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1.
Gunter Lochnit Roger D Dennis Ulrich Zahringer Rudolf Geyer 《Glycoconjugate journal》1997,14(3):389-399
The neutral glycosphingolipid fraction from adults of the pig parasitic nematode, Ascaris suum, was resolved into four components
on thin-layer chromatography. The high-performance liquid chromatography-isolated components were structurally analysed by:
methylation analysis; exoglycosidase cleavage; gas-liquid chromatography/mass spectrometry; liquid secondary-ion mass spectrometry;
and, in particular, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Their chemical structures
were determined as: Glc(β1-1)ceramide, Man(β1-4)Glc(β1-1)ceramide, GlcNAc(β1-3)Man(β1-4)Glc(β1-1)ceramide and Gal(α1-3)GalNAc(β1-4)GlcNAc(β1-3)Man(β1-4)Glc(β1-1)ceramide;
and were characterized as belonging to the arthro-series of protostomial glycosphingolipids. No glycosphingolipid component
corresponding to ceramide tetrasaccharide was detected during these analyses. The ceramide composition of the parent glycosphingolipids
was dominated by the 2-(R)-hydroxy C24:0 fatty acid, cerebronic acid, and C17 sphingoid-bases: 15-methylhexadecasphing-4-enine
and 15-methylhexadecaphinganine in approximately equal proportions. The component ceramide monohexoside was characterized
by an additional 15-methylhexadecaphytosphingosine. Abbreviations: CDH, ceramide dihexoside; Cer, ceramide; CMH, ceramide
monohexoside; CPH, ceramide pentahexoside; CTH, ceramide trihexoside; CTetH, ceramide tetrahexoside; Hex, hexose; HexNAc,
N-acetylhexosamine; HPTLC, high-performance thin-layer chromatography; LSIMS, liquid secondary-ion mass spectrometry; MALDI-TOF-MS,
matrix-assisted laser desorption/ionization time-of-flight mass spectrometry; N-, Nz- and A-glyco(sphingo)lipids, neutral,
neutralzwitterionic and acidic glyco(sphingo)lipids, respectively
This revised version was published online in November 2006 with corrections to the Cover Date. 相似文献
2.
3.
Lindy Holden-Dye Michelle Joyner Vincent O'Connor Robert J. Walker 《Parasitology international》2013,62(6):606-615
Nicotinic acetylcholine receptors (nAChRs) play a key role in the normal physiology of nematodes and provide an established target site for anthelmintics. The free-living nematode, Caenorhabditis elegans, has a large number of nAChR subunit genes in its genome and so provides an experimental model for testing novel anthelmintics which act at these sites. However, many parasitic nematodes lack specific genes present in C. elegans, and so care is required in extrapolating from studies using C. elegans to the situation in other nematodes. In this review the properties of C. elegans nAChRs are reviewed and compared to those of parasitic nematodes. This forms the basis for a discussion of the possible subunit composition of nAChRs from different species of parasitic nematodes. Currently our knowledge on this is largely based on studies using heterologous expression and pharmacological analysis of receptor subunits in Xenopus laevis oocytes. It is concluded that more information is required regarding the subunit composition and pharmacology of endogenous nAChRs in parasitic nematodes. 相似文献
4.
Atypical (RIO) protein kinases from Haemonchus contortus--promise as new targets for nematocidal drugs 总被引:1,自引:0,他引:1
Campbell BE Boag PR Hofmann A Cantacessi C Wang CK Taylor P Hu M Sindhu ZU Loukas A Sternberg PW Gasser RB 《Biotechnology advances》2011,29(3):338-350
Almost nothing is known about atypical kinases in multicellular organisms, including parasites. Supported by information and data available for the free-living nematode, Caenorhabditis elegans, and other eukaryotes, the present article describes three RIO kinase genes, riok-1, riok-2 and riok-3, from Haemonchus contortus, one of the most important parasitic nematodes of small ruminants. Analyses of these genes and their products predict that they each play critical roles in the developmental pathways of parasitic nematodes. The findings of this review indicate prospects for functional studies of these genes in C. elegans (as a surrogate) and opportunities for the design of a novel class of nematode-specific inhibitors of RIO kinases. The latter aspect is of paramount importance, given the serious problems linked to anthelmintic resistance in parasitic nematode populations of livestock. 相似文献
5.
