ID   VKTK2_DABRR             Reviewed;          84 AA.
AC   H6VC06;
DT   01-MAY-2013, integrated into UniProtKB/Swiss-Prot.
DT   18-APR-2012, sequence version 1.
DT   25-MAY-2022, entry version 29.
DE   RecName: Full=Kunitz-type serine protease inhibitor DrKIn-II;
DE   AltName: Full=Daboia russelii Kunitz Inhibitor-II;
DE   Flags: Precursor;
OS   Daboia russelii (Russel's viper) (Vipera russelii).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC   Lepidosauria; Squamata; Bifurcata; Unidentata; Episquamata; Toxicofera;
OC   Serpentes; Colubroidea; Viperidae; Viperinae; Daboia.
OX   NCBI_TaxID=8707;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA], FUNCTION, AND MASS SPECTROMETRY.
RC   TISSUE=Venom, and Venom gland;
RX   PubMed=22416129; DOI=10.1074/jbc.m111.323063;
RA   Cheng A.C., Wu H.L., Shi G.Y., Tsai I.H.;
RT   "A novel heparin-dependent inhibitor of activated protein C that
RT   potentiates consumptive coagulopathy in Russell's viper envenomation.";
RL   J. Biol. Chem. 287:15739-15748(2012).
RN   [2]
RP   FUNCTION.
RC   TISSUE=Venom;
RX   PubMed=23999090; DOI=10.1016/j.bbagen.2013.08.019;
RA   Cheng A.C., Tsai I.H.;
RT   "Functional characterization of a slow and tight-binding inhibitor of
RT   plasmin isolated from Russell's viper venom.";
RL   Biochim. Biophys. Acta 1840:153-159(2014).
CC   -!- FUNCTION: Serine protease inhibitor that inhibits plasmin (90%)
CC       (Ki=0.19 nM), trypsin (70%), FXIa/F11 (37%) (Ki=6 nM) and FXa/F10
CC       (20%), and prolonges the activated partial thromboplastin time. This
CC       antifibrinolytic property has been confirmed by a fibrin plate assay.
CC       Shows less antifibrinolytic activity that aprotinin. In vivo, reduces
CC       the bleeding time in a murine bleeding model, and prevents the increase
CC       of fibrin(ogen) degradation products in coagulation-stimulated mice.
CC       {ECO:0000269|PubMed:22416129, ECO:0000269|PubMed:23999090}.
CC   -!- SUBCELLULAR LOCATION: Secreted.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC   -!- MASS SPECTROMETRY: Mass=6940.3; Method=MALDI;
CC       Evidence={ECO:0000269|PubMed:22416129};
CC   -!- MISCELLANEOUS: Does not inhibit activated protein C (APC), in absence
CC       or presence of heparin. This is due to the absence of heparin-binding
CC       motifs. Consequently, heparin is unable to enhance the inhibition of
CC       activated protein C (APC) by this protein, as it does for DrKIn-I
CC       (PubMed:22416129). Does not inhibit tissue plasminogen activator
CC       (tPA/PLAT) and urokinase-type plasminogen activator (uPA/PLAU). Does
CC       not prolong the prothrombin time (PubMed:23999090).
CC       {ECO:0000305|PubMed:22416129, ECO:0000305|PubMed:23999090}.
CC   -!- SIMILARITY: Belongs to the venom Kunitz-type family. {ECO:0000305}.
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DR   EMBL; JN825730; AFB74192.1; -; mRNA.
DR   AlphaFoldDB; H6VC06; -.
DR   SMR; H6VC06; -.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0004867; F:serine-type endopeptidase inhibitor activity; IEA:UniProtKB-KW.
DR   GO; GO:0090729; F:toxin 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   Disulfide bond; Hemostasis impairing toxin; Protease inhibitor; Secreted;
KW   Serine protease inhibitor; Signal; Toxin.
FT   SIGNAL          1..24
FT   CHAIN           25..84
FT                   /note="Kunitz-type serine protease inhibitor DrKIn-II"
FT                   /id="PRO_0000422089"
FT   DOMAIN          31..81
FT                   /note="BPTI/Kunitz inhibitor"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00031"
FT   SITE            41..42
FT                   /note="Reactive bond for trypsin"
FT                   /evidence="ECO:0000250"
FT   DISULFID        31..81
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00031"
FT   DISULFID        40..64
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00031"
FT   DISULFID        56..77
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00031"
SQ   SEQUENCE   84 AA;  9385 MW;  F0FF4263BC93F474 CRC64;
     MSSGGLLLLL GLLTLWAELT PISGHDRPTF CNLAPESGRC RAHLRRIYYN LESNKCEVFF
     YGGCGGNDNN FSTWDECRHT CVGK