| EC |
4.2.1.78 |
| Accepted name: |
(S)-norcoclaurine synthase |
| Reaction: |
4-hydroxyphenylacetaldehyde + dopamine = (S)-norcoclaurine + H2O |
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For diagram of reaction, click here |
| Glossary: |
dopamine = 4-(2-aminoethyl)benzene-1,2-diol |
| Other name(s): |
(S)-norlaudanosoline synthase; 4-hydroxyphenylacetaldehyde hydro-lyase (adding dopamine) |
| Systematic name: |
4-hydroxyphenylacetaldehyde hydro-lyase [adding dopamine; (S)-norcoclaurine-forming] |
| Comments: |
The reaction makes a six-membered ring by forming a bond between C-6 of the 3,4-dihydroxyphenyl group of the dopamine and C-1 of the aldehyde in the imine formed between the substrates. The product is the precursor of the benzylisoquinoline alkaloids in plants. The enzyme, formerly known as (S)-norlaudanosoline synthase, will also catalyse the reaction of 4-(2-aminoethyl)benzene-1,2-diol + (3,4-dihydroxyphenyl)acetaldehyde to form (S)-norlaudanosoline, but this alkaloid has not been found to occur in plants. |
| Links to other databases: |
BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 79122-01-3 |
| References: |
| 1. |
Stadler, R., Zenk, M.H. A revision of the generally accepted pathway for the biosynthesis of the benzyltetrahydroisoquinoline reticuline. Liebigs Ann. Chem. (1990) 555–562. |
| 2. |
Stadler, R., Kutchan, T.M., Zenk, M.H. (S)-Norcoclaurine is the central intermediate in benzylisoquinoline alkaloid biosynthesis. Phytochemistry 28 (1989) 1083–1086. |
| 3. |
Samanani, N. and Facchini, P.J. Purification and characterization of norcoclaurine synthase. The first committed enzyme in benzylisoquinoline alkaloid biosynthesis in plants. J. Biol. Chem. 277 (2002) 33878–33883. [DOI] [PMID: 12107162] |
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| [EC 4.2.1.78 created 1984, modified 1999] |
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