We have synthesized an 18-amino acid peptide that contains the cysteine-rich region of the tat protein from human immunodeficiency virus. Previous experiments in vitro with the intact tat protein have shown that these cysteines serve as metal ligands, causing tat to form metal-linked dimers. Ultraviolet absorption spectra show that the synthetic peptide (tat21-38) binds two Cd2+ or two Zn2+ ion...

The cysteine-rich protein (CRP) contains two copies of the LIM sequence motif, CX2CX17HX2CX2CX2CX17-CX2C, that was first identified in the homeodomain proteins Lin-11, Is1-1, and Mec-3. The abundance and spacing of the cysteine residues in the LIM motif are reminiscent of a metal-binding domain. We examined the metal-binding properties of CRP isolated from chicken smooth muscle (cCRP) and from ...

Metallothionein is a naturally occurring metal-binding protein with high cysteine content. Oligopeptides containing three cysteinyl residues and having amino acid sequences analogous to portions of this protein were synthesized by the solid-phase method. Strong affinity of the synthetic peptides to Cd2+ and Zn2+ was observed, and the dissociation constants of the peptide-metal complexes were 2-...

The chemical and physical characteristics of Cd-binding peptides isolated from tobacco (Nicotiana tabacum) leaves and suspension-cultured tobacco cells were determined and compared with properties of rat liver Cd,Zn-thionein. Some emphasis was placed on metal-binding and specificity properties. Cd-peptides of apparent Mr 6000 and 2000 were induced in tobacco leaves by growth of plants with 90 m...

heavy metal toxicity has serious adverse effects on the environment. the metal sequestering characteristics of a novel metal binding peptide (glu-cys) 11 gly+linker+hexahistidine (ec 11 :his 6 ) was investigated to determine if it can absorb cu 2+ or zn 2+ cations. molecular dynamics simulations were carried out using a model of 6 cu 2+ or zn 2+ and other ions enclosed in a fully hydrated simul...

Amino acids and peptides are known to bind metal ions, in some cases very strongly. There are only a few examples of exploiting this binding in sensors. The review covers the current literature on the interaction of peptides and metals and the electrochemistry of bound metal ions. Peptides may be covalently attached to surfaces. Of particular interest is the attachment to gold via sulfur linkag...

Plants have evolved an extensive suite of adaptive responses to heavy metal toxicity. These include the immobilisation, exclusion, chelation and compartmentalisation of metal ions and often involve metal-binding ligands. A number of such ligands have been identified in plants and include organic acids, amino acids, peptides and polypeptides. Polypeptides include the metallothioneins (MTs), smal...

Cd from roots of maize was partitioned in seedlings exposed to 3 microM CdSO4 for 1 to 7 d. Most of the root Cd (92-94%) was buffer soluble and provided the classical metal-induced cysteine-rich, high-molecular-weight Cd-binding complex. This complex, however, bound only part of the Cd within the roots, from 19% after 1 d of exposure to 59% by d 7. Three families of peptides formed the Cd-bindi...

MARCO is a trimeric class A scavenger receptor of macrophages and dendritic cells that recognizes polyanionic particles and pathogens. The distal, scavenger receptor cysteine-rich (SRCR) domain of the extracellular part of this receptor has been implicated in ligand binding. To provide a structural basis for understanding the ligand-binding mechanisms of MARCO, we have determined the crystal st...