Here we report the structural and functional characterization of a covalent complex (MKP) obtained by cross-linking microperoxidase (Mp), the haem-undecapeptide obtained by the peptic digestion of cytochrome c, with a 21-residue synthetic peptide(P21) analogous to the S-peptide of the RNase A. The covalent complex has been prepared by introducing a disulphide bond between Cys-1 of P21 and Lys-13 of Mp, previously modified with a thiol-containing reagent. On formation of the complex (which is a monomer), the helical content of P21 increases significantly. The results obtained indicate that His-13 of P21 coordinates to the sixth co-ordination position of the haem iron, thus leading to the formation of a complex characterized by an equilibrium between an 'open' and a 'closed' structure, as confirmed by molecular dynamics simulations. Under acidic pH conditions, where His-13 of P21 is loosely bound to the haem iron ('open'conformation), MKP displays appreciable, quasireversible electrochemical activity; in contrast, at neutral pH ('closed' conformation) electrochemical behaviour is negligible, indicating that P21 interferes with the electron-transfer properties typical of Mp. On the whole, MKPis a suitable starting material for building a miniature haem system, with interesting potential for application to biosensor technology.

Ippoliti, R., Picciau, A., Santucci, R., Antonini, G., Brunori, M., Ranghino, G. (1997). Covalent complex of microperoxidase with a 21-residue synthetic peptide as a maquette for low-molecular-mass redox proteins. BIOCHEMICAL JOURNAL, 328(3), 833-840.

Covalent complex of microperoxidase with a 21-residue synthetic peptide as a maquette for low-molecular-mass redox proteins

SANTUCCI, ROBERTO;
1997

Abstract

Here we report the structural and functional characterization of a covalent complex (MKP) obtained by cross-linking microperoxidase (Mp), the haem-undecapeptide obtained by the peptic digestion of cytochrome c, with a 21-residue synthetic peptide(P21) analogous to the S-peptide of the RNase A. The covalent complex has been prepared by introducing a disulphide bond between Cys-1 of P21 and Lys-13 of Mp, previously modified with a thiol-containing reagent. On formation of the complex (which is a monomer), the helical content of P21 increases significantly. The results obtained indicate that His-13 of P21 coordinates to the sixth co-ordination position of the haem iron, thus leading to the formation of a complex characterized by an equilibrium between an 'open' and a 'closed' structure, as confirmed by molecular dynamics simulations. Under acidic pH conditions, where His-13 of P21 is loosely bound to the haem iron ('open'conformation), MKP displays appreciable, quasireversible electrochemical activity; in contrast, at neutral pH ('closed' conformation) electrochemical behaviour is negligible, indicating that P21 interferes with the electron-transfer properties typical of Mp. On the whole, MKPis a suitable starting material for building a miniature haem system, with interesting potential for application to biosensor technology.
Pubblicato
Rilevanza internazionale
Articolo
Sì, ma tipo non specificato
Settore BIO/10
English
Con Impact Factor ISI
cytochrome c; peroxidase; ribonuclease a; synthetic peptide; article; complex formation; disulfide bond; electrochemical analysis; molecular dynamics; oxidation reduction reaction; ph; priority journal; protein conformation; protein cross linking; structure activity relation; Amino Acid Sequence; Amino Acids; Chromatography, High Pressure Liquid; Circular Dichroism; Computer Simulation; Cross-Linking Reagents; Electrochemistry; Electron Transport; Hemeproteins; Imidazoles; Models, Molecular; Molecular Sequence Data; Oxidation-Reduction; Peptide Fragments; Peroxidases; Protein Binding; Protein Conformation; Protein Engineering; Protein Structure, Secondary; Ribonuclease, Pancreatic; Spectrophotometry
Ippoliti, R., Picciau, A., Santucci, R., Antonini, G., Brunori, M., Ranghino, G. (1997). Covalent complex of microperoxidase with a 21-residue synthetic peptide as a maquette for low-molecular-mass redox proteins. BIOCHEMICAL JOURNAL, 328(3), 833-840.
Ippoliti, R; Picciau, A; Santucci, R; Antonini, G; Brunori, M; Ranghino, G
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2108/49996
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