VKT3_HETMG
ID VKT3_HETMG Reviewed; 56 AA.
AC C0HK74;
DT 28-FEB-2018, integrated into UniProtKB/Swiss-Prot.
DT 28-FEB-2018, sequence version 1.
DT 25-MAY-2022, entry version 7.
DE RecName: Full=Kunitz-type serine protease inhibitor HMGS2 {ECO:0000303|PubMed:29191747};
DE AltName: Full=PI-stichotoxin-Hmg3c {ECO:0000305};
DE Short=PI-SHTX-Hmg3c {ECO:0000305};
OS Heteractis magnifica (Magnificent sea anemone) (Radianthus magnifica).
OC Eukaryota; Metazoa; Cnidaria; Anthozoa; Hexacorallia; Actiniaria;
OC Stichodactylidae; Heteractis.
OX NCBI_TaxID=38281 {ECO:0000303|PubMed:29191747};
RN [1] {ECO:0000305}
RP PROTEIN SEQUENCE, FUNCTION, MASS SPECTROMETRY, AND PRESENCE OF DISULFIDE
RP BONDS.
RX PubMed=29191747; DOI=10.1016/j.jprot.2017.11.019;
RA Sintsova O., Gladkikh I., Chausova V., Monastyrnaya M., Anastyuk S.,
RA Chernikov O., Yurchenko E., Aminin D., Isaeva M., Leychenko E.,
RA Kozlovskaya E.;
RT "Peptide fingerprinting of the sea anemone Heteractis magnifica mucus
RT revealed neurotoxins, Kunitz-type proteinase inhibitors and a new beta-
RT defensin alpha-amylase inhibitor.";
RL J. Proteomics 173:12-21(2018).
CC -!- FUNCTION: Serine protease inhibitor that inhibits trypsin (Ki=73.8 nM)
CC and chymotrypsin (Ki=993 nM). {ECO:0000250|UniProtKB:P0DMJ5}.
CC -!- SUBCELLULAR LOCATION: Secreted {ECO:0000305|PubMed:29191747}.
CC Nematocyst {ECO:0000305}.
CC -!- PTM: Contains three disulfide bonds. {ECO:0000269|PubMed:29191747}.
CC -!- MASS SPECTROMETRY: Mass=6107; Method=MALDI;
CC Evidence={ECO:0000269|PubMed:29191747};
CC -!- MISCELLANEOUS: Does not inhibit potassium channels (Kv1.1/KCNA1,
CC Kv1.2/KCNA2, Kv1.3/KCNA3, Kv1.4/KCNA4, Kv1.5/KCNA5, Kv1.6/KCNA6,
CC Shaker, Kv2.1/KCNB1, Kv3.1/KCNC1, Kv4.2/KCND2, Kv4.3/KCND3, hERG/KCNH2)
CC and TRPV1, the capsaicin receptors. Does not inhibit the serine
CC proteases plasmin, thrombin, kallikrein, the cysteine proteinase
CC papain, and the aspartic protease pepsin.
CC {ECO:0000250|UniProtKB:P0DMJ5}.
CC -!- SIMILARITY: Belongs to the venom Kunitz-type family. Sea anemone type 2
CC potassium channel toxin subfamily. {ECO:0000305}.
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DR AlphaFoldDB; C0HK74; -.
DR SMR; C0HK74; -.
DR GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR GO; GO:0042151; C:nematocyst; IEA:UniProtKB-SubCell.
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; Nematocyst; Protease inhibitor;
KW Secreted; Serine protease inhibitor.
FT PEPTIDE 1..56
FT /note="Kunitz-type serine protease inhibitor HMGS2"
FT /evidence="ECO:0000269|PubMed:29191747"
FT /id="PRO_0000443112"
FT DOMAIN 4..54
FT /note="BPTI/Kunitz inhibitor"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00031"
FT SITE 14..15
FT /note="Reactive bond for trypsin"
FT /evidence="ECO:0000250|UniProtKB:P31713"
FT DISULFID 4..54
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00031"
FT DISULFID 13..37
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00031"
FT DISULFID 29..50
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00031"
SQ SEQUENCE 56 AA; 6113 MW; 02F75583272C2B5A CRC64;
GSICLEPKVV GPCTAYFPRF YFDSETGKCT PFIYGGCEGN GNNFETLHAC RAICRA
