ID   3SAN_NAJNG              Reviewed;          60 AA.
AC   P0DSN1;
DT   05-JUN-2019, integrated into UniProtKB/Swiss-Prot.
DT   05-JUN-2019, sequence version 1.
DT   03-AUG-2022, entry version 10.
DE   RecName: Full=Naniproin {ECO:0000303|PubMed:27558950};
OS   Naja nigricollis (Black-necked spitting cobra).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC   Lepidosauria; Squamata; Bifurcata; Unidentata; Episquamata; Toxicofera;
OC   Serpentes; Colubroidea; Elapidae; Elapinae; Naja.
OX   NCBI_TaxID=8654;
RN   [1]
RP   PROTEIN SEQUENCE, AND SUBCELLULAR LOCATION.
RX   PubMed=27558950; DOI=10.1038/srep32036;
RA   Girish V.M., Kini R.M.;
RT   "Exactin: a specific inhibitor of Factor X activation by extrinsic tenase
RT   complex from the venom of Hemachatus haemachatus.";
RL   Sci. Rep. 6:32036-32036(2016).
CC   -!- FUNCTION: Basic protein that binds to cell membrane and depolarizes
CC       cardiomyocytes. This cytotoxin also possesses lytic activity on many
CC       other cells, including red blood cells. Interaction with sulfatides in
CC       the cell membrane induces pore formation and cell internalization and
CC       is responsible for cytotoxicity in cardiomyocytes. It targets the
CC       mitochondrial membrane and induces mitochondrial swelling and
CC       fragmentation. Inhibits protein kinases C. It binds to the integrin
CC       alpha-V/beta-3 with a moderate affinity.
CC       {ECO:0000250|UniProtKB:P01443}.
CC   -!- SUBUNIT: Monomer in solution; Homodimer and oligomer in the presence of
CC       negatively charged lipids forming a pore with a size ranging between 20
CC       and 30 angstroms. {ECO:0000250|UniProtKB:P60301}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:27558950}. Target
CC       cell membrane {ECO:0000250|UniProtKB:P60301}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC       {ECO:0000305|PubMed:27558950}.
CC   -!- MISCELLANEOUS: Positive charges of Lys residues are necessary for
CC       cytolytic activity of this toxin, but not for its binding ability.
CC       {ECO:0000250|UniProtKB:P01468}.
CC   -!- MISCELLANEOUS: Is classified as a P-type cytotoxin, since a proline
CC       residue stands at position 30 (Pro-31 in standard classification).
CC       {ECO:0000305}.
CC   -!- SIMILARITY: Belongs to the snake three-finger toxin family. Short-chain
CC       subfamily. Type IA cytotoxin sub-subfamily. {ECO:0000305}.
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DR   AlphaFoldDB; P0DSN1; -.
DR   SMR; P0DSN1; -.
DR   PRIDE; P0DSN1; -.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0016020; C:membrane; IEA:UniProtKB-KW.
DR   GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR   GO; GO:0044179; P:hemolysis in another organism; IEA:UniProtKB-KW.
DR   CDD; cd00206; snake_toxin; 1.
DR   Gene3D; 2.10.60.10; -; 1.
DR   InterPro; IPR003572; Cytotoxin_Cobra.
DR   InterPro; IPR003571; Snake_3FTx.
DR   InterPro; IPR045860; Snake_toxin-like_sf.
DR   InterPro; IPR018354; Snake_toxin_con_site.
DR   PRINTS; PR00282; CYTOTOXIN.
DR   SUPFAM; SSF57302; SSF57302; 1.
PE   1: Evidence at protein level;
KW   Cardiotoxin; Cytolysis; Direct protein sequencing; Disulfide bond;
KW   Hemolysis; Membrane; Secreted; Target cell membrane; Target membrane;
KW   Toxin.
FT   CHAIN           1..60
FT                   /note="Naniproin"
FT                   /evidence="ECO:0000305|PubMed:27558950"
FT                   /id="PRO_0000447300"
FT   DISULFID        3..21
FT                   /evidence="ECO:0000250|UniProtKB:P01468"
FT   DISULFID        14..38
FT                   /evidence="ECO:0000250|UniProtKB:P01468"
FT   DISULFID        42..53
FT                   /evidence="ECO:0000250|UniProtKB:P01468"
FT   DISULFID        54..59
FT                   /evidence="ECO:0000250|UniProtKB:P01468"
SQ   SEQUENCE   60 AA;  6895 MW;  01E1F64A8E287FAE CRC64;
     LKCNRLIPPF WKTCPEGKNL CYKMTMRLAP KVPVKRGCID VCPKSSLLIK YMCCTNDKCN