Enzymes
| UniProtKB help_outline | 8 proteins |
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Name help_outline
[Glu(-Cys)]n-Gly
Identifier
CHEBI:131728
Charge
-1
Formula
(C8H12N2O4S)n.C2H4NO2
Search links
Involved in 1 reaction(s)
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Form(s) in this reaction:
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Identifier: RHEA-COMP:12438Polymer name: [Glu(-Cys)](n)-GlyPolymerization index help_outline nFormula C2H4NO2(C8H12N2O4S)nCharge (-1)(0)nMol File for the polymer
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Identifier: RHEA-COMP:12439Polymer name: [Glu(-Cys)](n+1)-GlyPolymerization index help_outline n+1Formula C2H4NO2(C8H12N2O4S)n+1Charge (-1)(0)n+1Mol File for the polymer
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- Name help_outline glutathione Identifier CHEBI:57925 Charge -1 Formula C10H16N3O6S InChIKeyhelp_outline RWSXRVCMGQZWBV-WDSKDSINSA-M SMILEShelp_outline [NH3+][C@@H](CCC(=O)N[C@@H](CS)C(=O)NCC(=O)[O-])C(=O)[O-] 2D coordinates Mol file for the small molecule Search links Involved in 100 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline H+ Identifier CHEBI:15378 Charge 1 Formula H InChIKeyhelp_outline GPRLSGONYQIRFK-UHFFFAOYSA-N SMILEShelp_outline [H+] 2D coordinates Mol file for the small molecule Search links Involved in 9,176 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline glycine Identifier CHEBI:57305 Charge 0 Formula C2H5NO2 InChIKeyhelp_outline DHMQDGOQFOQNFH-UHFFFAOYSA-N SMILEShelp_outline [NH3+]CC([O-])=O 2D coordinates Mol file for the small molecule Search links Involved in 135 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Cross-references
| RHEA:17917 | RHEA:17918 | RHEA:17919 | RHEA:17920 | |
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| Reaction direction help_outline | undefined | left-to-right | right-to-left | bidirectional |
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Publications
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Phytochelatins, the heavy-metal-binding peptides of plants, are synthesized from glutathione by a specific gamma-glutamylcysteine dipeptidyl transpeptidase (phytochelatin synthase).
Grill E., Loffler S., Winnacker E.-L., Zenk M.H.
An enzyme has been discovered and characterized from Silene cucubalus cell suspension cultures that catalyzes the transfer of the gamma-glutamylcysteine dipeptide moiety of glutathione to an acceptor glutathione molecule or a growing chain of [Glu(-Cys)](n)-Gly oligomers, thus synthesizing phytoch ... >> More
An enzyme has been discovered and characterized from Silene cucubalus cell suspension cultures that catalyzes the transfer of the gamma-glutamylcysteine dipeptide moiety of glutathione to an acceptor glutathione molecule or a growing chain of [Glu(-Cys)](n)-Gly oligomers, thus synthesizing phytochelatins, the metal-binding peptides of higher plants and select fungi. The enzyme was named gamma-glutamylcysteine dipeptidyl transpeptidase and given the trivial name phytochelatin synthase. The primary reaction catalyzed is [Glu(-Cys)]-Gly + [Glu(-Cys)](n)-Gly --> [Glu(-Cys)](n+1)-Gly + Gly. The enzyme is isoelectric near pH 4.8 and has temperature and pH optima at 35 degrees C and 7.9, respectively. Phytochelatin synthase is constitutively present in cell cultures of various plant species and its formation is not noticeably induced by heavy metal ions in the growth medium. The enzyme (M(r)95,000) seems to be composed of four subunits, the dimer (M(r)50,000) being also catalytically active. Cd(2+) is by far the best metal activator of the enzyme followed by Ag(+), Bi(3+), Pb(2+), Zn(2+), Cu(2+), Hg(2+), and Au(+). The K(m) for glutathione is 6.7 mM. The enzyme activity seems to be self-regulated in that the product of the reaction (the phytochelatins) chelates the enzyme-activating metal, thus terminating the enzyme reaction. The molar ratio of the gamma-glutamylcysteine dipeptide in phytochelatin to Cd(2+) in the newly formed complex was 2:1. << Less
Proc. Natl. Acad. Sci. U.S.A. 86:6838-6842(1989) [PubMed] [EuropePMC]