Metalloenzyme design and engineering through strategic modifications of native protein scaffolds

Abstract

Metalloenzymes are among the major targets of protein design and engineering efforts aimed at attaining novel and efficient catalysis for biochemical transformation and biomedical applications, due to the diversity of functions imparted by the metallo-cofactors along with the versatility of the protein environment. Naturally evolved protein scaffolds can often serve as robust foundations for sustaining artificial active sites constructed by rational design, directed evolution, or a combination of the two strategies. Accumulated knowledge of structure-function relationship and advancement of tools such as computational algorithms and unnatural amino acids incorporation all contribute to the design of better metalloenzymes with catalytic properties approaching the needs of practical applications.

Peroxide Activation Regulated by Hydrogen Bonds within Artificial Cu Proteins

“…Because protein function is regulated largely by the structural properties of the protein matrix, it has been difficult to design model systems that closely mimic the local protein architecture that regulates O 2 activation. 2–6 Although site architectures are diverse in monooxygenases, they share the common characteristic that non-covalent interactions, especially hydrogen bonds (H-bonds), control metal-mediated O 2 activation. 7–9 For instance, dioxygen affinities to hemoglobins are correlated to H-bonding networks involving the Fe–O 2 unit (Figure 1B) where at least one H-bond to the proximal O-atom (O p ) is needed to form stable species.…”

An internal electron reservoir enhances catalytic CO2 reduction by a semisynthetic enzyme

“…Diverse approaches have been employed to generate these engineered systems, including cofactor substitution, 14 modification of an existing scaffold, and attachment of an unnatural moiety to a protein, 15-17 and there are many successful examples in which new functionality has been introduced into noncatalytic proteins. This approach often provides a straightforward route to tune the reactivity of a system, enabling novel chemical processes or benign reaction conditions that have otherwise been difficult to accomplish.…”

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

“…For example, Cys-heme cross-link has recently been successfully used for design of functional cyt c-like oxidoreductases [147]. Therefore, as reviewed herein, the tremendous progresses make us confident that design of heme-protein cross-links, ideally, in combination with other strategies [1][2][3][4][5][6][7][8][9][10][11]80,[148][149][150][151][152], may be applied to construct advanced artificial heme proteins with functionalities comparable to or even beyond those of natural heme proteins.…”