Target type: molecularfunction
Catalysis of the reaction: pyridoxal 5'-phosphate + H2O = pyridoxal + phosphate. [EC:3.1.3.74]
Pyridoxal phosphatase activity is a crucial enzymatic function involved in the metabolism of vitamin B6, specifically pyridoxal phosphate (PLP). PLP is a critical cofactor for over 140 enzymes involved in various metabolic processes, including amino acid metabolism, neurotransmitter synthesis, and glucose metabolism.
Pyridoxal phosphatases, also known as vitamin B6 phosphatases, catalyze the hydrolysis of PLP to pyridoxal (PL) and inorganic phosphate. This dephosphorylation reaction plays a significant role in regulating the intracellular concentration of PLP, ensuring an adequate supply for PLP-dependent enzymes.
The mechanism involves the following steps:
1. **Binding:** The enzyme binds to PLP, positioning the phosphate group for hydrolysis.
2. **Hydrolysis:** The enzyme utilizes a water molecule to break the phosphate bond, releasing inorganic phosphate.
3. **Product Release:** The enzyme releases both PL and inorganic phosphate.
Pyridoxal phosphatases are crucial for maintaining cellular homeostasis and preventing vitamin B6 deficiency. Deficiency in pyridoxal phosphatase activity can lead to various health problems, including seizures, anemia, and neurological disorders.
Furthermore, pyridoxal phosphatases are implicated in various physiological processes, including:
* **Regulation of PLP-dependent enzyme activity:** By controlling PLP levels, pyridoxal phosphatases indirectly regulate the activity of numerous enzymes involved in metabolism.
* **Cellular signaling:** PLP can act as a signaling molecule, and pyridoxal phosphatases contribute to its regulation by controlling its levels.
* **Drug development:** Understanding the mechanism of pyridoxal phosphatases can guide the development of drugs targeting vitamin B6 metabolism.
Overall, pyridoxal phosphatase activity plays a vital role in maintaining cellular function, regulating metabolism, and ensuring the proper utilization of vitamin B6.'
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| Protein | Definition | Taxonomy |
|---|---|---|
| Alkaline phosphatase, tissue-nonspecific isozyme | An alkaline phosphatase, tissue-nonspecific isozyme that is encoded in the genome of cow. [OMA:P09487, PRO:DNx] | Bos taurus (cattle) |
| Alkaline phosphatase, tissue-nonspecific isozyme | An alkaline phosphatase, tissue-nonspecific isozyme that is encoded in the genome of human. [PRO:DNx, UniProtKB:P05186] | Homo sapiens (human) |
| Compound | Definition | Classes | Roles |
|---|---|---|---|
| theophylline | dimethylxanthine | adenosine receptor antagonist; anti-asthmatic drug; anti-inflammatory agent; bronchodilator agent; drug metabolite; EC 3.1.4.* (phosphoric diester hydrolase) inhibitor; fungal metabolite; human blood serum metabolite; immunomodulator; muscle relaxant; vasodilator agent | |
| adenosine monophosphate | Adenosine Monophosphate: Adenine nucleotide containing one phosphate group esterified to the sugar moiety in the 2'-, 3'-, or 5'-position. | adenosine 5'-phosphate; purine ribonucleoside 5'-monophosphate | adenosine A1 receptor agonist; cofactor; EC 3.1.3.1 (alkaline phosphatase) inhibitor; EC 3.1.3.11 (fructose-bisphosphatase) inhibitor; fundamental metabolite; micronutrient; nutraceutical |
| leucine | leucine : A branched-chain amino acid that consists of glycine in which one of the hydrogens attached to the alpha-carbon is substituted by an isobutyl group. Leucine: An essential branched-chain amino acid important for hemoglobin formation. | amino acid zwitterion; L-alpha-amino acid; leucine; proteinogenic amino acid; pyruvate family amino acid | algal metabolite; Escherichia coli metabolite; human metabolite; mouse metabolite; plant metabolite; Saccharomyces cerevisiae metabolite |
