scholarly journals Perinatal developmental changes in hepatic UDP-glucuronyltransferase

1980 ◽  
Vol 186 (3) ◽  
pp. 841-845 ◽  
Author(s):  
R B Goldstein ◽  
D A Vessey ◽  
D Zakim ◽  
N Mock ◽  
M Thaler
Keyword(s):  
Kinetic Analysis ◽  
Active Sites ◽  
Glucuronic Acid ◽  
Membrane Lipid ◽  
The Other ◽  
Phospholipase A ◽  
Developmental Changes ◽  
Adult Liver ◽  
Allosteric Effector ◽  
Lipid Environment

Postnatal developmental changes in hapatic microsomal UDP-glucuronyltransferase were studied in the rat. The previously reported postnatal decline in the capacity of microsomal fractions to glucuronidate p-nitrophenol was found to be observable in unperturbed preparations only at non-saturating concentrations of the substrate UDP-glucuronic acid. At saturating concentrations of UDP-glucuronic acid, activity is identical in newborns and adults. Kinetic analysis revealed that the enzyme from liver of newborns has a much higher affinity for UDP-glucuronic acid than does the enzyme in adults, but the same activity at Vmax. On the other hand, the enzyme from adult liver microsomal fractions can be activated by the physiological allosteric effector UDP-N-acetylglucosamine, whereas the enzyme from newborns is largely unaffected by it. Thus it appears that the number of enzyme active sites is not changing; rather, the enzyme is maturing to a more highly regulable form. There were also differences between the enzymes in newborns and adults in their response to perturbation of the membrane-lipid environment by detergent and phospholipase A. Possible interpretations of these differences are discussed.

Binding of lead and copper(II) cations to hemicelluloses of rye bran

1986 ◽  
Vol 51 (10) ◽  
pp. 2250-2258 ◽  
Author(s):  
Rudolf Kohn ◽  
Zdena Hromádková ◽  
Anna Ebringerová
Keyword(s):  
Uronic Acid ◽  
Equilibrium Solution ◽  
Glucuronic Acid ◽  
The Other ◽  
Carboxyl Groups ◽  
Stoichiometric Ratio ◽  
Molar Ratios ◽  
Free Ions ◽  
Uronic Acid Content ◽  
The Relationship

Several fractions of acid hemicelluloses isolated from rye bran were characterized by molar ratios of saccharides (D-Xyl, L-Ara, D-Glc, D-Gal) and 4-O-methyl-D-glucuronic acid and protein content. Binding of Pb2+ and Cu2+ ions to these acid polysaccharides was considered according to function (M)b = f([M2+]f), expressing the relationship between the amount of metal (M)b bound to 1 g of the substance and the concentration of free ions [M2+]f in the equilibrium solution and according to the association degree β of these cations with carboxyl groups of uronic acid at a stoichiometric ratio of both components in the system under investigation. Acid hemicelluloses contained only a very small portion of uronic acid ((COOH) 0.05-0.18 mmol g-1); the model polysaccharide, 4-O-methyl-D-glucurono-D-xylan of beech, was substantially richer in uronic acid content ((COOH) 0.73 mmol g-1). Consequently, the amount of lead and copper bound to acid hemicelluloses is very small ((M)b 0.017-0.025 mmol g-1) at [M2+]f = 0.10 mmol l-1. On the other hand, much greater amount of cations ((M)f 0.09-0.10 mmol g-1) was bound to the glucuronoxylan. The association degree β was like with the majority of samples (β = 0.31-0.38). The amount of lead and copper(II) bound to acid hemicelluloses from rye bran is several times lower than that bound to dietary fiber isolated from vegetables (cabbage, carrot), rich in pectic substances.

scholarly journals Metals in Calluna vulgaris, Empetrum nigrum, Festuca vivipara and Thymus praecox ssp. arcticus in the geothermal areas of Iceland

2021 ◽  
Author(s):  
Adam Rajsz ◽  
Bronisław Wojtuń ◽  
Aleksandra Samecka-Cymerman ◽  
Paweł Wąsowicz ◽  
Lucyna Mróz ◽  
...  
Keyword(s):  
Active Sites ◽  
Calluna Vulgaris ◽  
Bioaccumulation Factor ◽  
The Other ◽  
Extreme Situation ◽  
Empetrum Nigrum ◽  
Geothermal Activity ◽  
High Concentrations ◽  
And Control ◽  
Festuca Vivipara

