Amino acids flanking the central core of Cu,Zn superoxide dismutase are important in retaining enzyme activity after autoclaving

2016 ◽  
Vol 34 (3) ◽  
pp. 475-485 ◽  
Author(s):  
Arun Kumar ◽  
Vinay Randhawa ◽  
Vishal Acharya ◽  
Kashmir Singh ◽  
Sanjay Kumar
Author(s):  
Ricardo Ortiz Ortega ◽  
Karla S. Martínez Elizalde ◽  
Tomás Ernesto Villamar-Duque

<p>Teratogenic effect of herbicide glyphosate-Roundup, sold under the name Glifotox on Wistar rats was evaluated. The biological material was treated intraperitoneally with glyphosate at concentrations of 100, 125, and 150 mg/kg from gestation day nine. Hysterectomy was performed on day 18 of gestation, and the uterine horns where the embryos were located, in addition to recording the percentage of malformed embryos by modifying the method of Wilson were observed. The liver was removed and quantified by spectrophotometry with transaminase activity showed higher concentrations malformation rate and higher enzyme activity was 125 mg/kg, below is the average of 100 mg/kg and higher concentrations such as 150 mg/kg a large number of resorptions was obtained. It is concluded that glyphosate is toxic affecting the liver and liver enzymes involved in the formation of amino acids also produce delay in embryonic development.</p>


1987 ◽  
Vol 7 (1) ◽  
pp. 294-304 ◽  
Author(s):  
D Pilgrim ◽  
E T Young

Alcohol dehydrogenase isoenzyme III (ADH III) in Saccharomyces cerevisiae, the product of the ADH3 gene, is located in the mitochondrial matrix. The ADH III protein was synthesized as a larger precursor in vitro when the gene was transcribed with the SP6 promoter and translated with a reticulocyte lysate. A precursor of the same size was detected when radioactively pulse-labeled proteins were immunoprecipitated with anti-ADH antibody. This precursor was rapidly processed to the mature form in vivo with a half-time of less than 3 min. The processing was blocked if the mitochondria were uncoupled with carbonyl cyanide m-chlorophenylhydrazone. Mutant enzymes in which only the amino-terminal 14 or 16 amino acids of the presequence were retained were correctly targeted and imported into the matrix. A mutant enzyme that was missing the amino-terminal 17 amino acids of the presequence produced an active enzyme, but the majority of the enzyme activity remained in the cytoplasmic compartment on cellular fractionation. Random amino acid changes were produced in the wild-type presequence by bisulfite mutagenesis of the ADH3 gene. The resulting ADH III protein was targeted to the mitochondria and imported into the matrix in all of the mutants tested, as judged by enzyme activity. Mutants containing amino acid changes in the carboxyl-proximal half of the ADH3 presequence were imported and processed to the mature form at a slower rate than the wild type, as judged by pulse-chase studies in vivo. The unprocessed precursor appeared to be unstable in vivo. It was concluded that only a small portion of the presequence contains the necessary information for correct targeting and import. Furthermore, the information for correct proteolytic processing of the presequence appears to be distinct from the targeting information and may involve secondary structure information in the presequence.


1981 ◽  
Vol 98 (1) ◽  
pp. 57-61 ◽  
Author(s):  
Shigeru Matsuzaki ◽  
Mitsuo Suzuki ◽  
Koei Hamana

Abstract. Effect of chronic methylthiouracil (MTU) treatment on the thyroid arginase activity and thyroidal concentration of arginine, ornithine and other amino acids was studied in the rat. The activity of thyroid arginase increased significantly at 15 days of MTU treatment and the elevated enzyme activity was reduced to normal by l-thyroxine (T4) injection. The thyroidal concentration of polyamines was increased by MTU and decreased by T4 with the exception of spermine. The thyroidal concentration of arginine and lysine, a substrate and an inhibitor for arginase respectively decreased significantly, while that of ornithine remained unchanged after MTU treatment. T4 injected to MTU-pretreated rats restored the decreased arginine concentration to normal. These results suggest that ornithine supply for polyamine biosynthesis is regulated by the level of both arginase and lysine in the thyroid.