Daisei Miyamoto Takao Ueno Sachiko Takashima Kazuhide Ohta Toshio Miyawaki Takashi Suzuki Yasuo Suzuki 《Glycoconjugate journal》1997,14(3):379-388
A new monoclonal antibody (TU-1) directed against the Galα1-4Galβ1-4Glc residue of the Gb3Cer/CD77 antigen was prepared by
the hybridoma technique following immunization of mice with an emulsion composed of monophosphoryl lipid A, trehalose dimycolate,
and Gb3Cer isolated from porcine erythrocytes. TU-1 showed reactivity towards Gb3Cer and lyso-Gb3Cer (Galα1-4Galβ1-4Glcβ1-1′Sph),
although the reactivity towards lyso-Gb3Cer was about 10-fold lower than that to Gb3Cer. But it did not react with other structurally-related
glycolipids, such as LacCer (Galβ1-4Glcβ1-1′Cer), Gg3Cer, Gg4Cer, Gb4Cer (GalNAcβ1-3Galα1-4Galβ1-4Glcβ1-1′Cer), galactosylparagloboside
(Galα1-3Galβ1-4GlcNAcβ1-3Galβ1-4Glcβ1-1′Cer), sulfatide (HSO3-3Galβ1-1′Cer), other gangliosides (GM3, GM2, GM1a, GD1a and
GT1b), or P1 antigen (Galα1-4Galβ1-4GlcNAcβ1-3Galβ1-4Glcβ1-1′Cer) among neutral glycolipids prepared from P1 phenotype red
blood cells. Furthermore, TU-1 reacted with viable lymphoma cells, such as human Burkitt lymphoma cell line, Daudi, and Epstein-Barr
virus (EBV)-transformed B cells by the immunofluorescence method, and also with germinal centre B cells in human tonsil and
vessel endothelial cells in human thymus histochemically. These results indicate that TU-1 is a monoclonal antibody directed
against Gb3Cer/CD77 antigen and can be utilized as a diagnostic reagent for Burkitt's lymphoma and also for detection of the
blood group Pk antigen in glycolipid extracts of erythrocytes. Abbreviations: ATL, adult T-cell leukaemia; BSA, bovine serum
albumin; Cer, ceramide; DPPC, L-α-dipalmitoylphosphatidylcholine; EBV, Epstein-Barr virus; FCS, fetal calf serum; GalCer,
Galβ1-1′Cer; GlcCer, Glcβ1-1′Cer; LacCer, Galβ1-4Glcβ1-1′Cer; Gb3Cer, Galα1-4Galβ1-4Glcβ1-1′Cer; Iyso-Gb3Cer, Galα1-4Galβ1-4Glc1-1′Sph;
Gb4Cer, GalNAcβ1-3Galα1-4Galβ1-4Glc1-1′Cer; galactosylparagloboside, Galα1-3Galβ1-4GlcNAcβ1-3Galβ1-4Glcβ1-1′Cer; Gg3Cer, GalNAcβ1-4Galβ1-4Glcβ1-1′Cer;
Gg4Cer, Galβ1-3GalNAcβ1-4Galβ1-4Glcβ1-1′Cer; GM3, Neu5Acα2-3Galβ1-4Glcβ1-1′Cer; GM2, GalNAcβ1-4(Neu5Acα2-3) Galβ1-4Glcβ1-1′Cer;
GM1a, Galβ1-3GalNAcβ1-4(Neu5Acα2-3)Galβ1-4Glcβ1-1′Cer; GD1a, Neu5Acα2-3Galβ1-3GalNAcβ1-4(Neu5Acα2-3)Galβ1-4Glcβ1-1′Cer; GD1b,
Galβ1-3GalNAcβ1-4(Neu5Acα2-8Neu5Acα2-3)Galβ1-4Glcβ1-1′Cer; GT1b, Neu5Acα2-3Galβ1-3GalNAcβ1-4(Neu5Acα2-8Neu5Acα2-3) Galβ1-4Glcβ1-1′Cer;
HRP, horseradish peroxidase; LDH, lactate dehydrogenase; MAb, monoclonal antibody; MPL, monophosphoryl lipid A; P1 antigen,
Galα1-4Galβ1-4GlcNAcβ1-3Galβ1-4Glcβ1-1′Cer; PVP, polyvinylpyrolidone; Sph, sphingosine; sulfatide, HSO3-Galβ1-1′Cer; TDM,
trehalose dimycolate; TLC, thin-layer chromatography
This revised version was published online in November 2006 with corrections to the Cover Date. 相似文献
6.
