Stevens C, Cody R M, Gudauskas R T, Patterson A
Isr J Med Sci. 1984 Oct;20(10):1022-4.
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.
利用荧光法，以精氨酸β-萘酰胺为底物，对利用精氨酸的植物致病螺原体的精氨酸氨肽酶活性进行了研究。用玉米矮化螺原体（CSS）和柑橘螺原体的肉汤培养物、洗涤浓缩的全细胞以及无细胞提取物证实了该底物的水解。在47 mM精氨酸存在的情况下培养CSS和柑橘螺原体，导致氨肽酶活性降低，这表明该酶的合成可能受分解代谢阻遏的控制。这些实验结果提示了植物致病螺原体在体内致病性的可能生化基础。
