Modified monooxygenases for the manufacture of hydroxylated hydrocarbons
The present invention relates to novel monooxygenases which are useful in the hydroxylation of aromatic hydrocarbons. They are particularly useful for the production of 1-naththol and 7-hydroxycoumarin from naphthol and 7-Ethoxycoumarin, respectively.
1. A modified P450 monooxygenase having an amino acid sequence with at least 90% sequence identity with SEQ ID NO: 1, wherein the asparagine at position 199 of the amino acid sequence of SEQ ID NO. 1 is substituted by an amino acid selected from the group consisting of glutamine, isoleucine, leucine, phenylalanine, histidine, methionine, arginine, serine, threonine, tyrosine, tryptophan, alanine, valine, and lysine to provide a functional mutation, wherein said functional mutation leads to an improved reactivity on hydroxylation of aromatic hydrocarbons as compared to a non-modified P450 monooxygenase.
2. The modified P450 monooxygenase of claim 1 , wherein the asparagine at position 199 is substituted by an amino acid selected from the group consisting of glutamine, isoleucine, leucine, phenylalanine, histidine, methionine, arginine, serine, tryptophan, alanine, and valine.
3. The modified P450 monooxygenase of claim 2 , wherein the asparagine at position 199 is substituted by glutamine or isoleucine.
4. The modified P450 monooxygenase according to claim 1 , wherein additionally
a) glutamic acid at position 88 is substituted by an amino acid selected from the group consisting of alanine, serine, histidine, threonine, cysteine, methionine, and asparagine, and/or
b) glutamine at position 209 is substituted by alanine.
5. The modified P450 monooxygenase according to claim 1 , wherein the sequence having at least 90% sequence identity with the sequence defined by SEQ ID NO. 1 comprises one or more conservative substitutions of amino acids as compared to the amino acid sequence defined by SEQ ID NO. 1.
6. The modified P450 monooxygenase according to claim 1 , having an addition of up to 35 amino acids at the N-terminus and/or the C-terminus.
7. The modified P450 monooxygenase according to claim 1 , having a deletion of up to 35 amino acids at the N-terminus and/or the C-terminus.
8. The modified P450 monooxygenase according to claim 1 , wherein the improved reactivity on hydroxylation of aromatic hydrocarbons comprises an increased activity on at least one hydrocarbon selected from the group consisting of naphthalene, 7-ethoxy-hydroxycoumarin, acenaphthene, fluorene, indene, methylbenzene, and ethylbenzene as compared to a non-modified P450 monooxygenase.
9. A method for the hydroxylation of an aromatic hydrocarbon, comprising
a1) having at least one of the modified P450 monooxygenases according to claim 1 mixed and reacted with said aromatic hydrocarbon and having said aromatic hydrocarbon thus hydroxylated; or
a2) having a recombinant microorganism expressing the modified P450 monooxygenase according to claim 1 mixed and reacted with said aromatic hydrocarbon.
10. The method according to claim 9 , wherein the aromatic hydrocarbon is selected from the group consisting of naphthalene, 7-ethoxy-hydroxycoumarin, acenaphthene, fluorene, indene, methylbenzene, ethylbenzene, and mixtures thereof.
11. The method according to claim 9 , wherein the hydroxylated aromatic hydrocarbon is selected from the group consisting of 1-naphthol, 7-hydroxycoumarin, 1-acenaphthylene, 9-benflumetol, indenol, benzyl alcohol, 3-methylbenzyl alcohol, and mixtures thereof.