The chemical composition of trypanosomes. I. Protein, amino acid and sugar analysis

Trypanosoma brucei, as well as Trypanosoma cruzi and more than 20 species of the genus Leishmania, form a group of flagellated protists that threaten human health. These organisms are transmitted by insects that, together with mammals, are their natural hosts. This implies that during their life cycles each of them faces environments with different physical, chemical, biochemical, and biological characteristics. In this work we review how amino acids are obtained from such environments, how they are metabolized, and how they and some of their intermediate metabolites are used as a survival toolbox to cope with the different conditions in which these parasites should establish the infections in the insects and mammalian hosts.

show abstract

“…Ala constitutes the majority of the free amino acid pool in trypanosomes [ 260 , 261 ] and Leishmania spp. [ 257 ].…”

Section: Amino Acid Metabolism In Tritrypsmentioning

confidence: 99%

The Uptake and Metabolism of Amino Acids, and Their Unique Role in the Biology of Pathogenic Trypanosomatids

et al. 2018

View full text Add to dashboard Cite

show abstract

“…Few measurements have been made on either free or bound amino acids of trypanosomes. Williamson & Desowitz (1961) analysed protein hydrolysates from several species of trypanosome for constituent amino acids; they detected little interspecies variation in either quality or quantity. Our data for the relative concentrations of protein amino acids of T. gambiense compare favourably with their determinations for the same species; differences include the level of glutamic acid (18 moles % in the analysis of Williamson and Desowitz as opposed to 9 moles % in ours) and low levels of proline and methionine not detected by Williamson and Desowitz.…”

Section: Discussionmentioning

confidence: 99%

Short-interval absorption and metabolism of some amino acids in Trypanosoma gambiense

1972

View full text Add to dashboard Cite

During 2 min incubations of Trypanosoma gambiense (bloodstream form) with [U-14C]glucose (1 mM) over 60% of absorbed label was detected in free alanine. In the presence of 12·5 mM unlabelled alanine, the amount of alanine synthesized from glucose was reduced by less than 10%. These data support previous observations on the high level of transaminase activity in African human trypanosomes.Alanine, aspartate and glutamate were metabolized to various other free amino acids whereas a significant amount of label derived from [14C]arginine could not be accounted for by amino acid assay.The sulphur containing amino acids, cysteic acid and taurine, were apparently synthesized from alanine, glutamate and arginine. The significance of these syntheses is poorly understood.Following incubations of trypanosomes for 2 min in exogenous amino acids the internal free pool became imbalanced due to accumulation and metabolism of the substrate amino acid.Evidence obtained indicated that the level of free endogenous glutamate may be rate limiting for the glutamate-pyruvate transaminase system.

show abstract

“…This eniyme is abuudant in Trypanozoon spp. and in thc blood of infected hosts ( 5 5 , 56,61). Solute efflux by T. equiperdum is not an isolated phenomcnon.…”

Section: Synthesis Of [14c]alanine By Parasites Incubated In [U-14c]mentioning

confidence: 99%

Carbohydrate Effects on Amino Acid Transport by *Trypanosoma equiperdum**

Jackson

Fisher

1977

The Journal of Protozoology

View full text Add to dashboard Cite

Uptake of 14C-labeled alanine, glutamate, lysine, methionine, proline, and phenylalanine by Trypanosoma equiperdum during 2-minute incubations occurred by diffusion and membrane-mediated processes. Amino acid metabolism was not detected by paper chromatography of trypanosome extracts. Most of 18 carbohydrates tested for ability to alter amino acid transport neither changed nor significantly inhibited transport. Glucose, however, stimulated glutamate, lysine and proline transport; fructose stimulated lysine uptake and 2-deoxy-D-glucose increased phenylalanine and methionine absorption. No evidence was found that the carbohydrates acted by binding to amino acid transport "sites." Glucose inhibition of alanine, phenylalanine, and methionine uptake was linked to glycolysis. The rapid formation of alanine form glucose stimulated alanine release and, when glycolysis was blocked, glucose no longer inhibited alanine transport. Methionine and phenylalanine release was also stimulated by glucose. Glucose changed the ability of lysine, glutamate, and proline to inhibit each others' uptake, indicating that certain amino acids are preferentially absorbed by respiring cells. Analysis of free pool amino acid levels suggested that some amino acid transport systems in T. equiperdum are linked in such a way to glycolysis as to control the cell concentrations of these amino acids.

show abstract

The chemical composition of trypanosomes. I. Protein, amino acid and sugar analysis

Cited by 54 publications

References 58 publications

The Uptake and Metabolism of Amino Acids, and Their Unique Role in the Biology of Pathogenic Trypanosomatids

The Uptake and Metabolism of Amino Acids, and Their Unique Role in the Biology of Pathogenic Trypanosomatids

Short-interval absorption and metabolism of some amino acids in Trypanosoma gambiense

Carbohydrate Effects on Amino Acid Transport by *Trypanosoma equiperdum**

Contact Info

Product

Resources

About

The chemical composition of trypanosomes. I. Protein, amino acid and sugar analysis

Cited by 54 publications

References 58 publications

The Uptake and Metabolism of Amino Acids, and Their Unique Role in the Biology of Pathogenic Trypanosomatids

The Uptake and Metabolism of Amino Acids, and Their Unique Role in the Biology of Pathogenic Trypanosomatids

Short-interval absorption and metabolism of some amino acids in Trypanosoma gambiense

Carbohydrate Effects on Amino Acid Transport by Trypanosoma equiperdum*

Contact Info

Product

Resources

About

Carbohydrate Effects on Amino Acid Transport by *Trypanosoma equiperdum**