ID   DEF4_ANDAU              Reviewed;          37 AA.
AC   P56686; P81618;
DT   15-JUL-1999, integrated into UniProtKB/Swiss-Prot.
DT   15-JUL-1999, sequence version 1.
DT   03-AUG-2022, entry version 67.
DE   RecName: Full=4 kDa defensin {ECO:0000250|UniProtKB:P41965};
OS   Androctonus australis (Sahara scorpion).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida;
OC   Scorpiones; Buthida; Buthoidea; Buthidae; Androctonus.
OX   NCBI_TaxID=6858;
RN   [1]
RP   PROTEIN SEQUENCE, CHARACTERIZATION, AND MASS SPECTROMETRY.
RC   STRAIN=Hector; TISSUE=Hemolymph;
RX   PubMed=8939880; DOI=10.1074/jbc.271.47.29537;
RA   Ehret-Sabatier L., Loew D., Goyffon M., Fehlbaum P., Hoffmann J.A.,
RA   van Dorsselaer A., Bulet P.;
RT   "Characterization of novel cysteine-rich antimicrobial peptides from
RT   scorpion blood.";
RL   J. Biol. Chem. 271:29537-29544(1996).
CC   -!- FUNCTION: Dual-function peptide with antimicrobial and potassium
CC       channel-blocking activities. Shows inhibitory activity against Gram-
CC       positive bacteria. Does not act on bacteria by disrupting membranes.
CC       Also moderately inhibits Kv1.1/KCNA1, Kv1.2/KCNA2, and Kv1.3/KCNA3
CC       potassium channels. Inhibits potassium channels by interacting with the
CC       pore region. Does not show hemolytic activity.
CC       {ECO:0000250|UniProtKB:P0DQT9}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000305|PubMed:8939880}.
CC   -!- DOMAIN: Has the structural arrangement of an alpha-helix connected to a
CC       beta-sheet by disulfide bonds (CSalpha/beta).
CC       {ECO:0000250|UniProtKB:P0DQT9}.
CC   -!- MASS SPECTROMETRY: Mass=4206.8; Method=Electrospray;
CC       Evidence={ECO:0000269|PubMed:8939880};
CC   -!- SIMILARITY: Belongs to the invertebrate defensin family. Type 2
CC       subfamily. {ECO:0000305}.
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DR   AlphaFoldDB; P56686; -.
DR   SMR; P56686; -.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0042742; P:defense response to bacterium; IEA:UniProtKB-KW.
DR   Gene3D; 3.30.30.10; -; 1.
DR   InterPro; IPR001542; Defensin_invertebrate/fungal.
DR   InterPro; IPR036574; Scorpion_toxin-like_sf.
DR   Pfam; PF01097; Defensin_2; 1.
DR   SUPFAM; SSF57095; SSF57095; 1.
DR   PROSITE; PS51378; INVERT_DEFENSINS; 1.
PE   1: Evidence at protein level;
KW   Antibiotic; Antimicrobial; Defensin; Direct protein sequencing;
KW   Disulfide bond; Secreted.
FT   PEPTIDE         1..37
FT                   /note="4 kDa defensin"
FT                   /evidence="ECO:0000269|PubMed:8939880"
FT                   /id="PRO_0000044711"
FT   DISULFID        4..25
FT                   /evidence="ECO:0000250|UniProtKB:A0A384E0Y8"
FT   DISULFID        11..33
FT                   /evidence="ECO:0000250|UniProtKB:A0A384E0Y8"
FT   DISULFID        15..35
FT                   /evidence="ECO:0000250|UniProtKB:A0A384E0Y8"
SQ   SEQUENCE   37 AA;  4212 MW;  AB1363ECE3FB84C1 CRC64;
     GFGCPFNQGA CHRHCRSIRR RGGYCAGLFK QTCTCYR