We previously showed that human melanoma, CHO and other cellscan convert ß-xylosides into structural analogs ofganglioside GM3. We have investigated several potential acceptorsincluding a series of n-alkyl-ß-D-glucosides (n =69). All were labeled with 3H-galactose when incubatedwith human melanoma cells. Octyl-ß-D-glucoside (GlcßOctyl)was the best acceptor, whereas neither octyl--D-glucoside norN-octanoyl-methylglucamine (MEGA 8) were labeled. Analysis ofthe products by a combination of chromatographic methods andspecific enzyme digestions showed that the acceptors first receiveda single Galß1,4 residue followed by an 2,3 linkedsialic acid. Synthesis of these products did not affect cellviability, adherence, protein biosynthesis, or incorporationof radio-labeled precursors into glycoprotein, glycolipid orproteoglycans. To determine which ß1,4 galactosyltransferase synthesized Galß1,4GlcßOctyl,we analyzed similar incubations using CHO cells and a mutantCHO line (CHO 761) which lacks GAG-core specific ß1,4galactosyltransferase. The mutant cells showed the same levelof incorporation as the control, eliminating this enzyme asa candidate. Thermal inactivation kinetics using melanoma cellmicrosomes and rat liver Golgi to galactosylate GlcßOctylshowed the same half-life as UDP-Gal:GlcNAc ß1,4 galactosyltransferase,whereas LacCer synthase was inactivated at a much faster rate.We show that GlcßOctyl is a substrate for purifiedbovine milk UDP-Gal:GlcNAc ß1,4 galactosyltransferaseFurthermore, the galactosylation of GlcßOctyl by CHOcell microsomes can be competitively inhibited by GlcNAc orGlcNAcßMU . These results indicate that UDP-Gal:GlcNAcß1,4 galactosyltransferase is the enzyme used forthe synthesis of the alkyl lactosides when cells or rat liverGolgi are incubated with alkyl ß glucosides. alkylglucosides galactosyltransferase glycolipid artificial acceptors 相似文献
7.
《International journal for parasitology》2022,52(1):77-85
Nematode parasite infections cause disease in humans and animals and threaten global food security by reducing productivity in livestock and crop farming. The escalation of anthelmintic resistance in economically important nematode parasites underscores the need for the identification of novel drug targets in these worms. Nematode neuropeptide signalling is an attractive system for chemotherapeutic exploitation, with neuropeptide G-protein coupled receptors (NP-GPCRs) representing the lead targets. In order to successfully validate NP-GPCRs for parasite control it is necessary to characterise their function and importance to nematode biology. This can be aided through identification of receptor activating ligand(s) via deorphanisation. Such efforts require the identification of all neuropeptide ligands within parasites. Here we mined the genomes of nine therapeutically relevant pathogenic nematodes to characterise the neuropeptide-like protein complements and demonstrate that: (i) parasitic nematodes possess a reduced complement of neuropeptide-like protein-encoding genes relative to Caenorhabditis elegans; (ii) parasite neuropeptide-like protein profiles are broadly conserved between nematode clades; (iii) five Ce-nlps are completely conserved across the nematode species examined; (iv) the extent and position of neuropeptide-like protein-motif conservation is variable; (v) novel RPamide-encoding genes are present in parasitic nematodes; (vi) novel Allatostatin-C-like peptide encoding genes are present in both C. elegans and parasitic nematodes; (vii) novel neuropeptide-like protein families are absent in C. elegans; and (viii) highly conserved nematode neuropeptide-like proteins are bioactive. These data highlight the complexity of nematode neuropeptide-like proteins and reveal the need for nomenclature revision in this diverse neuropeptide family. The identification of neuropeptide-like protein ligands, and characterisation of those with functional relevance, advance our understanding of neuropeptide signalling to support exploitation of the neuropeptidergic system as an anthelmintic target. 相似文献
8.