2012 ◽  
Vol 610-613 ◽  
pp. 229-234
Author(s):  
Han Feng Xiong ◽  
Qi Ling Tan

Eutrophication in water bodies affects the growth of aquatic plants. In this study, we conducted static experiments to better understand the metabolic responses of Elodea nattalii under eutrophication conditions. The nitrogen (N) and phosphorous (P) levels in tissue, malondiadehyde (MDA), and activities of three antioxidases (peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT)) of Elodea nattalii cultured at different nutrient levels (oligotropher, mesotropher, eutropher, and hypertrophics) were investigated. The results showed that with nutrient concentration increase, N and P contents of Elodea nattalii increased. The MDA content improved with nutrient increase. the POD activity initially increased and later decreased. CAT and SOD activities decreased during the experimental time period. These finding suggested that changes in stem the increase of antioxidant enzyme activity can be served as the indicators of the response of Elodea nattalii to eutrophication conditions.


Author(s):  
Б. В. Гутий

Розкрито особливості антиоксидантної системиорганізму щурів за хронічного кадмієвого токсикозу.Встановлено, що хлорид кадмію у токсичній дозісприяє зниженню активності ферментної й нефер-ментної системи антиоксидантного захисту, на щовказує зниження ферментів глутатіонпероксидази,глутатіонредуктази, супероксиддисмутази, катала-зи та відновленого глутатіону у печінці щурів. Ре-зультати досліджень вказують на те, що хронічнийкадмієвий токсикоз призводить до посиленої акти-вації процесів ліпопероксидації. The features of the antioxidant system of rats with chronic cadmium toxicosiare disclosed. It wasresearched that cadmium chloride in toxic doses reduces enzyme activity of antioxidant system, asindicated by the decrease in enzyme glutathione peroxidase, hlutationreduktazy, superoxide dismutase,catalase and restored glutathione in the liver and blood of rats. The results indicate that chroniccadmium toxicosis leads to enhanced activation of lipid peroxidation.


Author(s):  
AFRIWARDI AFRIWARDI ◽  
DELMI SULASTRI ◽  
YUNIAR LESTARI ◽  
DESMAWATI DESMAWATI ◽  
PRIMA MINERVA

Objective: The purpose of this research is to investigate the correlation between fat intake and plasma superoxide dismutase (SOD) enzyme activity with telomere length of Minangkabau ethnic men in West Sumatera, Indonesia. Materials and Methods: This cross-sectional study was conducted in Padang City in 2016, using a sample of 107 Minangkabau ethnic men, aged between 40 and 50 years. The total fat, saturated fatty acids (SFA), monounsaturated fatty acid (MUFA), and polyunsaturated fatty acid (PUFA) intake were collected using a food frequency questionnaire, and blood sample analysis to measure telomere length and plasma SOD activity. Results: This research indicated that an average telomere length was 584.59±305.92 bp, fat intake consists of total fat was 27.01±6.68% calorie, SFA was 24,7510.07% calorie, MUFA was 10.24±5.41% calorie, and PUFA was 7.35±3.54% calorie. Average of plasma SOD activity was 5.85±3.41 u/mL. There were no correlations between fat intake (total fat, SFA, MUFA, and PUFA) with telomere length (p>0.05), but there was a significant positive correlation between plasma SOD enzyme activity with telomere length (r=−0.202, p=0.037). Conclusion: Fat intake within normal limits does not correlate with telomere length, and plasma SOD activity is a risk factor for telomere shortening in ethnic Minangkabau men.


1995 ◽  
Vol 307 (2) ◽  
pp. 457-463 ◽  
Author(s):  
D A Brooks ◽  
D A Robertson ◽  
C Bindloss ◽  
T Litjens ◽  
D S Anson ◽  
...  

