Thiamine Hydrolase

THIAMINE HYDROLASE is an enzyme of the lyase class containing a monoanionic residue of the thioether group of pyridoxal phosphate as an active center. Thiamine diphosphate can also act as a substrate for thiamine decarboxylase. Thiamine mono- or diphosphate is a coenzyme of various transketolases and thiaminases. In animals it is produced by intestinal bacteria. Main function - catalyzes the conversion of homothioglucose and ketohexose-2-phosphate into thiaminehydroquinone and glucose. It is synthesized in almost all tissues, especially in the kidneys, lungs, liver, nervous system, scarlet fever, ringworm, and in people suffering from diabetes, hyper- and hypothyroidism. The level of thiamine diphosphate falls after the administration of thiazides and may decrease with long-term treatment with ranitidine, diphenoxinate, paracetamol, barbiturates, procarbazine or nitrofurans and increase in response to the administration of adenine, catecholamines (mexiletine), levodopa. An overdose of thiamine may cause seizures, peripheral neuropathy, and hyperuricemia. Ineffective in patients with heart failure. Indications for use: pernicious anemia associated with deficiency of vitamins B1 and B2, prevention of radial psychoneurological polyneuritis with combined treatment of high doses of penicillin.