scholarly journals Carnitine biosynthesis. Hydroxylation of N6-trimethyl-lysine to 3-hydroxy-N6-trimethyl-lysine

1980 ◽  
Vol 188 (2) ◽  
pp. 529-534 ◽  
Author(s):  
D S Sachan ◽  
C L Hoppel
Keyword(s):  
Protein Concentration ◽  
Citrate Synthase ◽  
Specific Activity ◽  
Rat Kidney ◽  
Fold Increase ◽  
Hydroxylase Activity ◽  
Distribution Profile ◽  
Bivalent Cations ◽  
Mitochondrial Distribution ◽  
Distribution Studies

Rat kidney homogenates metabolize N6-trimethyl-lysine to N-trimethylammoniobutyrate, but not to carnitine. The first step in this conversion is the hydroxylation of trimethyl-lysine to form 3-hydroxy-N6-trimethyl-lysine. An assay system was developed in which hydroxylation of trimethyl-lysine is linear with respect to both time and homogenate protein concentration. The rate is 5 nmol of 3-hydroxy-N6-trimethyl-lysine formed/min per mg of homogenate protein. The cofactors required are ascorbate, alpha-oxoglutarate, FeSO4, and O2. Catalase and dithiothreitol give a 20% stimulation. Ca2+ produces a 2-fold increase in specific activity and cannot be replaced by Mg2+, Mn2+ or Zn2+. These last three bivalent cations lead to a decreased activity. Subcellular distribution studies demonstrate that trimethyl-lysine hydroxylase activity parallels the distribution profile of succinate dehydrogenase and citrate synthase. Thus trimethyl-lysine hydroxylase has a mitochondrial localization. Distribution of trimethyl-lysine hydroxylase activity between cortex and medulla of kidney if 67 and 33% respectively, similar to mitochondrial distribution.

scholarly journals Effect of hepatic injury on prolyl 3-hydroxylase and 4-hydroxylase activities in rat liver and on immunoreactive prolyl 4-hydroxylase concentrations in the liver and serum

1978 ◽  
Vol 170 (1) ◽  
pp. 129-135 ◽  
Author(s):  
J Risteli ◽  
L Tuderman ◽  
K Tryggvason ◽  
K I Kivirikko
Keyword(s):  
Protein Concentration ◽  
Hepatic Injury ◽  
Specific Activity ◽  
Gel Filtration ◽  
Fold Increase ◽  
Partial Purification ◽  
Hydroxylase Activity ◽  
Enzyme Protein ◽  
Carbon Tetrachloride Administration ◽  
Total Enzyme

After severe hepatic injury induced by dimethylnitrosamine, approximately a 4-fold increase in hepatic prolyl 4-hydroxylase activity occurred within 4 days, whereas the increases in total immunoreactive prolyl 4-hydroxylase protein and in prolyl 3-hydroxylase activity were only about 1.4-fold. The different magnitudes of the increases in the prolyl 4-hydroxylase and 3-hydroxylase activities were verified after partial purification of the enzymes by gel filtration. The data support previous reports indicating differential increases in the activities of individual enzymes of collagen biosynthesis in hepatic injury. Separation of prolyl 4-hydroxylase tetramers from the monomer-size protein by gel filtration indicated that the increase in enzyme activity was similar to that in enzyme tetramers, and an increase had also occurred in the ratio of enzyme tetramers to total enzyme protein. Thus the specific activity of the tetramers had remained unchanged in liver injury. The administration of dimethylnitrosamine was also accompanied by a marked increase in the immunoreactive prolyl 4-hydroxylase protein concentration in the serum, and a similar effect was also noted after carbon tetrachloride administration, results suggesting that the increases originated in the liver.

