The role of the C-terminal region on the oligomeric state and enzymatic activity of Trypanosoma cruzi hypoxanthine phosphoribosyl transferase

2016 ◽  
Vol 1864 (6) ◽  
pp. 655-666 ◽  
Author(s):  
Wanda M. Valsecchi ◽  
Alexandra Cousido-Siah ◽  
Lucas A. Defelipe ◽  
André Mitschler ◽  
Alberto Podjarny ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Enzymatic Activity ◽  
Terminal Region ◽  
Hypoxanthine Phosphoribosyl Transferase ◽  
Oligomeric State ◽  
Phosphoribosyl Transferase

scholarly journals Neutral sphingomyelinase-2 is a redox sensitive enzyme: role of catalytic cysteine residues in regulation of enzymatic activity through changes in oligomeric state

2015 ◽  
Vol 465 (3) ◽  
pp. 371-382 ◽  
Author(s):  
P. Patrick Dotson ◽  
Alexander A. Karakashian ◽  
Mariana N. Nikolova-Karakashian
Keyword(s):  
Enzyme Activity ◽  
Enzymatic Activity ◽  
Cysteine Residues ◽  
Oligomeric State ◽  
Neutral Sphingomyelinase ◽  
Catalytic Cysteine

Neutral sphingomyelinase-2 (nSMase-2) regulates cellular levels of ceramide. This manuscript shows that nSMase-2 is a redox-sensitive enzyme that oligomerizes via Cys617-mediated intermolecular bonds that is linked to suppressed enzyme activity, and may be a substrate for thioredoxin.

The Role of the Unique Motifs in the Amino-Terminal Region of PKN on Its Enzymatic Activity

1996 ◽  
Vol 220 (3) ◽  
pp. 963-968 ◽  
Author(s):  
Michinori Kitagawa ◽  
Hideki Shibata ◽  
Masanao Toshimori ◽  
Hideyuki Mukai ◽  
Yoshitaka Ono
Keyword(s):  
Enzymatic Activity ◽  
Terminal Region ◽  
Amino Terminal

Dual role of the carboxyl-terminal region of pig liver L-kynurenine 3-monooxygenase: mitochondrial-targeting signal and enzymatic activity

2010 ◽  
Vol 148 (6) ◽  
pp. 639-650 ◽  
Author(s):  
K. Hirai ◽  
H. Kuroyanagi ◽  
Y. Tatebayashi ◽  
Y. Hayashi ◽  
K. Hirabayashi-Takahashi ◽  
...  
Keyword(s):  
Enzymatic Activity ◽  
Dual Role ◽  
Terminal Region ◽  
Mitochondrial Targeting ◽  
Pig Liver ◽  
Targeting Signal ◽  
Carboxyl Terminal

scholarly journals Potential Dual Role of West Nile Virus NS2B in Orchestrating NS3 Enzymatic Activity in Viral Replication

Viruses ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 216
Author(s):  
Alanna C. Tseng ◽  
Vivek R. Nerurkar ◽  
Kabi R. Neupane ◽  
Helmut Kae ◽  
Pakieli H. Kaufusi
Keyword(s):  
West Nile Virus ◽  
Enzymatic Activity ◽  
Nonstructural Protein ◽  
Antiviral Drug ◽  
West Nile ◽  
Biochemical Assays ◽  
In Trans ◽  
Viral Polyprotein ◽  
Ns3 Protease

West Nile virus (WNV) nonstructural protein 3 (NS3) harbors the viral triphosphatase and helicase for viral RNA synthesis and, together with NS2B, constitutes the protease responsible for polyprotein processing. NS3 is a soluble protein, but it is localized to specialized compartments at the rough endoplasmic reticulum (RER), where its enzymatic functions are essential for virus replication. However, the mechanistic details behind the recruitment of NS3 from the cytoplasm to the RER have not yet been fully elucidated. In this study, we employed immunofluorescence and biochemical assays to demonstrate that NS3, when expressed individually and when cleaved from the viral polyprotein, is localized exclusively to the cytoplasm. Furthermore, NS3 appeared to be peripherally recruited to the RER and proteolytically active when NS2B was provided in trans. Thus, we provide evidence for a potential additional role for NS2B in not only serving as the cofactor for the NS3 protease, but also in recruiting NS3 from the cytoplasm to the RER for proper enzymatic activity. Results from our study suggest that targeting the interaction between NS2B and NS3 in disrupting the NS3 ER localization may be an attractive avenue for antiviral drug discovery.

scholarly journals Absence of Bim sensitizes mice to experimental Trypanosoma cruzi infection

