ID   ISC2_BOMMO              Reviewed;          62 AA.
AC   P10832;
DT   01-JUL-1989, integrated into UniProtKB/Swiss-Prot.
DT   01-JUL-1989, sequence version 1.
DT   25-MAY-2022, entry version 89.
DE   RecName: Full=Chymotrypsin inhibitor SCI-II;
OS   Bombyx mori (Silk moth).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Hexapoda; Insecta; Pterygota;
OC   Neoptera; Endopterygota; Lepidoptera; Glossata; Ditrysia; Bombycoidea;
OC   Bombycidae; Bombycinae; Bombyx.
OX   NCBI_TaxID=7091;
RN   [1]
RP   PROTEIN SEQUENCE.
RC   TISSUE=Larval hemolymph;
RX   PubMed=3072972; DOI=10.1515/bchm3.1988.369.2.1235;
RA   Sasaki T.;
RT   "Amino-acid sequences of two basic chymotrypsin inhibitors from silkworm
RT   larval hemolymph.";
RL   Biol. Chem. Hoppe-Seyler 369:1235-1241(1988).
CC   -!- FUNCTION: Inhibits chymotrypsin and thus avoids the accidental
CC       chymotrypsin-mediated activation of prophenoloxidase. This enzyme is
CC       required by the insect immune system to produce melanin which is used
CC       to engulf foreign objects.
CC   -!- FUNCTION: Also inhibits trypsin weakly, this may be due to the presence
CC       of a pseudo-reactive bond in positions 44-45 (Lys-Gly).
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DR   PIR; S01803; S01803.
DR   AlphaFoldDB; P10832; -.
DR   SMR; P10832; -.
DR   Proteomes; UP000005204; Unassembled WGS sequence.
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; Serine protease inhibitor.
FT   CHAIN           1..62
FT                   /note="Chymotrypsin inhibitor SCI-II"
FT                   /id="PRO_0000155422"
FT   DOMAIN          9..60
FT                   /note="BPTI/Kunitz inhibitor"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00031"
FT   SITE            20..21
FT                   /note="Reactive bond"
FT                   /evidence="ECO:0000250"
FT   SITE            44..45
FT                   /note="Pseudo reactive bond for trypsin"
FT   DISULFID        9..60
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00031"
FT   DISULFID        19..43
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00031"
FT   DISULFID        35..56
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00031"
SQ   SEQUENCE   62 AA;  7067 MW;  7E7C013DA05AC6DA CRC64;
     DKPTTKPICE QAFGNSGPCF AYIKLYSYNQ KTKKCEEFIY GGCKGNDNRF DTLAECEQKC
     IK