Nippostrongylus brasiliensis:Characterisation of a Somatic Amphiphilic Acetylcholinesterase with Properties Distinct from the Secreted Enzymes

Hussein, Ayman S.; Grigg, Michael E.; Selkirk, Murray E.

doi:10.1006/expr.1998.4360

Cited by 13 publications

(8 citation statements)

References 42 publications

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“…Thus, membrane-bound (neuromuscular) AChEs have been characterized in parasitic nematodes such as Trichinella spiralis (DeVos and Dick 1992), Parascaris equorum (Talesa et al 1997), Nippostrongylus brasiliensis (Hussein et al 1999a) and Dictyocaulus viviparus (Lazari et al 2004; Pezzementi et al 2012). In the insect parasite Steinernema carpocapsae , two types of amphiphilic AChE were described by Arpagaus et al (1992).…”

Section: Introductionmentioning

confidence: 99%

Acetylcholinesterase secreted by Anisakis simplex larvae (Nematoda: Anisakidae) parasitizing herring, Clupea harengus: an inverse relationship of enzyme activity in the host–parasite system

Podolska

Nadolna

2014

Parasitol Res

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Acetylcholinesterase (AChE) is a key enzyme involved in nerve impulse transmission in both vertebrates and invertebrates. In addition to neuromuscular AChE, many parasitic nematodes synthesize AChE in secretory glands and release the enzyme into their external environment. In this study, we evaluate the activities of both somatic and secreted AChE from larvae (L3) of the parasitic nematode Anisakis simplex, and compare these to the AChE activity in its host, herring, Clupea harengus. A. simplex larvae were obtained from a herring sampled in three areas of the southern Baltic. Enzyme kinetics were determined for excretory/secretory (E/S) products and somatic extracts of larvae as well as for herring muscle tissue. The results reveal that mean AChE activity is approximately fourfold higher in E/S products and eightfold higher in somatic extracts of post-secretory A. simplex larvae than in host muscle tissue. The level of AChE activity in nematodes is inversely related to the enzyme activity in their hosts, i.e. reduced AChE activity in herring was accompanied by increased enzyme activity in its parasites. The physiological function of AChE secreted by parasitic nematodes has been widely discussed in the literature, and numerous roles for this form of enzyme have been suggested. The results of our investigation indicate that AChE secretion by A. simplex larvae may constitute an adaptive mechanism that promotes survival under adverse environmental conditions. Larvae probably increase secretion of AChE in response to a direct and/or indirect effect of neurotoxic compounds. This is the first report of such a phenomenon in A. simplex.

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Section: Introductionmentioning

confidence: 99%

Acetylcholinesterase secreted by Anisakis simplex larvae (Nematoda: Anisakidae) parasitizing herring, Clupea harengus: an inverse relationship of enzyme activity in the host–parasite system

Podolska

Nadolna

2014

Parasitol Res

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“…Secreted and intracellular globins have been characterized [25], and genes for both secretory [26,27] and neuronal [28] acetylcholinesterases cloned. A recombinant cystatin (cysteine protease inhibitor) has been shown functionally to inhibit host antigen-processing pathways [29].…”

Section: Introductionmentioning

confidence: 99%

Signal sequence analysis of expressed sequence tags from the nematode Nippostrongylus brasiliensisand the evolution of secreted proteins in parasites

et al. 2004

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Signal sequence analysis of expressed sequence tags from the nematode Nippostrongylus brasiliensis and the evolution of secreted proteins in parasites

Parasitism is a highly successful mode of life and one that requires suites of gene adaptations to permit survival within a potentially hostile host. Among such adaptations is the secretion of proteins capable of modifying or manipulating the host environment. Nippos-trongylus brasiliensis is a well-studied model nematode parasite of rodents, which secretes products known to modulate host immunity.

Abstract Background: Parasitism is a highly successful mode of life and one that requires suites of gene adaptations to permit survival within a potentially hostile host. Among such adaptations is the secretion of proteins capable of modifying or manipulating the host environment. Nippostrongylus brasiliensis is a well-studied model nematode parasite of rodents, which secretes products known to modulate host immunity.

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“…A single dimeric amphiphilic (G 2 a ) form has been described in Parascaris equorum (Talesa et al, 1997), and two forms of AChE have been detected in Trichinella spiralis which sedimented at 5.3 S and 13 S in sucrose gradients (deVos and Dick, 1992). We have identified a detergent soluble enzyme in somatic extracts of N. brasiliensis which resolved at 10.2 S and was shifted to 9.4 S in the presence of Triton X-100, suggestive of a tetrameric amphiphilic (G 4 a ) form (Hussein et al, 1999b). Although it has been suggested that parasitic nematodes might express a more restricted repertoire of AChEs than free-living forms (Talesa et al, 1997), we see no compelling reason for this assumption.…”

Section: Nematode Acetylcholinesterasesmentioning

confidence: 72%

“…These experiments suggest that the differences in substrate specificity between the nematode-secreted AChEs and other invertebrate neuronal enzymes can be explained by relatively simple substitutions in residues lining the active-site gorge. Nevertheless, anomalies exist in that both the wild type and mutant AChEs secreted by N. brasiliensis are insensitive to iso-OMPA (Hussein et al, 1999a(Hussein et al, , 2000 in contrast with analogous mutants of vertebrate AChEs and invertebrate enzymes, including the N. brasiliensis somatic AChE (Hussein et al, 1999b). It will therefore be informative to determine the primary structure of the somatic (neuronal) N. brasiliensis AChE(s), as it is not only inhibited by iso-OMPA but also displays significantly greater activity than the secreted enzymes against butyrylcholine (BuCh) (Fig.…”

Section: Forms and Properties Of The Secreted Enzymesmentioning

confidence: 99%

Acetylcholinesterase secretion by nematodes.

Selkirk¹,

Henson²,

Russell³

et al. 2001

Parasitic Nematodes: Molecular Biology, Biochemistry and Immunology

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Cholinesterase structure and function, genes coding nematode acetylcholinesterases (AChEs), AChE secretion by parasitic nematodes (Nippostrongylus brasiliensis, Trichostrongylus colubriformis, Oesophagostomum radiatum, Teladorsagia circumcincta, Haemonchus contortus, Dictyocaulus viviparus, Stephanurus dentatus, Ascaris and Necator americanus), forms and properties of the secreted enzymes, the putative functions for secreted AChEs (regulation of intestinal peristalsis or local spasm, intestinal transport processes and lymphoid/myeloid cell functions, hydrolysis of alternative substrates (platelet activating factor) and binding to ingested AChE inhibitors), acetylcholine expression in the intestinal tract of rats and nematode AChEs as drug targets are reviewed.

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Nippostrongylus brasiliensis:Characterisation of a Somatic Amphiphilic Acetylcholinesterase with Properties Distinct from the Secreted Enzymes

Cited by 13 publications

References 42 publications

Acetylcholinesterase secreted by Anisakis simplex larvae (Nematoda: Anisakidae) parasitizing herring, Clupea harengus: an inverse relationship of enzyme activity in the host–parasite system

Acetylcholinesterase secreted by Anisakis simplex larvae (Nematoda: Anisakidae) parasitizing herring, Clupea harengus: an inverse relationship of enzyme activity in the host–parasite system

Signal sequence analysis of expressed sequence tags from the nematode Nippostrongylus brasiliensisand the evolution of secreted proteins in parasites

Acetylcholinesterase secretion by nematodes.

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