Permeability and membrane transport in the larva of<i>Taenia crassiceps</i>

Pappas, Peter W.; Read, Clark P.

doi:10.1017/s0031182000044425

Cited by 19 publications

(6 citation statements)

References 16 publications

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“…Some controversy exists concerning proline uptake by metacestodes of Taenia crassiceps. Haynes & Taylor (1968) and Haynes (1970) considered proline absorption to be mediated, but this view has been disputed by Pappas & Read (1973), who concluded that proline uptake was entirely by diffusion. Separate transport loci for imino acids have been described in a number of vertebrate systems (e.g.…”

Section: Discussionmentioning

confidence: 99%

Echinococcus granulosus: absorption of cycloleucine and α-aminoisobutyric acid by protoscoleces

Jeffs

Arme

1986

Parasitology

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Protoscoleces of Echinococcus granulosus absorb the amino acids cycloleucine and alpha-aminoisobutyric acid (AIB) by a combination of mediated uptake and diffusion. After correcting for the latter, values for Kt and Vmax of 0.124 mM and 0.947 nmoles/mg protein/2 min for cycloleucine were calculated; corresponding values for AIB were 0.039 mM and 0.139 nmoles/mg protein/2 min. Both amino acids were accumulated against a concentration gradient and a comparison of Kt and Ki values determined in mutual inhibition experiments suggested that both cycloleucine and AIB share a common uptake locus (loci). Cycloleucine uptake was pH-dependent and could be inhibited by a variety of other amino acids. Neither D- nor L-proline inhibited cycloleucine absorption but D-methionine, D-alanine, D-leucine, D-valine and D-serine were much more effective inhibitors than their L-counterparts.

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Section: Discussionmentioning

confidence: 99%

Echinococcus granulosus: absorption of cycloleucine and α-aminoisobutyric acid by protoscoleces

Jeffs

Arme

1986

Parasitology

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“…A similar phenomenon occurs with the acquisition of fatty acids and cholesterol from the host environment [6,7]. Amino acid absorption in T. crassiceps was reported several decades ago, through the proposal of three mechanisms specific for neutral, basic, and acidic amino acids [8,9]. Analysis of the taeniid genomes also revealed the presence of coding genes for amino acid transporters [4].…”

Section: Introductionmentioning

confidence: 93%

Fate of uptaken host proteins in Taenia solium and Taenia crassiceps cysticerci

et al. 2018

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During the study of host-parasite relationships in taeniid parasite diseases, including cysticercosis and hydatidosis, reports have described the presence of host proteins in the cyst fluid and tissue of metacestodes. However, the fate or role of host elements inside the parasite remains barely explored. After the publication of genomes of four cestode species, it became clear that these organisms possess a limited biosynthetic capability. The initial goal of the present study was to determine if uptaken host proteins could be a source of essential amino acids for cysticerci. To track the utilization of uptaken proteins, we added metabolically labeled IgG-H and GFP-H to the culture medium of cysticerci. Incorporation of labeled amino acid was evaluated by fluorography in cysticerci extracts. Our results showed that the use of uptaken proteins by cysticerci as a source of amino acids appeared negligible. Exploring alternative fates for the host proteins, proteomic analysis of the protein matrix in calcareous corpuscles was carried out. Since does not contain calcareous corpuscles, proteomic analyses were performed in corpuscles of cysticerci. Our results demonstrated that host proteins represented approximately 70% of protein content in the calcareous corpuscles. The presence of the two major uptaken host proteins, namely albumin and IgG, was also demonstrated by Western blot in the matrix of corpuscles. Our findings strongly suggested that the uptake and disposal of host proteins involve calcareous corpuscles, expanding the physiological role of these mineral concretions to a far more important level than previously proposed.

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“…Diclidophora is clearly no exception in this respect but it appears to be unique in having such a high proportion of the total pool (> 70%) consisting of a single amino acid, proline. In previous studies on parasites proline has been found to be particularly abundant in Taenia crassiceps (Pappas & Read, 1973) but its percentage of the total pool was only 23%. In Fasciola hepatica Kurelec & Rijavec (1966) found that alanine, proline and histidine together accounted for some 50% of the total pool and these findings of relatively high proline levels were confirmed by Isseroff, Tunis & Read (1972).…”

Section: Discussionmentioning

confidence: 87%

Amino acids ofDiclidophora merlangi(Monogenea)

Arme

Whyte

1975

Parasitology

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The level of free amino acids in Diclidophora merlangi is high, comprising over 500 μmoles/g ethanol extracted dry weight. A single amino acid, proline, constitutes some 70% of the total pool. Analysis of parasite protein and host blood and mucus revealed low proline levels, suggesting that the high free pool content was not related to a requirement for protein synthesis or to its abundance in the diet of the worm. Experiments revealed that proline was not involved specifically in osmoregulation, and the reasons for the large amounts present in Diclidophora remain unknown.

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Permeability and membrane transport in the larva ofTaenia crassiceps

Cited by 19 publications

References 16 publications

Echinococcus granulosus: absorption of cycloleucine and α-aminoisobutyric acid by protoscoleces

Echinococcus granulosus: absorption of cycloleucine and α-aminoisobutyric acid by protoscoleces

Fate of uptaken host proteins in Taenia solium and Taenia crassiceps cysticerci

Amino acids ofDiclidophora merlangi(Monogenea)

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