Effect of photorespiratory inhibitors on in vivo nitrate reduction in the leaves of barley and maize

1989 ◽  
Vol 67 (11) ◽  
pp. 3426-3427
Author(s):  
P. A. Kumar ◽  
Y. P. Abrol
Keyword(s):  
Enzyme Activity ◽  
Nitrate Reduction ◽  
Pronounced Effect ◽  
Isonicotinyl Hydrazide

The effects of photorespiratory inhibitors, α-hydroxypyridinemethanesulphonate, isonicotinyl hydrazide, and amino-oxyacetate, on in vivo nitrate reduction in the leaves of barley (C3) and maize (C4) were studied. The inhibitors had a pronounced effect on enzyme activity in the leaves of barley but not of maize. Photorespiratory substrates, glycolate and glycine, enhanced nitrate reduction in the leaves of barley. The enhancement was reversed by the inhibitors. It is proposed that glycine oxidation supports nitrate reduction in C3 plants but not in C4 plants.

Controlled Nano–Bio Interface of Functional Nanoprobes for in Vivo Monitoring Enzyme Activity in Tumors

ACS Nano ◽  
2019 ◽  
Author(s):  
Ziyan Sun ◽  
Kai Cheng ◽  
Yuyu Yao ◽  
Fengyu Wu ◽  
Jonathan Fung ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
In Vivo Monitoring

Nutrient uptake and enzyme activity of the preattachment goat embryo developed in vivo

1994 ◽  
Vol 41 (1) ◽  
pp. 204 ◽  
Author(s):  
D.K. Gardner ◽  
M. Lane ◽  
P.A. Batt
Keyword(s):  
Enzyme Activity ◽  
Nutrient Uptake

scholarly journals Primary structure requirements for correct sorting of the yeast mitochondrial protein ADH III to the yeast mitochondrial matrix space.

1987 ◽  
Vol 7 (1) ◽  
pp. 294-304 ◽  
Author(s):  
D Pilgrim ◽  
E T Young
Keyword(s):  
Amino Acids ◽  
Enzyme Activity ◽  
Amino Acid ◽  
Proteolytic Processing ◽  
Mitochondrial Matrix ◽  
Wild Type ◽  
Mature Form ◽  
Amino Terminal ◽  
The Matrix

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.

Metabolic importance of Na+/K+-ATPase activity during sea urchin development.

1997 ◽  
Vol 200 (22) ◽  
pp. 2881-2892 ◽  
Author(s):  
P Leong ◽  
D Manahan
Keyword(s):  
Enzyme Activity ◽  
Atpase Activity ◽  
Sea Urchin ◽  
Sodium Pump ◽  
Sea Water ◽  
Strongylocentrotus Purpuratus ◽  
Lytechinus Pictus ◽  
Stimulation Of

Early stages of animal development have high mass-specific rates of metabolism. The biochemical processes that establish metabolic rate and how these processes change during development are not understood. In this study, changes in Na+/K+-ATPase activity (the sodium pump) and rate of oxygen consumption were measured during embryonic and early larval development for two species of sea urchin, Strongylocentrotus purpuratus and Lytechinus pictus. Total (in vitro) Na+/K+-ATPase activity increased during development and could potentially account for up to 77 % of larval oxygen consumption in Strongylocentrotus purpuratus (pluteus stage) and 80 % in Lytechinus pictus (prism stage). The critical issue was addressed of what percentage of total enzyme activity is physiologically active in living embryos and larvae and thus what percentage of metabolism is established by the activity of the sodium pump during development. Early developmental stages of sea urchins are ideal for understanding the in vivo metabolic importance of Na+/K+-ATPase because of their small size and high permeability to radioactive tracers (86Rb+) added to sea water. A comparison of total and in vivo Na+/K+-ATPase activities revealed that approximately half of the total activity was utilized in vivo. The remainder represented a functionally active reserve that was subject to regulation, as verified by stimulation of in vivo Na+/K+-ATPase activity in the presence of the ionophore monensin. In the presence of monensin, in vivo Na+/K+-ATPase activities in embryos of S. purpuratus increased to 94 % of the maximum enzyme activity measured in vitro. Stimulation of in vivo Na+/K+-ATPase activity was also observed in the presence of dissolved alanine, presumably due to the requirement to remove the additional intracellular Na+ that was cotransported with alanine from sea water. The metabolic cost of maintaining the ionic balance was found to be high, with this process alone accounting for 40 % of the metabolic rate of sea urchin larvae (based on the measured fraction of total Na+/K+-ATPase that is physiologically active in larvae of S. purpuratus). Ontogenetic changes in pump activity and environmentally induced regulation of reserve Na+/K+-ATPase activity are important factors that determine a major proportion of the metabolic costs of sea urchin development.

scholarly journals QUANTITATIVE AND HISTOCHEMICAL STUDIES ON THE DESORPTION AND READSORPTION OF ALDOLASE IN CROSS-STRIATED MUSCLE

