Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “GLUTARATES”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,225 records · Page 68Linked to original sources
PubMed1990

Metabolism of beta-methyl-heptadecanoic acid in the perfused rat heart and liver.

The metabolism of beta-methyl-[1-14C]heptadecanoic acid, a potential myocardial imaging agent, was investigated in perfused hearts and livers from rats. Hepatic uptake is approximately 4.5 times greater than cardiac uptake. In the heart, 66% of beta-methyl-heptadecanoic acid metabolism occurs via omega-oxidation, 33% by esterification and less than 1% via alpha-oxidation. In contrast, 53% of hepatic metabolism of beta-methyl-heptadecanoic acid occurs via alpha-oxidation, 27% via omega-oxidation, and 20% via esterification. Perfusion of hearts and livers with concentrations of beta-methyl-heptadecanoic acid 100 to 1000 times greater than that used for myocardial imaging does not alter any of the physiological and biochemical parameters measured. In the perfused liver, 3-methyl-[1-14C]glutarate was identified as the principal hydrosoluble catabolite of beta-methyl-heptadecanoic acid.

Animals↗
PubMed1977

[E. coli penicillin amidase. Physico-chemical properties of the enzyme covalently bound to the 2-(3'-amino-4'-methoxyphenyl)-sulfonylethyl ester of cellulose].

The effect of the procedure of the enzyme binding with the carrier on the properties of the heterogenous catalyst obtained by covalent binding of penicillinamidase (PA) with cellulose 2-(3'-amino-4'-methoxyphenyl)-sulphonylethyl ether by means of the bifunctional reagent, i.e. glutaric aldehyde was studied. It was shown that the amount of the bound enzyme increased with a rise in the amount of the enzyme taken for the binding, while the binding efficiency characterizing the part of the active enzyme in the total amount of the bound PA decreased practically 2 times. The use of the enzyme preparations with different purify levels for the binding provided differentiation of the effects resulting in the activity loss on immobilization. In other words it provided separate estimation of the inactivation effect of the matrix and the immobilization procedure, as well as the interaction of the enzyme molecules with each other and other protein molecules.

Amidohydrolases↗
PubMedDate not supplied

Daunorubicin coupled to monoclonal antibodies via a cis-aconitic anhydride linker: biochemical and cytotoxic properties revisited.

Daunorubicin (DNR) was coupled to monoclonal antibodies (Mab) reactive to breast tumor cells using the acid-labile linking agents cis-asonitic anhydride and two other non acid-labile analogs, glutaric anhydride and citraconic anhydride. The acid derivatives of DNR formed by reaction with the anhydrides were converted to their N-hydroxysuccinimide (NHS) active esters for coupling to MAb. The molar input of drug NHS ester to MAb ranged from 1:1 to 100:1. The resulting MAb-DNR conjugates were purified by gel filtration and analyzed by high performance liquid chromatography. Monomeric conjugates contained 0.2 to 11.0 moles of DNR/mole of MAb. No evidence of cell killing was observed up to a concentration of 10 micrograms/ml DNR bound to MAb, while DNR exhibited 50% killing of the breast tumor cell line MCF-7 at a concentration of 1 microgram/ml.

Aconitic Acid↗
PubMed1990

[10-Acyldithranol dimers; new derivatives of the antipsoriatic dithranol; synthesis, characterization and biochemical properties].

With regard to the synthesis of 10-(omega-carboxyacyl)-derivatives dithranol 1 was reacted with the carboxylic acid dichlorides of succinic acid, glutaric acid, adipic acid and pimelic acid in toluene and collidin as a base. Instead of the expected derivatives the 10-acyldithranol dimers 5-7 were isolated as main products except for the reaction of succinyl chloride where only lactone 2 was formed. Moreover the 6-ring lactone 3 as a side product and traces of the 7-ring lactone 4 could also be isolated and characterized. All compounds revealed to be inhibitors of the enzyme glucose-6-phosphate dehydrogenase, indicating antipsoriatic activity.

Anthralin↗
PubMed1990

Antitumor activity of T-2 toxin-conjugated monoclonal antibody to murine thymoma.

T-2 toxin (T-2(4)), one of the trichothecene mycotoxins produced by various gerera of Fusarium spp., is a potent inhibitor to the syntheses of protein and DNA in mammalian cells. The selective cytotoxicity of T-2 toxin-conjugated anti-EL-4 monoclonal antibodies (T-2-mAb) was investigated against murine thymoma EL-4 cells in vitro and in vivo systems. At first T-2 was converted to T-2 hemiglutarate by glutaric anhydride. Then T-2 hemiglutarate was activated to 3-[4-(N-succinimidoxycarbonyl)-butyryl]-T-2 (T-2-G-OSu) by N-hydroxysuccinimide. Thus obtained T-2-G-OSu was conjugated with mAb specific for EL-4 cells. The T-2-mAb markedly inhibited the proliferation of cultured EL-4 cells, but no such cytotoxic effect was observed against irrelevant SP2/0 cells. The cytotoxicity of T-2-conjugated normal gamma globulin (T-2-nGG) against EL-4 cells was far less than that of the above T-2-mAb. Ammonium chloride and monensin, inhibitors of lysosomal enzymes, enhanced the cytotoxicity of T-2-mAb. The presence of both 2-deoxyglucose together with sodium azide, inhibitors of energy-dependent reaction, reduced the cytotoxicity of T-2-mAb. Therefore, the selective binding to the target cells followed by an energy-dependent endocytosis and an intracellular liberation of T-2 by hydrolysis may account for the cytotoxicity of the T-2-mAb. In mice pre-transplanted with EL-4 cells, T-2-mAb increased the mean survival time (MST) with a direct dosage dependence.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1975

Factors contributing to the inhibition of aspartate aminotransferase by dicarboxylic acids.

