A complex of microperoxidase with a synthetic peptide: structural and functional characterization.
This paper reports the kinetic and thermodynamic characterization of the complex obtained by binding to microperoxidase (the heme-containing undecapeptide derived from peptic hydrolysis of cytochrome c) a 13 residues synthetic peptide with some propensity to acquire alpha-helical secondary structure (P13). Our results indicate that P13 binds to the sixth coordination position of the Fe(III) of microperoxidase (Keq = 4.8 x 10(4) M-1 at pH 7.0 and 25 degrees C) via the imidazole of His-12, forming a stable complex. The kinetics of complex formation, its secondary structure and its electrochemical activity are reported. This is a first step towards engineering a miniature-heme complex, for a better understanding of the mechanisms governing electron transfer in hemes and heme-proteins, and possibly for novel biotechnological applications.
Santucci
R
R
Dipartimento di Biologia M.C.A., Universitá di Camerino, Rome, Italy.
Picciau
A
A
Antonini
G
G
Campanella
L
L
D000595:Amino Acid Sequence; D002942:Circular Dichroism; D004563:Electrochemistry; D007700:Kinetics; D008969:Molecular Sequence Data; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism; D010544:Peroxidases / Q000737:chemistry* / Q000378:metabolism; D017433:Protein Structure, Secondary; D013816:Thermodynamics
D010455:Peptides; D010544:Peroxidases; C021799:microperoxidase