Arginine aminopeptidase activity of phytopathogenic spiroplasmas
Stevens, C.; Cody, R.M.; Gudauskas, R.T.; Patterson, A.
Israel Journal of Medical Sciences 20(10): 1022-1024
1984
ISSN/ISBN: 0021-2180 PMID: 6511313 Document Number: 226122
The arginine aminopeptidase activity of arginine-utilizing phytopathogenic spiroplasmas was investigated with arginine beta-naphthylamide substrate using the fluorometric method. Hydrolysis of this substrate was demonstrated with broth cultures, washed concentrated whole cells, and cell-free extracts of corn stunt spiroplasma (CSS) and Spiroplasma citri. Growing CSS and S. citri in the presence of 47 mM arginine resulted in a reduction in aminopeptidase activity, indicating that synthesis of the enzyme might be subject to control by catabolic repression. Results of these experiments suggest a possible biochemical basis for pathogenicity of phytopathogenic spiroplasmas in vivo.