Abstract：
:The influence of pH on the activity of purified pyruvate kinase (ATP:pyruvate 2-O-phosphotransferase, EC 2.7.1.40) from Trypanosoma brucei has been studied. The Km for the coenzyme ADP is pH-dependent and shows the involvement of a dissociable group on the free enzyme with a pKa of 6.5-6.7. The cooperative interaction of the multiple phosphoenolpyruvate (PEP) binding sites is independent of pH in the range of 5.7-7.8. Variation of the Vmax value with pH indicates the presence of a dissociated group (pKa 6.2-6.3) and of an undissociated group (pKa 7.5-7.6) in the enzyme-substrate complex. A doubly dissociated phosphate group on PEP is shown to be essential by the effects of pH on the S0.5 value for this substrate, as is an undissociated enzyme group with a pKa in the range 6.7-7.0. It is shown that PEP and frucotse-1,6-diphosphate (FDP) act entirely in conjunction in allosterically activating the enzyme, FDP, the heterotropic effector, decreases the interaction between PEP binding sites at low concentration, and decreases the S0.5 value for PEP at higher concentration. A model for the interaction of the enzyme with its substrates is discussed.
journal_name
Mol Biochem Parasitoljournal_title
Molecular and biochemical parasitologyauthors
Flynn IW,Bowman IBdoi
10.1016/0166-6851(81)90032-3subject
Has Abstractpub_date
1981-11-01 00:00:00pages
95-106issue
1-2eissn
0166-6851issn
1872-9428pii
0166-6851(81)90032-3journal_volume
4pub_type
杂志文章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：:We have cloned and expressed the full-length gene encoding the hypoxanthine-guanine-xanthine phosphoribosyltransferase (HGXPRTase) from the anaerobic protozoan parasite Tritrichomonas foetus. This enzyme is essential in nucleic acid metabolism of T. foetus because the parasite is unable to synthesize purine nucleotide...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(94)90058-2
更新日期：1994-02-01 00:00:00
abstract：:Multigene families are present on the telomeric and sub-telomeric regions of most chromosomes of the malaria parasite, Plasmodium. The largest gene family identified so far is the Plasmodium interspersed repeat (pir) multigene gene family and is shared by Plasmodium vivax, and simian and rodent malaria species. Most p...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章,评审
doi：10.1016/j.molbiopara.2009.12.010
更新日期：2010-04-01 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：:Two cloned chromosomal segments of the hemoprotozoan Babesa bovis bearing genes from the polymorphic locus designated BabR were inserted into plasmid vector YCp19, cloned in Escherichia coli and then introduced into Saccharomyces cerevisiae. Both genes were transcribed producing poly(A+) RNAs. In at least one case, th...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(84)90044-6
更新日期：1984-05-01 00:00:00
abstract：:Studies measuring the glycolytic intermediate and adenine nucleotide concentrations in Trypanosoma brucei metabolising glucose either aerobically or under conditions where glycerol-3-phosphate oxidase is inactive have shown the following: 1. Inhibition with 0.5 mM salicylhydroxamic acid (SHAM) accurately simulates ana...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(80)90032-8
更新日期：1980-12-01 00:00:00
abstract：:The aspartic protease cathepsin D (Clan AA, Family A1) is expressed in the schistosome gut where it plays an apical role in the digestion of hemoglobin released from ingested erythrocytes. In this report, RNA interference approaches were employed to investigate the effects of knockdown of schistosome cathepsin D. Cult...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/j.molbiopara.2007.10.009
更新日期：2008-02-01 00:00:00
abstract：:Genetic variation among malaria parasites has important consequences with regard to drug resistance, pathogenicity, immunity, transmission, and speciation. In this regard, malaria parasites have been shown to display a high degree of inter- and intra-species genetic divergence. The nuclear genomes of Plasmodium falcip...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/s0166-6851(98)00093-0
更新日期：1998-09-01 00:00:00
abstract：:In addition to their ability to help newly synthesized proteins to fold, molecular chaperones are also recognized for their participation in cellular processes ranging from protein trafficking, signal transduction, differentiation and development. Novel roles for this group of proteins have come to light through studi...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章,评审
doi：10.1016/j.molbiopara.2007.01.009
更新日期：2007-06-01 00:00:00
abstract：:Genetic diversity within and between tandemly arrayed copies of the Gp63 gene occurs in laboratory isolates of Leishmania spp., but the extent to which this represents natural genetic diversity has not been assessed. Here, the Gp63 locus is examined in 58 fresh isolates of L. peruviana, and clones derived from them, c...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(95)00079-g
更新日期：1995-06-01 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：:Giardia lamblia depends on glycolysis to obtain ATP, highlighting the suitability of glycolytic enzymes as targets for drug design. We studied triosephosphate isomerase from G. lamblia (GlTIM) as a potential species-specific drug target. Cysteine-reactive agents were used as probes, in order to test those regions near...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/j.molbiopara.2007.10.013
更新日期：2008-02-01 00:00:00
abstract：:Following the demonstration that the transport of melaminophenyl arsenical drugs in Trypanosoma brucei is dependent upon an unusual adenosine nucleoside transporter (Carter and Fairlamb, Nature 361 (1993) 173-175) we have investigated adenosine transport in the related parasite Trypanosoma equiperdum (Botat1.1) and a ...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(95)00120-p
更新日期：1995-07-01 00:00:00
abstract：:We have generated 2771 expressed sequence tags (ESTs) from two cDNA libraries of Trypanosoma cruzi CL-Brener. The libraries were constructed from trypomastigote and amastigotes, using a spliced leader primer to synthesize the cDNA second strand, thus selecting for full-length cDNAs. Since the libraries were not normal...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/j.molbiopara.2004.04.002
更新日期：2004-08-01 00:00:00
