Yeasts maceration juice from

The phosphorylation of adenosine to adenosine-5 -phosphate was demonstrated some time ago in crude yeast extracts. The extracts did not act on guanosine, and no yeast adenylic acid was formed. More recently it has been found that the synthesis involves transfer of phosphate from ATP to adenosine, and the term adenosine phosphoki-nasc has been applied to the enzyme. The activity occurs in yeast maceration juice and in kidney and liver extracts of the rat and rabbit. The enzyme is quite specific, for a partially purified brewers yeast preparation catalyzes the phosphorylation of only two nucleosides out of seventeen which have been tested. The two nucleosides are adenosine itself and 2,6-diaminopurine riboside (2-amino adenosine). The reactions are ... 

Synthesis of TPN from DPN was originally observed by incubating with ATP and yeast maceration juice. Later, a similar reaction was... 

Transamination in microorganisms is still less satisfactorily exploi-ed than in plants. Reaction GL— AL could not be detected in fresh or plas-molyzed yeast, in the writer s laboratory. In papers from Euler s institute scantily documented data are found on transamination in maceration juice from yeast and in E. coli (2,3). Cohen (61) states that E. eoli and Lebedew juice from brewer s yeast are active in the reaction GL, but not in AL— GL, while baker s yeast is inactive in both systems. Dicsfalusy (67) failed to detect the reactions mentioned in E. coli, Staphylococcus or B. mesenterieus, and Konikova (39) found no transamination of GL or AS with PU in heavy suspensions of B. brevis (Dubos strain BG). 

This conversion has been observed in the apozymase system under conditions similar to those under which the rev<>rse cliangc occurs. It takes place also in an aqueous extract ( maceration juice ) from dried ground bottom yeast, while this is catalyzing the oxidation of hexose diphosphate (1,24). Not any oxidation in which cozymase is involved is adequate for conversion of cozymase to coenzyme II the preparation oxidized alcohol... 

The intermediate steps of metabolism have been the subject of much discussion. Some aspects will be treated briefly below. Meyerhof (54) states that the glucose molecule passes anaerobically through twelve stable intermediary steps before forming alcohol and carbon dioxide at least three dissociable organic enzymes, twenty or more enzyme proteins and some bivalent metals (Mn and Mg) are necessary for the breakdown. This is a widely accepted conclusion from the work on fermentation by yeast extracts (press juice, maceration juice prepared from dried yeast, frozen yeast, or mechanically disrupted yeast) in which phosphoiylation is considered important in desmolysis. Decarboxylation of pyruvic acid appears to be the source of the carbon dioxide. Obviously then, carbon dioxide production is far from the initial step of permeation of glucose. 

Many reactions in yeast preparations can thus lead to conversion of coenzyme I to II. A single reaction which may be common to all the above systems and be the immediate source of coenzyme II has not yet been specified. Von Euler and Bauer (24 see also 26,27,115) found adenosine triphosphate necessary for the conversion in a preparation from maceration juice but in this system also a major reaction was proceeding. The preparation consisted of material precipitated by carbon dioxide from the yeast extract and dialyzed (117) the systems discussed above have not required added adenosine triphosphate and have presumably contiuned such adenosine derivatives. 

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