scholarly journals E-NTPDases: Possible Roles on Host-Parasite Interactions and Therapeutic Opportunities

2021 ◽  
Vol 11 ◽  
Author(s):  
Lisvane Paes-Vieira ◽  
André Luiz Gomes-Vieira ◽  
José Roberto Meyer-Fernandes
Keyword(s):  
Trichomonas Vaginalis ◽  
Biochemical Characterization ◽  
Divalent Cations ◽  
Parasite Clearance ◽  
Nucleoside Triphosphate ◽  
Host Parasite Interactions ◽  
Antiparasitic Drugs ◽  
Host Parasite ◽  
Hydrolysis Of

Belonging to the GDA1/CD39 protein superfamily, nucleoside triphosphate diphosphohydrolases (NTPDases) catalyze the hydrolysis of ATP and ADP to the monophosphate form (AMP) and inorganic phosphate (Pi). Several NTPDase isoforms have been described in different cells, from pathogenic organisms to animals and plants. Biochemical characterization of nucleotidases/NTPDases has revealed the existence of isoforms with different specificities regarding divalent cations (such as calcium and magnesium) and substrates. In mammals, NTPDases have been implicated in the regulation of thrombosis and inflammation. In parasites, such as Trichomonas vaginalis, Trypanosoma spp., Leishmania spp., Schistosoma spp. and Toxoplasma gondii, NTPDases were found on the surface of the cell, and important processes like growth, infectivity, and virulence seem to depend on their activity. For instance, experimental evidence has indicated that parasite NTPDases can regulate the levels of ATP and Adenosine (Ado) of the host cell, leading to the modulation of the host immune response. In this work, we provide a comprehensive review showing the involvement of the nucleotidases/NTPDases in parasites infectivity and virulence, and how inhibition of NTPDases contributes to parasite clearance and the development of new antiparasitic drugs.

Ultrastructural characterization of host–parasite interactions of Plasmodium coatneyi in rhesus macaques

Parasitology ◽  
2021 ◽  
pp. 1-35
Author(s):  
ED Lombardini ◽  
B Malleret ◽  
A Rungojn ◽  
N Popruk ◽  
T Kaewamatawong ◽  
...  
Keyword(s):  
Rhesus Macaques ◽  
Host Parasite Interactions ◽  
Ultrastructural Characterization ◽  
Host Parasite ◽  
Plasmodium Coatneyi

Biochemical characterization of the tartrate-resistant acid phosphatase of human spleen with leukemic reticuloendotheliosis as a pyrophosphatase.

1977 ◽  
Vol 23 (1) ◽  
pp. 89-94 ◽  
Author(s):  
K W Lam ◽  
L T Yam
Keyword(s):  
Acid Phosphatase ◽  
Biochemical Characterization ◽  
Normal Animal ◽  
Tartrate Resistant Acid Phosphatase ◽  
Animal Tissues ◽  
Human Spleen ◽  
Optimal Activity ◽  
Catalytic Function ◽  
Hydrolysis Of

Abstract A tartrate-resistant acid phosphatase was isolated from a human leukemic spleen by freeze-thawing in saline and purified by repeated chromatography on carboxymethyl-cellulose. The purified enzyme has a molecular weight of 64 000. It catalyzes the hydrolysis of inorganic and organic pyrophosphate as well as the phenolic ester of monoorthophosphate, with optimal activity between pH 5 and 6. However, there is no activity toward mono-orthophosphate esters of aliphatic alcohols. The present data have identified its catalytic function as a pyrophosphatase. However, it has properties different from the pyrophosphatase previously observed in normal animal tissues.

scholarly journals Overproduction and Biochemical Characterization of the Chryseobacterium meningosepticum BlaB Metallo-β-Lactamase

2002 ◽  
Vol 46 (6) ◽  
pp. 1921-1927 ◽  
Author(s):  
Sandrine Vessillier ◽  
Jean-Denis Docquier ◽  
Sandrine Rival ◽  
Jean-Marie Frere ◽  
Moreno Galleni ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Ion Exchange ◽  
Kinetic Parameters ◽  
Culture Supernatant ◽  
Biochemical Characterization ◽  
Expression System ◽  
T7 Promoter ◽  
Hydrolysis Of

ABSTRACT The BlaB metallo-β-lactamase of Chryseobacterium meningosepticum CCUG4310 was overproduced in Escherichia coli by means of a T7 promoter-based expression system. The overproducing system, scaled up in a 15-liter fermentor, yielded approximately 10 mg of BlaB protein per liter, mostly released in the culture supernatant. The enzyme was purified by two ion-exchange chromatographic steps with an overall yield of 66%. Analysis of the kinetic parameters revealed efficient activities (k cat/Km ratios of >106 M−1 s−1) toward most penam and carbapenem compounds, with the exception of the 6-α-methoxypenam derivative temocillin and of biapenem, which were poorer substrates. Hydrolysis of cephalosporins was overall less efficient, with a remarkable variability that was largely due to variable affinities of the BlaB enzyme for different compounds. BlaB was also able to hydrolyze serine-β-lactamase inhibitors, including β-iodopenicillanate, sulbactam and, although less efficiently, tazobactam.

