Soluble endothelin degradation enzyme activities in various rat tissues

1992 ◽  
Vol 70 (12) ◽  
pp. 1385-1389 ◽  
Author(s):  
Yilun Deng ◽  
Arco Y. Jeng
Keyword(s):  
Enzyme Activity ◽  
Protease Inhibitors ◽  
Rat Kidney ◽  
Cathepsin L ◽  
Biochemical Properties ◽  
Rat Tissues ◽  
Thiol Protease ◽  
Endothelin 1 ◽  
Cathepsin H ◽  
Thiol Proteases

From soluble extract of rat kidney we have previously identified an endothelin degradation enzyme that rapidly and specifically cleaves off the C-terminal tryptophan of endothelin-1, resulting in a peptide that is three orders of magnitude weaker in potency than endothelin-1 in causing smooh muscle contraction. The tissue distribution of this enzyme was examined, and the soluble extracts of rat kidney were found to contain the highest enzyme activity, followed by the spleen and the liver. In contrast, no enzyme activity was detected in the soluble extracts of brain, heart, and lung. The biochemical properties of the partially purified enzyme from kidney were further investigated. The optimal pH of the enzyme was between 5 and 7. The endothelin degrading activity was effectively blocked by thiol protease inhibitors such as benzyloxycarbonyl-Phe-Ala-diazomethyl ketone and p-hydroxymereuribenzoic acid, as well as by phenylmethylsulfonyl fluoride, but not by metalloprotease and other serine protease inhibitors. This enzyme displayed a clear difference in substrate specificity when compared with other thiol proteases such as cathepsin B, cathepsin H, and cathepsin L, known to be present in the kidney. These results suggest that a novel protease with endothelin degrading activity is widely distributed in a number of tissues.Key words: endothelin, endothelin degradation enzyme, thiol protease, carboxypeptidase.

scholarly journals Cloning of rat brain succinyl-CoA:3-oxoacid CoA-transferase cDNA. Regulation of the mRNA in different rat tissues and during brain development

1987 ◽  
Vol 248 (3) ◽  
pp. 853-857 ◽  
Author(s):  
M K Ganapathi ◽  
M Kwon ◽  
P M Haney ◽  
C McTiernan ◽  
A A Javed ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Rat Brain ◽  
Ketone Bodies ◽  
Rat Kidney ◽  
Relative Rate ◽  
Cdna Clones ◽  
Rat Tissues ◽  
Transferase Activity ◽  
Coa Transferase ◽  
Old Rats

3-Oxoacid CoA-transferase, which catalyses the first committed step in the oxidation of ketone bodies, is uniquely regulated in developing rat brain. Changes in 3-oxoacid CoA-transferase activity in rat brain during the postnatal period are due to changes in the relative rate of synthesis of the enzyme. To study the regulation of this enzyme, we identified, with a specific polyclonal rabbit anti-(rat 3-oxoacid CoA-transferase), two positive cDNA clones (approx. 800 bp) in a lambda gtll expression library, constructed from poly(A)+ RNA from brains of 12-day-old rats. One of these clones (lambda CoA3) was subcloned into M13mp18 and subjected to further characterization. Labelled single-stranded probes prepared by primer extension of the M13mp18 recombinant hybridized to a 3.6 kb mRNA. Rat brain mRNA enriched by polysome immunoadsorption for a single protein of size 60 kDa which corresponds to the precursor form of 3-oxoacid CoA-transferase was also found to be similarly enriched for the hybridizable 3.6 kb mRNA complementary to lambda CoA3. Affinity-selected antibody to the lambda CoA3 fusion protein inhibited 3-oxoacid CoA-transferase activity present in rat brain mitochondrial extracts. The 3.6 kb mRNA for 3-oxoacid CoA-transferase was present in relative abundance in rat kidney and heart, to a lesser extent in suckling brain and mammary gland and negligible in the liver. The specific mRNA was also found to be 3-fold more abundant in the brain from 12-day-old rats as compared with 18-day-old foetuses and adult rats, corresponding to the enzyme activity and relative rate of synthesis profile during development. These data suggest that 3-oxoacid CoA-transferase enzyme activity is regulated at a pretranslational level.

