Papain: Difference between revisions
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[[Image:papayas.jpg| | <StructureSection load='9pap' size='350' side='right' scene='Papain/Primary_scene/2' caption='Click on the links to the left to view different structural aspects of papain. | ||
PDB code [[9pap]]'> | |||
[[Image:papayas.jpg|200px|left|thumb|Papaya<ref>[http://dailyfitnessmagz.com/2011/03/papayas-nutrition-facts/] Papaya's Nutrition Facts</ref>]] | |||
== Introduction == | == Introduction == | ||
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Papain's enzymatic use was first discovered in 1873 by G.C. Roy who published his results in the Calcutta Medical Journal in the article, "The Solvent Action of Papaya Juice on Nitrogenous Articles of Food." In 1879, Papain was named officially by Wurtz and Bouchut, who managed to partially purify the product from the sap of papaya. It wasn't until the mid-twentieth century that the complete purification and isolation of Papain was achieved. In 1968, Drenth et al. determined the structure of Papain by [[X-ray crystallography|x-ray crystallography]], making it the second enzyme whose structure was successfully determined by x-ray crystallography. Additionally, Papain was the first cysteine protease to have its structure identified.<ref name="Worthington" /> In 1984, Kamphuis et al. determined the geometry of the active site, and the three-dimensional structure was visualized to a 1.65 Angstrom solution.<ref name="Structure">PMID:6502713</ref> Today, studies continue on the stability of Papain, involving changes in environmental conditions as well as testing of inhibitors such as phenylmethanesulfonylfluoride (PMSF), TLCK, TPCK, aplh2-macroglobulin, heavy metals, AEBSF, antipain, cystatin, E-64, leupeptin, sulfhydryl binding agents, carbonyl reagents, and alkylating agents.<ref name="Worthington" /> | Papain's enzymatic use was first discovered in 1873 by G.C. Roy who published his results in the Calcutta Medical Journal in the article, "The Solvent Action of Papaya Juice on Nitrogenous Articles of Food." In 1879, Papain was named officially by Wurtz and Bouchut, who managed to partially purify the product from the sap of papaya. It wasn't until the mid-twentieth century that the complete purification and isolation of Papain was achieved. In 1968, Drenth et al. determined the structure of Papain by [[X-ray crystallography|x-ray crystallography]], making it the second enzyme whose structure was successfully determined by x-ray crystallography. Additionally, Papain was the first cysteine protease to have its structure identified.<ref name="Worthington" /> In 1984, Kamphuis et al. determined the geometry of the active site, and the three-dimensional structure was visualized to a 1.65 Angstrom solution.<ref name="Structure">PMID:6502713</ref> Today, studies continue on the stability of Papain, involving changes in environmental conditions as well as testing of inhibitors such as phenylmethanesulfonylfluoride (PMSF), TLCK, TPCK, aplh2-macroglobulin, heavy metals, AEBSF, antipain, cystatin, E-64, leupeptin, sulfhydryl binding agents, carbonyl reagents, and alkylating agents.<ref name="Worthington" /> | ||
Papain is synthesised as an inactive precursor with a '''pro region''' of 107 residues in the N-terminal<ref>PMID:7738022</ref>. | |||
==Structure== | ==Structure== | ||
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{{#tree:id=OrganizedByTopic|openlevels=0| | {{#tree:id=OrganizedByTopic|openlevels=0| | ||
*Papain | *Papain residues 134-345 | ||
**[[ | **[[2pad]], [[9pap]], [[1ppn]], [[3lfy]] – PAP - papaya<br /> | ||
**[[ | **[[1pad]], [[4pad]], [[5pad]], [[6pad]], [[1bqi]] – PAP + methyl ketone substrate analog <br /> | ||
**[[1pe6]], [[1pip]], [[1ppp]], [[1bp4]], [[1cvz]], [[6tcx]] – PAP + inhibitor<br /> | |||
**[[1pe6]], [[1pip]], [[1ppp]], [[1bp4]], [[1cvz]] – PAP + inhibitor<br /> | |||
**[[1khp]], [[1khq]] - PAP + peptide inhibitor<br /> | **[[1khp]], [[1khq]] - PAP + peptide inhibitor<br /> | ||
**[[1ppd]] – hydroxyethyl-thioPAP<br /> | **[[1ppd]] – hydroxyethyl-thioPAP<br /> | ||
**[[ | **[[6h8t]] – PAP + Ru complex<br /> | ||
*Papain complex with protein inhibitor | *Papain complex with protein inhibitor | ||
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**[[3e1z]] - PAP + chagasin<br /> | **[[3e1z]] - PAP + chagasin<br /> | ||
**[[3ima]] - PAP + tarocystatin | **[[3ima]] - PAP + tarocystatin | ||
*Pro-papain residues 27-345 | |||
**[[3tnx]], [[3usv]], [[4qrg]], [[4qrv]], [[4qrx]] – PPAP (mutant)<br /> | |||
}} | }} | ||