Boonlayangoor P, Albach R A, Booden T
Arch Invest Med (Mex). 1980;11(1 Suppl):83-8.
Entamoeba histolytica, axenically grown, were unable to incorporate 14C-glycine into extractable purines, even after 16 hours incubation in the presence of this compound. Similarly, amoebas did not incorporate 14C-sodium formate into purines. Such data indicate a total absence of a de novo purine biosynthetic pathway in this amoeba. When amoebas were incubated in the presence of 3H-adenine and 3H-adenosine for one hour, considerable radioactivity was associated with AMP, ADP and ATP; no appreciable radioactivity was recoverable in the various guanine residues. However, after 16 hours incubation, a small percentage of guanine derivatives were labelled. Amoebas incubated for similar time periods in medium containing 3H-guanosine yielded high levels of radioactive guanosine and guanine nucleotides after one hour, and 3H-guanosine was not converted to adenine derivatives; after 16 hours incubation some 3H-guanosine was converted to adenine derivatives.
在无菌条件下培养的溶组织内阿米巴，即使在该化合物存在的情况下孵育16小时后，也无法将14C-甘氨酸掺入可提取的嘌呤中。同样，变形虫也不会将14C-甲酸钠掺入嘌呤中。这些数据表明，这种变形虫完全没有从头合成嘌呤的生物合成途径。当变形虫在3H-腺嘌呤和3H-腺苷存在的情况下孵育1小时时，相当多的放射性与AMP、ADP和ATP相关；在各种鸟嘌呤残基中没有可检测到的明显放射性。然而，孵育16小时后，有一小部分鸟嘌呤衍生物被标记。在含有3H-鸟苷的培养基中孵育相似时间段的变形虫，1小时后产生了高水平的放射性鸟苷和鸟嘌呤核苷酸，并且3H-鸟苷没有转化为腺嘌呤衍生物；孵育16小时后，一些3H-鸟苷转化为腺嘌呤衍生物。
