Papain: Difference between revisions
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It is a cysteine hydrolase | It is a [[Cysteine hydrolase|cysteine hydrolase]] that is stable and active under a awide range of conditions. It is very stable even at elevated temperatures <ref>Cohen, L., Coghlan, V and Dihel, L. (1986) Cloning and Sequencing of papain-encoding cDna, Gene 48, 219, 1986</ref>. The [[Latex|latex]] of ''[[Carica papaya|Carica papaya]]'' is a rich source of four [[Cysteine endopeptidases|cysteine endopeptidases]] including papain, [[Chymopapain|chymopapain]], [[Glycyl endopeptidase|glycyl endopeptidase]], and [[Caricain|caricain]]. The proteins are synthesized as inactive precursors that become active with two minutes of the plant being wounded and the latex expelled. Papain is a minor constituent, but has been more widely studied because it is more easily purified <ref>Akahane, K. and Umeyama,H. (1986) Binding Specificity of Papain and Cathepepsin B, Emzyme 36, 141</ref>.<br> | ||
=== Molecular Weight: === | |||
Molecular Weight: | |||
*23.4 kDa (theoretical) | *23.4 kDa (theoretical) | ||
*23.0 kDa ( | *23.0 kDa <ref>Drenth, J., Jansonius, J. Koekoek,R., Swen, H., and Wolters, B.(1968) Structure of Papain, Nature 218, 929</ref><br> | ||
=== Active site residies: === | |||
*[[Cysteine|cysteine]] (c158) | |||
*[[Histidine|histidine]] (h292) | |||
*[[Asparagine|asparagine]] (n308)<br> | |||
=== Applications: === | |||
*Cell isolation where it is more gentle than other [[Proteases|proteases]] (i.e. [[Cortical neurons|cortical neurons]], [[Retina|retina]], and [[Smooth muscle|smooth muscle]]) | |||
*Protein structural studies, peptide mapping | |||
*[[Red cells|Red cell]] surface modification for antibody screening or identification | |||
*Fab preparation from [[IgG|IgG]] and [[IgM|IgM]] [[Antibody|antibodies]] | |||
* | |||
* | |||
*Red cell surface modification for antibody screening or identification | |||
*Fab preparation from IgG and IgM antibodies | |||
*Solubilization of integral membrane proteins | *Solubilization of integral membrane proteins | ||
* | *Production of [[Glycoproteins|glycopeptides]] from purified [[Proteoglycans|proteoglycans]] | ||
*Enzymatic wound debridement | *Enzymatic wound debridement<br> | ||
<br> | |||
=== References === | |||
<br> | <references /><br> | ||
<br> | <br> | ||
Latest revision as of 12:50, 28 November 2012
It is a cysteine hydrolase that is stable and active under a awide range of conditions. It is very stable even at elevated temperatures [1]. The latex of Carica papaya is a rich source of four cysteine endopeptidases including papain, chymopapain, glycyl endopeptidase, and caricain. The proteins are synthesized as inactive precursors that become active with two minutes of the plant being wounded and the latex expelled. Papain is a minor constituent, but has been more widely studied because it is more easily purified [2].
Molecular Weight:
- 23.4 kDa (theoretical)
- 23.0 kDa [3]
Active site residies:
- cysteine (c158)
- histidine (h292)
- asparagine (n308)
Applications:
- Cell isolation where it is more gentle than other proteases (i.e. cortical neurons, retina, and smooth muscle)
- Protein structural studies, peptide mapping
- Red cell surface modification for antibody screening or identification
- Fab preparation from IgG and IgM antibodies
- Solubilization of integral membrane proteins
- Production of glycopeptides from purified proteoglycans
- Enzymatic wound debridement
References
- ↑ Cohen, L., Coghlan, V and Dihel, L. (1986) Cloning and Sequencing of papain-encoding cDna, Gene 48, 219, 1986
- ↑ Akahane, K. and Umeyama,H. (1986) Binding Specificity of Papain and Cathepepsin B, Emzyme 36, 141
- ↑ Drenth, J., Jansonius, J. Koekoek,R., Swen, H., and Wolters, B.(1968) Structure of Papain, Nature 218, 929