Pyrroloquinoline quinone was discovered in 1964 as the third redox cofactor after nicotinamide and flavin in bacteria.
Enzymes containing PQQ are called quinoproteins.
There are at least four human quinoproteins, the enzyme activity of which is dependent on PQQ:
- serine/threonine-protein kinase/endoribonuclease IRE1 (Inositol-requiring protein 1, involved in unfolded protein response, sequence O75460 in Uniprot, ERN1_HUMAN),
- Choline dehydrogenase 184.108.40.206 (CHDH_HUMAN)
- flavin reductase (Biliverdin reductase B, P30043 in Uniprot, BLVRB_HUMAN),
- Acyl-CoA synthetase family member 4 (L-aminoadipate-semialdehyde dehydrogenase, Q4L235 in Uniprot, ACSF4_HUMAN)
- Dopamine beta-hydroxylase (Dopamine beta-monooxygenase, P09172 in Uniprot, DOPO_HUMAN).
- 3,4-dihydroxyphenethylamine + ascorbate + O2 = noradrenaline + dehydroascorbate + H2O.
Binds 1 PQQ per subunit.
Binds 2 copper ions per subunit.
- L-aminoadipate-semialdehyde dehydrogenase enzyme (AL7A1_HUMAN)??
- Diamine oxidase DAO
- 1PQQ + 1 copper
Nutritional biochemistry: A new redox-cofactor vitamin for mammals, 2003
Paper and comments
Diet, energy metabolism and mitochondrial biogenesis. 2007
PURPOSE OF REVIEW:
This review highlights some recent findings regarding nutritional and endocrine regulators of mitochondrial mass and function and their association with insulin resistance.
Insulin resistance is central to many chronic metabolic diseases, including obesity, type 2 diabetes, dyslipidemia, and hypertension. Insulin resistance in skeletal muscle is associated with lower mitochondrial mass and reduced oxidative phosphorylation. Part of the mitochondrial dysfunction can be triggered by adverse nutrition. Increased fatty acid exposure, resulting from high fats diets or overfeeding, is linked to both decreased mitochondrial number and markers of oxidative phosphorylation. Caloric restriction and the adiponectin signaling pathway, however, can stimulate mitochondrial biogenesis by elevating the transcriptional machinery that regulates mitochondrial mass, improving mitochondrial efficiency, activating the peroxisome proliferator-activated receptor coactivator 1alpha mediated reactive oxygen species scavenging mechanism, and lowering reactive oxygen species production.
States of insulin resistance are characterized by defects in lipid and carbohydrate metabolism. Abnormalities in oxidative capacity, however, can be partially normalized by caloric restriction by modulating mitochondrial mass in an insulin sensitizing manner.
Pyrroloquinoline quinone improves growth and reproductive performance in mice fed chemically defined diets. 2003
Growth, reproductive performance, and indices of collagen maturation and expression were investigated in Balb/c mice fed chemically defined, amino acid-based diets with or without the addition 6 micro Mpyrroloquinoline quinone (PQQ)/kg diet. The diets were fed to virgin mice for 8 weeks before breeding. At weaning, the pups from successful pregnancies were fed the same diet as their respective dams. Reproductive performance was compromised in mice fed diets devoid of PQQ, and their offspring grew at slower rates than offspring from mice fed diets supplemented with PQQ. Successful mating (confirmed vaginal plugs) was not affected by the presence or absence of PQQ; however, pup viability (number of pups at parturition/number of pups at Day 4 of lactation) was decreased in PQQ-deprived mice. Conception (percentage of females giving live births) and fertility (percentage of births) were also decreased in PQQ-deprived mice. The slower rates of growth in offspring from PQQ-deprived mice were associated with decreased steady-state mRNA levels for Type I procollagen alpha(1)-chains in skin and lungs from neonatal mice. Values for lysyl oxidase accumulation as protein in PQQ-deficient mice also tended to be lower than corresponding values from PQQ-supplemented or -replete mice. Skin collagen solubility was increased in PQQ-deprived mice. These results indicate that PQQ supplementation can improve reproductive performance, growth, and may modulate indices of neonatal extracellular matrix production and maturation in mice fed chemically defined, but otherwise nutritionally complete diets.
Pyrroloquinoline Quinone (PQQ) Prevents Cognitive Deficit Caused by Oxidative Stress in Rats, 2008
Is the antioxidant, anti-inflammatory putative new vitamin, PQQ, involved with nitric oxide in bone metabolism? 1993
The metabolism and functions of PQQ and ascorbate may be coupled.