abstract：:Human and porcine cysticercosis is a parasitic disease caused by the larval stage (cysts) of the tapeworm Taenia solium. Cysts may live in several host tissues such as skeletal muscle or brain. We have previously described the presence of host haptoglobin (Hp) and hemoglobin (Hb) in different protein extracts of the T...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/j.molbiopara.2016.05.010
更新日期：2016-06-01 00:00:00
abstract：:Glycosomes are peroxisome-like organelles present in trypanosomatid pathogens. These organelles compartmentalize glycolysis, among other reactions, and are essential in both bloodstream and procyclic form Trypanosoma brucei. Peroxins (PEXs) are proteins necessary for biogenesis of peroxisomes and glycosomes. In each a...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/j.molbiopara.2005.03.008
更新日期：2005-07-01 00:00:00
abstract：:Cathepsin B-like cysteine protease (cbl) genes produce the most abundant mRNAs ( approximately 16%) detected in the adult female intestine of the parasitic nematode Haemonchus contortus. CBL enzymes appear to digest host proteins and are vaccine candidates for immune control of H. contortus and potentially other paras...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/j.molbiopara.2004.06.010
更新日期：2004-10-01 00:00:00
abstract：:The precursor of the glycosylphosphatidylinositol membrane anchor of the variant surface glycoprotein of Trypanosoma brucei is known as glycolipid A and it has the structure: EtN-PO4-6Man alpha 1-2Man alpha 1-6Man alpha 1-4GlcN alpha 1-6myo-inositol-PO4-(sn-1,2-dimyristoylglycerol). This precursor exists in equilibriu...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(96)02585-6
更新日期：1996-05-01 00:00:00
abstract：:Schistosoma mansoni eggs, consisting of an ovum surrounded by nutritive vitelline cells packaged in a tanned protein shell, are produced by paired worms residing in the mesenteric veins of the human host. The vitelline cells are degraded as the larval miracidium matures, the fully developed egg either crossing the gut...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/j.molbiopara.2010.10.005
更新日期：2011-02-01 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：:Repetitive DNA sequences of the Leishmania donovani genome have been identified by screening a recombinant DNA library made by cloning sheared genomic DNA into the vector pAT153. Bacterial clones containing a highly repetitive DNA sequence have been isolated. DNA sequencing has shown that this sequence is composed of ...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(88)90114-4
更新日期：1988-05-01 00:00:00
abstract：:The Trypanosoma brucei flagellum controls motility and is crucial for cell polarity and division. Unique features of trypanosome motility suggest that flagellar beat regulation in this organism is unusual and worthy of study. The flagellar axoneme, required for motility, has a structure that is highly conserved among ...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/j.molbiopara.2010.09.005
更新日期：2011-01-01 00:00:00
abstract：:Cytoadherence of infected erythrocytes is a hallmark of Plasmodium falciparum infection and a key determinant in the particular virulence of this species. Infected erythrocytes bind a variety of host receptors but certain adhesion traits are associated with more severe disease. A large, diverse protein family named P....
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/s0166-6851(03)00099-9
更新日期：2003-06-01 00:00:00
abstract：:GRA3 is a 30-kDa protein located inside the dense granules of Toxoplasma gondii. Following invasion and exocytosis of dense granules within the parasitophorous vacuole, GRA3 becomes associated with the parasitophorous vacuolar membrane (PVM) and extensions of the PVM which protrude into the cytoplasm. A partial cDNA e...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(94)90169-4
更新日期：1994-12-01 00:00:00
abstract：:A total of 518 expressed sequence tags (ESTs) have been generated from clones randomly selected from a cDNA library and a spliced leader sub-library of a Trypanosoma brucei rhodesiense bloodstream clone. 205 (39%) of the clones were identified based on matches to 113 unique genes in the public databases. Of these, 71 ...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(95)00098-l
更新日期：1995-07-01 00:00:00
abstract：:The merozoite of Plasmodium vivax possesses a high molecular mass surface protein called Pv-merozoite surface protein 1, PvMSP-1, which exhibits antigenic diversity among isolates. In this study, the extent of sequence variation in the polymorphic region and the flanking interspecies conserved blocks (ICBs) 5 and 6 of...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/s0166-6851(96)02786-7
更新日期：1997-01-01 00:00:00
abstract：:Laminin is a major constituent of the basal lamina surrounding the midgut of the malaria vectors that has been implicated in the development of the Plasmodium oocyst. In this report we describe the cloning of the Anopheles gambiae gene encoding the laminin gamma 1 polypeptide and follow its expression during mosquito ...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/s0166-6851(00)00371-6
更新日期：2001-02-01 00:00:00
abstract：:Helminths are masterful immunoregulators. A characteristic feature of helminth infection is a Th2-dominated immune response, but stimulation of immunoregulatory cell populations, such as regulatory T cells and alternatively activated macrophages, is equally common. Typically, Th1/17 immunity is blocked and productive ...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章,评审
doi：10.1016/j.molbiopara.2009.04.008
更新日期：2009-09-01 00:00:00
abstract：:The karyotype and chromosomes of the human malaria parasite Plasmodium falciparum have been well characterized in recent years. Here we present karyotype maps of the three other human malaria species, P. vivax, P. malariae and P. ovale. Chromosomes of these species were found to be of significantly higher molecular we...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/s0166-6851(99)00045-6
更新日期：1999-06-25 00:00:00
abstract：:The enzyme pterin-4a-carbinolamine dehydratase (PCD) is important for the recycling of pterins within eukaryotic cells. A recombinant expression system for PCD from the apicomplexan parasite Toxoplasma gondii has been prepared, the protein purified and crystallised. Single crystal X-ray diffraction methods have produc...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/j.molbiopara.2007.12.002
更新日期：2008-04-01 00:00:00
