Thiaminase

Thiamine pyridinylase
Identifiers
EC no.2.5.1.2
CAS no.9030-35-7
Databases
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Aminopyrimidine aminohydrolase
Identifiers
EC no.3.5.99.2
Databases
IntEnzIntEnz view
BRENDABRENDA entry
ExPASyNiceZyme view
KEGGKEGG entry
MetaCycmetabolic pathway
PRIAMprofile
PDB structuresRCSB PDB PDBe PDBsum
Gene OntologyAmiGO / QuickGO
Search
PMCarticles
PubMedarticles
NCBIproteins
Thiamine

Thiaminase is an enzyme that metabolizes or breaks down thiamine into pyrimidine and thiazole. It is an antinutrient when consumed.

The old name was "aneurinase".[1]

There are two types with different Enzyme Commission numbers:[2]

  • Thiamine pyridinylase, Thiaminase I (EC 2.5.1.2, InterProIPR030901)
    • pyridine + thiamine <=> 5-(2-hydroxyethyl)-4-methylthiazole + heteropyrithiamine[3]
    • Secreted by Paenibacillus thiaminolyticus,[4] an anaerobic organism that occurs in the human small intestine
  • Aminopyrimidine aminohydrolase, Thinaminase II (EC 3.5.99.2, InterProIPR027574, IPR004305)
    • 4-amino-5-aminomethyl-2-methylpyrimidine + H2O <=> 4-amino-5-hydroxymethyl-2-methylpyrimidine + NH2+[5]
    • H2O + thiamine <=> 4-amino-5-hydroxymethyl-2-methylpyrimidine + 5-(2-hydroxyethyl)-4-methylthiazole + H+[5]
    • Produced by a wide range of plants and bacteria. In these organisms, it is mainly responsible for salvage of thiamine pyrimidine from degradation products, rather than the breakdown of thiamine.[5] In bacteria, it stays inside their cells.[6]
  1. ^ Fujita A, Nose Y, Kozuka S, Tashiro T, Ueda K, Sakamoto S (May 1952). "Studies on thiaminase. I. Activation of thiamine breakdown by organic bases". The Journal of Biological Chemistry. 196 (1): 289–95. doi:10.1016/S0021-9258(18)55732-X. PMID 12980969.
  2. ^ Thiaminases
  3. ^ "ENZYME - 2.5.1.2 thiamine pyridinylase". enzyme.expasy.org.
  4. ^ "UniProt P45741". www.uniprot.org.
  5. ^ a b c "ENZYME - 3.5.99.2 aminopyrimidine aminohydrolase". enzyme.expasy.org.
  6. ^ Cite error: The named reference aneurinolyticus was invoked but never defined (see the help page).