Nematode cys-loop ligand gated ion channels (CLGIC) mediate neurotransmission and are important targets for anthelmintics
in parasitic nematodes. The CLGIC superfamily in nematodes includes ion channels gated by acetylcholine, γ-amino butyric acid
(GABA), glutamate, glycine and 5-HT. The macrocyclic lactones and the nicotinic agonists are important groups of anthelmintics
that target the glutamate gated chloride channels and the nicotinic acetylcholine receptors, respectively. The model organism
Caenorhabditis elegans has the most diverse families of cys-loop LGIC known in any organism. Many parasitic nematodes have homologues of C. elegans receptors but to date no genome wide investigations have been done. The genome sequencing projects of Brugia malayi (clade III) and Trichinella spiralis (clade I) have allowed us to characterise the CLGIC families in these species. Although the main groups of CLGICs targeted
by anthelmintics are represented in both the nematode genomes investigated here, the CLGIC family is much smaller in B. malayi and T. spiralis, suggesting that care must be taken when using C. elegans as a model organism for distantly related nematodes. 相似文献
9.
Johannes Muthing 《Glycoconjugate journal》1997,14(2):241-248
The gangliosides GM1b, GalNAc-GM1b and GD1α are typical compounds of concanavalin A stimulated splenic T lymphoblasts of CBA/J
inbred mice. Their structural characterization has been described in previous studies. The intention of this work was the
comparative TLC immunostaining analysis of the glycosphingolipid composition of lectin stimulated splenic T lymphoblasts obtained
from six genetically different inbred mouse strains. The strains examined were AKR, BALB/c, C57BL/6, CBA/J, DBA/2 and WHT/Ht,
which are commonly used for biochemical and immunological studies. The neutral glycosphingolipid GgOse4Cer, the precursor
for GM1b-type gangliosides, was expressed by all six strains investigated. AKR, C57BL/6 and DBA/2 showed high and BALB/c,
CBA/J and WHT/Ht diminished expression in T lymphoblasts, based on single cell calculation. The gangliosides GM1b and GalNAc-GM1b,
elongation products of GgOse4Cer, displayed strain-specific differences in their intensities, which were found to correlate
with the intensities of GgOse4Cer expression of the same strains. Concerning sialic acid substitution of gangliosides, GM1b
and GalNAc-GM1b predominantly carry N-acetylneuraminic acid, whereas choleragenoid receptors GM1a and Gal-GalNAc-GM1b, which
are also expressed by all six strains, are characterized by dominance of N-glycolylneuraminic acid. Two highly polar gangliosides, designated with X and Y, which have not been previously recognized
in murine lymphoid tissue, were detected by positive anti-GalNAc-GM1b antibody and choleragenoid binding, respectively. Both
gangliosides were restricted to AKR, DBA/2 and C57BL/6 mice. The other three strains BALB/c, CBA/J and WHT/Ht are lacking
these structures. In summary, the GM1b-type pathway is quite active in all six strains analysed in this study. Strain-specific
genetic variations in T lymphoblast gangliosides were observed with the occurrence of gangliosides X and Y. This study and
data from other groups strongly indicate for GM1b-type gangliosides a functional association with T cell activation and leukocyte
mediated reactions. Abbreviations: ConA, concanavalin A; GSL(s), glycosphingolipid(s); HPTLC, high-performance thin-layer
chromatography; NeuAc, N-acetylneuraminic acid; NeuGc, N-glycolylneuraminic acid. The designation of the following glycosphingolipids
follows the IUPAC-IUB recommendations (1977) [48] and the ganglioside nomenclature system of Svennerholm [49] for GM1a-type
gangliosides. Glucosylceramide or GlcCer, Glcβ1-1Cer; lactosylceramide or LacCer, Galβ1-4Glcβ1-1Cer; gangliotriaosylceramide
or GgOse3Cer or Gg3, GalNAcβ1-4Galβ1-4Glcβ1-1Cer; gangliotetraosylceramide or GgOse4Cer or Gg4, Galβ1-3GalNAcβ1-4Galβ1-4Glcβ1-1Cer;
gangliopentaosylceramide or GgOse5Cer, GalNAcβ1-4Galβ1-3GalNAcβ1-4Galβ1-4Glcβ1-1Cer; gangliohexaosylceramide or GgOse6Cer,
Galβ1-3GalNAcβ1-4Galβ1-3GalNAcβ1-4Galβ1-4Glcβ1-1Cer. GM3, II3NeuAc-LacCer; GM1 or GM1a, II3NeuAc-GgOse4Cer; GM1b, IV3NeuAc-GgOse4Cer;
GalNAc-GM1b, IV3NeuAc-GgOse5Cer; GD1a, IV3NeuAc, II3NeuAc-GgOse4Cer; GD1b, II3(NeuAc)2-GgOse4Cer; GD1c, IV3(NeuAc)2-GgOse4Cer;
GD1α, IV3NeuAc, III6NeuAc-GgOse4Cer. Only NeuAc-substituted gangliosides are presented in this list of abbreviations
This revised version was published online in November 2006 with corrections to the Cover Date. 相似文献
10.