1969 ◽  
Vol 17 (5) ◽  
pp. 314-320 ◽  
Author(s):  
H. ARNOLD ◽  
J. NOLTE ◽  
D. PETTE
Keyword(s):  
Enzyme Activity ◽  
Actin Filaments ◽  
Phosphate Buffer ◽  
Striated Muscle ◽  
Psoas Muscle ◽  
Histochemical Staining ◽  
Intracellular Location ◽  
Successive Extraction ◽  
Complete Extraction

Complete extraction of aldolase from minced rabbit psoas muscle was achieved by successive extraction steps in 0.1 M phosphate buffer. Aldolase was then readsorbed quantitatively to the depleted myofibrils. Extraction, readsorption and a final redsorption of the enzyme were followed quantitatively by enzyme activity determinations and qualitatively by histochemical staining of aldolase. The intracellular location of the readsorbed enzyme was found to be identical with that of aldolase in native muscle. In both cases, aldolase was localized within the isotropic bands. These results as well as the previously demonstrated binding of the enzyme to F-actin suggest that aldolase is located within the interfilamentary sarcoplasm of the isotropic bands and is probably also bound in vivo to the actin filaments.

scholarly journals In Vivo Enzymes Activities of Some Ru(II) Compounds with N-Alkylphenothiazines

2016 ◽  
Vol 66 (4) ◽  
pp. 497-508
Author(s):  
P. Milena Krstić ◽  
Z. Sunčica Borozan ◽  
P. Sofija Sovilj ◽  
R. Sanja Grgurić-Šipka ◽  
M. Jelena Oljarević
Keyword(s):  
Antioxidant Activity ◽  
Enzyme Activity ◽  
Lactate Dehydrogenase ◽  
Normal Activity ◽  
Protective Effects ◽  
Toxic Compounds ◽  
Physiological Conditions ◽  
Positive Effects ◽  
Ldh Activity

Abstract The purpose of the present study was to investigate and compare the effects of two ruthenium complexes with trifluoperazine on acethylcholinesterase enzyme activity and lactate dehydrogenase levels in vivo under physiological conditions in rats blood. Complexes 1 and 2 showed positive effects on acethylcholinesterase at all doses and did not disturb its normal activity. Total LDH activity was inhibited in the presence of both complexes, but Ru(II) complexes showed different effects on the activity of LDH isoenzymes. The activities of LDH1 and LDH2 isoenzymes were decreased in all applied doses of the complex 2, while the activity of LDH2 reduced using complex 1 in the same doses. Results of the present study suggest the neuro- and cardio protective potential of oral administration of complexes 1 and 2, as non-toxic compounds under physiological conditions. These protective effects are the result of their potent antioxidant activity.

Abstract 71: Novel Bach1 Modulators Increase HMOX1 and Suppress Hypertension in the Goldblatt Model of Renovascular Hypertension

Hypertension ◽  
2013 ◽  
Vol 62 (suppl_1) ◽  
Author(s):  
Matthew Kostura ◽  
Otis Attucks ◽  
Jareer Kassis ◽  
Suparna Gupta ◽  
Samuel Victory ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Enzyme Activity ◽  
Renovascular Hypertension ◽  
Transcriptional Repressor ◽  
Plasma Aldosterone ◽  
Lung Fibroblasts ◽  
Left Renal Artery ◽  
Dependent Manner ◽  
Sprague Dawley

We report for the first time a novel class of compounds that specifically modulate the Bach1 transcriptional repressor pathway. In cellula, the compounds selectively inhibit the activity of the transcriptional repressor Bach1 resulting in transcription of a network of antioxidant and cytoprotective genes including HMOX1. HPP-1971, a member of this class, is a potent and selective Bach1 inhibitor that induces HMOX1 > 40-fold with a potency of 408 nM in human lung fibroblasts. To assess activity in vivo, we tested HPP-1971 in the Goldblatt model of renovascular hypertension. Sprague Dawley rats were implanted with in dwelling pressure telemeter probes and subsequently underwent sham surgery or placement of a 0.25 mm silver clip around the left renal artery. HPP-1971 treatment, dosed orally at 1,3,10 and 30 mpk, commenced three days following clip surgery, and continued for 18 days. At study completion, blood pressure, clipped kidney weight, renal HMOX1 enzyme activity and plasma aldosterone levels were measured (see Table). HPP-1971 attenuated both kidney atrophy and the increase in blood pressure in a dose dependent manner with significant differences seen at 3, 10 and 30 mpk (p<.0001). HMOX1 enzyme activity in the clipped kidney increased with treatment, reaching a maximum of 5.7 ± 0.9 nM/hr/mg at 30 mpk relative to sham operated animals (p<.0001). Plasma aldosterone levels increased in 2K1C animals compared to sham controls but were reduced by HPP-1971 treatment. These findings define a novel role for Bach1 suppressors in counteracting the influence of the RAAS system on hypertension and kidney atrophy in the 2K1C model of renovascular hypertension.

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