Document Type
Article
Abstract
F420-dependent glucose-6-phosphate dehydrogenase (FGD) catalyzes the conversion of glucose-6-phosphate to 6-phosphogluconolactone using the deazaflavin, Cofactor F420. FGD from Mycobacterium tuberculosis has been investigated due to its health relevance to prodrug activation. More recently, FGD from Cryptosporangium arvum (Cryar- FGD) has been investigated due to its broader substrate specificity toward multiple sugar phosphates. Kinetic and NMR studies have shown that Cryar-FGD has dual catalytic activity as a dehydrogenase and isomerase. Further investigations are being conducted on Cryar-FGD to characterize key residues involved in catalysis.
To investigate the catalytically active residues of Cryar-FGD, we employ steady-state temperature-dependent and pH profiling experiments. Additionally, we conduct inactivation experiments using the histidine-modifying reagent diethylpyrocarbonate (DEPC) to determine the role of an active site histidine. The ΔHion obtained from the temperature-dependent and pH profile experiments suggests that a cationic imidazole (histidine) is needed for catalysis. Inactivation with DEPC, which reacts with deprotonated histidine residues, was monophasic. The decreased enzyme activity upon treatment with DEPC supported that at least one histidine residue is involved in catalysis. This catalytic activity is implicated as Cryar-FGD’s Histidine-38.
Disciplines
Biochemistry, Biophysics, and Structural Biology | Chemistry
Publication Date
2026
License
This work is licensed under a Creative Commons Attribution 4.0 International License.
Recommended Citation
Al-Noubani, Sarah T., "BIOCHEMICAL INVESTIGATIONS OF F420-DEPENDENT GLUCOSE-6-PHOSPHATE DEHYDROGENASE FROM CRYPTOSPORANGIUM ARVUM" (2026). 2026 Spring Honors Capstones Projects. 3.
https://mavmatrix.uta.edu/honors_spring2026/3