Nik AIIN Him Victoria Gillan Richard D Emes Kirsty Maitland Eileen Devaney 《BMC evolutionary biology》2009,9(1):254
Background
Hsp-90 from the free-living nematode Caenorhabditis elegans is unique in that it fails to bind to the specific Hsp-90 inhibitor, geldanamycin (GA). Here we surveyed 24 different free-living or parasitic nematodes with the aim of determining whether C. elegans Hsp-90 was the exception or the norm amongst the nematodes. We combined these data with codon evolution models in an attempt to identify whether hsp-90 from GA-binding and non-binding species has evolved under different evolutionary constraints. 相似文献11.
Lucía Otero Laura Romanelli-Cedrez Anton A. Turanov Vadim N. Gladyshev Antonio Miranda-Vizuete Gustavo Salinas 《RNA (New York, N.Y.)》2014,20(7):1023-1034
Selenocysteine (Sec) is encoded by an UGA codon with the help of a SECIS element present in selenoprotein mRNAs. SECIS-binding protein (SBP2/SCBP-2) mediates Sec insertion, but the roles of its domains and the impact of its deficiency on Sec insertion are not fully understood. We used Caenorhabditis elegans to examine SBP2 function since it possesses a single selenoprotein, thioredoxin reductase-1 (TRXR-1). All SBP2 described so far have an RNA-binding domain (RBD) and a Sec-incorporation domain (SID). Surprisingly, C. elegans SBP2 lacks SID and consists only of an RBD. An sbp2 deletion mutant strain ablated Sec incorporation demonstrating SBP2 essentiality for Sec incorporation. Further in silico analyses of nematode genomes revealed conservation of SBP2 lacking SID and maintenance of Sec incorporation linked to TRXR-1. Remarkably, parasitic plant nematodes lost the ability to incorporate Sec, but retained SecP43, a gene associated with Sec incorporation. Interestingly, both selenophosphate synthetase (SPS) genes are absent in plant parasitic nematodes, while only Cys-containing SPS2 is present in Sec-incorporating nematodes. Our results indicate that C. elegans and the nematode lineage provide key insights into Sec incorporation and the evolution of Sec utilization trait, selenoproteomes, selenoproteins, and Sec residues. Finally, our study provides evidence of noncanonical translation initiation in C. elegans, not previously known for this well-established animal model. 相似文献
12.
