ISSN:
1432-072X
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary Trypanosoma (Schizotrypanum) cruzi (Corpus Christi strain) was cultivated at 28°C over a monolayer of African Green Monkey kidney cells (Vero line). The epimastigote was converted into the trypomastigote by serial passage of the organisms at 33°C in a modified culture system. This resulted in preparations containing better than 90% trypomastigotes. The biochemical composition of the epimastigotes and trypomastigotes was determined in whole cells and cell-free homogenates of organisms grown in these systems. The epimastigote contained 50±2 μg of protein, 2.0±0.1 μg of RNA, and 1.7±0.2 μg of DNA per 107 organisms; while the trypomastigote contained: 24±1 μg of protein, 1.4±0.1 μg of RNA, and 2.4±0.3 μg of DNA per 107 organisms. Data was also obtained on the specific activities of certain metabolically important enzymes. The following (in nmoles min-1mg-1 of protein) are given in the order; enzyme, epimastigote activity, trypomastigote activity: aspartic aminotransferase, 1058±139, 466±16; alanine aminotransferase, 1076±131, 474±27; aldolase, 172±8, 11±0.6; isocitric dehydrogenase (NADP-linked), 137±7, 58±4; malic dehydrogenase, 2270±116, 1073±93; glucose-6-phosphate dehydrogenase, 50±3, 115±16; 6-phosphogluconic acid dehydrogenase, 101±7, 30±2. These results were consistent with the hypothesis that the trypomastigote is an intermediate, “resting” form of T. (S.) cruzi possessing a reduced level of metabolic activity, especially with respect to carbohydrates. Differentation of the epimastigote into the trypomastigote form is accompanied by an adjustment of enzyme concentrations which reflect this reduction in metabolic activity.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00409283
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