scholarly journals Effects of Five Substances with Different Modes of Action on Cathepsin H, C and L Activities in Zebrafish Embryos

2019 ◽  
Vol 16 (20) ◽  
pp. 3956
Author(s):  
Eberhard Küster ◽  
Stefan Kalkhof ◽  
Silke Aulhorn ◽  
Martin von Bergen ◽  
Ulrike Gündel
Keyword(s):  
Enzyme Activity ◽  
Zebrafish Embryo ◽  
Statistical Significance ◽  
Cathepsin L ◽  
Atp Synthesis ◽  
Chemical Exposure ◽  
Zebrafish Embryos ◽  
Modes Of Action ◽  
Cathepsin H

Cathepsins have been proposed as biomarkers of chemical exposure in the zebrafish embryo model but it is unclear whether they can also be used to detect sublethal stress. The present study evaluates three cathepsin types as candidate biomarkers in zebrafish embryos. In addition to other functions, cathepsins are also involved in yolk lysosomal processes for the internal nutrition of embryos of oviparous animals until external feeding starts. The baseline enzyme activity of cathepsin types H, C and L during the embryonic development of zebrafish in the first 96 h post fertilisation was studied. Secondly, the effect of leupeptin, a known cathepsin inhibitor, and four embryotoxic xenobiotic compounds with different modes of action (phenanthrene—baseline toxicity; rotenone—an inhibitor of electron transport chain in mitochondria; DNOC (Dinitro-ortho-cresol)—an inhibitor of ATP synthesis; and tebuconazole—a sterol biosynthesis inhibitor) on in vivo cathepsin H, C and L total activities have been tested. The positive control leupeptin showed effects on cathepsin L at a 20-fold lower concentration compared to the respective LC50 (0.4 mM) of the zebrafish embryo assay (FET). The observed effects on the enzyme activity of the four other xenobiotics were not or just slightly more sensitive (factor of 1.5 to 3), but the differences did not reach statistical significance. Results of this study indicate that the analysed cathepsins are not susceptible to toxins other than the known peptide-like inhibitors. However, specific cathepsin inhibitors might be identified using the zebrafish embryo.

scholarly journals Studies of Inhibitory Mechanisms of Propeptide-Like Cysteine Protease Inhibitors

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Bui T. T. Nga ◽  
Yuki Takeshita ◽  
Misa Yamamoto ◽  
Yoshimi Yamamoto
Keyword(s):  
Protease Inhibitors ◽  
Cysteine Protease ◽  
Cathepsin L ◽  
Cysteine Residue ◽  
Cysteine Protease Inhibitor ◽  
Inhibition Mechanism ◽  
Cysteine Protease Inhibitors ◽  
Inhibitory Potency ◽  
Inhibitory Mechanisms

Mouse cytotoxic T-lymphocyte antigen-2α (CTLA-2α), Drosophila CTLA-2-like protein (crammer), and Bombyx cysteine protease inhibitor (BCPI) belong to a novel family of cysteine protease inhibitors (I29). Their inhibitory mechanisms were studied comparatively. CTLA-2α contains a cysteine residue (C75), which is essential for its inhibitory potency. The CTLA-2α monomer was converted to a disulfide-bonded dimer in vitro and in vivo. The dimer was fully inhibitory, but the monomer, which possessed a free thiol residue, was not. A disulfide-bonded CTLA-2α/cathepsin L complex was isolated, and a cathepsin L subunit with a molecular weight of 24,000 was identified as the interactive enzyme protein. Crammer also contains a cysteine residue (C72). Both dimeric and monomeric forms of crammer were inhibitory. A crammer mutant with Cys72 to alanine (C72A) was fully inhibitory, while the replacement of Gly73 with alanine (G73A) caused a significant loss in inhibitory potency, which suggests a different inhibition mechanism from CTLA-2α. BCPI does not contain cysteine residue. C-terminal region (L77-R80) of BCPI was essential for its inhibitory potency. CTLA-2α was inhibitory in the acidic pH condition but stabilized cathepsin L under neutral pH conditions. The different inhibition mechanisms and functional considerations of these inhibitors are discussed.