Kathryn S. Evans Janneke Wit Lewis Stevens Steffen R. Hahnel Briana Rodriguez Grace Park Mostafa Zamanian Shannon C. Brady Ellen Chao Katherine Introcaso Robyn E. Tanny Erik C. Andersen 《PLoS pathogens》2021,17(3)
Parasitic nematodes cause a massive worldwide burden on human health along with a loss of livestock and agriculture productivity. Anthelmintics have been widely successful in treating parasitic nematodes. However, resistance is increasing, and little is known about the molecular and genetic causes of resistance for most of these drugs. The free-living roundworm Caenorhabditis elegans provides a tractable model to identify genes that underlie resistance. Unlike parasitic nematodes, C. elegans is easy to maintain in the laboratory, has a complete and well annotated genome, and has many genetic tools. Using a combination of wild isolates and a panel of recombinant inbred lines constructed from crosses of two genetically and phenotypically divergent strains, we identified three genomic regions on chromosome V that underlie natural differences in response to the macrocyclic lactone (ML) abamectin. One locus was identified previously and encodes an alpha subunit of a glutamate-gated chloride channel (glc-1). Here, we validate and narrow two novel loci using near-isogenic lines. Additionally, we generate a list of prioritized candidate genes identified in C. elegans and in the parasite Haemonchus contortus by comparison of ML resistance loci. These genes could represent previously unidentified resistance genes shared across nematode species and should be evaluated in the future. Our work highlights the advantages of using C. elegans as a model to better understand ML resistance in parasitic nematodes. 相似文献
13.
S Gerdt R D Dennis G Borgonie R Schnabel R Geyer 《European journal of biochemistry》1999,266(3):952-963
Caenorhabditis elegans displays three neutral glycosphingolipids with structural homology to glycosphingolipids from the porcine nematode parasite, Ascaris suum. The present findings extend the degree of structural conservation between the two nematode species to glycosphingolipids with a phosphodiester substitution. Using a combination of hydrofluoric acid pretreatment, immunochemical characterization and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, three zwitterionic, phosphorylcholine-substituted glycosphingolipids could be identified in the neutral glycolipid fraction of C. elegans. The components were isolated as their zwitterionic, phosphorylcholine-substituted, pyridylaminated oligosaccharides by HPLC. Structural analysis was performed using hydrofluoric acid treatment, partial acid hydrolysis, methylation analysis, gas chromatography-mass spectrometry, cleavage with exoglycosidases and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Their chemical structures are proposed as: component Nz1, GalNAc(beta1-4)[phosphorylcholine]GlcNAc(beta1-3)Man(beta1-4)Glc-cera mide; component Nz2, Gal(alpha1-3)GalNAc(beta1-4)[phosphorylcholine]-GlcNAc(beta1-3)Man(be ta1-4)Glc-ceramide; and component Nz3, Gal(beta1-3)- Gal(alpha1-3)GalNAc(beta1-4)[phosphorylcholine]GlcNAc(beta1-3)Man(bet a1-4)Glc-ceramide. The oligosaccharide core is characteristic of the biosynthetic arthro-carbohydrate series of protostomial glycosphingolipids. The ceramide moiety was specified by a d17 : 1 sphingoid-base with iso-branching and anteiso-branching, and 2-hydroxy, saturated fatty acids as represented by docosanoic and tetracosanoic acids. Analysis of the spatial and temporal expression of the phosphorylcholine epitope, during embryonic and postembryonic development, showed it to be localized predominantly in seam cells and basement membranes, respectively. In early embryonic ontogenesis the phosphorylcholine epitope was only lipid bound, while in late embryonic and postembryonic development this epitope was both lipid bound and protein bound. 相似文献
14.
15.
《Biochimica et Biophysica Acta (BBA)/General Subjects》2017,1861(2):418-430
BackgroundThe porcine nodule worm Oesophagostomum dentatum is a strongylid class V nematode rather closely related to the model organism Caenorhabditis elegans. However, in contrast to the non-parasitic C. elegans, the parasitic O. dentatum is an obligate sexual organism, which makes both a gender and developmental glycomic comparison possible.MethodsDifferent enzymatic and chemical methods were used to release N-glycans from male and female O. dentatum as well as from L3 and L4 larvae. Glycans were analysed by MALDI-TOF MS after either 2D-HPLC (normal then reversed phase) or fused core RP-HPLC.ResultsWhereas the L3 N-glycome was simpler and more dominated by phosphorylcholine-modified structures, the male and female worms express a wide range of core fucosylated N-glycans with up to three fucose residues. Seemingly, simple methylated paucimannosidic structures can be considered ‘male’, while methylation of fucosylated glycans was more pronounced in females. On the other hand, while many of the fucosylated paucimannosidic glycans are identical with examples from other nematode species, but simpler than the tetrafucosylated glycans of C. elegans, there is a wide range of phosphorylcholine-modified glycans with extended HexNAc2–4PC2–4 motifs not observed in our previous studies on other nematodes.ConclusionThe interspecies tendency of class V nematodes to share most, but not all, N-glycans applies also to O. dentatum; furthermore, we establish, for the first time in a parasitic nematode, that glycomes vary upon development and sexual differentiation.General significanceUnusual methylated, core fucosylated and phosphorylcholine-containing N-glycans vary between stages and genders in a parasitic nematode. 相似文献
16.