Octopus mantle citrate synthase

1976 ◽  
Vol 54 (6) ◽  
pp. 886-891 ◽  
Author(s):  
J. H. A. Fields ◽  
H. Guderley ◽  
K. B. Storey ◽  
P. W. Hochachka
Keyword(s):  
Citrate Synthase ◽  
Specific Activity ◽  
Energy Charge ◽  
Krebs Cycle ◽  
Fold Increase ◽  
Adenylate Energy Charge ◽  
Michaelis Constant ◽  
Acetyl Coa ◽  
Muscle Work ◽  
Krebs Cycle Intermediates

Citrate synthase (EC 4.1.3.7) in mantle muscle of the octopus, Octopus cyanea, occurs in relatively low specific activity and is largely independent of pH between 7.5 and 9.0. Catalytic activity is regulated by the adenylate energy charge and by at least two Krebs cycle intermediates, α-ketoglutarate and citrate. Of the adenylates, ATP is by far the most potent inhibitor, at near-physiological concentrations (4 mM), causing almost a 20-fold increase in the Michaelis constant for acetyl-CoA. Citrate and α-ketoglutarate, on the other hand, are competitive with respect to oxaloacetate, rather than acetyl-CoA, and bring about large increases in the Michaelis constant for oxaloacetate. The regulatory properties of citrate synthase allow a curtailment of carbon flow into the Krebs cycle during periods of burst muscle work, when mantle anaerobic glycolysis is strongly activated.

scholarly journals Regulation of pyruvate carboxylase in 3T3-L1 cells

1995 ◽  
Vol 306 (1) ◽  
pp. 205-210 ◽  
Author(s):  
J Zhang ◽  
W L Xia ◽  
F Ahmad
Keyword(s):  
Enzyme Activity ◽  
Relative Abundance ◽  
Pyruvate Carboxylase ◽  
Protein Concentration ◽  
Specific Activity ◽  
Cdna Probe ◽  
Fold Increase ◽  
Spatial Arrangement ◽  
Cellular Protein ◽  
Prosthetic Group

When 3T3-L1 fibroblasts differentiate to adipocytes, the specific activity of pyruvate carboxylase (PC) increases about 25-fold in parallel with its intracellular protein concentration. The increase in PC protein concentration is accompanied by a 9-10-fold increase in the relative abundance of 4.2 kb PC mRNA measured by Northern-blot analysis using a cDNA probe encoding a segment of the PC gene of 3T3-L1 adipocytes. The effects of cyclic AMP (cAMP) alone and together with insulin on levels of cellular protein, PC activity, PC protein and on the relative abundance of PC mRNA were examined in mature 3T3-L1 adipocytes. Adipocytes exposed to cAMP for 24 h exhibited a 25% decrease in cellular protein and marked decreases in enzyme activity (88%) and PC mRNA abundance (98%) compared with untreated adipocyte controls. After 48 h of exposure to cAMP, PC activity and PC mRNA diminished to levels approaching their detection limits. When exposed to medium containing cAMP plus insulin, adipocyte enzyme activity and PC mRNA declined more slowly during the first 24 h exposure (about 20% decrease) but after 48 h fell to values comparable with those of adipocytes exposed to cAMP alone. Despite these decreases in enzyme activity, the PC protein content of adipocytes treated with cAMP alone or cAMP plus insulin are nearly identical with that of control adipocytes. The inactivation of PC in cAMP-treated adipocytes does not involve loss of the prosthetic group from the holoenzyme. Cross-linking experiments suggest that the spatial arrangement of protomers in inactive PC may differ from that in the active tetrameric enzyme. Data presented suggest that, in addition to inducing inactivation, cAMP may also regulate adipocyte PC by decreasing transcription of the PC gene and/or enhancing the rate of degradation of PC mRNA.

