Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 2 of 2
Full-Text Articles in Enzymes and Coenzymes
Quef And Quef-Like: Diverse Chemistries In A Common Fold, Adriana Bon Ramos
Quef And Quef-Like: Diverse Chemistries In A Common Fold, Adriana Bon Ramos
Dissertations and Theses
The tunneling fold (T-Fold) superfamily is a small superfamily of enzymes found in organisms encompassing all kingdoms of life. Seven members have been identified thus far. Despite sharing a common three-dimensional structure these enzymes perform very diverse chemistries.
QueF is a bacterial NADPH-dependent oxidoreductase that catalyzes the reduction of the nitrile group of 7-cyano-7-deazaguanine (preQ0) to a primary amine (preQ1) in the queuosine biosynthetic pathway. Previous work on this enzyme has revealed the mechanism of reaction but the cofactor binding residues remain unknown. The experiments discussed herein aim to elucidate the role of residues lysine 80, …
Partial Purification And Characterization Of F₄₂₀-Dependent Nadp Reductase From Methanobrevibacter Smithii Strain De1, Scott D. Sheridan
Partial Purification And Characterization Of F₄₂₀-Dependent Nadp Reductase From Methanobrevibacter Smithii Strain De1, Scott D. Sheridan
Dissertations and Theses
The F420-dependent NADP reductase of Methanobrevibacter smithii has been partially purified employing a combination of affinity chromatography with Blue Sepharose (Cl-6B) and molecular sieve chromatography with Sephacryl S-200, The enzyme, which requires reduced F420 as an electron donor, has been purified over 145 fold with a recovery of 6%. A molecular weight of 120,00 for the native enzyme was determined by Sephacryl S-200 chromatography. A subunit molecular weight of 28,200 was determined by SDS-PAGE, indicating that the native enzyme is a tetramer. The optimal temperature for enzymatic activity was found to be 45°C, with a pH optimum …