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Research describes the gene encoding a copper chaperone from Bacillus subtilis genome. It bears a 39% homology to protein sequences of similar proteins from Enterococcus hirae. B. subtilis protein consists of 73 amino acids, binds copper(I), and exhibits folding in both copper-bound and copper-free forms.

Electron paramagnetic resonance and nuclear magnetic resonance spectroscopies are used to study the two Asp242 and two stable Phe190 mutants of Mn peroxidase. Results show that all four mutants display three pH-dependent transitions and that the transition at intermediate pH has various pKa values that are associated to the altered affinity of the calcium binding site in the distal pocket. From these results, it can be inferred that mutations on the proximal side residues have an effect on changes in the distal side.

A study on the role of oxalate in manganese binding in manganese peroxidase (MnP) is presented. Water proton relaxation measurements have been made to find out if oxalate replaces water molecules and binds to the Mn(super 2+) ions. MnPs are generated by filamentous fungi and catalyze the oxidative depolymerization of lignin. It also catalyzes the oxidation of divalent Mn into trivalent Mn. Results show that oxalate does not bind with Mn(super 2+) ions but to the tripositive ions such as lanthanide when bound to MnP.

Study is conducted to investigate the possibility of weak intermolecular interactions between reduced cytochrome c and a binary of 325 small molecules. Study found a specific binding for p-aminophenol.

The structure and dynamics of the second domain of the human Menkes protein (MNK2), which is expressed in Escherichia coli, are analyzed by NMR in both the apo- and copper-loaded forms. The results are compared with metallochaperones and soluble domains of P-type ATPase in order to relate the primary structure to the occurrence of structural rearrangements upon copper binding.

Research shows that methionine of the M-X-C-X-X-C copper(I) binding motif of the apo CopZ protein from Bacillus subtilis is directed toward the solvent, while its sulfur atom is close to the metal ion. Data indicate that metal binding affects a hydrophobic patch around the metal site.

The molecular basis of copper trafficking, in relation to Bacillus subtilis copper(I)-transporting protein, is described employing data from XAS studies and NMR characterization. Research discusses the copper coordination and its ligands with respect to protein-protein aggregation.

Results show that CopZ and CopA proteins interact for the transport of copper in Bacillus subtilis and are involved in the copper detoxification process and copper homeostasis. Data indicate that there is an equilibrium between the homodimeric Copz and a heterodimeric CopZ-CopAb, together mediating the transfer of copper under physiological conditions.

The behaviour of the 31 mer peptide (Ac-NSFVNDIFERIAG13EASRL18A19H20YNKRS25TITSRENH2), modelling the histone-fold domain (63 to 93 residues) of H2B, towards Ni(II) was investigated by multidimensional NMR spectroscopy (1D, 2D TOCSY, NOESY and 13C-HSQC). The coordination involved the imidazole of His20 and three amide nitrogens of His20, Ala19 and Leu18, similar to the one shown by the hexapeptide LAHYNK contained in the 31 mer peptide. The solution structure of the Ni(II) complex with the tridecapeptide comprising histone's H2B 75-87 residues, was elucidated from the NOE cross correlations observed in the 2D-NOESY spectrum. A severe change in the peptide's conformation was observed, passing from a partially helical to a well-defined ordered structure around the metal ion. A remarkable structural feature is the position of the aromatic ring of Tyr21 below the coordination plane. This and the hydrophobic fence created by Leu18 and Ala19, together with the position of Arg17 and Arg24 side chains seem to be relevant to the complex stability. We believe that these structural modifications may be physiologically important in the mechanism of nickel induced carcinogenesis. [ABSTRACT FROM AUTHOR]