ID   IP2B_SOLTU              Reviewed;          40 AA.
AC   P01082;
DT   21-JUL-1986, integrated into UniProtKB/Swiss-Prot.
DT   21-JUL-1986, sequence version 1.
DT   25-MAY-2022, entry version 68.
DE   RecName: Full=Proteinase inhibitor IIB;
DE   Flags: Fragments;
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   PROTEIN SEQUENCE.
RX   PubMed=924994; DOI=10.1093/oxfordjournals.jbchem.a131804;
RA   Iwasaki T., Wada J., Kiyohara T., Yoshikawa M.;
RT   "Amino acid sequence of an active fragment of potato proteinase inhibitor
RT   IIb.";
RL   J. Biochem. 82:991-1004(1977).
CC   -!- FUNCTION: Inhibits chymotrypsin and subtilisin strongly.
CC   -!- SUBCELLULAR LOCATION: Secreted.
CC   -!- SIMILARITY: Belongs to the protease inhibitor I20 (potato type II
CC       proteinase inhibitor) family. {ECO:0000305}.
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DR   PIR; A01321; XKPO2B.
DR   AlphaFoldDB; P01082; -.
DR   SMR; P01082; -.
DR   MEROPS; I20.001; -.
DR   Proteomes; UP000011115; Unassembled WGS sequence.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
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   Reference proteome; Secreted; Serine protease inhibitor.
FT   CHAIN           <1..>40
FT                   /note="Proteinase inhibitor IIB"
FT                   /id="PRO_0000217676"
FT   SITE            26..27
FT                   /note="Reactive bond"
FT   DISULFID        2..16
FT                   /evidence="ECO:0000269|PubMed:924994"
FT   DISULFID        6..28
FT                   /evidence="ECO:0000269|PubMed:924994"
FT   DISULFID        12..38
FT                   /evidence="ECO:0000269|PubMed:924994"
FT   NON_CONS        14..15
FT                   /evidence="ECO:0000305"
FT   NON_TER         1
FT   NON_TER         40
SQ   SEQUENCE   40 AA;  4412 MW;  AC00F5EF4F0A3EED CRC64;
     ICTNNCAGYK GCNYACPLND HPIAYKSCEG EFDPKSKCPR