Abstract：
:gamma-Glutamyl transpeptidase, which is of central importance in the degradation of glutathione, was purified from Ascaris suum to apparent homogeneity. The enzyme was found to be a predominantly membrane-bound protein and was solubilized by Triton X-100. The purified enzyme, which exhibits a specific activity of 1009 U (mg protein)-1, showed a molecular mass of 70 kDa and was found to be composed of two non-identical subunits of molecular mass 43 and 30 kDa. Concerning the kinetic properties of the enzyme, the data presented in this study showed that various amino acids and dipeptides with L-configuration served as acceptors for the gamma-glutamyl moieties of the enzyme reaction products and showed Km-values in the mM range. The apparent Km-value for the gamma-glutamyl donor L-glutamyl-gamma-7-amido-4-methylcoumarin of the enzyme was found to be 0.03 mM. L- and D-serine in combination with borate ions were competitive inhibitors of the enzyme activity with Ki-values of 0.30 and 0.61 mM, respectively. Acivicin was an irreversible inhibitor of the enzyme with a Ki-value of 0.42 mM and with a pseudo-first-order kinetics (kinact) of 0.18 min-1. In vitro treatment of the adult A. suum with acivicin resulted in a dose-dependent inhibition of the enzyme activity and an increase of the glutathione levels. These findings indicate the physiological role of the gamma-glutamyl transpeptidase of this parasitic nematode in the catabolism of glutathione.
journal_name
Mol Biochem Parasitoljournal_title
Molecular and biochemical parasitologyauthors
Hussein AS,Walter RDdoi
10.1016/0166-6851(96)02573-xsubject
Has Abstractpub_date
1996-04-01 00:00:00pages
41-7issue
1eissn
0166-6851issn
1872-9428pii
016668519602573Xjournal_volume
77pub_type
杂志文章abstract：:Procyclic Trypanosoma brucei brucei strain 366D is susceptible to DL-alpha-difluoromethylornithine (DFMO) with an in vitro ED50 value of 225 microM. A mutant of the procyclic strain resistant to 20 mM of DFMO was isolated by serial in vitro passages of the organisms in increasing concentrations of the drug. Drug resis...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(87)90064-8
更新日期：1987-01-02 00:00:00
abstract：:Adults of Onchocerca volvulus and Onchocerca gibsoni were identically fractionated into a surface-enriched fraction, a phosphate buffered saline (PBS) extract and a PBS insoluble-detergent soluble fraction. Glycoproteins were prepared from these extracts and all fractions were examined by the Western blot technique us...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(86)90102-7
更新日期：1986-09-01 00:00:00
abstract：:Telomeric DNA of trypanosomatids possesses a modified thymine base, called base J, that is synthesized in a two-step process; the base is hydroxylated by a thymidine hydroxylase forming hydroxymethyluracil (hmU) and a glucose moiety is then attached by the J-associated glucosyltransferase (JGT). To examine the importa...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/j.molbiopara.2016.01.005
更新日期：2015-12-01 00:00:00
abstract：:In Trypanosoma brucei, the generation of knockout mutants is relatively easy compared to other organisms as transfection methods are well established. These methods have their limitations, however, when it comes to the generation of genome-wide libraries that require a minimum of several hundred thousand transformants...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/j.molbiopara.2017.02.002
更新日期：2017-04-01 00:00:00
abstract：:Intra-erythrocytic Plasmodium parasites digest host cell haemoglobin and use the liberated amino acids for protein synthesis. Although several endoproteases (aspartic, cysteine, and metallo-) have been shown to be involved in the initial stages of haemoglobin degradation, little is known about the steps immediately be...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/s0166-6851(01)00327-9
更新日期：2001-09-28 00:00:00
abstract：:We report the isolation and sequence of a part of a gene encoding a collagen from the genome of the human filarial parasite Brugia malayi. The deduced amino acid sequence of the sequenced portion of this gene, which we have designated BmCol1, differs from the most catalogued nematode collagens in that it is composed p...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(91)90027-4
更新日期：1991-03-01 00:00:00
abstract：:The promoter region of the ribosomal RNA (rRNA) genes of Leishmania amazonensis was characterised and the transcription start point, defined by primer extension, was shown to be a T residue, 1048 nucleotides upstream of the beginning of the 18S sequence. A repetitive element of 60 bp was identified in the intergenic s...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(95)02562-6
更新日期：1996-02-01 00:00:00