| phenylalanine | L-phenylalanine : The L-enantiomer of phenylalanine. phenylalanine : An aromatic amino acid that is alanine in which one of the methyl hydrogens is substituted by a phenyl group. Phenylalanine: An essential aromatic amino acid that is a precursor of MELANIN; DOPAMINE; noradrenalin (NOREPINEPHRINE), and THYROXINE. | amino acid zwitterion; erythrose 4-phosphate/phosphoenolpyruvate family amino acid; L-alpha-amino acid; phenylalanine; proteinogenic amino acid | algal metabolite; EC 3.1.3.1 (alkaline phosphatase) inhibitor; Escherichia coli metabolite; human xenobiotic metabolite; micronutrient; mouse metabolite; nutraceutical; plant metabolite; Saccharomyces cerevisiae metabolite |
| tryptophan | tryptophan : An alpha-amino acid that is alanine bearing an indol-3-yl substituent at position 3. Tryptophan: An essential amino acid that is necessary for normal growth in infants and for NITROGEN balance in adults. It is a precursor of INDOLE ALKALOIDS in plants. It is a precursor of SEROTONIN (hence its use as an antidepressant and sleep aid). It can be a precursor to NIACIN, albeit inefficiently, in mammals. | erythrose 4-phosphate/phosphoenolpyruvate family amino acid; L-alpha-amino acid; L-alpha-amino acid zwitterion; proteinogenic amino acid; tryptophan; tryptophan zwitterion | antidepressant; Escherichia coli metabolite; human metabolite; micronutrient; mouse metabolite; nutraceutical; plant metabolite; Saccharomyces cerevisiae metabolite |
| homoarginine | L-homoarginine : An L-lysine derivative that is the L-enantiomer of homoarginine. | homoarginine; L-lysine derivative; non-proteinogenic L-alpha-amino acid | biomarker; EC 3.1.3.1 (alkaline phosphatase) inhibitor; human metabolite; rat metabolite; xenobiotic metabolite |
| levamisole | levamisole : A 6-phenyl-2,3,5,6-tetrahydroimidazo[2,1-b][1,3]thiazole that has S configuration. It is used (generally as the monohydrochloride salt) to treat parasitic worm infections in pigs, sheep and cattle and was formerly used in humans as an adjuvant to chemotherapy for the treatment of various cancers. It is also widely used as an adulterant to coccaine. Levamisole: An antihelminthic drug that has been tried experimentally in rheumatic disorders where it apparently restores the immune response by increasing macrophage chemotaxis and T-lymphocyte function. Paradoxically, this immune enhancement appears to be beneficial in rheumatoid arthritis where dermatitis, leukopenia, and thrombocytopenia, and nausea and vomiting have been reported as side effects. (From Smith and Reynard, Textbook of Pharmacology, 1991, p435-6) | 6-phenyl-2,3,5,6-tetrahydroimidazo[2,1-b][1,3]thiazole | antinematodal drug; antirheumatic drug; EC 3.1.3.1 (alkaline phosphatase) inhibitor; immunological adjuvant; immunomodulator |
| levamisole hydrochloride | organic molecular entity | ||
| 1-(3,4-dihydroxyphenyl)-2-(1-imidazolyl)ethanone | aromatic ketone | ||
| 1-(3,4-dihydroxyphenyl)-2-[(4,6-dimethyl-2-pyrimidinyl)thio]ethanone | aromatic ketone | ||
| 2,5-dimethoxy-n-(quinolin-3-yl)benzenesulfonamide | 2,5-dimethoxy-N-(quinolin-3-yl)benzenesulfonamide: a tissue-nonspecific alkaline phosphatase inhibitor; structure in first source | quinolines | |
| 3-nitrobenzaldehyde isonicotinoylhydrazone | 3-nitrobenzaldehyde isonicotinoylhydrazone: structure in first source | ||
| salinazid | aromatic carboxylic acid; pyridinemonocarboxylic acid | ||
| phthivazide |