scholarly journals Biological and biochemical properties in evaluation of forest soil quality

2014 ◽  
Vol 56 (1) ◽  
pp. 23-29 ◽  
Author(s):  
Ewa Błońska ◽  
Jarosław Lasota
Keyword(s):  
Enzyme Activity ◽  
Forest Soil ◽  
Soil Quality ◽  
Soil Ph ◽  
Chemical Properties ◽  
Biochemical Properties ◽  
Essential Elements ◽  
Forest Site ◽  
Physico Chemical ◽  
Density And Biomass

Abstract The aim of this study was to assess the possibility of using biological and biochemical parameters in the evaluation of forest soil quality and changes caused by land use. The study attempted to determine a relationship between the enzymatic activity of soil, the number of earthworms and soil physico-chemical properties. The study was carried out in central Poland in adjoining Forest Districts (Przedbórz and Smardzewice). In soil samples taken from 12 research plots, basic physico-chemical properties, enzyme activity (dehydrogenase, urease) and density and biomass of earthworms were examined. Enzyme activity showed a large diversity within the forest site types studied. The correlations between the activity of the enzymes studied and C/N ratio indicated considerable importance of these enzymes in metabolism of essential elements of organic matter of forest soils. Urease and dehydrogenase activity and earthworm number showed susceptibility to soil pH, which confirmed relationships between enzyme activity and abundance of earthworms and soil pH in H2O and KCl.

Effect of Apolipoprotein A-I on ATP Binding Cassette Transporter A1 Degradation and Cholesterol Efflux in THP-1 Macrophage-derived Foam Cells

2004 ◽  
Vol 36 (3) ◽  
pp. 218-226 ◽  
Author(s):  
Chao-Ke Tang ◽  
Guo-Hua Tang ◽  
Guang-Hui Yi ◽  
Zuo Wang ◽  
Lu-Shan Liu ◽  
...  
Keyword(s):  
Protease Inhibitors ◽  
Cholesterol Efflux ◽  
Foam Cells ◽  
Atp Binding ◽  
Thiol Protease ◽  
Atp Binding Cassette Transporter ◽  
Apolipoprotein A ◽  
Abca1 Protein ◽  
Abca1 Mrna ◽  
Atp Binding Cassette

Abstract Cholesterol-loaded macrophage foam cells are a central component of atherosclerotic lesions. ATP binding cassette transporter A1 (ABCA1), the defective molecule in Tangier disease, mediates the efflux of phospholipid and cholesterol from cells to apolipoprotein A-I (apoA-I), reversing foam cell formation. This study investigated the effect of apoA-I on ABCA1 degradation and cholesterol efflux in THP-1 macrophage-derived foam cells. After exposure of the cultured THP-1 macrophage-derived foam cells to apoA-I for different time, cholesterol efflux, ABCA1 mRNA and protein levels were determined by FJ-2107P type liquid scintillator, RT-PCR and Western blot, respectively. The mean ABCA1 fluorescence intensity on THP-1 macrophage-derived foam cells was detected by flow cytometry. Results showed that apoA-I markedly increased ABCA1-mediated cholesterol efflux from THP-1 macrophage-derived foam cells. This was accompanied by an increase in the content of ABCA1. ApoA-I did not alter ABCA1 mRNA abundance. Significantly, thiol protease inhibitors increased the level of ABCA1 protein and slowed its decay in THP-1 macrophage-derived foam cells, whereas none of the proteosome-specific inhibitor lactacystin, other protease inhibitors, or the lysosomal inhibitor NH4Cl showed such effects. The apoA-I-mediated cellular cholesterol efflux was enhanced by thiol protease inhibitors. Our results suggested that thiol protease inhibitors might provide an alternative way to upregulate ABCA1 protein. This strategy is especially appealing since it may mimic the stabilizing effect of the natural ligands apoA-I.

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