abstract：:Trypanosoma brucei harbors a unique multifunctional RNA polymerase (pol) I which transcribes, in addition to ribosomal RNA genes, the gene units encoding the major cell surface antigens variant surface glycoprotein and procyclin. In consequence, this RNA pol I is recruited to three structurally different types of prom...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/j.molbiopara.2006.02.023
更新日期：2006-09-01 00:00:00
abstract：:Two different classes of small nematode specific lipid-binding proteins, the nematode polyprotein allergens/antigens (NPAs) and the fatty acid- and retinol-binding (FAR) proteins, are secreted by helminth parasites. Until now, there was no evidence of the expression or secretion of these two families of proteins in Ha...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/j.molbiopara.2009.07.001
更新日期：2009-11-01 00:00:00
abstract：:Toxoplasma gondii differentially expresses two forms of lactate dehydrogenase in tachyzoites and bradyzoites, respectively, designated LDH1 and LDH2. Previously it was demonstrated that LDH1 and LDH2 share a unique structural feature with LDH from the malarial parasite Plasmodium falciparum (pLDH), namely, the additio...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/s0166-6851(01)00360-7
更新日期：2001-11-01 00:00:00
abstract：:Human infections from Plasmodium knowlesi present challenges to malaria control in Southeast Asia. P. knowlesi also offers a model for other human malaria species including Plasmodium vivax. P. knowlesi parasites can be cultivated in the laboratory, and their transformation is standardly performed by direct electropor...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/j.molbiopara.2017.10.001
更新日期：2017-12-01 00:00:00
abstract：:Actin-related proteins (Arps) constitute a family of eukaryotic cytoskeletal proteins involved in such diverse events as cell motility, cytokinesis, vesicle transport, and chromatin remodelling. Previously, in a study of Plasmodium berghei gene expression in ookinetes and oocysts, we detected stage-specific increased ...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/j.molbiopara.2010.05.008
更新日期：2010-10-01 00:00:00
abstract：:Entamoeba histolytica is a human intestinal parasite that causes amebic dysentery. A cell surface amebic adhesin, the galactose and N-acetyl-D-galactosamine inhibitable (GalNAc) lectin mediates amebic adherence to and contact-dependent killing of host cells. Previous work has suggested that the GalNAc lectin transduce...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/s0166-6851(02)00326-2
更新日期：2003-04-03 00:00:00
abstract：:The protozoan parasite Trypanosoma brucei relies on trans-splicing to process its mRNAs. A novel nuclear serine/arginine (SR)-rich trypanosomal protein (TSR1) was characterized which contains two RNA recognition motifs. The TSR1 protein appears to be homologous to RNA-binding SR proteins of the cis-splicing machinery ...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/s0166-6851(99)00091-2
更新日期：1999-07-30 00:00:00
abstract：:The mature-parasite-infected erythrocyte surface antigen (MESA, also known as PfEMP-2 and pp300) of Plasmodium falciparum is a phosphoprotein of approx. 250-300 kDa that is exported from the parasite to the erythrocyte membrane skeleton where it binds to protein 4.1. Determination of the primary sequence of MESA revea...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(92)90231-8
更新日期：1992-02-01 00:00:00
abstract：:Transcriptional control of the hgl5 gene of Entamoeba histolytica is mediated through an unusual core promoter composed of TATA, GAAC and Initiator elements. In the hgl5 promoter the GAAC element (AATGAACT) determines the site and rate of transcription initiation. Here we tested the role of the GAAC element in transcr...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/s0166-6851(01)00441-8
更新日期：2002-03-01 00:00:00
abstract：:A family of Schistosoma mansoni proteins (18-22 kDa, pI 5.3-5.8) are biosynthesized in juvenile worms and immunoprecipitated by antibodies uniquely present in protective Fischer rat antiserum. A cDNA clone, lambda gt11-40, expressing epitopes common to this protein family was used to obtain a genomic DNA clone, by hyb...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(91)90132-p
更新日期：1991-11-01 00:00:00
abstract：:Leucine aminopeptidases (LAP; EC 3.4.11.1) are a group of metalloexopeptidases, which catalyze the sequential removal of leucine amino acids from the N-termini of the polypeptides or proteins. In this study, we identified two novel genes that encode LAPs of Clonorchis sinensis (CsLAP1 and CsLAP2) and characterized the...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/j.molbiopara.2011.11.009
更新日期：2012-03-01 00:00:00
abstract：:Two short DNA segments were isolated by screening of a lambda gt11 library from Plasmodium falciparum schizont cDNA with an antiserum against the 140 kDa protein, which confers protective immunity to monkeys. The segments were used to identify a genomic fragment which carries the entire coding sequence for a protein o...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(89)90131-x
