Heavy Metal-Binding Peptides and Proteins in Plants. A Review

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Title:Heavy Metal-Binding Peptides and Proteins in Plants. A Review
Creators:
Kotrba, Pavel
Macek, Tomáš
Ruml, Tomáš
Journal or Publication Title:
Collection of Czechoslovak Chemical Communications, 64, 7, pp. 1057-1086
Uncontrolled Keywords:Metal homeostasis, Metallothioneins, Metallothionein-like proteins, Metalloproteins, Phytochelatins, Metal binding, Metal tolerance

Abstract

In plants, two kinds of specific metal-binding peptides or proteins are synthesized. Plant metallothioneins (MTs) and MT-like proteins are cysteine-rich translation products of genes inducible in tissue-specific manner during embryogenesis and plant development. In addition, differential expression of MT-like protein genes could be due to variation of external heavy metal concentrations (especially of Cu<sup>2+</sup> and Fe<sup>2+</sup>), influence of various stress factors (heat shock, sucrose starvation, oxidative stress, wounding, plant pathogens). The principal role of plant MTs and MT-like proteins seems to be in homeostasis of essential transition metals rather than in metal detoxification. Phytochelatins (PCs) have general structure (γ-Glu-Cys)<i><sub>n</sub></i>-Xaa, where <i>n</i> = 2-11 and Xaa amino acids Gly, β-Ala, Ser, and Glu which depend on the species; the des-Xaa forms of PC also exist. PCs are synthesized in plants and some yeasts by a constitutive enzyme phytochelatin synthase (active only in the presence of free heavy metal ion) from glutathione or its anologue. Despite the PC capability of forming complexes with transition metal ions (their role in metal homeostasis could not be excluded) and virtually prominent role in Cd<sup>2+</sup> detoxification within plant cell, there is no evidence that elevated production of PCs may contribute to differential tolerance and/or could be responsible for the resistance to toxic metals. A review with 172 references.

Title:Heavy Metal-Binding Peptides and Proteins in Plants. A Review
Creators:
Kotrba, Pavel
Macek, Tomáš
Ruml, Tomáš
Uncontrolled Keywords:Metal homeostasis, Metallothioneins, Metallothionein-like proteins, Metalloproteins, Phytochelatins, Metal binding, Metal tolerance
Divisions:Life and Chemical Sciences > Institute of Organic Chemistry and Biochemistry > Collection of Czechoslovak Chemical Communications
Journal or Publication Title:Collection of Czechoslovak Chemical Communications
Volume:64
Number:7
Page Range:pp. 1057-1086
ISSN:0010-0765
E-ISSN:1212-6950
Publisher:Institute of Organic Chemistry and Biochemistry
Related URLs:
URLURL Type
http://dx.doi.org/10.1135/cccc19991057UNSPECIFIED
ID Code:1538
Item Type:Article
Deposited On:06 Feb 2009 17:10
Last Modified:06 Feb 2009 16:10

Citation

Kotrba, Pavel; Macek, Tomáš; Ruml, Tomáš (1999) Heavy Metal-Binding Peptides and Proteins in Plants. A Review. Collection of Czechoslovak Chemical Communications, 64 (7). pp. 1057-1086. ISSN 0010-0765

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