scholarly journals Kinetic characterization of human butyrylcholinesterase mutants for the hydrolysis of cocaethylene

2014 ◽  
Vol 460 (3) ◽  
pp. 447-457 ◽  
Author(s):  
Shurong Hou ◽  
Max Zhan ◽  
Xirong Zheng ◽  
Chang-Guo Zhan ◽  
Fang Zheng
Keyword(s):  
Kinetic Modelling ◽  
Kinetic Characterization ◽  
In Vivo Tests ◽  
Hydrolysis Of ◽  
Human Butyrylcholinesterase

Catalytic parameters of butyrylcholinesterase and its mutants against cocaethylene have been characterized in comparison with those against cocaine, indicating that the mutants can efficiently metabolize cocaethylene, in addition to cocaine. Further in vivo tests and kinetic modelling support the indication.

scholarly journals Kinetic characterization of high-activity mutants of human butyrylcholinesterase for the cocaine metabolite norcocaine

2013 ◽  
Vol 457 (1) ◽  
pp. 197-206 ◽  
Author(s):  
Max Zhan ◽  
Shurong Hou ◽  
Chang-Guo Zhan ◽  
Fang Zheng
Keyword(s):  
High Activity ◽  
Kinetic Modelling ◽  
Kinetic Characterization ◽  
In Vivo Tests ◽  
Human Butyrylcholinesterase

Catalytic parameters of butyrylcholinesterase and its mutants against norcocaine have been characterized in comparison with those against cocaine, indicating that the mutants can efficiently metabolize norcocaine, in addition to cocaine. Further in vivo tests and kinetic modelling support the indication.

scholarly journals Kinetic characterization of a cocaine hydrolase engineered from mouse butyrylcholinesterase

2015 ◽  
Vol 466 (2) ◽  
pp. 243-251 ◽  
Author(s):  
Xiabin Chen ◽  
Xiaoqin Huang ◽  
Liyi Geng ◽  
Liu Xue ◽  
Shurong Hou ◽  
...  
Keyword(s):  
Amino Acid ◽  
Substrate Inhibition ◽  
Kinetic Characterization ◽  
Substrate Activation ◽  
Amino Acid Mutations ◽  
Human Butyrylcholinesterase

Mouse (mBChE) and human butyrylcholinesterase (hBChE)-based cocaine hydrolases (mCocH and hCocH) have remarkably different catalytic efficiencies against cocaine, but with little differences in catalytic efficiencies against acetylcholine (ACh) and butyrylthiocholine (BTC). The amino-acid mutations have remarkably converted substrate activation of the enzymes into substrate inhibition.

scholarly journals Molecular characterization of virulence factors in Aeromonas hydrophila obtained from fish

2012 ◽  
Vol 32 (8) ◽  
pp. 701-706 ◽  
Author(s):  
Samira T.L. Oliveira ◽  
Gisele Veneroni-Gouveia ◽  
Mateus M. Costa
Keyword(s):  
Virulence Factors ◽  
Aeromonas Hydrophila ◽  
Nile Tilapia ◽  
Virulence Genes ◽  
Saline Solution ◽  
Specific Primers ◽  
In Vivo Tests ◽  
Polymerase Chain

Multiple factors can be involved in the virulence processes of Aeromonas hydrophila. The objective of the present paper was to verify the presence of aerolysin, hidrolipase, elastase and lipase virulence genes through the polymerase chain reaction (PCR) in A. hydrophila isolates obtained from fish of the São Francisco River Valley, and to evaluate virulence according to the presence of these genes in Nile tilapia fingerlings. One hundred and fourteen isolates from the bacteria were used. DNA was heat extracted and PCR undertaken using specific primers described in the literature. For in vivo tests Nile tilapia fingerlings were used. From the PCR tests, negative isolates for all genes tested were selected, positive isolates for two genes (aerolysin and elastase) and positive for the four genes tested. These were inoculated at a concentration of 10(8) UFC/ml into the tilapias, considered as treatments; another group of animals was used as control (with inoculation of saline solution). In all, 12 distinct standards regarding the presence of virulence factors in isolates from A. hydrophila, were observed. Of the 114 isolates analyzed, 100 (87.72%) presented at least one of the virulence factors under study. The virulence factors were widely distributed among the A. hydrophila isolates. Aerolysin was the most frequent virulence factor present in the isolates analyzed. A. hydrophila led to the mortality of the Nile tilapia fingerlings, regardless of the absence or quantity of virulence genes tested.

scholarly journals A Ral GAP complex links PI 3-kinase/Akt signaling to RalA activation in insulin action

2011 ◽  
Vol 22 (1) ◽  
pp. 141-152 ◽  
Author(s):  
Xiao-Wei Chen ◽  
Dara Leto ◽  
Tingting Xiong ◽  
Genggeng Yu ◽  
Alan Cheng ◽  
...  
Keyword(s):  
Glucose Transporter ◽  
Critical Role ◽  
Inhibitory Effect ◽  
Small Gtpase ◽  
Regulatory Subunit ◽  
Hydrolysis Of ◽  
Identification And Characterization

Insulin stimulates glucose transport in muscle  and adipose tissue by translocation of glucose transporter 4 (GLUT4) to the plasma membrane. We previously reported that activation of the small GTPase RalA downstream of PI 3-kinase plays a critical role in this process by mobilizing the exocyst complex for GLUT4 vesicle targeting in adipocytes. Here we report the identification and characterization of a Ral GAP complex (RGC) that mediates the activation of RalA downstream of the PI 3-kinase/Akt pathway. The complex is composed of an RGC1 regulatory subunit and an RGC2 catalytic subunit (previously identified as AS250) that directly stimulates the guanosine triphosphate hydrolysis of RalA. Knockdown of RGC proteins leads to increased RalA activity and glucose uptake in adipocytes. Insulin inhibits the GAP complex through Akt2-catalyzed phosphorylation of RGC2 in vitro and in vivo, while activated Akt relieves the inhibitory effect of RGC proteins on RalA activity. The RGC complex thus connects PI 3-kinase/Akt activity to the transport machineries responsible for GLUT4 translocation.