The sulphatase family of enzymes have regions of sequence similarity, but relatively little is known about either the structure-function relationships of sulphatases, or the role of highly conserved amino acids. The sequence of amino acids CTPSR at position 91-95 of 4-sulphatase has been shown to be highly conserved in all of the sequenced sulphatase enzymes. The cysteine at amino acid 91 of 4-sulphatase was selected for mutation analysis due to its potential role in either the active site, substrate-binding site or part of a key structural domain of 4-sulphatase and due to the absence of naturally occurring mutations in this residue in mucopolysaccharidosis type VI (MPS VI) patients. Two mutations, C91S and C91T, altering amino acid 91 of 4-sulphatase were generated and expressed in Chinese hamster ovary cells. Biochemical analysis of protein from a C91S cell line demonstrated no detectable 4-sulphatase enzyme activity but a relatively normal level of 4-sulphatase polypeptide (180% of the wild-type control protein level). Epitope detection, using a panel of ten monoclonal antibodies, demonstrated that the C91S polypeptide had a similar immunoreactivity to wild-type 4-sulphatase, suggesting that the C91S substitution does not induce a major structural change in the protein. Reduced catalytic activity associated with normal levels of 4-sulphatase protein have not been observed in any of the MPS VI patients tested and all show evidence of structural modification of 4-sulphatase protein with the same panel of antibodies [Brooks, McCourt, Gibson, Ashton, Shutter and Hopwood (1991) Am. J. Hum. Genet. 48, 710-719]. The loss of enzyme activity without a detectable protein conformation change suggests that Cys-91 may be a critical residue in the catalytic process. In contrast, analysis of protein from a C91T cell line revealed low levels of catalytically inactive 4-sulphatase polypeptide (0.37% of the wild-type control protein level) which had missing or masked epitopes, suggesting an altered protein structure or conformation. Subcellular fractionation studies of the C91T cell line demonstrated a high proportion of 4-sulphatase polypeptide content in organelles characteristic of microsomes. The aberrant intracellular localization and the reduced cellular content of 4-sulphatase polypeptide was consistent with the observed structural modification leading to retention and degradation of the protein within an early vacuolar compartment.


1997 ◽  
Vol 43 (3) ◽  
pp. 292-295 ◽  
Author(s):  
Salim K. Mujawar ◽  
Jaiprakash G. Shewale

Aspergillus sp. strain O20 produces inducible D-amino acid oxidase intracellularly, only in the presence of some amino acids. The enzyme was induced most effectively by the addition of DL-alanine (1% w/v) to the production medium. Among the various compounds studied, production of the D-amino acid oxidase was enhanced by Aerosol-22, glucose, and sodium nitrate. D-Amino acid oxidase formation was observed during the onset of the stationary growth phase. Maximum enzyme activity was recorded after 96 h of fermentation (1000 IU/L).Key words: D-amino acid oxidase, Aspergillus sp., 7-aminocephalosporanic acid, cephalosporin C.


2008 ◽  
Vol 80 (2) ◽  
pp. 127-135 ◽  
Author(s):  
Matthew J. Higgins ◽  
Gregory Adams ◽  
Yen-Chih Chen ◽  
Zeynep Erdal ◽  
Robert H. Forbes ◽  
...  

Genes ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 25 ◽  
Author(s):  
Xue Yang ◽  
Jinchi Wei ◽  
Zhihai Wu ◽  
Jie Gao

Glutathione S-transferases (GSTs)—an especially plant-specific tau class of GSTs—are key enzymes involved in biotic and abiotic stress responses. To improve the stress resistance of crops via the genetic modification of GSTs, we predicted the amino acids present in the GSH binding site (G-site) and hydrophobic substrate-binding site (H-site) of OsGSTU17, a tau class GST in rice. We then examined the enzyme activity, substrate specificity, enzyme kinetics and thermodynamic stability of the mutant enzymes. Our results showed that the hydrogen bonds between Lys42, Val56, Glu68, and Ser69 of the G-site and glutathione were essential for enzyme activity and thermal stability. The hydrophobic side chains of amino acids of the H-site contributed to enzyme activity toward 4-nitrobenzyl chloride but had an inhibitory effect on enzyme activity toward 1-chloro-2,4-dinitrobenzene and cumene hydroperoxide. Different amino acids of the H-site had different effects on enzyme activity toward a different substrate, 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole. Moreover, Leu112 and Phe162 were found to inhibit the catalytic efficiency of OsGSTU17 to 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole, while Pro16, Leu112, and Trp165 contributed to structural stability. The results of this research enhance the understanding of the relationship between the structure and function of tau class GSTs to improve the abiotic stress resistance of crops.


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