A method of demethylizing an opioid to a nor-opioid is provided. The method comprises contacting an opioid with at least one enzyme. Contacting the opioid with the at least one enzyme converts the opioid to a nor-opioid. A method of converting a nor-opioid to a nal-opioid is provided. The method comprises contacting a nor-opioid with at least one enzyme. Contacting the nor-opioid with the at least one enzyme converts the nor-opioid to a nal-opioid.

A genetic construct comprises a promoter operably linked to a first coding sequence, which encodes tyrosine hydroxylase (TH), and a second coding sequence, which encodes GTP cyclohydrolase 1 (GCH1), wherein the second coding sequence is 3 to the first coding sequence, and the first and second coding sequences are part of a single operon. The genetic construct does not encode aromatic amino acid decarboxylase (AADC).

Disclosed herein are methods that may be used for the synthesis of benzylisoquinoline alkaloids (BIAs) such as alkaloid morphinan. The methods disclosed can be used to produce thebaine, oripavine, codeine, morphine, oxycodone, hydrocodone, oxymorphone, hydromorphone, naltrexone, naloxone, hydroxycodeinone, neopinone, and/or buprenorphine. Compositions and organisms useful for the synthesis of BIAs, including thebaine synthesis polypeptides, purine permeases, and polynucleotides encoding the same, are provided.

Provided is a construct comprising (i) a nucleotide sequence which encodes tyrosine hydroxylase (TH), (ii) a nucleotide sequence which encodes GTP-cyclohydrolase I (CH1) and (iii) a nucleotide sequence which encodes Aromatic Amino Acid Dopa Decarboxylase (AADC) wherein the nucleotide sequence encoding TH is linked to the nucleotide sequence encoding CH1 such that they encode a fusion protein TH-CH1. Also provided is a construct comprising (i) a nucleotide sequence which encodes tyrosine hydroxylase (TH), (ii) a nucleotide sequence which encodes GTP-cyclohydrolase I (CH1) and (iii) a nucleotide sequence which encodes Aromatic Amino Acid Dopa Decarboxylase (AADC) wherein the nucleotide sequence encoding AADC is linked to the nucleotide sequence encoding TH such that they encode a fusion protein AADC-TH or TH-AADC. Further provided is a viral vector comprising such nucleotide sequences and its use in the treatment and/or prevention of Parkinson's disease.

In embodiments the invention relates to means and methods for the treatment of Parkinson's disease. In some embodiments the means and methods involve a GUCY2C agonist. The invention also relates to test systems and cells that are suited to identify new candidate compounds for the treatment of Parkinson's disease.

The present disclosure provides a variant tyrosine hydroxylase that provides for increased production of L-DOPA in a host cell that expresses the tyrosine hydroxylase. The present disclosure provides nucleic acids encoding the variant tyrosine hydroxylase, and host cells genetically modified with the nucleic acids. The present disclosure provides methods of making L-DOPA in a host cell. The present disclosure provides methods of making a benzylisoquinoline alkaloid (BIA), or a BIA precursor. The present disclosure provides methods of detecting L-DOPA level in a cell. The present disclosure provides methods of identifying tyrosine hydroxylase variants that provide for increased L-DOPA production; and methods of identifying gene products that provide for increased tyrosine production.

A method of demethylizing an opioid to a nor-opioid is provided. The method comprises contacting an opioid with at least one enzyme. Contacting the opioid with the at least one enzyme converts the opioid to a nor-opioid. A method of converting a nor-opioid to a nal-opioid is provided. The method comprises contacting a nor-opioid with at least one enzyme. Contacting the nor-opioid with the at least one enzyme converts the nor-opioid to a nal-opioid.

Described herein are recombinant microbial host cells comprising biosynthetic pathways and their use in producing oxidation products and downstream products, e.g., melatonin and related compounds, as well as enzyme variants, nucleic acids, vectors and methods useful for preparing and using such cells. In specific aspects, the present invention relates to monooxygenases, e.g., amino acid hydroxylases, with a modified cofactor-dependency, and to enzyme variants and microbial cells providing for an improved supply of cofactors.

Methods and engineered yeast cells for generating a benzylisoquinoline alkaloid product are provided herein. A method comprises providing engineered yeast cells and a feedstock to a reactor. In the reactor, the engineered yeast cells are subjected to fermentation by incubating the engineered yeast cells for a time period to produce a solution comprising the BIA product and cellular material. The solution comprises not more than one class of molecule selected from the group of protoberberine, morphinan, isopavine, aporphine, and benzylisoquinoline. Additionally, at least one separation unit is used to separate the BIA product from the cellular material to provide the product stream comprising the BIA product.

The present invention relates to an expression system for enzyme replacement therapy with the aim of obtaining or maintaining a steady level of L-DOPA in the blood of an individual, achieved through systemic administration of the expression system. The invention is thus useful in the treatment of catecholamine deficient disorders, such as dopamine deficient disorders including Parkinson's Disease.