Leucyl aminopeptidase
Leucine aminopeptidase | |||||||
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Chr. 4 p15.33 | |||||||
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Leucyl aminopeptidases (
Enzyme description, structure, and active site
The
Mechanism(s)
Historically, the mechanisms of carboxypeptidases and endoprotease have been much more well-studied and understood by researchers (Ref #6 Lipscomb 1990). Work within the past two decades has provided vital knowledge regarding the mechanisms of aminopeptidases. The mechanism of
bovine lens LAP and PepA have been elucidated (Ref 1 and 2), however, the exact mechanism of tomato LAP-A is unknown at this time. A search of current literature does not indicate that new research is underway to determine the exact mechanism of LAP-A. Based on the biochemical similarities of the LAPs between kingdoms, the mechanism of LAP-A may be similar to bovine lens LAP and PepA.
Biological function
Once thought of as a
Background on plant immune response
In order to survive, plants must be able to respond to many
The plant response in this octadecanoid pathway is similar to
Octadecanoid pathway
(LAP-A), a product of the octadecanoid pathway in some solanaceous plants, has been shown by Fowler et al. to have a regulatory role in the late wound response of tomato. Experiments were conducted using three
Osmoregulation
LAP proteins are expressed in a variety of marine organisms as a method of coping with the osmotic threat high salinity poses to the cell. During bouts of high salinity, LAP begins the catalysis of proteins in order to release amino acids into the cell in an attempt to balance the high ion concentrations in the external environment.[5]
References
- Sources
- Sträter N, Sun L, Kantrowitz ER, Lipscomb WN (September 1999). "A bicarbonate ion as a general base in the mechanism of peptide hydrolysis by dizinc leucine aminopeptidase". PMID 10500145.
- Sträter N, Lipscomb WN (November 1995). "Two-metal ion mechanism of bovine lens leucine aminopeptidase: active site solvent structure and binding mode of L-leucinal, a gem-diolate transition state analogue, by X-ray crystallography". PMID 7578088.
- Gu YQ, Walling LL (March 2002). "Identification of residues critical for activity of the wound-induced leucine aminopeptidase (LAP-A) of tomato". PMID 11895433.
- Gu YQ, Holzer FM, Walling LL (August 1999). "Overexpression, purification and biochemical characterization of the wound-induced leucine aminopeptidase of tomato". PMID 10469136.
- Kraft M, Schleberger C, Weckesser J, Schulz GE (December 2006). "Binding structure of the leucine aminopeptidase inhibitor microginin FR1". S2CID 6425967.
- Walling LL (June 2000). "The Myriad Plant Responses to Herbivores". S2CID 11842328.
- Burley SK, David PR, Lipscomb WN (August 1991). "Leucine aminopeptidase: bestatin inhibition and a model for enzyme-catalyzed peptide hydrolysis". PMID 1871107.
- Orozco-Cárdenas ML, Narváez-Vásquez J, Ryan CA (January 2001). "Hydrogen peroxide acts as a second messenger for the induction of defense genes in tomato plants in response to wounding, systemin, and methyl jasmonate". PMID 11158538.
- Ryan CA (March 2000). "The systemin signaling pathway: differential activation of plant defensive genes". Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology. 1477 (1–2): 112–21. PMID 10708853.
- Johnson R, Narvaez J, An G, Ryan C (December 1989). "Expression of proteinase inhibitors I and II in transgenic tobacco plants: effects on natural defense against Manduca sexta larvae". PMID 2602379.
- Fowler JH, Narváez-Vásquez J, Aromdee DN, Pautot V, Holzer FM, Walling LL (April 2009). "Leucine aminopeptidase regulates defense and wound signaling in tomato downstream of jasmonic acid". PMID 19376935.
External links
- The MEROPS online database for peptidases and their inhibitors: Animal:M17.001, Bacteria:M17.003, Plant::M17.002.
- Leucyl+aminopeptidase at the U.S. National Library of Medicine Medical Subject Headings (MeSH)