Protein Needles as Molecular Templates for Artificial Metalloenzymes

Abstract

Construction of artificial metalloenzymes based on protein assemblies is a promising strategy for development of new catalysts because the three-dimensional nanostructures of proteins with defined individual sizes can be used as molecular platforms which allow arrangement of catalytic active centers on their surfaces. Protein needles/tubes/fibers are suitable for supporting various functional molecules including metal complexes, synthetic molecules, metal nanoparticles, and enzymes with high density and precise locations. Compared to bulk systems, the protein tube-and fiber-based materials have higher activities for catalytic reactions and electron transfer, as well as enhanced functions used in electronic devices. The natural and synthetic protein tubes and fibers are constructed by self-assembly of monomer proteins or peptides. For more precise designs of arrangements of metal complexes, we have developed a new conceptual framework based on isolation of a robust needle structure from the cell-puncturing domains of bacteriophage. The artificial protein needle shows great promise for use in creating efficient catalytic systems by providing the means to arrange the locations of various metal complexes on the protein surface. In this account, we discuss the recent development of protein needle-based metalloenzymes and the future developments we are anticipating in this field.

The broad diversity of heme-protein cross-links: An overview

“…Based on these observations, Hayashi and co-workers [9,119] developed a novel approach for assembling heme proteins to create supramolecular systems, such as a successive heme protein array with a length of 200-800 nm including 50-200 protein molecules [120,121]. Moreover, as reviewed recently by Hayashi [9,119], Ueno [122] and their co-workers, this strategy is useful for constructing hybrid materials with electrodes, nanoparticles or nanocups, generating novel biomaterials, biodevices and bioreactors with improved properties and functions.…”

Coordination complexes and biomolecules: A wise wedding for catalysis upgrade

“…(i) Auto-assembling structures: Some promising examples involving auto-assembling proteins, including fibres, needles, disc and rod structures obtained with amphiphilic proteins and peptides recently appeared in literature, showing interesting extension of this research field to heterogeneous catalysis [109,110]. This approach using amyloid type fibres has been recently developed for hydrolytic purpose [111].…”

Use of the confined spaces of apo-ferritin and virus capsids as nanoreactors for catalytic reactions

“…Other protein assemblies such as protein needles/tubes are also promising candidates for development as artificial metalloenzymes [52]. The nanocup of the protein needle known as (gp27-gp5) 3 has been modified with Fe(III) protoporphyrin and the resulting modified species has been demonstrated to catalyze H 2 O 2 -dependent sulfoxidation of thioanisole with activity 6-10 times higher than that of free Fe(III) protoporphyrin complex [53].…”