|Protein Name||Glucose-6-phosphate 1-dehydrogenase|
|Milk Fraction||MFGM, Exosome|
|Ref Sequence ID||NP_001231064.1|
|Protein Existence Status||Unreviewed: Experimental evidence at protein level|
|Protein Function||key regulatory enzyme of the pentose phosphate pathway and produces NADPH and riboses; necessary for reduction of oxidized glutathione by glutathione reductase; elevated in response to external stimuli and oxidative stress; G6PD activity is of major importance for NADPH production for defense against oxidative stress|
|Biochemical Properties||NADP+ is essential for both stability and enzymatic activity - high concentrations of NADP+ increase the stability of some G6PD enzyme variants; susceptible to urea, losing close to 80% of their activity; substrate for NADPH oxidase in activated macrophages and polymorphonuclear leukocytes to produce oxygen radicals; substrate for phase I and II biotransformation and detoxification enzymes|
|Significance in milk||G6PDH activity is a noninvasive biomarker of metabolic status and energy balance in early lactating cows; G6PDH activity increases from mid-pregnancy to lactation in rabbits; G6PDH is synthesized in the mammary gland in response to hormonal stimuli during pregnancy and lactation in humans; elevated G6PDH activity in early lactation reects increased shunting of G6P to the pentose phosphate pathway|
| Site(s) of PTM(s) |
|Additional Comments||G6PD deficiency interferes with the protection of the erythrocyte against oxidative stress, and causes a wide range of clinical symptoms|
|Bibliography||1. Frederiks, W. M., Bosch, K. S., De Jong, J. S. S. G., & Van Noorden, C. J. F. (2003). Post-translational regulation of glucose-6-phosphate dehydrogenase activity in (pre)neoplastic lesions in rat liver. The Journal of Histochemistry and Cytochemistry : Official Journal of the Histochemistry Society, 51(1), 105–112. https://doi.org/10.1177/002215540305100112. |
2. Zachut, M., Kra, G., Portnik, Y., Shapiro, F., & Silanikove, N. (2016). Milk glucose-6-phosphate dehydrogenase activity and glucose-6-phosphate are associated with oxidative stress and serve as indicators of energy balance in dairy cows. RSC Advances, 6(70), 65412–65417. https://doi.org/10.1039/c6ra11924g.
3. Gómez-Manzo, S., Marcial-Quino, J., Ortega-Cuellar, D., Serrano-Posada, H., González-Valdez, A., Vanoye-Carlo, A., … Reyes-Vivas, H. (2017, May 1). Functional and biochemical analysis of glucose-6-phosphate dehydrogenase (G6PD) variants: Elucidating the molecular basis of G6PD deficiency. Catalysts, Vol. 7. https://doi.org/10.3390/catal7050135.