Editing King cobra (section)

===Composition===
[[Venom]] of the king cobra, produced by the postorbital [[venom gland]]s, consists primarily of [[three-finger toxin]]s (3FTx) and [[Metalloproteinase|snake venom metalloproteinases]] (SVMPs).<ref>{{cite journal |author1=Li, J. |author2=Zhang, H. |author3=Liu, J. |author4=Xu, K. |year=2006 |title=Novel genes encoding six kinds of three-finger toxins in ''Ophiophagus hannah'' (king cobra) and function characterization of two recombinant long-chain neurotoxins |journal=Biochemical Journal |volume=398 |issue=2 |pages=233–342 |doi=10.1042/BJ20060004|pmid=16689684 |pmc=1550305}}</ref><ref name="HT">{{cite journal |pmid=20071329 |title=Structural and Functional Characterization of a Novel Homodimeric Three-finger Neurotoxin from the Venom of ''Ophiophagus hannah'' (King Cobra) |year=2010 |last1=Roy |first1=A. |last2=Zhou |first2=X. |last3=Chong |first3=M. Z. |last4=d'Hoedt |first4=D. |last5=Foo |first5=C. S. |last6=Rajagopalan |first6=N. |last7=Nirthanan |first7=S. |last8=Bertrand |first8=D. |last9=Sivaraman |first9=J. |volume=285 |issue=11 |pages=8302–8315 |doi=10.1074/jbc.M109.074161 |pmc=2832981 |journal=The Journal of Biological Chemistry |last10=Kini|first10=R. M. |doi-access=free}}</ref>

Of all the 3FTx, [[alpha-neurotoxin]]s are the predominant and most lethal components when [[cytotoxins]] and [[cardiotoxin|beta-cardiotoxin]]s also exhibit toxicological activities.<ref>{{cite journal |author=Chang, L.-S. |author2=Liou, J.-C. |author3=Lin, S.-R. |author4=Huang, H.-B. |pmid=12056805 |year=2002 |title=Purification and characterization of a neurotoxin from the venom of ''Ophiophagus hannah'' (king cobra) |volume=294 |issue=3 |pages=574–578 |doi=10.1016/S0006-291X(02)00518-1 |journal=Biochemical and Biophysical Research Communications}}</ref><ref>{{cite journal |author1=He, Y. Y. |author2=Lee, W. H. |author3=Zhang, Y. |year=2004 |title=Cloning and purification of alpha-neurotoxins from king cobra (''Ophiophagus hannah'') |journal=Toxicon |volume=44 |issue=3 |pages=295–303 |doi=10.1016/j.toxicon.2004.06.003|pmid=15302536 |bibcode=2004Txcn...44..295H}}</ref><ref>{{cite journal |author=Rajagopalan, N. |author2=Pung, Y. F. |author3=Zhu, Y. Z. |author4=Wong, P. T. H. |author5=Kumar, P. P. |author6=Kini, R. M. |title=β-Cardiotoxin: A new three-finger toxin from ''Ophiophagus hannah'' (King Cobra) venom with beta-blocker activity |doi=10.1096/fj.07-8658com |year=2007 |journal=The FASEB Journal |volume=21 |issue=13 |pages=3685–3695 |doi-access=free |pmid=17616557|s2cid=21235585}}</ref> It is reported that [[cytotoxicity]] of its venom varies significantly, depending upon the age and locality of an individual.<ref>{{cite journal |author=Bianca Op den Brouw|author2=Manuel Fernandez-Rojo|author3=Tom Charlton|author4=Bryan G. Fry|author5=Maria P. Ikonomopoulou|pmid=12056805 |year=2023 |title=Malaysian and Chinese King Cobra Venom Cytotoxicity in Melanoma and Neonatal Foreskin Fibroblasts Is Mediated by Age and Geography |volume=15|issue=9 |doi=10.3390/toxins15090549|journal= Toxins|pages=574–578 |doi-access=free |pmc=10534572}}</ref> Clinical [[cardiotoxicity]] is not widely observed, nor is [[nephrotoxicity]] present among patients bitten by this species, presumably due to the low abundance of the toxins.<ref name="Davidson"/>