A novel endo-β-1,4-xylanase GH30 from Dickeya dadantii DCE-01: Clone, expression, characterization, and ramie biological degumming function

2017 ◽  
Vol 89 (4) ◽  
pp. 463-472 ◽  
Author(s):  
Ruijun Wang ◽  
Zhengchu Liu ◽  
Lifeng Cheng ◽  
Shengwen Duan ◽  
Xiangyuan Feng ◽  
...  
Keyword(s):  
Biochemical Characterization ◽  
Ph Value ◽  
Hydrolytic Activity ◽  
Glycoside Hydrolase Family ◽  
Dickeya Dadantii ◽  
Beechwood Xylan ◽  
Expression Characterization ◽  
Hydrolysis Of ◽  
Hydrolase Family

Xylanase plays an important role in the hydrolysis of hemicellulose and has gained much attention in the field of biological degumming. The research for xylanases with cellulase-free and high activity for biological degumming has intensified in recent years. In the present research, heterologous expression of a novel endo-β-1,4-xylanase (GH30) from Dickeya dadantii DCE-01 in Escherichia coli BL21 (DE3) was reported. Biochemical characterization of the enzyme and a potential application in ramie biological degumming was discussed. The results showed that the xylanase gene consists of 1251 nucleotides, belonging to glycoside hydrolase family 30 (GH30). The optimal activity of the xylanase was observed at 50℃ and a pH value of 6.4. The Km and Vmax values for beechwood xylan were 14.25 mg/mL and 296.6 μmol/mg, respectively. The catalytic activity was enhanced by addition of 1 mM Cu2+, Ca2+, Mg2+, and K+. The recombinant enzyme was specific for xylan substrates. The enzyme exhibited hydrolytic activity toward ramie hemicellulose. The recombinant xylanase could be effectively applied to ramie degumming.

Biochemical characterization of an aryl acetic ester hydrolase isolated from human monocytes.

1978 ◽  
Vol 24 (7) ◽  
pp. 1177-1181 ◽  
Author(s):  
W K Lam ◽  
E Taft ◽  
L T Yam
Keyword(s):  
Biochemical Characterization ◽  
Competitive Inhibition ◽  
Sucrose Density Gradient ◽  
Relative Molecular Mass ◽  
Ester Hydrolase ◽  
Carboxylic Ester Hydrolase ◽  
Myelomonocytic Leukemia ◽  
Hydrolysis Of ◽  
Sucrose Density Gradient Sedimentation

Abstract A carboxylic-ester hydrolase was isolated from the leukocytes of a patient with myelomonocytic leukemia. Its relative molecular mass as estimated by sucrose density-gradient sedimentation is about 70 000. The purified enzyme is specific for acetyl esters of aromatic alcohols. It is inhibited by fluoride, but insensitive to eserine or p-chloromercuriphenylsulfonate. Hydrolysis of 1-naphthyl acetate was optimal above pH 6.0; of o-nitrophenyl acetate, above 8.0. The common catalytic site for the two types of substrates on the enzyme was confirmed by competitive inhibition data.

scholarly journals Identification and characterization of mutations in the UPF1 gene that affect nonsense suppression and the formation of the Upf protein complex but not mRNA turnover.

1996 ◽  
Vol 16 (10) ◽  
pp. 5491-5506 ◽  
Author(s):  
Y Weng ◽  
K Czaplinski ◽  
S W Peltz
Keyword(s):  
Mrna Decay ◽  
Rna Binding ◽  
Biochemical Characterization ◽  
Translation Termination ◽  
Nonsense Suppression ◽  
Nucleoside Triphosphate ◽  
Rich Region ◽  
Amino Terminal ◽  
Nonsense Mediated Mrna Decay

To understand the relationship between translation and mRNA decay, we have been studying how premature translation termination accelerates the degradation of mRNAs. In the yeast Saccharomyces cerevisiae, the Upf1 protein (Upf1p), which contains a cysteine- and histidine-rich region and nucleoside triphosphate hydrolysis and helicase motifs, was shown to be a trans-acting factor in this decay pathway. A UPF1 gene disruption results in the stabilization of nonsense-containing mRNAs and leads to a nonsense suppression phenotype. Biochemical analysis of the wild-type Upf1p demonstrated that it has RNA-dependent ATPase, RNA helicase, and RNA binding activities. In the work described in the accompanying paper (Y. Weng, K. Czaplinski, and S. W. Peltz, Mol. Cell. Biol. 16:5477-5490, 1996) mutations in the helicase region of Upf1p that inactivated its mRNA decay function but prevented suppression of leu2-2 and tyr7-1 nonsense alleles are identified. On the basis of these results, we suggested that Upf1p is a multifunctional protein involved in modulating mRNA decay and translation termination at nonsense codons. If this is true, we predict that UPF1 mutations with the converse phenotype should be identified. In this report, we describe the identification and biochemical characterization of mutations in the amino-terminal cysteine- and histidine-rich region of Upf1p that have normal nonsense-mediated mRNA decay activities but are able to suppress leu2-2 and tyr7-1 nonsense alleles. Biochemical characterization of these mutant proteins demonstrated that they have altered RNA binding properties. Furthermore, using the two-hybrid system, we characterized the Upf1p-Upf2p interactions and demonstrated that Upf2p interacts with Upf3p. Mutations in the cysteine- and histidine-rich region of Upf1p abolish Upf1p-Upf2p interaction. On the basis of these results, the role of the Upf complex in nonsense-mediated mRNA decay and nonsense suppression is discussed.

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