title: A heme-peptide metalloenzyme mimetic with natural peroxidase-like activity.
abstract: Mimicking enzymes with alternative molecules represents an important objective in synthetic biology, aimed to obtain new chemical entities for specific applications. This objective is hampered by the large size and complexity of enzymes. The manipulation of their structures often leads to a reduction of enzyme activity. Herein, we describe the spectroscopic and functional characterization of Fe(III)-mimochrome VI, a 3.5 kDa synthetic heme-protein model, which displays a peroxidase-like catalytic activity. By the use of hydrogen peroxide, Fe(III)-mimochrome VI efficiently catalyzes the oxidation of several substrates, with a typical Michaelis-Menten mechanism and with several multiple turnovers. The catalytic efficiency of Fe(III)-mimochrome VI in the oxidation of 2,2'-azino-di(3-ethyl-benzothiazoline-6-sulfonic acid (ABTS) and guaiacol (k(cat)/K(m)=4417 and 870 mM(-1) s(-1), respectively) is comparable to that of native horseradish peroxidase (HRP, k(cat)/K(m)=5125 and 500 mM(-1) s(-1), respectively). Fe(III)-mimochrome VI also converts phenol to 4- and 2-nitrophenol in the presence of NO(2) (-) and H(2) O(2) in high yields. These results demonstrate that small synthetic peptides can impart high enzyme activities to metal cofactors, and anticipate the possibility of constructing new biocatalysts tailored to specific functions.
authors.affiliation: Department of Chemistry, Complesso Universitario Monte S. Angelo, University of Naples Federico II, Via Cintia, 80126 Naples, Italy.
authors.forename: Flavia
authors.initials: F
authors.lastname: Nastri
authors.forename: Liliana
authors.initials: L
authors.lastname: Lista
authors.forename: Paola
authors.initials: P
authors.lastname: Ringhieri
authors.forename: Rosa
authors.initials: R
authors.lastname: Vitale
authors.forename: Marina
authors.initials: M
authors.lastname: Faiella
authors.forename: Concetta
authors.initials: C
authors.lastname: Andreozzi
authors.forename: Paola
authors.initials: P
authors.lastname: Travascio
authors.forename: Ornella
authors.initials: O
authors.lastname: Maglio
authors.forename: Angela
authors.initials: A
authors.lastname: Lombardi
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Pavone
mesh_terms: D000595:Amino Acid Sequence; D002384:Catalysis; D006418:Heme / Q000737:chemistry*; D006735:Horseradish Peroxidase / Q000737:chemistry / Q000378:metabolism; D008956:Models, Chemical; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D010544:Peroxidases / Q000737:chemistry / Q000378:metabolism*; D011506:Proteins / Q000737:chemistry*
chemical_list: D011506:Proteins; D006418:Heme; D006735:Horseradish Peroxidase; D010544:Peroxidases