Biomaterial Database

Purification and properties of the activating enzyme for iron protein of nitrogenase from the photosynthetic bacterium Rhodospirillum rubrum. 1984

L L Saari, and E W Triplett, and P W Ludden

The oxygen-labile, activating enzyme for iron protein from the photosynthetic bacterium, Rhodospirillum rubrum, was purified 11,800-fold using a combination of chromatophore washing, DE52-cellulose chromatography, hydroxylapatite chromatography, reactive red-120 cross-linked agarose chromatography, reactive red-120 cross-linked agarose chromatography, and Sephadex G-75 gel filtration. Activating enzyme appeared homogeneous on silver-stained sodium dodecyl sulfate-polyacrylamide gels, and the staining intensity of the activating-enzyme band was correlated with the activating-enzyme activity observed in in vitro assays. Either formaldehyde fixation or higher acrylamide concentration was required to accurately assess the purity of activating enzyme on silver-stained gels. Activating enzyme was stable for 30 days at 4 degrees C. Dithiothreitol was a necessary component for the stability of partially purified activating enzyme. NaCl inhibited the coupled assay for activating enzyme. The pI of activating enzyme was determined to be 6.5. Activating enzyme is composed of a minimum of 336 amino acids and a minimum calculated Mr is 32,032. The Mr of activating enzyme was estimated to be 21,700 by analytical gel filtration and 32,800 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. An absorption maximum at 280 nm was observed for the activating enzyme.

UI	MeSH Term	Description	Entries
D007501	Iron	A metallic element with atomic symbol Fe, atomic number 26, and atomic weight 55.85. It is an essential constituent of HEMOGLOBINS; CYTOCHROMES; and IRON-BINDING PROTEINS. It plays a role in cellular redox reactions and in the transport of OXYGEN.	Iron-56,Iron 56
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008970	Molecular Weight	The sum of the weight of all the atoms in a molecule.	Molecular Weights,Weight, Molecular,Weights, Molecular
D009699	N-Glycosyl Hydrolases	A class of enzymes involved in the hydrolysis of the N-glycosidic bond of nitrogen-linked sugars.	Glycoside Hydrolases, Nitrogen-linked,Hydrolases, N-Glycosyl,Nucleosidase,Nucleosidases,Nucleoside Hydrolase,Nitrogen-linked Glycoside Hydrolases,Nucleoside Hydrolases,Glycoside Hydrolases, Nitrogen linked,Hydrolase, Nucleoside,Hydrolases, N Glycosyl,Hydrolases, Nitrogen-linked Glycoside,Hydrolases, Nucleoside,N Glycosyl Hydrolases,Nitrogen linked Glycoside Hydrolases
D004798	Enzymes	Biological molecules that possess catalytic activity. They may occur naturally or be synthetically created. Enzymes are usually proteins, however CATALYTIC RNA and CATALYTIC DNA molecules have also been identified.	Biocatalyst,Enzyme,Biocatalysts
D006026	Glycoside Hydrolases	Any member of the class of enzymes that catalyze the cleavage of the glycosidic linkage of glycosides and the addition of water to the resulting molecules.	Endoglycosidase,Exoglycosidase,Glycohydrolase,Glycosidase,Glycosidases,Glycoside Hydrolase,Endoglycosidases,Exoglycosidases,Glycohydrolases,Hydrolase, Glycoside,Hydrolases, Glycoside
D000596	Amino Acids	Organic compounds that generally contain an amino (-NH2) and a carboxyl (-COOH) group. Twenty alpha-amino acids are the subunits which are polymerized to form proteins.	Amino Acid,Acid, Amino,Acids, Amino
D012247	Rhodospirillum rubrum	Vibrio- to spiral-shaped phototrophic bacteria found in stagnant water and mud exposed to light.
D013056	Spectrophotometry, Ultraviolet	Determination of the spectra of ultraviolet absorption by specific molecules in gases or liquids, for example Cl2, SO2, NO2, CS2, ozone, mercury vapor, and various unsaturated compounds. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Ultraviolet Spectrophotometry