Biomaterial Database

Malate dehydrogenase isolated from extremely halophilic bacteria of the Dead Sea. 1. Purification and molecular characterization. 1977

M Mevarech, and H Eisenberg, and E Neumann

The complete purification of malate dehydrogenase (EC 1.1.1.37) from extremely halophilic bacteria of the Dead Sea is described. The purification procedure includes (a) precipitation by ammonium sulfate, (b) fractionation on Sepharose 4B using a decreasing concentration gradient of ammonium sulfate, (c) gel permeation chromatography on Sephadex G-100, (d) chromatography on hydroxylapatite, and (e) affinity chromatography on 8-(6-aminohexyl)amino-NAD+-Sepharose at 4.26 M NaCl. The absorption and fluorescence spectra of the native and denatured enzyme were measured, and the extinction coefficient at 280 nm in 4.26 M NaCl was found to be 0.803 cm2mg-1. The amino acid composition analysis showed an excess of 10.4 mol % of acidic amino acids. The apparent specific "volume" phi' of the active enzyme at 4.26 M NaCl was found to be 0.680 +/- 0.015 mL/g. The molecular weight of the native enzyme was found to be 84 000 +/- 4000 determined in 4.26 M NaCl from equilibrium sedimentation data. The molecular weight of the subunits is 39 000 as measured by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Thus, the native enzyme is composed of two subunits.

UI	MeSH Term	Description	Entries
D008291	Malate Dehydrogenase	An enzyme that catalyzes the conversion of (S)-malate and NAD+ to oxaloacetate and NADH. EC 1.1.1.37.	Malic Dehydrogenase,NAD-Malate Dehydrogenase,Dehydrogenase, Malate,Dehydrogenase, Malic,Dehydrogenase, NAD-Malate,NAD Malate Dehydrogenase
D008970	Molecular Weight	The sum of the weight of all the atoms in a molecule.	Molecular Weights,Weight, Molecular,Weights, Molecular
D006217	Halobacterium	A genus of HALOBACTERIACEAE whose growth requires a high concentration of salt. Binary fission is by constriction.
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
D013045	Species Specificity	The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.	Species Specificities,Specificities, Species,Specificity, Species
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