Propriétés d'un noyau cytochromique b2 résultant d'une protéolyse de la l-lactate: Cytochrome c oxydoréductase de la levure

Abstract

• 1.

  1. The tryptic hydrolysis of cytochrome b₂ (yeast l-lactate: cytochrome c oxidoreductase, EC 1.1.2.3) liberates a cytochromic polypeptide which can be separated from the other fragments by gel filtration.

• 2.

  2. The properties of this new product, called “noyau cytochromique b₂”, have been investigated: the molecular weight is about 11 000 and this molecule is associated with one heme group; its spectral properties are very similar in the visible region to those of cytochrome b₂. The redox potential is −0.028 V to be compared with the value 0.000 V relative to cytochrome b₂ (pH 7.00; 30°). Severa, different components have been detected by electrophoresis. These data have been used in a discussion on the structural aspects of the active molecule of lactate dehydrogenase.