The Structure of a Biosynthetic Intermediate of Pyrroloquinoline Quinone (PQQ) and Elucidation of the Final Step of PQQ Biosynthesis

2004 ◽  
Vol 126 (17) ◽  
pp. 5342-5343 ◽  
Author(s):  
Olafur T. Magnusson ◽  
Hirohide Toyama ◽  
Megumi Saeki ◽  
Robert Schwarzenbacher ◽  
Judith P. Klinman
2006 ◽  
Vol 188 (21) ◽  
pp. 7668-7676 ◽  
Author(s):  
Tina Hölscher ◽  
Helmut Görisch

ABSTRACT In Gluconobacter oxydans, pyrroloquinoline quinone (PQQ) serves as the cofactor for various membrane-bound dehydrogenases that oxidize sugars and alcohols in the periplasm. Proteins for the biosynthesis of PQQ are encoded by the pqqABCDE gene cluster. Our reverse transcription-PCR and promoter analysis data indicated that the pqqA promoter represents the only promoter within the pqqABCDE cluster of G. oxydans 621H. PQQ overproduction in G. oxydans was achieved by transformation with the plasmid-carried pqqA gene or the complete pqqABCDE cluster. A G. oxydans mutant unable to produce PQQ was obtained by site-directed disruption of the pqqA gene. In contrast to the wild-type strain, the pqqA mutant did not grow with d-mannitol, d-glucose, or glycerol as the sole energy source, showing that in G. oxydans 621H, PQQ is essential for growth with these substrates. Growth of the pqqA mutant, however, was found with d-gluconate as the energy source. The growth behavior of the pqqA mutant correlated with the presence or absence of the respective PQQ-dependent membrane-bound dehydrogenase activities, demonstrating the vital role of these enzymes in G. oxydans metabolism. A different PQQ-deficient mutant was generated by Tn5 transposon mutagenesis. This mutant showed a defect in a gene with high homology to the Escherichia coli tldD gene, which encodes a peptidase. Our results indicate that the tldD gene in G. oxydans 621H is involved in PQQ biosynthesis, possibly with a similar function to that of the pqqF genes found in other PQQ-synthesizing bacteria.


2011 ◽  
Vol 318 (1) ◽  
pp. 55-60 ◽  
Author(s):  
Irina G. Andreeva ◽  
Lyubov I. Golubeva ◽  
Tatiana M. Kuvaeva ◽  
Evgueni R. Gak ◽  
Joanna I. Katashkina ◽  
...  

2021 ◽  
Vol 22 (3) ◽  
pp. 1458
Author(s):  
Kai Qiu ◽  
Qin Zhao ◽  
Jing Wang ◽  
Guang-Hai Qi ◽  
Shu-Geng Wu ◽  
...  

Metabolic dysfunction-associated fatty liver disease (MAFLD) and its interaction with many metabolic pathways raises global public health concerns. This study aimed to determine the therapeutic effects of Pyrroloquinoline quinone (PQQ, provided by PQQ.Na2) on MAFLD in a chick model and primary chicken hepatocytes with a focus on lipid metabolism, anti-oxidative capacity, and mitochondrial biogenesis. The MAFLD chick model was established on laying hens by feeding them a high-energy low-protein (HELP) diet. Primary hepatocytes isolated from the liver of laying hens were induced for steatosis by free fatty acids (FFA) and for oxidative stress by hydrogen peroxide (H2O2). In the MAFLD chick model, the dietary supplementation of PQQ conspicuously ameliorated the negative effects of the HELP diet on liver biological functions, suppressed the progression of MAFLD mainly through enhanced lipid metabolism and protection of liver from oxidative injury. In the steatosis and oxidative stress cell models, PQQ functions in the improvement of the lipid metabolism and hepatocytes tolerance to fatty degradation and oxidative damage by enhancing mitochondrial biogenesis and then increasing the anti-oxidative activity and anti-apoptosis capacity. At both the cellular and individual levels, PQQ was demonstrated to exert protective effects of hepatocyte and liver from fat accumulation through the improvement of mitochondrial biogenesis and maintenance of redox homeostasis. The key findings of the present study provide an in-depth knowledge on the ameliorative effects of PQQ on the progression of fatty liver and its mechanism of action, thus providing a theoretical basis for the application of PQQ, as an effective nutrient, into the prevention of MAFLD.


Author(s):  
Saad Alkahtani ◽  
Saud Alarifi ◽  
Abdullah A. Alkahtane ◽  
Gadah Albasher ◽  
Mohammed AL-Zharani ◽  
...  

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