The Morphology of the Rat Kidney Following Folic Acid Administration

1970 ◽  
Vol 28 ◽  
pp. 200-201
Author(s):  
Aline Byrnes ◽  
Elsa E. Ramos ◽  
Minoru Suzuki ◽  
E.D. Mayfield
Keyword(s):  
Folic Acid ◽  
De Novo ◽  
Specific Activity ◽  
Rat Kidney ◽  
Present Report ◽  
Intracellular Localization ◽  
Male Rats ◽  
Renal Hypertrophy ◽  
Electron Microscopic ◽  
Biochemical Alterations

Renal hypertrophy was induced in 100 g male rats by the injection of 250 mg folic acid (FA) dissolved in 0.3 M NaHCO3/kg body weight (i.v.). Preliminary studies of the biochemical alterations in ribonucleic acid (RNA) metabolism of the renal tissue have been reported recently (1). They are: RNA content and concentration, orotic acid-c14 incorporation into RNA and acid soluble nucleotide pool, intracellular localization of the newly synthesized RNA, and the specific activity of enzymes of the de novo pyrimidine biosynthesis pathway. The present report describes the light and electron microscopic observations in these animals. For light microscopy, kidney slices were fixed in formalin, embedded, sectioned, and stained with H & E and PAS.

Influence of Seeding Conditions on Initial Biofilm Development during the Startup of Anaerobic Fluidized Bed Reactors

1989 ◽  
Vol 21 (4-5) ◽  
pp. 157-165 ◽  
Author(s):  
F. Ehlinger ◽  
J. M. Audic ◽  
G. M. Faup
Keyword(s):  
Fluidized Bed ◽  
Future Development ◽  
Protein Concentration ◽  
Specific Activity ◽  
Fluidized Bed Reactor ◽  
Fluidized Bed Reactors ◽  
Support Material ◽  
Biofilm Development ◽  
Initial Biofilm

The characterization of the biofilm of an anaerobic fluidized-bed reactor was completed under standard conditions. The distribution of the fixed protein concentration depended on the level in the reactor. The protein concentration reached 1520 µg.g−1 of support at the top of the reactor and only 1200 µg.g−1 at the bottom after 504 hours of operation but the specific activity of the biofilm was 33×10−4 µM acetate.h−1.mg−1 proteins at the bottom and only 26×10−4 µM.h−1.mg−1 at the top. The efficiency of a fluidized bed reactor and the composition of the biofilm changed with an increase of the pH from 7 to 8.5 during the seeding of the support material. Future development of the biofilm and the specific activity of the support were affected.

Large-scale production of citrate synthase from a cloned gene

1982 ◽  
Vol 60 (12) ◽  
pp. 1143-1147 ◽  
Author(s):  
Harry W. Duckworth ◽  
Alexander W. Bell
Keyword(s):  
Escherichia Coli ◽  
Large Scale ◽  
Citrate Synthase ◽  
Specific Activity ◽  
Tetracycline Resistance ◽  
Scale Production ◽  
Ampicillin Resistance ◽  
Colicin E1 ◽  
Large Scale Production ◽  
Cloned Gene

Starting with a colicin E1 resistance recombinant plasmid which contains gltA, the gene for citrate synthase in Escherichia coli, we have constructed an ampicillin-resistance plasmid containing the gltA region as a 2.9-kilobase-pair insert in the tetracycline-resistance region of pBR322. Escherichia coli HB101 harbouring this plasmid, when grown on rich medium containing ampicillin, contains citrate synthase as about 8% of its soluble protein. The enzyme has been purified from this rich source and is identical to the chromosomal enzyme prepared previously in every property tested, except for specific activity, which is 64 U∙mg−1 as compared with 45–50 U∙mg−1 previously obtained. The N-terminal sequences of both enzymes are reported, and they are identical up to residue 16 at least. The overall yield of pure enzyme, starting with the cells grown in 15 L of medium, is 600–800 mg.

scholarly journals Thermostable glucose isomerase from psychrotolerant Streptomyces species