AbstractThis investigation was conducted to identify the content of metals in Calluna vulgaris (family Ericaceae), Empetrum nigrum (family Ericaceae), Festuca vivipara (family Poaceae) and Thymus praecox subsp. arcticus (family Lamiaceae), as well as in the soils where they were growing in eight geothermal heathlands in Iceland. Investigation into the vegetation of geothermal areas is crucial and may contribute to their proper protection in the future and bring more understanding under what conditions the plants respond to an ecologically more extreme situation. Plants from geothermally active sites were enriched with metals as compared to the same species from non-geothermal control sites (at an average from about 150 m from geothermal activity). The enriched metals consisted of Cd, Co, Cu, Fe and Ni in C. vulgaris; Cd, Mn and Ti in E. nigrum; Hg and Pb in F. vivipara; and Cd, Fe and Hg in T. praecox. Notably, C. vulgaris, E. nigrum, F. vivipara and T. praecox had remarkably high concentrations of Ti at levels typical of toxicity thresholds. Cd and Pb (except for C. vulgaris and F. vivipara) were not accumulated in the shoots of geothermal plants. C. vulgaris from geothermal and control sites was characterised by the highest bioaccumulation factor (BF) of Ti and Mn; E. nigrum and F. vivipara by the highest BF of Ti and Cr; and T. praecox by the highest BF of Ti and Zn compared to the other elements. In comparison with the other examined species, F. vivipara from geothermal sites had the highest concentration of Ti in above-ground parts at any concentration of plant-available Ti in soil.

scholarly journals Involvement of loop 5 lysine residues and the N-terminal β-hairpin of the ribotoxin hirsutellin A on its insecticidal activity

2016 ◽  
Vol 397 (2) ◽  
pp. 135-145 ◽  
Author(s):  
Miriam Olombrada ◽  
Lucía García-Ortega ◽  
Javier Lacadena ◽  
Mercedes Oñaderra ◽  
José G. Gavilanes ◽  
...  
Keyword(s):  
Active Sites ◽  
Structural Changes ◽  
The Other ◽  
Spatial Proximity ◽  
Ribonucleolytic Activity ◽  
The Family ◽  
Lysine Residues ◽  
Hirsutella Thompsonii ◽  
Close Spatial Proximity ◽  
High Degree

Abstract Ribotoxins are cytotoxic members of the family of fungal extracellular ribonucleases best represented by RNase T1. They share a high degree of sequence identity and a common structural fold, including the geometric arrangement of their active sites. However, ribotoxins are larger, with a well-defined N-terminal β-hairpin, and display longer and positively charged unstructured loops. These structural differences account for their cytotoxic properties. Unexpectedly, the discovery of hirsutellin A (HtA), a ribotoxin produced by the invertebrate pathogen Hirsutella thompsonii, showed how it was possible to accommodate these features into a shorter amino acid sequence. Examination of HtA N-terminal β-hairpin reveals differences in terms of length, charge, and spatial distribution. Consequently, four different HtA mutants were prepared and characterized. One of them was the result of deleting this hairpin [Δ(8-15)] while the other three affected single Lys residues in its close spatial proximity (K115E, K118E, and K123E). The results obtained support the general conclusion that HtA active site would show a high degree of plasticity, being able to accommodate electrostatic and structural changes not suitable for the other previously known larger ribotoxins, as the variants described here only presented small differences in terms of ribonucleolytic activity and cytotoxicity against cultured insect cells.

THE ALDOBIOURONIC ACIDS OF HEMICELLULOSE B OF OAT HULLS

1956 ◽  
Vol 34 (3) ◽  
pp. 338-344 ◽  
Author(s):  
E. L. Falconer ◽  
G. A. Adams
Keyword(s):  
Glucuronic Acid ◽  
The Other ◽  
Partial Hydrolysis ◽  
Oat Hulls ◽  
Hydrolysis Of

Partial hydrolysis of hemicellulose B from oat hulls yielded two aldobiouronic acids, which were identified as 2-O-(4-O-methyl-α-D-glucopyruronosyl)-D-xylose and 2-O-(α-D-glucopyruronosyl)-D-xylose respectively. In addition, two aldotriouronic acids were isolated, one yielding on hydrolysis xylose and 4-O-methyl-glucuronic acid, and the other, xylose, galactose, and glucurone.