Brendan D. Galvin Zhiru Li Estelle Villemaine Catherine B. Poole Melissa S. Chapman Michael P. Pollastri Paul G. Wyatt Clotilde K. S. Carlow 《PLoS neglected tropical diseases》2014,8(9)
Myristoylation is a lipid modification involving the addition of a 14-carbon unsaturated fatty acid, myristic acid, to the N-terminal glycine of a subset of proteins, a modification that promotes their binding to cell membranes for varied biological functions. The process is catalyzed by myristoyl-CoA:protein N-myristoyltransferase (NMT), an enzyme which has been validated as a drug target in human cancers, and for infectious diseases caused by fungi, viruses and protozoan parasites. We purified Caenorhabditis elegans and Brugia malayi NMTs as active recombinant proteins and carried out kinetic analyses with their essential fatty acid donor, myristoyl-CoA and peptide substrates. Biochemical and structural analyses both revealed that the nematode enzymes are canonical NMTs, sharing a high degree of conservation with protozoan NMT enzymes. Inhibitory compounds that target NMT in protozoan species inhibited the nematode NMTs with IC50 values of 2.5–10 nM, and were active against B. malayi microfilariae and adult worms at 12.5 µM and 50 µM respectively, and C. elegans (25 µM) in culture. RNA interference and gene deletion in C. elegans further showed that NMT is essential for nematode viability. The effects observed are likely due to disruption of the function of several downstream target proteins. Potential substrates of NMT in B. malayi are predicted using bioinformatic analysis. Our genetic and chemical studies highlight the importance of myristoylation in the synthesis of functional proteins in nematodes and have shown for the first time that NMT is required for viability in parasitic nematodes. These results suggest that targeting NMT could be a valid approach for the development of chemotherapeutic agents against nematode diseases including filariasis. 相似文献
17.
Michael J. Kimber Laura Sayegh Chuanzhe Song Debra J. Woods Paula Ribeiro 《International journal for parasitology》2009,39(11):1215-1222
Acetylcholine (ACh) is a neurotransmitter/neuromodulator in the nematode nervous system and induces its effects through interaction with both ligand-gated ion channels (LGICs) and G protein-coupled receptors (GPCRs). The structure, pharmacology and physiological importance of LGICs have been appreciably elucidated in model nematodes, including parasitic species where they are targets for anthelmintic drugs. Significantly less, however, is understood about nematode ACh GPCRs, termed GARs (G protein-linked ACh receptors). What is known comes from the free-living Caenorhabditis elegans as no GARs have been characterized from parasitic species. Here we clone a putative GAR from the pig gastrointestinal nematode Ascaris suum with high structural homology to the C. elegans receptor GAR-1. Our GPCR, dubbed AsGAR-1, is alternatively spliced and expressed in the head and tail of adult worms but not in dorsal or ventral body wall muscle, or the ovijector. ACh activated AsGAR-1 in a concentration-dependent manner but the receptor was not activated by other small neurotransmitters. The classical muscarinic agonists carbachol, arecoline, oxotremorine M and bethanechol were also AsGAR-1 agonists but pilocarpine was ineffective. AsGAR-1 activation by ACh was partially antagonized by the muscarinic blocker atropine but pirenzepine and scopolamine were largely ineffective. Certain biogenic amine GPCR antagonists were also found to block AsGAR-1. Our conclusion is that Ascaris possesses G protein-coupled ACh receptors that are homologous in structure to those present in C. elegans, and that although they have some sequence homology to vertebrate muscarinic receptors, their pharmacology is atypically muscarinic. 相似文献
18.
