Weitere Untersuchungen über die Hefen-Co-Zymase.

Abstract

The authors report further attempts to prepare a pure cozymase from yeast extract and present arguments and analytical evidence to show that the cozymase is a nucleotide closely related chemically to adenylic acid. Methods of preparation are given. The various preparations have an ACo of about 85000 to 164000 and vary in P content from 8.64-9.08% while adenylic acid has 8.94%. The molecular weight of a barium salt preparation was found to be about 390. The cozymase and other adenine derivatives have an absorption zone in the ultra-violet with a maximum at about 2580-2600 A. The position of the absorption maximum and the form of the absorption curve are similar for adenosine, muscle adenylic acid, adenosine-triphosphoric acid, and for calcium adenosine triphosphate. The cozymase is, in general, more or less quickly inactivated by extracts from animal organs. This may be due either to enzymatic deamination of the adenine residue or to a liberation of phosphoric acid by a nucleotidase which in some instances is apparently a non-specific phosphatase. Treatment for 20 hours at 30[degree] C. with a highly active phosphatase preparation, however, had no effect on the cozymase. It is inactivated by heating for an hour on the water bath at the natural acidity (pH = about 3). In a note in a later volume (214) attention is called to the fact that measurements of the absorption spectra of nucleotides and purine derivatives, similar to those made by the authors, had previously been made by Ch. Dhere and that his measurements confirm the close agreement of the absorption spectra of the cozymase and the adenine derivatives.