1970 ◽  
Vol 1 ◽  
pp. 6-10 ◽  
Author(s):  
Bidur Dhungel ◽  
Manoj Subedi ◽  
Kiran Babu Tiwari ◽  
Upendra Thapa Shrestha ◽  
Subarna Pokhrel ◽  
...  
Keyword(s):  
Specific Activity ◽  
Fold Increase ◽  
Glucose Isomerase ◽  
Enzyme Concentration ◽  
Maximal Velocity ◽  
Ph Optimum ◽  
Streptomyces Spp ◽  
Optimum Ph ◽  
Optimum Reaction ◽  
Sepharose 4B

Glucose isomerase (EC 5.3.1.5) was extracted from Streptomyces spp., isolated from Mt. Everest soil sample, and purified by ammonium sulfate fractionation and Sepharose-4B chromatography. A 7.1 fold increase in specific activity of the purified enzyme over crude was observed. Using glucose as substrate, the Michaelis constant (KM<) and maximal velocity (Vmax) were found to be 0.45M and 0.18U/mg. respectively. The optimum substrate (glucose) concentration, optimum enzyme concentration, optimum pH, optimum temperature, and optimum reaction time were 0.6M, 62.14μg/100μl, 6.9, 70ºC, and 30 minutes, respectively. Optimum concentrations of Mg2+ and Co2+ were 5mM and 0.5mM, respectively. The enzyme was thermostable with half-life 30 minutes at 100ºC.DOI: 10.3126/ijls.v1i0.2300 Int J Life Sci 1 : 6-10

Biochemical studies of intrauterine components of the tammar wallaby Macropus eugenii during pregnancy

Development ◽  
1981 ◽  
Vol 62 (1) ◽  
pp. 325-338
Author(s):  
Elizabeth J. Thornber ◽  
Marilyn B. Renfree ◽  
Gregory I. Wallace
Keyword(s):  
Protein Concentration ◽  
Specific Binding ◽  
Polyacrylamide Gel Electrophoresis ◽  
Fold Increase ◽  
Tammar Wallaby ◽  
Macropus Eugenii ◽  
Tenfold Increase ◽  
Specific Proteins ◽  
Wet Weight

The in vitro uptake and incorporation of [3H]ui idine by blastocysts of the tammar wallaby showed a 16- and 30-fold increase from day 0 to day 10 after removal of pouch young, respectively. Two of the six non-expanded blastocysts recovered on day 5 showed a tenfold increase in incorporation. During the first ten days after removal of pouch young the diameter of the blastocyst increased threefold. Endometrial exudate from gravid uteri had a higher protein concentration than exudate from nongravid uteri (39·5 ± 0·9 and 32·0 ± 2·0 mg/ml (mean ± s.e.m.), respectively). Endometrial exudates from uteri where the blastocyst was actively growing were found to contain six uterine-specific proteins. These were separated by gradient polyacrylamide gel electrophoresis. Two of the proteins were pre-albumins and the others were larger molecules (M.W. 153000–670000). Two proteins were only present at particular stages of pregnancy: the other four were present at all stages from diapause to birth, in exudate from gravid and nongravid uteri. The specific binding of progesterone and androstenedione to proteins in endometrial exudates or uterine flushings from pregnant wallabies was less than one per cent of the value obtained from day-5 pregnant rabbits. The ability of mouse blastocysts to take up and incorporate [3H]uridine into acidinsoluble material increased threefold in the presence of day-10 endometrial exudates from wallabies. However, this was less than ten percent of the values obtained in the presence of bovine serum albumin. The concentration of calcium in endometrial exudates increased from 23·6 to 45·2 μg/ml during pregnancy; in endometrium it remained at 88·7 μg/g (wet weight) throughout pregnancy, and in plasma it was 53·3 μg/ml. The concentration of zinc in endometrial exudates was 4·5 μg/ml; in endometrium it decreased from 21·8 to 13·3 μg/g (wet weight) during pregnancy and in plasma it was 0·6 μg/ml.

