TX2_HETMC
ID TX2_HETMC Reviewed; 38 AA.
AC P60993;
DT 26-APR-2004, integrated into UniProtKB/Swiss-Prot.
DT 26-APR-2004, sequence version 1.
DT 25-MAY-2022, entry version 58.
DE RecName: Full=Kappa-theraphotoxin-Hm2a;
DE Short=Kappa-TRTX-Hm2a;
DE AltName: Full=Heteroscodratoxin-2 {ECO:0000303|PubMed:12065754};
DE Short=HmTx2 {ECO:0000303|PubMed:12065754};
OS Heteroscodra maculata (Togo starburst tarantula) (Togo starburst baboon
OS spider).
OC Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida; Araneae;
OC Mygalomorphae; Theraphosidae; Heteroscodra.
OX NCBI_TaxID=268413;
RN [1]
RP PROTEIN SEQUENCE, FUNCTION, MASS SPECTROMETRY, 3D-STRUCTURE MODELING,
RP SUBCELLULAR LOCATION, AND AMIDATION AT PHE-38.
RC TISSUE=Venom;
RX PubMed=12065754; DOI=10.1124/mol.62.1.48;
RA Escoubas P., Diochot S., Celerier M.-L., Nakajima T., Lazdunski M.;
RT "Novel tarantula toxins for subtypes of voltage-dependent potassium
RT channels in the Kv2 and Kv4 subfamilies.";
RL Mol. Pharmacol. 62:48-57(2002).
CC -!- FUNCTION: Inhibitor of voltage-gated potassium channels. It
CC specifically inhibits Kv2.1/KCNB1 channels.
CC {ECO:0000269|PubMed:12065754}.
CC -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:12065754}.
CC -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC {ECO:0000305|PubMed:12065754}.
CC -!- DOMAIN: The presence of a 'disulfide through disulfide knot'
CC structurally defines this protein as a knottin.
CC {ECO:0000250|UniProtKB:P60590}.
CC -!- MASS SPECTROMETRY: Mass=4754.09; Method=MALDI;
CC Evidence={ECO:0000269|PubMed:12065754};
CC -!- MISCELLANEOUS: Percentage of current inhibition is 18% on Kv2.1/KCNB1
CC at 300 nM. Has no activity on Kv2.2/KCNB2, Kv4.1/KCND1, Kv4.2/KCND2 and
CC Kv4.3/KCND3. Intracerebroventricular injection into mice does not
CC induce observable neurotoxicity symptoms (PubMed:12065754).
CC {ECO:0000269|PubMed:12065754}.
CC -!- SIMILARITY: Belongs to the neurotoxin 10 (Hwtx-1) family. 13 (Hntx-13)
CC subfamily. {ECO:0000305}.
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DR AlphaFoldDB; P60993; -.
DR SMR; P60993; -.
DR ArachnoServer; AS000250; kappa-theraphotoxin-Hm2a.
DR GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR GO; GO:0008200; F:ion channel inhibitor activity; IEA:InterPro.
DR GO; GO:0015459; F:potassium channel regulator activity; IEA:UniProtKB-KW.
DR GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR InterPro; IPR011696; Huwentoxin-1.
DR Pfam; PF07740; Toxin_12; 1.
PE 1: Evidence at protein level;
KW Amidation; Direct protein sequencing; Disulfide bond;
KW Ion channel impairing toxin; Knottin; Neurotoxin;
KW Potassium channel impairing toxin; Secreted; Toxin;
KW Voltage-gated potassium channel impairing toxin.
FT PEPTIDE 1..38
FT /note="Kappa-theraphotoxin-Hm2a"
FT /evidence="ECO:0000269|PubMed:12065754"
FT /id="PRO_0000045018"
FT MOD_RES 38
FT /note="Phenylalanine amide"
FT /evidence="ECO:0000269|PubMed:12065754"
FT DISULFID 2..16
FT /evidence="ECO:0000250|UniProtKB:P60590"
FT DISULFID 9..21
FT /evidence="ECO:0000250|UniProtKB:P60590"
FT DISULFID 15..32
FT /evidence="ECO:0000250|UniProtKB:P60590"
SQ SEQUENCE 38 AA; 4765 MW; 7619F696D3F53A5F CRC64;
ECRYFWGECN DEMVCCEHLV CKEKWPITYK ICVWDRTF
