Metal-binding polypeptides

Metal-binding polypeptides in roots of copper-tolerant Mimulus... 

Steffens, J.C., Hunt, D.F. Williams, B.G. (1986). Accumulation of non-protein metal-binding polypeptides (gamma-glutamyl-cysteinyl) -glycine in selected cadmium-resistant tomato cells. Journal of Biochemistry 261, 13879-82. 

The speciation of Cd in the tissue of plants is an important factor in determining its accumulation in human body. Cd has been found to bind to cytoplasmic proteins that usually contain cysteine, collectively called phytochelatins. Some plants appear to be able to produce metal-binding polypeptides to sequester metals and render them unavailable for transport within the plant (Steffens, 1990). Elevated concentrations of Cd in plant tissues may trigger the formation of phytochelatins (Grill et al, 1987 Scheller et al, 1987 Salt et al., 1989). However, the exact mechanism of the triggering of phytochelatins by heavy metals such as Cd is still not known. 

Metallothioneins (MTs) are small, sulfur-rich metal-binding polypeptides produced in response to a variety of physiological and envirOTunental stresses. In the presence of iron and NO, both apo-metallothionein and Zn-metaIlothi(Miein form EPR spectra similar to DNIC [289]. 

The exposure of plants to metals results in the synthesis of phytochelatins, a metal binding polypeptide (Stem, 2000). Phytocheletins are known to sequester and detoxify metals through the formation of metals. Phytochelatin complexes (Stern, 2000 Clemens et al 1999, Ha et al, 1999). Plant nutrient elements such as Ca, Mn, Fe and Zn for example may enter through Ca charmels or by means of broad-range metal transporter previously identified as Fe transporter (Clemens et al, 1999). Edema (2006) reported that the levels of Fe in WSF before and after exposure to Pistia were far above the highest desirable limit for drinking water and still within the maximum permissible limit of l.Omg/1 of WHO value. 

Two metal-binding polypeptides (4871 and 8596 Da) were identified as significant risk factors [82],... 

Synthesis, metal-binding properties and polypeptide solubilization of Crowned arbo-rols. [T. Nagasaki, O. Kimura, M. Ukon, S. Arimori, I. Hamachi, S. Shinkai, J. Chem. Soc., Perkin Trans. 1 1994, 75-81] [ 315],... 

Thai CK, Dai HX, Sastry MSR, Saiikaya M, Schwartz DT, Baneyx F (2004) Identification and characterization of Cu20- and ZnO-binding polypeptides by Escherichia coli cell surface display toward an understanding of metal oxide binding. Biotechnol Bioeng 87 129-137... 

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