Exercise training increases GLUT-4 protein concentration in previously sedentary middle-aged men

1993 ◽  
Vol 264 (6) ◽  
pp. E896-E901 ◽  
Author(s):  
J. A. Houmard ◽  
M. H. Shinebarger ◽  
P. L. Dolan ◽  
N. Leggett-Frazier ◽  
R. K. Bruner ◽  
...  
Keyword(s):  
Exercise Training ◽  
Protein Concentration ◽  
Glucose Transporter ◽  
Citrate Synthase ◽  
Sensitivity Index ◽  
Insulin Sensitivity Index ◽  
Middle Aged ◽  
Lateral Gastrocnemius ◽  
Transporter Protein ◽  
Glut 4

The purpose of this study was to determine if 14 wk of exercise training would increase insulin-sensitive glucose transporter protein (GLUT-4) concentration in skeletal muscle of previously sedentary middle-aged men (47.2 +/- 1.3 yr; n = 13). Muscle samples (lateral gastrocnemius) and insulin action [insulin sensitivity index (ISI), minimal model] were obtained in the sedentary condition and 48 h after the final training bout. GLUT-4 protein concentration increased (P < 0.001, 2,629 +/- 331 to 4,140 +/- 391 absorbance units/100 micrograms protein) with exercise training by 1.8-fold. ISI increased by twofold (P < 0.05, 2.1 +/- 0.5 to 3.4 +/- 0.7 SI x 10(5) min/pM) with training. The percentage of GLUT-4 rich type IIa muscle fibers increased by approximately 10% (P < 0.01), which may have contributed to the elevation in transporter protein. GLUT-4 concentration and citrate synthase activity (1.7-fold, P < 0.001) also increased by similar increments. These findings indicate that GLUT-4 protein concentration is elevated in middle-aged individuals with exercise training.

Development of metabolic enzyme activity in locomotor and cardiac muscles of the migratory barnacle goose

1995 ◽  
Vol 269 (1) ◽  
pp. R64-R72 ◽  
Author(s):  
C. M. Bishop ◽  
P. J. Butler ◽  
S. Egginton ◽  
A. J. el Haj ◽  
G. W. Gabrielsen
Keyword(s):  
Plasma Glucose ◽  
Citrate Synthase ◽  
Specific Activity ◽  
Glycolytic Enzymes ◽  
Metabolic Enzyme ◽  
Mitochondrial Enzymes ◽  
Pectoralis Muscle ◽  
Barnacle Goose ◽  
Average Maximum ◽  
Cardiac Muscles

Preflight development of the goslings was typified by rapid increases in the mitochondrial enzymes of the semimembranosus and heart ventricular muscles resulting in near-adult values by 3 wk of age. In contrast, aerobic capacity of the pectoralis muscle initially developed slowly but showed a rapid increase between 5 and 7 wk of age, in preparation for becoming airborne. Activities of glycolytic enzymes in the pectoralis muscle showed similar patterns of development as those found for the aerobic enzymes, except for hexokinase, which was low at all ages, indicating an adaptation for catabolism of both intracellular glycogen and plasma fatty acids in preference to plasma glucose. Muscle mass specific activity of citrate synthase in the pectoralis increased by only 33% from goslings during the first few days of flight, compared with premigratory geese. Activities of anaerobic glycolytic enzymes in the ventricles were low, but values for hexokinase, which is involved in the phosphorylation of plasma glucose, developed rapidly. Values for lactate dehydrogenase were also high, reflecting the capacity of the heart to catabolize plasma lactate. Substrate flux supplied by carnitine palmitoyltransferase and oxoglutarate dehydrogenase (OGD), in the pectoralis muscles of the premigratory geese, appears to have the smallest excess capacities to meet the requirements of sustained aerobic flight. The average maximum oxygen uptake for premigratory geese during flight, as indicated by values for OGD, is calculated to be 484 ml O2/min (or 208 ml O2.min-1.kg-1).

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