ID   CI2S_ARAAG              Reviewed;          94 AA.
AC   C0HLT8;
DT   02-JUN-2021, integrated into UniProtKB/Swiss-Prot.
DT   02-JUN-2021, sequence version 1.
DT   25-MAY-2022, entry version 4.
DE   RecName: Full=2S albumin-like cysteine protease inhibitor {ECO:0000305|PubMed:33266031};
DE            Short=AaCI-2S {ECO:0000303|PubMed:33266031};
DE   Flags: Fragments;
OS   Araucaria angustifolia (Brazilian pine tree).
OC   Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC   Spermatophyta; Pinopsida; Pinidae; Conifers II; Araucariales;
OC   Araucariaceae; Araucaria.
OX   NCBI_TaxID=56992 {ECO:0000303|PubMed:33266031};
RN   [1]
RP   PROTEIN SEQUENCE, FUNCTION, BIOPHYSICOCHEMICAL PROPERTIES, AND TISSUE
RP   SPECIFICITY.
RC   TISSUE=Seed {ECO:0000303|PubMed:33266031};
RX   PubMed=33266031; DOI=10.3390/plants9121676;
RA   Sallai R.C., Salu B.R., Silva-Lucca R.A., Alves F.L., Napoleao T.H.,
RA   Paiva P.M.G., da Silva Ferreira R., Sampaio M.U., Vilela Oliva M.L.;
RT   "Biotechnological Potential of Araucaria angustifolia Pine Nuts Extract and
RT   the Cysteine Protease Inhibitor AaCI-2S.";
RL   Plants (Basel) 9:0-0(2020).
CC   -!- FUNCTION: Cysteine protease inhibitor that likely functions in defense
CC       against insects by inhibiting cysteine proteases in the midgut of
CC       herbivore insects such as C.maculatus (PubMed:33266031). Selectively
CC       inhibits cathepsin L, as well as papain, ficin and bromelain with lower
CC       efficiency (PubMed:33266031). Shows antitumor activity, inhibiting the
CC       growth of prostate cancer cell lines PC3 and DU145, and the gastric
CC       cancer cell line Hs746T (PubMed:33266031). No activity against
CC       cathepsin B or serine proteases (trypsin, human plasma kallikrein and
CC       elastase) (PubMed:33266031). {ECO:0000269|PubMed:33266031}.
CC   -!- BIOPHYSICOCHEMICAL PROPERTIES:
CC       pH dependence:
CC         Optimum pH is around 6. Stable from pH 2 to 10.
CC         {ECO:0000269|PubMed:33266031};
CC       Temperature dependence:
CC         Thermostable. Active from 25 to 100 degrees Celsius. Retains 80% of
CC         its maximal activity after heating for 2 hours at 100 degrees and
CC         retains around 30% of its maximal activity after heating for 4 hours
CC         at 100 degrees. {ECO:0000269|PubMed:33266031};
CC   -!- TISSUE SPECIFICITY: Expressed in seeds (at protein level).
CC       {ECO:0000269|PubMed:33266031}.
CC   -!- SIMILARITY: Belongs to the 2S seed storage albumins family.
CC       {ECO:0000305}.
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DR   AlphaFoldDB; C0HLT8; -.
DR   SMR; C0HLT8; -.
DR   GO; GO:0004869; F:cysteine-type endopeptidase inhibitor activity; IDA:UniProtKB.
DR   GO; GO:0002213; P:defense response to insect; IDA:UniProtKB.
DR   GO; GO:0010951; P:negative regulation of endopeptidase activity; IDA:UniProtKB.
DR   CDD; cd00261; AAI_SS; 1.
DR   Gene3D; 1.10.110.10; -; 1.
DR   InterPro; IPR044723; AAI_SS_dom.
DR   InterPro; IPR036312; Bifun_inhib/LTP/seed_sf.
DR   InterPro; IPR016140; Bifunc_inhib/LTP/seed_store.
DR   Pfam; PF00234; Tryp_alpha_amyl; 1.
DR   SMART; SM00499; AAI; 1.
DR   SUPFAM; SSF47699; SSF47699; 1.
PE   1: Evidence at protein level;
KW   Direct protein sequencing; Disulfide bond; Protease inhibitor.
FT   CHAIN           1..94
FT                   /note="2S albumin-like cysteine protease inhibitor"
FT                   /id="PRO_0000452814"
FT   DISULFID        12..35
FT                   /note="Interchain (between small and large chains)"
FT                   /evidence="ECO:0000250|UniProtKB:P04403"
FT   DISULFID        36..82
FT                   /evidence="ECO:0000250|UniProtKB:P04403"
FT   DISULFID        48..89
FT                   /evidence="ECO:0000250|UniProtKB:P04403"
FT   NON_CONS        23..24
FT                   /evidence="ECO:0000303|PubMed:33266031"
FT   NON_CONS        61..62
FT                   /evidence="ECO:0000303|PubMed:33266031"
FT   NON_TER         1
FT                   /evidence="ECO:0000303|PubMed:33266031"
FT   NON_TER         94
FT                   /evidence="ECO:0000303|PubMed:33266031"
SQ   SEQUENCE   94 AA;  11012 MW;  09690E53C3B35F73 CRC64;
     ERRCDPRRLS DCEDFVRGRS KGGRGEKECR LSERCCTELQ KMPRECRCEA VEGMYKEAER
     KERGEGEQRQ RLERARALPG LCSIEPSYCE IRPS