更新日期：1989-01-01 00:00:00
abstract：:The variant surface glycoproteins (VSGs) of both metacyclic and bloodstream forms of Trypanosoma congolense are shown to be anchored to the plasma membrane through a glycolipid similar to that found in Trypanosoma brucei. Release of soluble VSG from both metacyclic and bloodstream forms is associated with the exposure...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(87)90045-4
更新日期：1987-01-15 00:00:00
abstract：:The (Ca(2+)-Mg2+)ATPase activity in microsomes of Schistosoma mansoni is fully inhibited by vanadate (I50 = 2.5 microM). 45Ca2+ is accumulated within microsomal vesicles in an ATP-dependent process that is enhanced 5-fold in the presence of 40 mM phosphate. Accumulated 45Ca2+ is rapidly released by 5 microM of the Ca2...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(92)90049-p
更新日期：1992-06-01 00:00:00
abstract：:A group of Leishmania mexicana cysteine proteases that differ from those previously found in this protozoon are described. The enzymes characteristically have a preference for peptidyl substrates with a phenylalanyl-valyl-arginyl moiety, do not hydrolyse gelatin in substrate-sodium dodecyl sulphate polyacrylamide gels...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(93)90116-f
更新日期：1993-12-01 00:00:00
abstract：:The 31P NMR spectrum of the adult tapeworm, Hymenolepis diminuta, at 37 degrees C during perfusion with physiological saline was composed of 10 peaks. Based on chemical shifts and analysis of worm extracts, the phosphorus components included glucose-6-phosphate, fructose-6-phosphate, phosphorylcholine, glycerophosphor...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(87)90068-5
更新日期：1987-01-02 00:00:00
abstract：:Plasmodium LCCL proteins comprise a family of six proteins that function as a protein complex and have essential roles in sporozoite transmission. In Plasmodium berghei, family members PbLAP1, PbLAP2 and PbLAP3 have been shown to be expressed in gametocytes and, following gametogenesis and fertilization, to be targete...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/j.molbiopara.2013.04.006
更新日期：2013-05-01 00:00:00
abstract：:During the replicative cycle of many double-stranded RNA viruses, transcription of particles with a double-stranded RNA genome alternates with replication of particles containing a single-stranded genome. In virions infecting some strains of Leishmania guyanensis the putative transcriptase and replicase activities of ...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(92)90053-m
更新日期：1992-06-01 00:00:00
abstract：:TgPrx2 represents a recently discovered cytosolic 1-Cys peroxiredoxin (Prx) from the intracellular parasite Toxoplasma gondii. Over-expression of the respective gene confers protection against H(2)O(2), suggesting that the protein possesses peroxidase activity. According to the current nomenclature eukaryotic typical ...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/j.molbiopara.2004.12.008
更新日期：2005-03-01 00:00:00
abstract：:Thirteen monoclonal antibodies (MAbs) specific for the membrane of live Trypanosoma cruzi have been obtained from BALB/c infected mice. Most of them had greater avidity for intact than for disrupted parasites. According to the staining by indirect immunofluorescence of the different live developmental stages of the pa...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(88)90073-4
更新日期：1988-06-01 00:00:00
abstract：:During blood-stage infection, malaria parasites export numerous proteins to the host erythrocyte. The Poly-Helical Interspersed Sub-Telomeric (PHIST) proteins are an exported family that share a common 'PRESAN' domain, and include numerous members in Plasmodium falciparum, Plasmodium vivax and Plasmodium knowlesi. In ...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/j.molbiopara.2014.07.011
更新日期：2014-08-01 00:00:00
abstract：:The glycosome, a microbody organelle found only in kinetoplastid protozoa, compartmentalizes the first six enzymes of glycolysis. In order to better understand the regulation and targeting of glycolytic enzymes in trypanosomes, we have cloned and analyzed the three genes of the phosphoglycerate kinase (PGK) complex of...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(94)00208-5
更新日期：1995-02-01 00:00:00
abstract：:A novel Plasmodium falciparum sporozoite antigen, STARP (Sporozoite Threonine and Asparagine-Rich Protein), detected consistently on the surface of sporozoites obtained from laboratory strains and field isolates, has been identified and cloned, following a systematic approach aimed at isolating novel non-CS sporozoite...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(94)00012-3
更新日期：1994-04-01 00:00:00
