Search

CYP152A1 (cytochrome P450BSβ) is a fatty acid peroxygenase, which specifically catalyses the oxidation of long-chain fatty acids using hydrogen peroxide as an oxidant. We have found that CYP152A1 possesses catalase activity, which competes with the hydroxylation of long-chain fatty acids, the oxidation of non-native substrates, and haem degradation. Using hydrogen peroxide, Compound I of CYP152A1 could not be observed, due to its swift decomposition via catalase activity, where Compound I reacts with another molecule of hydrogen peroxide to form O2. In contrast, a clear spectral change indicative of Compound I formation was observed when mCPBA was employed as the oxidant. This work presents valuable insights into an important role for the catalase activity of CYP152A1 in avoiding enzyme deactivation when no substrate is available for oxidation. [ABSTRACT FROM AUTHOR]

We report the enhanced cis- and enantioselective cyclopropanation of styrene catalysed by cytochrome P450BM3 in the presence of dummy substrates, i.e. decoy molecules. With the aid of the decoy molecule R-Ibu-Phe, diastereoselectivity for the cis diastereomers reached 91%, and the enantiomeric ratio for the (1S,2R) isomer reached 94%. Molecular dynamics simulations underpin the experimental data, revealing the mechanism of how enantioselectivity is controlled by the addition of decoy molecules. [ABSTRACT FROM AUTHOR]

We prepared enzyme-immobilized hydrogels and investigated the effects of the cross-linking density and polymer properties on their oxidation reaction rate. The oxidation rate of enzyme-immobilized hydrogels increased as the cross-linking density in the hydrogels increased. In addition, we controlled the oxidation rate using hydrogels exhibiting an appropriate interaction with a decoy molecule in the hydrogel. [ABSTRACT FROM AUTHOR]

Oligonucleotides represent powerful DNA-recognition tools, but the formation of undesirable "self-duplexes" becomes more probable with increasing DNA affinity. Herein, we have developed a modified nucleobase with "self-avoiding" properties. Facile methylation of guanine yields a cationic N7-methylguanine, which suppresses the formation of self-duplexes whilst improving DNA affinity through electrostatic interaction. [ABSTRACT FROM AUTHOR]

Haem substitution is an effective approach to tweak the function of haemoproteins. Herein, we report a facile haem substitution method for self-sufficient cytochrome P450BM3 (CYP102A1) from Bacillus megaterium utilising the transpeptidase Sortase A from Staphylococcus aureus. We successfully constructed Mn-substituted BM3 and investigated its catalytic activity. [ABSTRACT FROM AUTHOR]

The heme of hydrogen peroxide-dependent cytochrome P450BSβ (P450BSβ) was removed by apomyoglobin under mild conditions to give apo-P450BSβ without the need for acidic conditions and organic solvents. The circular dichroism spectrum of the apo-P450BSβ was essentially identical to that of holo-P450BSβ, showing a small structural change resulting from the removal of heme using apomyoglobin. The apo-P450BSβ was reconstituted with hemin or manganese protoporphyrin IX (MnPPIX), and the resulting reconstituted P450BSβ catalyzed the one-electron oxidation of guaiacol using hydrogen peroxide as an oxidant. A higher catalytic activity was observed for P450BSβ reconstituted with MnPPIX when meta-chloroperoxybenzoic acid (mCPBA) was used as the oxidant. [ABSTRACT FROM AUTHOR]

Enzyme performance can be improved using decoy molecules or engineered variants to accelerate the activity without affecting selectivity. Here we combine a rate accelerator variant of cytochrome P450Bm3 with decoy molecules to enhance the oxidation activity of a range of small organic molecules. This combined approach offers superior biocatalytic efficiency without modifying the product distribution. [ABSTRACT FROM AUTHOR]

Cytochrome P450SPα (P450SPα) and cytochrome P450BSβ (P450BSβ) belonging to the CYP152 family of enzymes (CYP152s) can utilize H2O2 efficiently as an oxidant for the generation of compound I. Although P450SPα and P450BSβ have very high substrate specificity and catalyse hydroxylation of long-chain fatty acids exclusively, we found that they can oxidize non-native substrates such as styrene simply by including medium chain length n-alkyl carboxylic acids as “decoy molecules.” Although we had assumed that acetic acid did not serve as a decoy molecule, P450SPα and P450BSβ efficiently catalysed oxidation of non-native substrates when the reaction was carried out at a high concentration of acetate anion. The turnover rate for epoxidation of styrene catalysed by P450BSβ in the presence of 1 M acetate anion reached 590 ± 30 min−1. [ABSTRACT FROM AUTHOR]

The use of biological host-guest interactions, specifically the binding of hemoprotein to heme, has attracted significant research interest in the design of artificial protein assemblies. However, because of the inherent flexibility of the propionic acid group of heme, it is difficult to control the positioning and orientation of the protein unit and to construct well-ordered structures. Herein, we report a heme-substituted protein dimer composed of the native hemoprotein HasA, which accommodates a tetraphenylporphyrin bearing an additional metal coordination site. The specific binding of the tetraphenylporphyrin with an additional metal coordination site that protrudes in a fixed direction confines the configuration of the dimer structure to a defined bent form. The small-angle X-ray scattering profile shows the dimer structure with a bent form and suggests dynamic rotational behavior while keeping its bent-core structure, resembling a bevel gear. This unique dimer structure demonstrates that the design of heme-substituted protein assemblies can be expanded to protein assemblies while maintaining the rotational freedom of the individual protein units., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)