Tokuji Kimura

PARTICIPATION OF FLAVIN-ADENINE DINUCLEOTIDE IN THE ACTIVITY OF MALATE DEHYDROGENASE FROM MYCOBACTERIUM AVIUM.

Abstract 1. 1. Malate dehydrogenase was extracted from the insoluble cell fragments of Mycobacterium avium (Strain Takeo), and partially purified by ammonium sulphate fractionation. 2. 2. In particulate preparations a number of oxidants, particularly 2,6-dichlorophenolindophenol, phenazine methosulphate, and cytochrome c, serve as efficient electron-acceptors. With the extracted enzyme, a greater specificity is required in the electron-acceptor; phenazine methosulphate is the best oxidant and, to a lesser extent, ferricyanide is also active. 3. 3. Pyridine nucleotides do not participate in the action of the enzyme. The extracted dehydrogenase is activated, however, by low concentrations of FAD, but not by FMN. 4. 4. Malate dehydrogenase activity is completely inhibited by the addition of Amytal (sodium 5-ethyl-5-isoamyl-barbiturate) and heavy metals in the phenazine methosulphate assay.

Detection of labile sulfide in serum albumin

Abstract An artificial non-heme iron protein was synthesized from serum albumin in the presence of ferrous ammonium sulfate and mercaptoethanol.The absorption spectrum of the synthesized protein displays maxima at 279 mμ and 386 mμ with two broad peaks at 327 mμ and 630 my. By chemical analyses, the protein contains non-heme iron and labile sulfide in approximately equimolar amounts. It is concluded that labile sulfide originates from an iron-coordinared complex.