Cytochrome c undergoes structural variations upon binding of cardiolipin, one of the phospholipids constituting the mitochondrial membrane. Although several mechanisms governing cytochrome c/cardiolipin (cyt c/CL) recognition have been proposed, the interpretation of the process remains, at least in part, unknown. To better define the steps characterizing the cyt c-CL interaction, the role of Lys72 and Lys73, two residues thought to be important in the protein/lipid binding interaction, were recently investigated by mutagenesis. The substitution of the two (positively charged) Lys residues with Asn revealed that such mutations cancel the CL-dependent peroxidase activity of cyt c; furthermore, CL does not interact with the Lys72Asn mutant. In the present paper, we extend our study to the Lys → Arg mutants to investigate the influence exerted by the charge possessed by the residues located at positions 72 and 73 on the cyt c/CL interaction. On the basis of the present work a number of overall conclusions can be drawn: (i) position 72 must be occupied by a positively charged residue to assure cyt c/CL recognition; (ii) the Arg residues located at positions 72 and 73 permit cyt c to react with CL; (iii) the replacement of Lys72 with Arg weakens the second (low-affinity) binding transition; (iv) the Lys73Arg mutation strongly increases the peroxidase activity of the CL-bound protein.
Sinibaldi, F., Milazzo, L., Howes, B., Piro, M.c., Fiorucci, L., Polticelli, F., et al. (2017). The key role played by charge in the interaction of cytochrome c with cardiolipin. JBIC, 22(1), 19-29.
|Tipologia:||Articolo su rivista|
|Citazione:||Sinibaldi, F., Milazzo, L., Howes, B., Piro, M.c., Fiorucci, L., Polticelli, F., et al. (2017). The key role played by charge in the interaction of cytochrome c with cardiolipin. JBIC, 22(1), 19-29.|
|IF:||Con Impact Factor ISI|
|Settore Scientifico Disciplinare:||Settore BIO/10|
|Revisione (peer review):||Esperti anonimi|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1007/s00775-016-1404-5|
|Stato di pubblicazione:||Pubblicato|
|Data di pubblicazione:||2017|
|Titolo:||The key role played by charge in the interaction of cytochrome c with cardiolipin|
|Autori:||Sinibaldi, F; Milazzo, L; Howes, B; Piro, Mc; Fiorucci, L; Polticelli, F; Ascenzi, P; Coletta, M; Smulevich, G; Santucci, R|
|Appare nelle tipologie:||01 - Articolo su rivista|