AGGRESSION IN PRESCHOOLERS: ITS RELATION TO SOCIALIZATION

PEDIATRICS ◽  
1994 ◽  
Vol 93 (2) ◽  
pp. 163-163
Author(s):  
Klaus Minde
Keyword(s):  
Aggressive Behavior ◽  
Perspective Taking ◽  
Normal Control Group ◽  
The Other ◽  
Developmental Changes ◽  
Control Group ◽  
Clinical Implications ◽  
Significant Delay ◽  
Short Term ◽  
Aggressive Children

The present article discusses developmental changes of aggression seen in preschool children and reports on an 18-month short-term prospective study of three preschool populations: a group referred for aggressive behavior problems, a normal control group, and a group of youngsters who had lived in violent homes, but showed no aggressive behaviors. Results indicate that the aggressive children, in comparison with the other two groups at age 4, showed a significant delay in their interpersonal awareness and perspective taking ability. However, although the aggressive children caught up with their peers in the course of the study period, there was no accompanying decrease in their aggressive behavior. The theoretical and clinical implications of these findings are discussed.

Effects of glucuronic acid and N-acetyl-D-glucosamine supplementation on the perivitelline space during the IVM of pig oocytes

2020 ◽  
Vol 32 (10) ◽  
pp. 941
Author(s):  
J. Z. Current ◽  
B. D. Whitaker
Keyword(s):  
Hyaluronic Acid ◽  
Glutathione Peroxidase ◽  
Embryo Development ◽  
Glucuronic Acid ◽  
The Other ◽  
Perivitelline Space

The objective of this study was to minimise polyspermic penetration by increasing the perivitelline space (PVS) thickness through supplementation of the hyaluronic acid components glucuronic acid and N-acetyl-d-glucosamine (GlcNAc). Oocytes (n=4690) were supplemented during the first 24h and/or the remainder of maturation (final 16–18h) with 0.01mM glucuronic acid and 0.01mM GlcNAc and then evaluated for PVS thickness, hyaluronic acid, glutathione and glutathione peroxidase concentrations. Fertilised oocytes were evaluated for polyspermic penetration and embryo development. The PVS thickness and amount of hyaluronic acid was significantly (P<0.05) greater in oocytes supplemented with 0.01mM glucuronic acid and 0.01mM GlcNAc during the second part or all of maturation compared with the other treatments. In addition, polyspermic penetration was significantly (P<0.05) less in oocytes supplemented with 0.01mM glucuronic acid and 0.01mM GlcNAc during the second part or all of maturation compared with the other treatments. Supplementing 0.01mM glucuronic acid and GlcNAc during maturation significantly (P<0.05) increased the percentage of cleaved embryos by 48h after IVF and blastocysts formed by 144h after IVF compared those not supplemented. These results indicate that supplementing PVS components during maturation decreases polyspermic penetration by increasing PVS thickness.

scholarly journals Dynamic modulation of mitochondrial membrane physical properties and ATPase activity by diet lipid

1981 ◽  
Vol 198 (1) ◽  
pp. 167-175 ◽  
Author(s):  
S M Innis ◽  
M T Clandinin
Keyword(s):  
Fatty Acid ◽  
Rapeseed Oil ◽  
Membrane Lipid ◽  
Dietary Lipid ◽  
Soya Bean ◽  
The Body ◽  
Kinetic Properties ◽  
Mitochondrial Atpase ◽  
Lipid Environment

