Canale-Parola E, Kidder G W
J Bacteriol. 1982 Dec;152(3):1105-10. doi: 10.1128/jb.152.3.1105-1110.1982.
Enzymatic activities that catalyze the interconversion of purines and purine derivatives were detected in cell extracts of Spirochaeta aurantia, Spirochaeta stenostrepta, Treponema succinifaciens, and Treponema denticola. Phosphoribosyltransferase activities present in cell extracts of each of the four spirochete species functioned in the conversion of adenine, hypoxanthine, and guanine to AMP, IMP, and GMP, respectively. Nucleotidase activities in the extracts mediated the formation of nucleosides from nucleotides. The conversion of adenosine, inosine, and guanosine to the respective purine bases was catalyzed by nucleoside phosphorylase and, in some instances, by nucleoside hydrolase activities. Guanine deaminase activity was found in both S. aurantia and S. stenostrepta, whereas adenosine deaminase activity was detected only in S. aurantia. Adenine deaminase activity in T. succinifaciens extracts was sensitive to O2 and was relatively resistant to heating. Our results indicate that the four species of spirochetes studied possess a broad spectrum of purine interconversion enzymes. It is suggested that these enzymes may function in metabolic processes important for the survival of spirochetes in nutrient-poor natural environments.
在橙色螺旋体、窄链螺旋体、琥珀酸密螺旋体和龋齿密螺旋体的细胞提取物中检测到了催化嘌呤和嘌呤衍生物相互转化的酶活性。这四种螺旋体物种的细胞提取物中存在的磷酸核糖基转移酶活性分别在将腺嘌呤、次黄嘌呤和鸟嘌呤转化为AMP、IMP和GMP的过程中发挥作用。提取物中的核苷酸酶活性介导了核苷酸形成核苷的过程。腺苷、肌苷和鸟苷向各自嘌呤碱的转化由核苷磷酸化酶催化，在某些情况下，也由核苷水解酶活性催化。在橙色螺旋体和窄链螺旋体中均发现了鸟嘌呤脱氨酶活性，而仅在橙色螺旋体中检测到腺苷脱氨酶活性。琥珀酸密螺旋体提取物中的腺嘌呤脱氨酶活性对氧气敏感，且相对耐热。我们的结果表明，所研究的四种螺旋体物种拥有广泛的嘌呤相互转化酶。有人认为，这些酶可能在对螺旋体在营养贫乏的自然环境中生存至关重要的代谢过程中发挥作用。
