West T P
Olson Biochemistry Laboratories, Department of Chemistry, South Dakota State University, Brookings 57007, USA.
Microbiol Res. 1995 May;150(2):149-52. doi: 10.1016/S0944-5013(11)80049-2.
Pyrimidine nucleoside catabolism in the human pathogen Sphingomonas paucimobilis was studied. It was observed that S. paucimobilis was only capable of utilizing cytidine or deoxycytidine as a sole nitrogen source when glucose served as the carbon source. Thinlayer chromatographic analyses of cytidine and uridine catabolic products revealed that the enzymes cytidine deaminase and uridine phosphorylase were active in the extracts prepared from S. paucimobilis cells. The levels of cytidine deaminase and cytosine deaminase activities were lowered after growth on cytidine or deoxycytidine as a nitrogen source instead of ammonium sulfate. Uridine phosphorylase activity increased more than 4-fold after growth on deoxycytidine as a nitrogen source while growth on the nitrogen source cytidine caused a depression in phosphorylase activity.
对人类病原体少动鞘氨醇单胞菌中的嘧啶核苷分解代谢进行了研究。观察到，当葡萄糖作为碳源时，少动鞘氨醇单胞菌仅能够利用胞苷或脱氧胞苷作为唯一氮源。对胞苷和尿苷分解代谢产物的薄层色谱分析表明，胞苷脱氨酶和尿苷磷酸化酶在少动鞘氨醇单胞菌细胞制备的提取物中具有活性。以胞苷或脱氧胞苷作为氮源而非硫酸铵生长后，胞苷脱氨酶和胞嘧啶脱氨酶的活性水平降低。以脱氧胞苷作为氮源生长后，尿苷磷酸化酶活性增加了4倍多，而以氮源胞苷生长则导致磷酸化酶活性降低。
