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.

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.

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.

The present disclosure relates to a tyrosine hydroxylase (TH) variant lacking 60 to 120 amino acid residues at the N terminus, and a pharmaceutical composition comprising the TH variant lacking 60 to 120 amino acid residues at the N terminus and the aromatic L-amino acid decarboxylase (AADC). The present disclosure further relates to a nucleotide construct, a vector plasmid, a cell or a virus comprising the TH variant or the pharmaceutical composition, as well as use of the virus in the manufacture of a medicament for treating neurodegenerative diseases (e.g., Parkinson's Disease).

A method of improving motor function and reducing dyskinesia in a subject suffering from a neurodegenerative disease or a disease where endogenous dopamine levels are reduced in the subject comprising administering an effective amount of a viral vector comprising a nucleic acid construct comprising (i) a nucleotide sequence which encodes tyrosine hydroxylase (TH), (ii) a nucleotide sequence which encodes GTP-cyclohydrolase I (CH1), (iii) a nucleotide sequence which encodes Aromatic Amino Acid Dopa Decarboxylase (AADC), or any combination thereof to the subject.

The invention relates to microbial cells and microbial cells for use as a medicament, the cells expressing a recombinant nucleic acid encoding a eukaryotic tyrosine hydroxylase. The cells produce L-DOPA and dopamine.

The invention relate to genetically modified hosts cell comprising a pathway having enhanced production of one or more benzylisoquinoline alkaloids wherein the cell expresses heterologous insect genes encoding insect demethylases converting thebaine into northebaine, thebaine into oripavine, thebaine into nororipavine and/or oripavine into nororipavine.

The invention relates to the use of genetic constructs, expression cassettes and recombinant vectors comprising such constructs and cassettes for gene therapy and methods for treating neurodegenerative disorders, such as Parkinson's disease (PD). The constructs comprise 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). The second coding sequence is 3′ to the first coding sequence, and the first and second coding sequences are part of a single operon, wherein the genetic construct does not encode aromatic amino acid decarboxylase (AADC). The construct is delivered to the cerebrospinal fluid (CSF) of the subject.

The invention relates to tyrosine hydroxylase inhibitor compositions and methods thereof. Specifically, the invention relates to a sustained release formulation of a tyrosine hydroxylase inhibitor, particularly α-methyl-para-tyrosine.