Designed Rubredoxin miniature in a fully artificial electron chain triggered by visible light

Abstract

Designing metal sites into de novo proteins has significantly improved, recently. However, identifying the minimal coordination spheres, able to encompass the necessary information for metal binding and activity, still represents a great challenge, today. Here, we test our understanding with a benchmark, nevertheless difficult, case. We assemble into a miniature 28-residue protein, the quintessential elements required to fold properly around a FeCys4 redox center, and to function efficiently in electron-transfer. This study addresses a challenge in de novo protein design, as it reports the crystal structure of a designed tetra-thiolate metal-binding protein in sub-Å agreement with the intended design. This allows us to well correlate structure to spectroscopic and electrochemical properties. Given its high reduction potential compared to natural and designed FeCys4-containing proteins, we exploit it as terminal electron acceptor of a fully artificial chain triggered by visible light.

Differences in heavy metal binding to cysteine‐containing coiled‐coil peptides

“…It was somewhat anticipated that Zn(II) might not interact with these peptides as, to the best of our knowledge, all cases of Zn(II) binding to coiled‐coil peptides have been in cases where both Cys and His ligands were present. However, it should be noted that Zn(II) does indeed bind to designed, non‐coiled‐coil, peptides containing only Cys ligands 24,25 …”

MetalHawk: Enhanced Classification of Metal Coordination Geometries by Artificial Neural Networks

“…Although remarkable in their implementation, the most accurate among the aforementioned methods also tend to be the most computationally intensive, making it difficult to propose their application for classifying very large numbers of sites. Availability of annotated properties for known compounds is a necessary precondition to gain valid insight from experimentally characterized systems, either by statistical inference or by ML-based techniques and to use it to design either novel metal compounds , or metalloproteins de novo. − …”

Dye Decolorization by a Miniaturized Peroxidase Fe-MimochromeVI*a

“…Besides oxidation, the metal replacement in MC6*a leads to significant shifts in the reactivity. Indeed, a manganese complex is a competent catalyst in the selective monooxygenation of thioanisole and indoles [ 40 , 45 ], the cobalt derivative is active as the hydrogen evolution catalyst [ 46 , 47 , 48 ], and the zinc one is suitable as a photosensitizer [ 49 ] ( Figure 1 ).…”

“…Besides oxidation, the metal replacement in MC6*a leads to significant shifts in the reactivity. Indeed, a manganese complex is a competent catalyst in the selective monooxygenation of thioanisole and indoles [40,45], the cobalt derivative is active as the hydrogen evolution catalyst [46][47][48], and the zinc one is suitable as a photosensitizer [49] (Figure 1). transition metal catalysts, highly oxidizing species are produced, which, in turn, based on their molecular properties, perform the specific oxidation of substrates.…”

“…Besides oxidation, the metal replacement in MC6*a leads to significant shifts in the reactivity. Indeed, a manganese complex is a competent catalyst in the selective monooxygenation of thioanisole and indoles [40,45], the cobalt derivative is active as the hydrogen evolution catalyst [46][47][48], and the zinc one is suitable as a photosensitizer [49] (Figure 1). In this study, we show that FeMC6*a displays a remarkable activity in the decolorization of four dyes: Neutral Red (NR), Methylene Blue (MB), Xylenol Orange (XO), and Bromophenol Blue (BPB).…”