tubers (Solanum tuberosum L.).";
RL   Nucleic Acids Res. 18:4605-4605(1990).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RC   STRAIN=cv. Pentland squire; TISSUE=Tuber;
RX   PubMed=1515078; DOI=10.1515/bchm3.1992.373.2.477;
RA   Strukelj B., Pungercar J., Mesko P., Barlic-Maganja D., Gubensek F.,
RA   Kregar I., Turk V.;
RT   "Characterization of aspartic proteinase inhibitors from potato at the
RT   gene, cDNA and protein levels.";
RL   Biol. Chem. Hoppe-Seyler 373:477-482(1992).
CC   -!- FUNCTION: Inhibitor of cathepsin D (aspartic protease) and trypsin
CC       (serine protease). May protect the plant by inhibiting proteases of
CC       invading organisms.
CC   -!- SUBCELLULAR LOCATION: Vacuole {ECO:0000250}.
CC   -!- SIMILARITY: Belongs to the protease inhibitor I3 (leguminous Kunitz-
CC       type inhibitor) family. {ECO:0000305}.
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DR   EMBL; X53470; CAA37566.1; -; mRNA.
DR   PIR; S10721; S10721.
DR   PIR; S10979; XKPOD.
DR   AlphaFoldDB; P17979; -.
DR   SMR; P17979; -.
DR   STRING; 4113.PGSC0003DMT400024598; -.
DR   MEROPS; I03.002; -.
DR   PRIDE; P17979; -.
DR   Proteomes; UP000011115; Unassembled WGS sequence.
DR   ExpressionAtlas; P17979; baseline.
DR   GO; GO:0005773; C:vacuole; IEA:UniProtKB-SubCell.
DR   GO; GO:0019828; F:aspartic-type endopeptidase inhibitor activity; IEA:UniProtKB-KW.
DR   GO; GO:0004867; F:serine-type endopeptidase inhibitor activity; IEA:UniProtKB-KW.
DR   CDD; cd00178; STI; 1.
DR   InterPro; IPR011065; Kunitz_inhibitor_STI-like_sf.
DR   InterPro; IPR002160; Prot_inh_Kunz-lg.
DR   PANTHER; PTHR33107; PTHR33107; 1.
DR   Pfam; PF00197; Kunitz_legume; 1.
DR   PRINTS; PR00291; KUNITZINHBTR.
DR   SMART; SM00452; STI; 1.
DR   SUPFAM; SSF50386; SSF50386; 1.
DR   PROSITE; PS00283; SOYBEAN_KUNITZ; 1.
PE   2: Evidence at transcript level;
KW   Aspartic protease inhibitor; Disulfide bond; Protease inhibitor;
KW   Reference proteome; Serine protease inhibitor; Signal; Vacuole.
FT   SIGNAL          1..23
FT                   /evidence="ECO:0000250"
FT   PROPEP          24..32
FT                   /evidence="ECO:0000250"
FT                   /id="PRO_0000016920"
FT   CHAIN           33..220
FT                   /note="Aspartic protease inhibitor 8"
FT                   /id="PRO_0000016921"
FT   SITE            99..100
FT                   /note="Reactive bond for trypsin"
FT                   /evidence="ECO:0000250"
FT   SITE            143..144
FT                   /note="Reactive bond for chymotrypsin"
FT                   /evidence="ECO:0000250"
FT   DISULFID        80..125
FT                   /evidence="ECO:0000250"
FT   DISULFID        174..185
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   220 AA;  24190 MW;  CE2A118C44025782 CRC64;
     MMKCLFLLCL CLLPIVVFSS TFTSQNLIDL PSESPLPKPV LDTNGKELNP DSSYRIISIG
     RGALGGDVYL GKSPNSDAPC PDGVFRYNSD VGPSGTPVRF IPLSGGIFED QLLNIQFNIP
     TVKLCVSYTI WKVGNLNAYF RTMLLETGGT IGQADSSYFK IVKLSNFGYN LLYCPITPPF
     LCPFCRDDNF CAKVGVVIQN GKRRLALVNE NPLDVLFQEV