Inhibition of nitrite reductase and urease by arginine and proline in the cyanobacterium Anabaena cycadeae

✍ Scribed by Surendra Singh; Prof. P. S. Bisen

• Publisher: John Wiley and Sons
• Year: 1994
• Tongue: English
• Weight: 298 KB
• Volume: 34
• Category: Article
• ISSN: 0233-111X
• DOI: 10.1002/jobm.3620340606

✦ Synopsis

The arginine and proline inhibition of nitrite reductase and urease activities have been studied in the cyanobacterium Anabaena cycadeae and its mutant strain lacking glutamine synthetase (GS)') activity. Arginine and proline inhibited the nitrite reductase and urease activities in the parent strain, however, they could not do so in the mutant strain. The level of arginine-and proline-dependent NH: production in the outer medium was several fold higher in the mutant strain as compared to its parent strain. These results suggest that (1) nitrite reductase and urease activities are arginine-and proline-repressible;

(2) the catalytic function of GS is necessarily required for the arginine and proline inhibition of nitrite reductase and urease systems; and (3) the NH: resulting from the catabolism of arginine and proline should be metabolized via GS for repression of nitrite reductase and urease to occur. I ) Abbreviations: GOGAT, glutamate synthase; GS, glutamine synthetase; Hepes, 4-(2-hydroxyethyl)-1 -piperazineethane sulphonic acid; MTA, mixed alkyltrimethyl ammonium bromide; MOPS, 3-(N-morpholine) propane sulphonic acid