R D Dennis R Geyer H Egge H Menges S Stirm H Wiegandt 《European journal of biochemistry》1985,146(1):51-58
The presence of glycosphingolipids in the pupae of the blowfly, Calliphora vicina, was established. The thin layer chromatographic pattern of the total neutral glycolipids revealed the presence of more than 13 components, the major one being ceramide monohexoside. By the use of high performance liquid chromatography, the three simplest components were isolated and their chemical structures determined: Glc(beta 1-1)Cer, Man(beta 1-4)-Glc(beta 1-1)Cer [with minor component Gal(beta 1-4)Glc(beta 1-1)Cer] and GlcNAc(beta 1-3)Man(beta 1-4)Glc(beta 1-1)-Cer. The ceramide composition of the parent insect glycosphingolipids is dominated by the 20:0 fatty acid, arachidic acid, and the sphingoid tetradecasphing-4-enine. 相似文献
19.
Stephen Henry Per-Ake Jovall Sohbat Ghardashkhani Anders Elmgren Tommy Martinsson Goran Larson Bo Samuelsson 《Glycoconjugate journal》1997,14(2):209-223
Total nonacid glycosphingolipids were isolated from small intestine mucosal scrapings of a red cell blood group O Le(a-b-)
nonsecretor cadaver. Glycolipids were extracted and fractionated into five fractions based on chromatographic and immunostaining
properties. These glycolipid fractions were then analysed by thin-layer chromatography for Lewis activity with antibodies
reactive to the type 1 precursor (Lec), H type 1 (Led), Lea and Leb epitopes. Fractions were structurally characterized by
mass spectrometry (EI-MS and EI-MS/MS-TOF) and proton NMR spectroscopy. EI-MS/MS-TOF allowed for the identification of trace
substances in fractions containing several other glycolipid species. Consistent with the red cell phenotype, large amounts
of lactotetraosylceramide (Lec-4) were detected. Inconsistent with the red cell phenotype, small quantities of Lea-5, H-5-1
and Leb-6 glycolipids were immunochemically and structurally identified in the small intestine of this individual. By EI-MS/MS-TOF
several large glycolipids with 9 and 10 sugar residues were also identified. The extensive carbohydrate chain elongation seen
in this individual with a Lewis negative nonsecretor phenotype supports the concept that Lewis and Secretor blood group fucosylation
may be a mechanism to control type 1 glycoconjugate chain extension. Abbreviations: FUT1, H gene; FUT2, Secretor gene, (gene
bank accession no. U17894); FUT3, Lewis gene or Fuc-TIII gene, (gene bank accession no. X53578); FUT5, Fuc-TV gene; [Imm]+,
immonium ion; Lea-5, Galβ1-3(Fucα1-4)GlcNAcβ1-3Galβ1-4Glcβ1-1Cer; Leb-6, Fucα1-2Galβ1-3(Fucα1-4)GlcNAcβ1-3Galβ1-4Glcβ1-1Cer;
Lec-4, Galβ1-3GlcNAcβ1-3Galβ1-4Glcβ1-1Cer; Led or H-5-1, Fucα1-2Galβ1-3GlcNAcβ1-3Galβ1-4Glcβ1-1Cer; Lex-5, Galβ1-4(Fucα1-3)GlcNAcβ1-3Galβ1-4Glcβ1-1Cer;
MAb, monoclonal antibody; MS, mass spectrometry; CID, collision-induced dissociation; EI, electron impact ionisation; MS/MS-TOF,
tandem mass spectrometry using a time-of-flight mass spectrometer as the second mass spectrometer: m/Cz, mass-to-charge ratio;
NMR, nuclear magnetic resonance; PCR, polymerase chain reaction; RFLP, restriction fragment length polymorphism; TLC, (high
performance) thin layer chromatography. Saccharide types are abbreviated to Hex for hexose, HexNAc for N-acetylhexosamine
and dHex for deoxyhexose (fucose). Ceramide is abbreviated to Cer, and ceramide types are abbreviated to d for dihydroxy and
t for trihydroxy base, n for non-hydroxy and h for hydroxy fatty acids
This revised version was published online in November 2006 with corrections to the Cover Date. 相似文献