ID   ITR2_OPUST              Reviewed;          38 AA.
AC   P86388;
DT   24-NOV-2009, integrated into UniProtKB/Swiss-Prot.
DT   24-NOV-2009, sequence version 1.
DT   25-MAY-2022, entry version 14.
DE   RecName: Full=Trypsin inhibitor 2 {ECO:0000303|PubMed:19765785};
DE            Short=OsTI 2 {ECO:0000303|PubMed:19765785};
OS   Opuntia streptacantha (Prickly pear cactus) (Opuntia cardona).
OC   Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC   Spermatophyta; Magnoliopsida; eudicotyledons; Gunneridae; Pentapetalae;
OC   Caryophyllales; Cactineae; Cactaceae; Opuntioideae; Opuntia.
OX   NCBI_TaxID=393608;
RN   [1] {ECO:0000305}
RP   PROTEIN SEQUENCE, FUNCTION, BIOPHYSICOCHEMICAL PROPERTIES, DISULFIDE BONDS,
RP   MASS SPECTROMETRY, AND PYROGLUTAMATE FORMATION AT GLN-1.
RC   TISSUE=Seed {ECO:0000269|PubMed:19765785};
RX   PubMed=19765785; DOI=10.1016/j.phytochem.2009.08.009;
RA   Torres-Castillo J.A., Mondragon Jacobo C., Blanco-Labra A.;
RT   "Characterization of a highly stable trypsin-like proteinase inhibitor from
RT   the seeds of Opuntia streptacantha (O. streptacantha Lemaire).";
RL   Phytochemistry 70:1374-1381(2009).
CC   -!- FUNCTION: Inhibits trypsin-like proteases from the guts of the insect
CC       pests P.truncatus, P.americana, Acheta sp and Gryllus sp.
CC       {ECO:0000269|PubMed:19765785}.
CC   -!- BIOPHYSICOCHEMICAL PROPERTIES:
CC       pH dependence:
CC         Optimum pH is 8.0. Alkaline pH values decrease the thermostability of
CC         this inhibitor. {ECO:0000269|PubMed:19765785};
CC       Temperature dependence:
CC         Thermostable. 10% inactivation is seen after incubation at 95 degrees
CC         Celsius for 2 hours at pH 9.0. Retains activity after incubation at
CC         120 degrees Celsius for 1 hour at pH 3.0 and pH 7.0, but at pH 9.0
CC         40% of the activity is lost. {ECO:0000269|PubMed:19765785};
CC   -!- PTM: Contains disulfide bonds. {ECO:0000269|PubMed:19765785}.
CC   -!- MASS SPECTROMETRY: Mass=4190; Method=MALDI;
CC       Evidence={ECO:0000269|PubMed:19765785};
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DR   AlphaFoldDB; P86388; -.
DR   GO; GO:0004867; F:serine-type endopeptidase inhibitor activity; IEA:UniProtKB-KW.
PE   1: Evidence at protein level;
KW   Direct protein sequencing; Disulfide bond; Protease inhibitor;
KW   Pyrrolidone carboxylic acid; Serine protease inhibitor.
FT   CHAIN           1..38
FT                   /note="Trypsin inhibitor 2"
FT                   /id="PRO_0000389518"
FT   MOD_RES         1
FT                   /note="Pyrrolidone carboxylic acid"
FT                   /evidence="ECO:0000269|PubMed:19765785"
FT   UNSURE          2
FT                   /note="Q or K"
FT                   /evidence="ECO:0000269|PubMed:19765785"
FT   UNSURE          8
FT                   /note="Q or K"
FT                   /evidence="ECO:0000269|PubMed:19765785"
FT   UNSURE          26
FT                   /note="Q or K"
FT                   /evidence="ECO:0000269|PubMed:19765785"
SQ   SEQUENCE   38 AA;  4192 MW;  CD88A180D97E2821 CRC64;
     QQCAERGQSC NPYEGIECCG DILCIQPRIW PPVPGRCA