ID   POI_MUSDO               Reviewed;          38 AA.
AC   P81765;
DT   10-JAN-2003, integrated into UniProtKB/Swiss-Prot.
DT   10-JAN-2003, sequence version 1.
DT   25-MAY-2022, entry version 46.
DE   RecName: Full=Tyrosinase inhibitor;
DE   AltName: Full=Phenol oxidase inhibitor;
DE   AltName: Full=Phenoloxidase inhibitor;
DE            Short=POI;
OS   Musca domestica (House fly).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Hexapoda; Insecta; Pterygota;
OC   Neoptera; Endopterygota; Diptera; Brachycera; Muscomorpha; Muscoidea;
OC   Muscidae; Musca.
OX   NCBI_TaxID=7370;
RN   [1]
RP   PROTEIN SEQUENCE, CHARACTERIZATION, HYDROXYLATION AT TYR-32, AND MASS
RP   SPECTROMETRY.
RC   TISSUE=Hemolymph;
RX   PubMed=7708756; DOI=10.1073/pnas.92.7.2964;
RA   Daquinag A.C., Nakamura S., Takao T., Shimonishi Y., Tsukamoto T.;
RT   "Primary structure of a potent endogenous dopa-containing inhibitor of
RT   phenol oxidase from Musca domestica.";
RL   Proc. Natl. Acad. Sci. U.S.A. 92:2964-2968(1995).
RN   [2]
RP   PROTEIN SEQUENCE OF 6-9, CHARACTERIZATION, AND DEVELOPMENTAL STAGE.
RC   TISSUE=Hemolymph;
RX   PubMed=1567460; DOI=10.1016/0006-291x(92)91161-i;
RA   Tsukamoto T., Ichimaru Y., Kanegae N., Watanabe K., Yamaura I., Katsura Y.,
RA   Funatsu M.;
RT   "Identification and isolation of endogenous insect phenoloxidase
RT   inhibitors.";
RL   Biochem. Biophys. Res. Commun. 184:86-92(1992).
RN   [3]
RP   SYNTHESIS, AND DISULFIDE BONDS.
RX   PubMed=10026302; DOI=10.1021/bi9819834;
RA   Daquinag A.C., Sato T., Koda H., Takao T., Fukuda M., Shimonishi Y.,
RA   Tsukamoto T.;
RT   "A novel endogenous inhibitor of phenoloxidase from Musca domestica has a
RT   cystine motif commonly found in snail and spider toxins.";
RL   Biochemistry 38:2179-2188(1999).
CC   -!- FUNCTION: Potent reversible, competitive inhibitor of tyrosinase
CC       (phenol oxidase) in the nanomolar range.
CC   -!- SUBUNIT: Monomer.
CC   -!- SUBCELLULAR LOCATION: Secreted.
CC   -!- DEVELOPMENTAL STAGE: POI activity increases throughout pupariation, and
CC       is highest in final instar pupae. No activity in newly emerged adults.
CC       {ECO:0000269|PubMed:1567460}.
CC   -!- DOMAIN: The presence of a 'disulfide through disulfide knot'
CC       structurally defines this protein as a knottin.
CC   -!- PTM: Contains L-DOPA (3',4'-dihydroxyphenylalanine).
CC   -!- MASS SPECTROMETRY: Mass=4213.1; Mass_error=0.2; Method=Electrospray;
CC       Evidence={ECO:0000269|PubMed:7708756};
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DR   AlphaFoldDB; P81765; -.
DR   SMR; P81765; -.
DR   Proteomes; UP000095301; Whole Genome Shotgun Assembly.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
PE   1: Evidence at protein level;
KW   Direct protein sequencing; Disulfide bond; Hydroxylation; Knottin;
KW   Secreted.
FT   PEPTIDE         1..38
FT                   /note="Tyrosinase inhibitor"
FT                   /id="PRO_0000044781"
FT   MOD_RES         32
FT                   /note="3',4'-dihydroxyphenylalanine"
FT                   /evidence="ECO:0000269|PubMed:7708756"
FT   DISULFID        11..25
FT                   /evidence="ECO:0000269|PubMed:10026302"
FT   DISULFID        18..29
FT                   /evidence="ECO:0000269|PubMed:10026302"
FT   DISULFID        24..36
FT                   /evidence="ECO:0000269|PubMed:10026302"
SQ   SEQUENCE   38 AA;  4204 MW;  E597BE0BFF286792 CRC64;
     AVTDNEIVPQ CLANGSKCYS HDVCCTKRCH NYAKKCVT