2021 ◽  
Vol 12 (7) ◽  
Author(s):  
Marcela Hernández-Torres ◽  
Rogério Silva do Nascimento ◽  
Monica Cardozo Rebouças ◽  
Alexandra Cassado ◽  
Kely Catarine Matteucci ◽  
...  
Keyword(s):  
T Cells ◽  
Trypanosoma Cruzi ◽  
Chagas Disease ◽  
Parasite Load ◽  
Peritoneal Macrophages ◽  
T Cell Response ◽  
No Production ◽  
Similar Reduction ◽  
Ifn Γ

AbstractChagas disease is a life-threatening disorder caused by the protozoan parasite Trypanosoma cruzi. Parasite-specific antibodies, CD8+ T cells, as well as IFN-γ and nitric oxide (NO) are key elements of the adaptive and innate immunity against the extracellular and intracellular forms of the parasite. Bim is a potent pro-apoptotic member of the Bcl-2 family implicated in different aspects of the immune regulation, such as negative selection of self-reactive thymocytes and elimination of antigen-specific T cells at the end of an immune response. Interestingly, the role of Bim during infections remains largely unidentified. To explore the role of Bim in Chagas disease, we infected WT, Bim+/−, Bim−/− mice with trypomastigotes forms of the Y strain of T. cruzi. Strikingly, our data revealed that Bim−/− mice exhibit a delay in the development of parasitemia followed by a deficiency in the control of parasite load in the bloodstream and a decreased survival compared to WT and Bim+/− mice. At the peak of parasitemia, peritoneal macrophages of Bim−/− mice exhibit decreased NO production, which correlated with a decrease in the pro-inflammatory Small Peritoneal Macrophage (SPM) subset. A similar reduction in NO secretion, as well as in the pro-inflammatory cytokines IFN-γ and IL-6, was also observed in Bim−/− splenocytes. Moreover, an impaired anti-T. cruzi CD8+ T-cell response was found in Bim−/− mice at this time point. Taken together, our results suggest that these alterations may contribute to the establishment of a delayed yet enlarged parasitic load observed at day 9 after infection of Bim−/− mice and place Bim as an important protein in the control of T. cruzi infections.

scholarly journals Role of the carboxyl-terminal region of arrestin in binding to phosphorylated rhodopsin

1991 ◽  
Vol 266 (23) ◽  
pp. 15334-15339 ◽  
Author(s):  
K. Palczewski ◽  
J. Buczyłko ◽  
N.R. Imami ◽  
J.H. McDowell ◽  
P.A. Hargrave
Keyword(s):  
Terminal Region ◽  
Carboxyl Terminal

scholarly journals Role of the amino-terminal region of the DnaA protein in opening of the duplex DNA at theoriCregion

1999 ◽  
Vol 176 (1) ◽  
pp. 163-167 ◽  
Author(s):  
Shinji Mima ◽  
Yoshihiro Yamagachi ◽  
Taemi Kondo ◽  
Tomofusa Tsuchiya ◽  
Tohru Mizushima
Keyword(s):  
Terminal Region ◽  
Duplex Dna ◽  
Dnaa Protein ◽  
Amino Terminal

Acetylsalicylic acid hydrolase of gastric mucosa.

1978 ◽  
Vol 234 (6) ◽  
pp. E606
Author(s):  
J G Spenney
Keyword(s):  
Gastric Mucosa ◽  
Enzymatic Activity ◽  
Acetylsalicylic Acid ◽  
Sodium Dodecyl ◽  
Sodium Cholate ◽  
Acid Hydrolase ◽  
Sulfhydryl Reagents ◽  
Ph Optimum ◽  
Diisopropyl Fluorophosphate

Acetylsalicylic acid hydrolase activity of rabbit fundic gastric mucosa has been isolated from the soluble 100,000 X g supernate. The enzymatic activity was partially purified by ammonium sulfate precipitation. The Km for acetylsalicylate was 2 mM and pH optimum was 8.6. The activity was insensitive to ionic strength, slightly inhibited by inclusion of 100 mM Cl-, and demonstrated no requirement for Ca2+ or Mg2+. Acetylsalicylic acid esterase was markedly inhibited by sodium cholate and sodium dodecyl sulfate. The enzyme was insensitive to sulfhydryl reagents with the exception of p-chloromercuribenzenesulfonic acid, which markedly inhibited the enzyme. Diisopropyl fluorophosphate (DFP) inhibited enzymatic activity with a Ki of 9 X 10(-9)M. Eserine was also inhibitory with a Ki of 0.25 mM. Inhibition by DFP at low concentration and by eserine at millimolar concentrations suggests that this enzyme is related to the group of aliphatic esterases. Identification of potent inhibitors will enable studies to define the role of this enzyme with the use of experimental preparations in which systemic toxicity can be avoided.

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