Abstract：
:A 2118-base pair gene encoding the bifunctional hydroxymethyldihydropterin pyrophosphokinase-dihydropteroate syntheses of Plasmodium falciparum (pfPPPK-DHPS) was expressed under the control of the T5 promoter in a DHPS-deficient Escherichia coli strain. The enzyme was purified to near homogeneity using nickel affinity chromatography followed by gel filtration and migrates as an intense band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis with apparent mass of approximately 83 kDa. Gel filtration suggested that the native pfPPPK-DHPS might exist as a tetramer of identical subunits. The enzyme was found to be Mg2+ - and ATP-dependent and had optimal temperature ranging from 37 to 45 degrees C with peak activity at pH 10. Sodium chloride and potassium chloride at 0.2 and 0.4 M, respectively, activated the activity of the enzyme but higher salt concentrations were inhibitory. Guanidine-HCl and urea inhibited the enzyme activity by 50% at 0.25 and 0.9 M, respectively. Kinetic properties of the recombinant pfPPPK-DHPS were investigated. Sulfathiazole and dapsone were potent inhibitors of pfPPPK-DHPS, whilst sulfadoxine, sulfanilamide, sulfacetamide and p-aminosalicylic acid were less inhibitory. Our construct provides an abundant source of recombinant pfPPPK-DHPS for crystallization and drug screening.
journal_name
Mol Biochem Parasitoljournal_title
Molecular and biochemical parasitologyauthors
Kasekarn W,Sirawaraporn R,Chahomchuen T,Cowman AF,Sirawaraporn Wdoi
10.1016/j.molbiopara.2004.04.012subject
Has Abstractpub_date
2004-09-01 00:00:00pages
43-53issue
1eissn
0166-6851issn
1872-9428pii
S0166685104001409journal_volume
137pub_type
杂志文章abstract：:Trypanosoma brucei is a unicellular parasite that is transmitted from one mammalian host to the next by tsetse flies. The expression of many trypanosome genes is regulated during the life cycle but there is no evidence for developmental control of transcription by RNA polymerase II. T. brucei expresses at least two he...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(95)02503-0
更新日期：1995-12-01 00:00:00
abstract：:Release of sporozoites from Eimeria oocysts/sporocysts is an essential step in the intracellular development of the parasite in its host. Little is known about this process except that elevated temperature (∼ 40 °C) plus trypsin and bile salts are required for sporozoite to escape from sporocysts. In this study, it wa...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/j.molbiopara.2019.111219
更新日期：2019-10-01 00:00:00
abstract：:Surface proteins of male and female gametes of Plasmodium gallinaceum were radioiodinated by the lactoperoxidase method, immunoprecipitated with stage specific antisera and separated on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Stage specificity of the surface antigens was further studied by competiti...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(84)90061-6
更新日期：1984-04-01 00:00:00
abstract：:The function of the ecdysone receptor (EcR) during development and molting has been thoroughly investigated in some arthropods such as insects but rarely in crustacean copepods such as the salmon louse Lepeophtheirus salmonis (L. salmonis) (Copepoda, Caligidae). The salmon louse is an ectoparasite on Atlantic salmon t...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/j.molbiopara.2016.06.007
更新日期：2016-08-01 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 principal constituents of the free amino acid pool in Leishmania tropica promastigotes include alanine, glycine, serine, threonine, alpha-aminobutyric acid and ethanolamine. Changes in levels of the pool constituents during starvation, nutrient supplementation and treatment with a metabolic inhibitor (sodium fluor...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(83)90056-7
更新日期：1983-09-01 00:00:00
abstract：:The microtubular cytoskeleton of most single-celled eukaryotes radiates from an organizing center called the flagellar apparatus, which is essential for locomotion, feeding and reproduction. The structure of the flagellar apparatus tends to be conserved within diverse clades of eukaryotes, and modifications of this ov...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章,评审
doi：10.1016/j.molbiopara.2016.02.002
更新日期：2016-01-01 00:00:00
abstract：:Malaria parasites export 'a secretome' of hundreds of proteins, including major virulence determinants, from their endoplasmic reticulum (ER), past the parasite plasma and vacuolar membranes to the host erythrocyte. The export mechanism is high affinity (nanomolar) binding of a host (cell) targeting (HT) motif RxLxE/D...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/j.molbiopara.2012.07.004
更新日期：2012-10-01 00:00:00
abstract：:The primary S(1) subsite specificity of a recombinant cysteine proteinase, CPB2.8 Delta CTE, of Leishmania mexicana was investigated in a systematic way using a series of peptides derived from Abz-KLRFSKQ-EDDnp in which Arg was substituted by all natural amino acids (where Abz is ortho-amino-benzoyl and EDDnp is N-[2,...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/s0166-6851(01)00290-0
更新日期：2001-08-01 00:00:00
abstract：:A hydrophobic, galactose-specific lectin was isolated by means of affinity chromatography from Sarcocystis gigantea. Adsorbents with different spacer lengths were tested. S. gigantea lectin differs from sheep muscle lectin in the spacer length needed for adsorption. Sodium dodecyl sulfate-gel electrophoresis of the S....
