Team:Copenhagen/Project

CyperMan - Kills fungus

We hope to be able to develop bacteria that can kill fungus.
We will introduce a biological system to ''E.coli'' utilizing the plant cytochrome p450 79’s ability to produce small molecules called oximes which are toxic to fungus, as they inhibit the ability of the mitochondrial peroxidases to breakdown potentially harmful hydrogen peroxides. The oximes are produced from natural metabolites in plants.

We will exploit this activity of cytochromes p450 in the bioconversion of xenobiotics to neutralize damaging medical residues in waste water.

Cytochromes p450 are defined as heme-thiolate proteins featuring a particular spectral signature at 450 nm, thus the name [7]. Despite the label as cytochromes, these proteins are not involved in electron transfers, but act as monooxygenases in a wide range of reactions such as epoxidation, N-dealkylation, O-dealkylation, S-oxidation and hydroxylation [8].

We will focus on the hydroxylating property of the cytochromes, which is also the defining reaction for these enzymes. The reductive activation of molecular oxygen reduces one of the oxygen atoms to a molecule of water, as the other is inserted into the substrate [7].

Fig 1

RH + NAD(P)H + O2 + H+ -> ROH + NAD(P)+ + H2O

A key donor of electrons for the reduction of molecular oxygen is the NADPH dependent cytochrome p450 reductase (CPR). This protein shuttles electrons from NADPH through the FAD and FMN- coenzymes into the iron of the prosthetic heme group of cytochrome p450 [9].

A characterization of the cytochromes p450 is the main objective with this project. We will exploit the wide specificity of these cytochromes to target many different damaging agents continuously by hydroxylation, which can reduce the damaging activity of e.g. estrogen.

Figure 1The P450 catalytic cycle in hydroxylation