Peptide-based metalloprotein models represent useful systems to help understand how metalloproteins can support different functions, by the use of similar metal ion cofactors. In order to shed light on the role of the protein matrix in modulating the heme properties, we developed new models: mimochromes. They are pseudo-C2 symmetric systems, composed of two helical peptides covalently linked to the deuteroporphyrin. The use of C2 symmetry is particularly advantageous, because it simplifies the design, synthesis and characterization. However, it leaves the problem of possible diastereomeric forms. In the cobalt complex of the first derivative, mimochrome I, L and D isomers were indeed experimentally observed. All the insights derived from the Co(III)-mimochrome I structure were used to obtain a re-designed molecule, mimochrome IV. The spectroscopic characterization of the iron and cobalt derivatives suggested the presence of the L isomer as unique species. The NMR solution structure of the diamagnetic Co(III)mimochrome IV confirmed the ability of the molecule to adopt a unique topology, and revealed the peptide chains to be in helical conformation, as designed. The insertion of intramolecular, inter-chain interactions was successful in favoring the formation of one of the two possible diastereomers. The stereochemically stable structure of mimochrome IV provides an attractive model for modulating the redox potential of the heme, by simple changing the peptide chain composition around the heme.

Design of a new mimochrome with unique topology / Lombardi, Angelina; Nastri, Flavia; Marasco, Daniela; O., Maglio; G., DE SANCTIS; F., Sinibaldi; R., Santucci; M., Coletta; Pavone, Vincenzo. - In: CHEMISTRY-A EUROPEAN JOURNAL. - ISSN 0947-6539. - STAMPA. - 9:(2003), pp. 5643-5654. [10.1002/chem.200304831]

Design of a new mimochrome with unique topology

LOMBARDI, ANGELINA;NASTRI, FLAVIA;MARASCO, DANIELA;PAVONE, VINCENZO
2003

Abstract

Peptide-based metalloprotein models represent useful systems to help understand how metalloproteins can support different functions, by the use of similar metal ion cofactors. In order to shed light on the role of the protein matrix in modulating the heme properties, we developed new models: mimochromes. They are pseudo-C2 symmetric systems, composed of two helical peptides covalently linked to the deuteroporphyrin. The use of C2 symmetry is particularly advantageous, because it simplifies the design, synthesis and characterization. However, it leaves the problem of possible diastereomeric forms. In the cobalt complex of the first derivative, mimochrome I, L and D isomers were indeed experimentally observed. All the insights derived from the Co(III)-mimochrome I structure were used to obtain a re-designed molecule, mimochrome IV. The spectroscopic characterization of the iron and cobalt derivatives suggested the presence of the L isomer as unique species. The NMR solution structure of the diamagnetic Co(III)mimochrome IV confirmed the ability of the molecule to adopt a unique topology, and revealed the peptide chains to be in helical conformation, as designed. The insertion of intramolecular, inter-chain interactions was successful in favoring the formation of one of the two possible diastereomers. The stereochemically stable structure of mimochrome IV provides an attractive model for modulating the redox potential of the heme, by simple changing the peptide chain composition around the heme.
2003
Design of a new mimochrome with unique topology / Lombardi, Angelina; Nastri, Flavia; Marasco, Daniela; O., Maglio; G., DE SANCTIS; F., Sinibaldi; R., Santucci; M., Coletta; Pavone, Vincenzo. - In: CHEMISTRY-A EUROPEAN JOURNAL. - ISSN 0947-6539. - STAMPA. - 9:(2003), pp. 5643-5654. [10.1002/chem.200304831]
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11588/147716
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 47
  • ???jsp.display-item.citation.isi??? 41
social impact