Halogenation of complex organic compounds
The disclosure provides biocatalysts that halogenate complex chemical compounds in specific and predictable ways. Also disclosed are halogenated complex organic compounds. The disclosure further provides methods for the halogenation of complex chemical compounds and methods of inhibiting the contraction of smooth muscle in mammals.
1. A flavin-dependent halogenase (FDH) variant comprising one or two amino acid substitutions compared to the amino acid sequence set forth in SEQ ID NO:2 or SEQ ID NO:4, wherein the FDH variant comprises the sequence set forth in SEQ ID NO:2 with the one or two amino acid substitutions at position 129, 253, 129/253, 109, 489, 409, 265, 263, 82, 129/131, 131, 129/493, 493, 129/85, and/or 85, or wherein the FDH variant comprises the sequence set forth in SEQ ID NO:4 with the one or two amino acid substitutions at position 494, 253, 129, 129/493, 493, 129/85, 85, 129/131, and/or 131, and wherein the FDH variant is capable of catalyzing the halogenation of a complex organic compound.
2. The flavin-dependent halogenase (FDH) variant of claim 1 wherein the FDH variant comprises the sequence set forth in SEQ ID NO:2 with the one or two amino acid substitutions being S129A, H253F, S129A/H253F, H253A, D109A, F489H, 5 409A, W265A, W263A, S82A, S129A/G131S, G131S, S129A/I493S, I493S, S129A/P85S, and/or P85S, or wherein the FDH variant comprises the sequence set forth in SEQ ID NO:4 with the one or two amino acid substitutions being E494D, H253F, S129A, S129A/I493S, I493S, S129A/P85S, P85S, S129A/G131S, and/or G131S, and wherein the FDH variant is capable of catalyzing the halogenation of a complex organic compound.
3. The FDH variant of claim 2 wherein the complex organic compound is an aromatic heterocyclic organic compound.
4. The FDH variant of claim 3 wherein the aromatic heterocyclic organic compound comprises a bicyclo[2.2.2]diazaoctane ring.
5. The FDH variant of claim 3 wherein the aromatic heterocyclic organic compound comprises indole.
6. The FDH variant of claim 5 wherein the compound is an indole alkaloid.
7. The FDH variant of claim 6 wherein the indole alkaloid is a prenylated indole alkaloid.
8. The FDH variant of claim 2 wherein the FDH variant is derived from a fungal FDH.
9. The FDH variant of claim 2 wherein the FDH variant is derived from a bacterial FDH.
10. The FDH variant of claim 2 wherein the FDH variant is not derived from a fungal FDH or a bacterial FDH.
11. The FDH variant of claim 2 wherein the FDH variant is a Malbrancheamide A (MalA) halogenase variant.
12. The FDH variant of claim 11 wherein the FDH variant comprises one or two amino acid substitutions of the sequence set forth in SEQ ID NO:2, wherein each substitution is S129A, H253F, S129A/H253F, H253A, D109A, F489H, S409A, W265A, W263A, S82A, S129A/G131S, G131S, S129A/I493S, I493S, S129A/P85S, or P85S.
13. The FDH variant of claim 11 wherein the MalA halogenase comprises the sequence set forth in SEQ ID NO:6, 8, 12, or 16.
14. The FDH variant of claim 2 wherein the FDH variant is a Malbrancheamide A′ (MaIA′) halogenase variant.
15. The FDH variant of claim 13 wherein the FDH variant comprises one or two amino acid substitutions of the sequence set forth in SEQ ID NO:4, wherein each substitution is at position 494, 253, 129, 129/493, 493, 129/85, 85, 129/131, or 131.
16. The FDH variant of claim 15 wherein the FDH variant comprises an amino acid substitution variant of the sequence set forth in SEQ ID NO:4, wherein the substitution is E494D, H253F, S129A, S129A/I493S, I493S, S129A/P85S, P85S, S129A/G131S, or G131S.
17. The FDH variant of claim 14 wherein the MalA′ halogenase comprises the sequence set forth in SEQ ID NO:10, 14, or 18.
18. A polynucleotide encoding a FDH variant of claim 2 .
19. The polynucleotide of claim 18 wherein the encoded FDH variant is a Malbrancheamide A (MalA) halogenase variant or a Malbrancheamide A′ (MaIA′) halogenase variant.