Study on the Docking Analysis of Homocitrate Synthase Responsible for Hydrogen Production in Nostoc punctiforme ATCC29133

In the case of Nitrogenase-based Hydrogen production, inactivation of the uptake hydrogenase (Hup) leads to significant increase in hydrogen production activity but it lasts only for few hours under the combined nitrogen atmosphere supplied by active hydrogenase. The catalytic FeMo cofactor of nitrogenase binds homocitrate, which is required for efficient nitrogen fixation. Hence blocking of Homocitrate synthase will be an efficient strategy for the significant hydrogen production. Nostoc punctiforme ATCC29133, a nitrogen fixing cyanobacterium that has the genes encoding only for the homocitrate synthase and not for uptake hydrogenase. Since the structure of homocitrate synthase is not yet elucidated, it was taken for modeling using Modeler9v5. The inhibitors for homocitrate synthase were identified from literature and were retrieved from Pubchem. The inhibitors identified were 1,10-phenanthroline, 2,2’-Dipyridyl, Hydroxylysine, Iodoacetic acid, Oxalylglycine, Pipecolic acid, Thialysine, and oxalate were docked with the homocitrate synthase using Argus lab to compare their activities. However, among these eight inhibitors screened, 1,10-phenanthroline and Oxalylglycine were found to have best docking score and proved efficient in terms of both binding affinity and strong hydrogen bond interactions.