SVMPs are the second most protein family isolated from the king cobra's venom, accounting from 11.9% to 24.4% of total venom proteins.<ref name=Malaysian/><ref name=Indonesian>{{Cite journal|last1=Petras |first1=D. |last2=Heiss |first2=P. |last3=Süssmuth |first3=R. D. |last4=Calvete |first4=J. J. |date=2015 |title=Venom proteomics of Indonesian King Cobra, ''Ophiophagus hannah'': Integrating top-down and bottom-up approaches |journal=Journal of Proteome Research |volume=14 |issue=6 |pages=2539–2556 |doi=10.1021/acs.jproteome.5b00305 |pmid=25896403 |doi-access=free}}</ref><ref name = Taiwanese>{{Cite journal |last1=Liu |first1=C.-C. |last2=You |first2=C.-H. |last3=Wang |first3=P.-J. |last4=Yu |first4=J.-S. |last5=Huang|first5=G.-J. |last6=Liu |first6=C.-H. |last7=Hsieh |first7=W.-C. |last8=Lin |first8=C.-C. |date=2017 |title=Analysis of the efficacy of Taiwanese freeze-dried neurotoxic antivenom against ''Naja kaouthia'', ''Naja siamensis'' and ''Ophiophagus hannah'' through proteomics and animal model approaches|journal=PLOS Neglected Tropical Diseases |volume=11 |issue=12 |page=e0006138 |doi=10.1371/journal.pntd.0006138 |pmid=29244815 |pmc=5747474 |doi-access=free}}</ref> The abundance is much higher than that of most [[Naja|cobras]] which is usually less than 1%.<ref>{{Cite journal |last1=Vonk |first1=F. J.|last2=Casewell |first2=N. R.|last3=Henkel |first3=C. V.|last4=Heimberg|first4=A. M. |last5=Jansen |first5=H. J.|last6=McCleary|first6=Ryan J. R.|last7=Kerkkamp|first7=Harald M. E.|last8=Vos|first8=Rutger A. |last9=Guerreiro |first9=I. |last10=Calvete |first10=J. J.|last11=Wüster |first11=W. |date=2013 |title=The king cobra genome reveals dynamic gene evolution and adaptation in the snake venom system |journal=Proceedings of the National Academy of Sciences |volume=110 |issue=51|pages=20651–20656 |doi=10.1073/pnas.1314702110 |pmid=24297900 |pmc=3870661 |bibcode=2013PNAS..11020651V |doi-access=free}}</ref> This protein family includes principal toxins responsible for [[vasculature]] damage and interference with [[haemostasis]], contributing to [[bleeding]] and [[coagulopathy]] caused by envenomation of [[vipers]]. While there are such haemorrhagins isolated from the king cobra's venom, they only induce species-sensitive haemorrhagic and lethal activities on rabbits and hares, but with minimal effects on mice.<ref name=haemorrhagins>{{Cite journal|last1=Tan|first1=N.H.|last2=Saifuddin |first2=M.N.|year=1990 |title=solation and characterization of a hemorrhagin from the venom of ''Ophiophagus hannah'' (king cobra) |journal=Toxicon |volume=28 |issue=4 |pages=385–392 |doi=10.1016/0041-0101(90)90076-j |pmid=2190359 |bibcode=1990Txcn...28..385T|doi-access=free}}</ref> Clinical pathophysiology of the king cobra's SVMPs has yet to be well studied, although its substantial quantity suggests involvement in tissue damage and necrosis as a result of inflammatory and proteolytic activities, which are instrumental for foraging and digestive purposes.<ref name = haemorrhagins/><ref name="Davidson"/>

Ohanin, a minor vespryn protein component specific to this species, causes [[hypolocomotion]] and [[hyperalgesia]] in experimental mice. It is believed that it contributes to neurotoxicity on the [[central nervous system]] of the victim.<ref>{{cite journal |author=Pung, Y. F. |author2=Kumar, S. V. |author3=Rajagopalan, N. |author4=Fry, B. G. |author5=Kumar, P. P. |author6=Kini, R. M. |pmid=16472942 |year=2006 |title=Ohanin, a novel protein from king cobra venom: Its cDNA and genomic organization |volume=371 |issue=2 |pages=246–256 |doi=10.1016/j.gene.2005.12.002 |journal=Gene}}</ref>