Premium
Repression der Ureasebiosynthese in Neurospora crassa durch Ammoniumionen
Author(s) -
Schluttig A.,
Fritsche W.
Publication year - 1975
Publication title -
zeitschrift für allgemeine mikrobiologie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.58
H-Index - 54
eISSN - 1521-4028
pISSN - 0044-2208
DOI - 10.1002/jobm.19750150509
Subject(s) - neurospora crassa , urease , cycloheximide , ammonium , enzyme , enzyme repression , urea , neurospora , chemistry , psychological repression , biochemistry , ammonia , substrate (aquarium) , biosynthesis , protein biosynthesis , biology , organic chemistry , gene expression , ecology , mutant , gene
The regulation of the synthesis of the enzyme urease (urea amido hydrolase E.C. 3.5.1.5.) in Neurospora crassa was investigated. The biosynthesis of urease is repressed by ammonium ions. Under ammonium excess conditions the specific activity of urease decreases from 0.980 to 0.180 μmoles NH 3 /min/mg protein. By addition of cycloheximide it was shown that ammonia influences the synthesis of this enzyme. Enzyme induction by the substrate could be excluded. Even under the conditions of highest repression a specific activity of urease of 0.180 μmoles NH 3 /min/mg protein was measured. Possible causes of this constitutive enzyme level are discussed.