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(85)90067-2
更新日期：1985-09-01 00:00:00
abstract：:The influence of growth in the presence of nifurtimox on total lipids of Trypanosoma cruzi epimastigotes was determined. Nifurtimox-treated organisms showed greater amounts of unsaturated fatty acids as compared with control cells. 18:2 was the major component in the total esterified lipid fraction. Similar results we...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(86)90127-1
更新日期：1986-12-01 00:00:00
abstract：:The spontaneous emission of chemiluminescence by Trypanosoma cruzi epimastigotes was 133 +/- 5 counts s-1 (mg protein)-1. The measured intracellular steady state concentration of hydrogen peroxide in the same cells was 1.5 +/- 0.5 microM. These two values are about 12- and 15-times higher than the corresponding ones f...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(88)90093-x
更新日期：1988-09-01 00:00:00
abstract：:To investigate whether the lysosomes of Trypanosoma brucei are capable of uptake of macromolecules after internalization by the cell, we used Triton WR-1339, a non-digestible macromolecular compound, which is known to cause a marked decrease in the density of hepatic lysosomes due to massive intralysosomal storage. In...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(82)90077-9
更新日期：1982-09-01 00:00:00
abstract：:Ribosomal RNA isolated from the malaria parasite Plasmodium falciparum consists of two species with molecular weight of 1.49 +/- 0.09 X 10(6) and 0.78 +/- 0.02 X 10(6) present in equimolar quantities. Their molecular weights are comparable with those of other protozoa but quite distinct from those of the human host. T...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(81)90061-x
更新日期：1981-12-31 00:00:00
abstract：:Purified GP57/51, a Trypanosoma cruzi glycoprotein earlier identified as a major antigen in infected humans, was subjected to N-terminal sequence analysis. Alignment of the first 30 amino acids revealed that its N-terminal region is virtually identical to that reported for a cysteine-proteinase isolated from the Tulah...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(90)90127-8
更新日期：1990-11-01 00:00:00
abstract：:Surface and metabolic labeling procedures were used to characterize the composition and the time of expression of Brugia malayi L2 and L3 surface-associated molecules as the larvae develop within the mosquito vector. Larvae were harvested from mosquito tissues at 5 (early L2), 8 (late L2) and 11 (L3) days post-infecti...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(92)90039-m
更新日期：1992-05-01 00:00:00
abstract：:Evidence is presented that Giardia lamblia and Entamoeba histolytica, phylogenetically unrelated aerotolerant anaerobes, have crucial thiol groups on or easily accessible to their external surface. Both parasites were killed by three structurally unrelated thiol-blocking reagents which penetrate intact cells poorly or...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(84)90096-3
更新日期：1984-09-01 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：: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：: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：:Both the alpha- and beta-tubulin genes of Leishmania enriettii are encoded by mRNA of 2.0-2.2 kb in length. We have shown previously that the alpha- and beta-tubulin genes are arranged in separate, tandem repeats of 2 and 4 kb, respectively, and now report the mapping of mature mRNA onto these cloned genes. Here we sh...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(85)90029-5
更新日期：1985-04-01 00:00:00
abstract：:The pfmdr 1 gene encodes a Plasmodium falciparum homologue of the human P-glycoprotein expressed on the surface of the parasite food vacuole. Variation in copy number and specific codon mutations of pfmdr 1 have been implicated in the development of parasite resistance to antimalarial drugs. We describe here the techn...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/s0166-6851(96)02822-8
更新日期：1997-04-01 00:00:00
abstract：:Strongyloides and related genera are advantageous subjects for transgenesis in parasitic nematodes, primarily by gonadal microinjection as has been used with Caenorhabditis elegans. Transgenesis has been achieved in Strongyloides stercoralis and in Parastrongyloides trichosuri, but both of these lack well-adapted, con...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/j.molbiopara.2011.06.002
更新日期：2011-10-01 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：:Apicomplexan parasites utilize a peripheral membrane system called the inner membrane complex (IMC) to facilitate host cell invasion and parasite replication. We recently identified a novel family of Toxoplasma IMC Sub-compartment Proteins (ISP1/2/3) that localize to sub-domains of the IMC using a targeting mechanism ...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/j.molbiopara.2012.05.002
更新日期：2012-08-01 00:00:00
abstract：:In Ascaris muscle mitochondria the major respiratory chain-linked phosphorylation activity is accomplished by a NADH-linked reduction of fumarate to succinate. Oxygen can also be employed as a terminal electron acceptor via a cyanide- and salicyl-hydroxamate-resistant terminal oxidase. As in fumarate-dependent electro...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(80)90002-x
更新日期：1980-04-01 00:00:00
abstract：:CK2 is a ubiquitous but enigmatic kinase. The difficulty in assigning a role to CK2 centers on the fact that, to date, no biologically relevant modulator of its function has been identified. One common theme revolves around a constellation of known substrates involved in growth control, compatible with its concentrati...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/j.molbiopara.2006.10.002
更新日期：2007-01-01 00:00:00
abstract：:The membrane potential and pH gradient over the plasma membrane of the protozoan parasite Trypanosoma brucei were measured with radioactive indicators in combination with the silicone oil centrifugation technique over a range of temperatures. At 37 degrees C a small membrane potential and pH gradient of similar magnit...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(92)90123-2
更新日期：1992-10-01 00:00:00
abstract：:The nucleotide sequence of the cloned Echinococcus multilocularis DNA probe pAL1 was determined in order to simplify and improve the sensitivity of a diagnostic assay through the application of the polymerase chain reaction (PCR). The insert-specific oligonucleotides BG1 and BG2 define a 2.6-kb fragment in the genomic...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(91)90004-p
更新日期：1991-02-01 00:00:00
abstract：:The cysteine proteinase B of Leishmania parasites is an important virulence factor. In this study we have expressed, isolated and characterized for the first time a recombinant CPB from Leishmania braziliensis, the causative agent of mucocutaneous leishmaniosis. The mature region of the recombinant CPB shares a high p...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/j.molbiopara.2008.06.005
更新日期：2008-10-01 00:00:00
