The Life History of Pyrroloquinoline Quinone (PQQ): A Versatile Molecule with Novel Impacts on Living Systems

Pyrroloquinoline quinone (PQQ) acting as redox cofactor of Glucose dehydrogenase is orthocyclic antioxidant acting under multifarious environmental stress and rich conditions in prokaryotes as well as eukaryotes. Microbes are the exclusive source of PQQ biosynthesis and for biocatalysis of glucose into gluconic acid and 2-ketogluconic acid by gram positive and negative bacteria. This study focus to describe PQQ biography (1979-2016) highlighted its applications acts as biocatalyst by enhanced production of NADH from pqqC, involved in several important mechanisms like bacterial energy transduction by m-ATPase, production of biocontrol substances, growth stimulating activities and DNA repair. PQQ acting as anti-neurological, anti-degenerative, anti-melanogenic and anti-cancer agent due to its antioxidant nature by scavenging free radicals. PQQ is modulator of immunity by CD4 cells count and IL-2, sleep maintenance by PGC-1 alpha pathway and inflammation due to ROS. The mineral phosphate solubilization results in plant growth promotional, biocontrol, antifungal and ISR activities. PQQ nanoparticles used for production of Biofuels cells and sulfonated polymers. It acts as a modulator of diverse signaling pathways like STAT, MAPK, JAK, JNK, P13K/Akt, mTOR, EGFR and Raps for cell proliferation, differentiation, apoptosis, Box translocation and metabolic pathways by phosphorylation of ADP and suppression of reactive oxygen species. It protects from oxidative stress by acting as Alpha AA modulator of lysine metabolism, TrxR1 in selenium metabolism, low density lipoprotein in lipid metabolism, ATP production in Energy, Glucose and carbohydrate metabolism. It has been structurally characterized with bioinformatics tools and future perspectives being molecular modeling and docking for analytical drug design.