Kinetic characterization of hydrolysis of camel and bovine milk proteins by pancreatic enzymes

2008 ◽  
Vol 18 (12) ◽  
pp. 1097-1102 ◽  
Author(s):  
Maryam Salami ◽  
Reza Yousefi ◽  
Mohammad Reza Ehsani ◽  
Michèle Dalgalarrondo ◽  
Jean-Marc Chobert ◽  
...  
Keyword(s):  
Bovine Milk ◽  
Milk Proteins ◽  
Pancreatic Enzymes ◽  
Kinetic Characterization ◽  
Hydrolysis Of ◽  
Bovine Milk Proteins

scholarly journals Characterization of Fibrous Mordenite: A First Step for the Evaluation of Its Potential Toxicity

Crystals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 769 ◽  
Author(s):  
Dario Di Giuseppe
Keyword(s):  
Surface Characteristics ◽  
International Agency ◽  
Precautionary Approach ◽  
Adverse Health Effects ◽  
In Vivo Tests ◽  
Pathogenic Agents ◽  
Geological Formations

In nature, a huge number of unregulated minerals fibers share the same characteristics as asbestos and therefore have potential adverse health effects. However, in addition to asbestos minerals, only fluoro-edenite and erionite are currently classified as toxic/pathogenic agents by the International Agency for Research on Cancer (IARC). Mordenite is one of the most abundant zeolites in nature and commonly occurs with a fibrous crystalline habit. The goal of this paper is to highlight how fibrous mordenite shares several common features with the well-known carcinogenic fibrous erionite. In particular, this study has shown that the morphology, biodurability, and surface characteristics of mordenite fibers are similar to those of erionite and asbestos. These properties make fibrous mordenite potentially toxic and exposure to its fibers can be associated with deadly diseases such as those associated with regulated mineral fibers. Since the presence of fibrous mordenite concerns widespread geological formations, this mineral fiber should be considered dangerous for health and the precautionary approach should be applied when this material is handled. Future in vitro and in vivo tests are necessary to provide further experimental confirmation of the outcome of this work.

scholarly journals Characterization of the small molecule ARC39, a direct and specific inhibitor of acid sphingomyelinase in vitro

2020 ◽  
Vol 61 (6) ◽  
pp. 896-910 ◽  
Author(s):  
Eyad Naser ◽  
Stephanie Kadow ◽  
Fabian Schumacher ◽  
Zainelabdeen H. Mohamed ◽  
Christian Kappe ◽  
...  
Keyword(s):  
Cultured Cells ◽  
Specific Inhibitor ◽  
Acid Sphingomyelinase ◽  
Intact Cells ◽  
Protein Levels ◽  
High Doses ◽  
Hydrolysis Of

Inhibition of acid sphingomyelinase (ASM), a lysosomal enzyme that catalyzes the hydrolysis of sphingomyelin into ceramide and phosphorylcholine, may serve as an investigational tool or a therapeutic intervention to control many diseases. Specific ASM inhibitors are currently not sufficiently characterized. Here, we found that 1-aminodecylidene bis-phosphonic acid (ARC39) specifically and efficiently (>90%) inhibits both lysosomal and secretory ASM in vitro. Results from investigating sphingomyelin phosphodiesterase 1 (SMPD1/Smpd1) mRNA and ASM protein levels suggested that ARC39 directly inhibits ASM’s catalytic activity in cultured cells, a mechanism that differs from that of functional inhibitors of ASM. We further provide evidence that ARC39 dose- and time-dependently inhibits lysosomal ASM in intact cells, and we show that ARC39 also reduces platelet- and ASM-promoted adhesion of tumor cells. The observed toxicity of ARC39 is low at concentrations relevant for ASM inhibition in vitro, and it does not strongly alter the lysosomal compartment or induce phospholipidosis in vitro. When applied intraperitoneally in vivo, even subtoxic high doses administered short-term induced sphingomyelin accumulation only locally in the peritoneal lavage without significant accumulation in plasma, liver, spleen, or brain. These findings require further investigation with other possible chemical modifications. In conclusion, our results indicate that ARC39 potently and selectively inhibits ASM in vitro and highlight the need for developing compounds that can reach tissue concentrations sufficient for ASM inhibition in vivo.

Kinetic characterization of CYP2E1 inhibition in vivo and in vitro by the chloroethylenes

1998 ◽  
Vol 72 (10) ◽  
pp. 609-621 ◽  
Author(s):  
Patrick D. Lilly ◽  
Janice R. Thornton-Manning ◽  
Michael L. Gargas ◽  
Harvey J. Clewell ◽  
Melvin E. Andersen ◽  
...  
Keyword(s):  
Kinetic Characterization
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