ID   DEF4_LEIHE              Reviewed;          38 AA.
AC   P41965;
DT   01-NOV-1995, integrated into UniProtKB/Swiss-Prot.
DT   01-NOV-1995, sequence version 1.
DT   03-AUG-2022, entry version 64.
DE   RecName: Full=4 kDa defensin {ECO:0000305|PubMed:8333834};
DE   AltName: Full=Antibacterial 4 kDa peptide {ECO:0000303|PubMed:8333834};
OS   Leiurus hebraeus (Deathstalker scorpion) (Leiurus quinquestriatus
OS   hebraeus).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida;
OC   Scorpiones; Buthida; Buthoidea; Buthidae; Leiurus.
OX   NCBI_TaxID=6884;
RN   [1]
RP   PROTEIN SEQUENCE, AND FUNCTION.
RC   TISSUE=Hemolymph;
RX   PubMed=8333834; DOI=10.1006/bbrc.1993.1778;
RA   Cociancich S., Goyffon M., Bontems F., Bulet P., Bouet F., Menez A.,
RA   Hoffmann J.A.;
RT   "Purification and characterization of a scorpion defensin, a 4kDa
RT   antibacterial peptide presenting structural similarities with insect
RT   defensins and scorpion toxins.";
RL   Biochem. Biophys. Res. Commun. 194:17-22(1993).
CC   -!- FUNCTION: Dual-function peptide with antimicrobial and potassium
CC       channel-blocking activities (By similarity). Shows inhibitory activity
CC       against Gram-positive bacteria such as M.luteus, S.aureus, B.subtilis,
CC       and M.luteus as well as methicillin-resistant S.aureus (MIC=0.1-20 uM)
CC       (By similarity) (PubMed:8333834). Does not act on bacteria by
CC       disrupting membranes (By similarity). Also moderately inhibits
CC       Kv1.1/KCNA1, Kv1.2/KCNA2, and Kv1.3/KCNA3 potassium channels (By
CC       similarity). Inhibits potassium channels by interacting with the pore
CC       region (By similarity). Does not show hemolytic activity (By
CC       similarity). {ECO:0000250|UniProtKB:P0DQT9,
CC       ECO:0000269|PubMed:8333834}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000305|PubMed:8333834}.
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   -!- SIMILARITY: Belongs to the invertebrate defensin family. Type 2
CC       subfamily. {ECO:0000305}.
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DR   PIR; JN0613; JN0613.
DR   AlphaFoldDB; P41965; -.
DR   SMR; P41965; -.
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..38
FT                   /note="4 kDa defensin"
FT                   /id="PRO_0000044712"
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   38 AA;  4326 MW;  DF35FB21ECE3FB84 CRC64;
     GFGCPLNQGA CHRHCRSIRR RGGYCAGFFK QTCTCYRN