A longitudinal cross-over feeding design was used to investigate the relationship of dietary lipid composition to the membrane lipid environment and activity of mitochondrial ATPase in vivo. Rats were fed a polyunsaturated fatty-acid-rich oil (soya-bean oil) for 12 days, crossed-over to a monounsaturated fatty-acid-rich oil (rapeseed oil) for the next 11 days, then returned to soya-bean oil for 11 more days. Additional rats were fed either soya-bean oil or rapeseed oil throughout. Rats fed rapeseed oil had lower rates of ATPase-catalysed ATP/[32P]Pi exchange than rats fed soya-bean oil. Arrhenius plots showed higher transition temperature (Tt) and activation energy (Ea) for rats fed rapeseed oil. Switching from soya-bean oil to rapeseed oil was dynamically followed by changes in the thermotropic and kinetic properties of the mitochondrial ATPase exchange reaction. Returning to soya-bean oil reversed these changes. The rapid and reversible modulation of Tt caused by a change of the type of fat ingested suggests that membrane physicochemical properties are not under rigid intrinsic control but are continually modified by the profile of exogenously derived fatty acids. The studies suggest that in vivo the activity of mitochondrial ATPase is in part determined by dietary lipid via its influence on the microenvironment of the enzyme. The rapidity and ready reversibility of changes observed for this subcellular-membrane-bound enzyme suggest that dietary fatty-acid balance may be an important determinant of other membrane functions in the body.

scholarly journals Pre- and posthatch developmental changes in hypothalamic thyrotropin-releasing hormone and somatostatin concentrations and in circulating growth hormone and thyrotropin levels in the chicken

1998 ◽  
Vol 159 (2) ◽  
pp. 219-225 ◽  
Author(s):  
KL Geris ◽  
LR Berghman ◽  
ER Kuhn ◽  
VM Darras
Keyword(s):  
Growth Hormone ◽  
Embryonic Development ◽  
Present Report ◽  
Thyrotropin Releasing Hormone ◽  
The Other ◽  
Developmental Changes ◽  
Releasing Hormone ◽  
Steep Increase ◽  
Plasma Gh ◽  
Tsh Levels

Thyrotropin-releasing hormone (TRH) and somatostatin (SRIH) concentrations were determined by RIA during both embryonic development and posthatch growth of the chicken. Both TRH and SRIH were already detectable in hypothalami of 14-day-old embryos (E14). Towards the end of incubation, hypothalamic TRH levels increased progressively, followed by a further increase in newly hatched fowl. SRIH concentrations remained stable from E14 to E17 and doubled between E17 and E18 to a concentration which was observed up to hatching. Plasma GH levels remained low during embryonic development, ending in a steep increase at hatching. Plasma TSH levels on the other hand decreased during the last week of the incubation. During growth, TRH concentrations further increased, whereas SRIH concentrations fell progressively towards those of adult animals. Plasma TSH levels increased threefold up to adulthood; the rise in plasma GH levels during growth was followed by a drop in adults. In conclusion, the present report shows that important changes occur in the hypothalamic TRH and SRIH concentration during both embryonic development and posthatch growth of the chicken. Since TRH and SRIH control GH and TSH release in the chicken, the hypothalamic data are compared with plasma GH and TSH fluctuations.

THE METABOLISM OF MUCOPOLYSACCHARIDES: II. THE EFFECT OF ADRENALECTOMY ON ENZYMES INVOLVED IN GLUCURONIDE SYNTHESIS AND METABOLISM IN CONNECTIVE TISSUE

1965 ◽  
Vol 43 (9) ◽  
pp. 1417-1425 ◽  
Author(s):  
T. S. Foster
Keyword(s):  
Connective Tissue ◽  
Glucuronic Acid ◽  
Sesame Oil ◽  
The Other ◽  
Hexokinase Activity ◽  
Sham Injection ◽  
Glucuronosyl Transferase ◽  
Adrenalectomized Rats

The levels of activity of hexokinase, phosphoglucomutase, uridine diphosphoglucose pyrophosphorylase, and uridine diphosphoglucose dehydrogenase, which are involved in the synthesis of glucuronic acid, and the activities of glucuronosyl transferase and β-glucuronidase, which are involved in its metabolism, were studied in connective tissue from sham-operated and adrenalectomized rats. Adrenalectomy resulted in a significant decrease in phosphoglucomutase activity and in significant increases in the activities of hexokinase, uridine diphosphoglucose dehydrogenase, and β-glucuronidase. Adrenalectomy had no effect upon the activities of uridine diphosphoglucose pyrophosphorylase or glucuronosyl transferase.The added stress of either a sham injection or injection of sesame oil, both given daily and intraperitoneally, resulted in a significant increase in hexokinase activity and a decrease in glucuronosyl transferase and β-glucuronidase activities, in both sham-operated and adrenalectomized animals. The other enzymes were unaffected.

Sign in / Sign up

Export Citation Format

Share Document