At pH 8.0 aspartate aminotransferase (L-aspartate:2-oxoglutarate aminotransferase, EC 2.6.1.1) reacts with the modified substrate, erythro-beta-hydroxy-L-aspartate, to form a mixture of enzyme-substrate complexes absorbing at 492 nm. A variety of dicarboxylic acids were studied spectrophotometrically as competitive inhibitors of this reaction. All of the inhibitory dicarboxylic acids form a complex with the enzyme, absorbing at 362 nm. In addition, some of the dicarboxylic acids form a protonated complex absorbing at about 435 nm. This complex, which is the conjugate acid of that absorbing at 362 nm, is formed only by those dicarboxylic acids which can assume a configuration in which the two carboxyl groups are positioned as in maleic acid. Bulky substituents, such as aromatic rings or even methyl groups, prevent the formation of the protonated complex, presumably because of steric restrictions at the active site. Substitution of the central carbon atom of glutaric acid by heteroatoms of increasing charge density results in a progressive decrease in inhibitory effectiveness, at pH 8, primarily due to a loss of this pH-dependent stabilization of the enzyme-dicarboxylic acid complex. Acids with an aromatic ring are among the most potent dicarboxylic acid inhibitors of this enzyme in spite of the fact that they do not undergo the pH-dependent stabilization of their enzyme complexes. From these observations it was concluded that the affinity of aspartate aminotransferase for dicarboxylic acids is determined as much by the mechanism of binding as by the solvation and steric effects.

Animals↗
PubMed1986

[Use of immunospecific components labelled with beta-lactamase and horseradish peroxidase for immunoenzyme analysis].

A system for enzyme immunoassay with the use of beta-lactamase as an enzyme marker is described. Similar sensitivity of the enzyme immunoassays with the use of beta-lactamase and horse-raddish peroxidase as enzyme markers was shown. The data on decrease of the antigen binding capacity of the antibodies in the conjugates with beta-lactamase are presented. It is suggested that such a decrease may be associated with glutaric dialdehyde conjugation. The use of the schemes for enzyme immunoassay with simultaneous application of two independently recorded enzymes i. e. horse-raddish peroxidase and beta-lactamase provided confirmation of univalency of the conjugate of the melted capsular antigen of the plague causative agent with beta-lactamase. Identity of the antigenic determinants of the melted antigen and capsular antigen of the plague microbe was demonstrated.

Animals↗
PubMedDate not supplied

[Isolation and purification of proteolytic enzymes on organo-silica sorbents with immobilized gramicidin S].

Biospecific sorbents for affinity chromatography of proteolytic enzymes have been synthesized by attaching cyclopeptide antibiotic gramicidin S to organo-silica supports. It is shown possible to attach gramicidin S to the organo-silica supports using glutaric aldehyde, p-benzoquinone, soluble and insoluble carbodiimides. The sorbents prepared by these methods were successfully applied for the purification of the crude pepsin from horse gastric juice and proteolytic complex produced by Acremonium chrysogenum.

Animals↗
PubMed1988

[Determination of the O antigen of Shigella sonnei by a competitive immunoenzyme method].

A technique for immunoenzymatic diagnosis of dysentery by Shigella sonnei O-antigen was developed. For induction of antibodies to O-antigen rabbits were immunized by intravenous administration of a commercial antidysentery vaccine. Specific antibodies to O-antigen belonging to class G immunoglobulins and not binding to O-antigens of Sh. flexneri and Salmonella typhimurium were obtained. beta-Lactamase of Bacillus licheniformis 749/c was used as a marker enzyme in the immunoenzymatic assay. To increase the sensitivity, beta-lactamase molecules were preliminarily linked with glutaric aldehyde into oligomers. Conjugates of Sh. sonnei O-antigen with the oligomers of B. licheniformis 749/c beta-lactamase were prepared with the periodate method by oxidizing O-antigen. The conjugate was used in competing solid phase immunoenzymatic assay for determination of Sh. sonnei O-antigen in blood serum of patients with dysentery. The sensitivity of the assay is 0.5-1 ng per 1 ml of O-antigen.

Animals↗
PubMedDate not supplied

[Studies of microbiological contamination of ultrasonic apparatus used in pediatric aerosol therapy].

It was found that inflating tube is most rarely contaminated with microorganisms during the use of ultrasonic inhalator TUR USI 70. Glass cylinder is contaminated more frequently whereas a diaphragm, aerosol preparation, inhaling mask and a pipe joining it with the device are contaminated most frequently. Sporadic contamination of the inflating tube indicate an efficient work of air filters while frequent contamination of the diaphragm, aerosol preparation and glass cylinder prove that the contamination is caused by a coupling fluid. It was also found that ultrasound exerts a destructive effect on microorganisms in the aerosol preparation. The investigations have shown that the inhaling mask and tubes joining it with the device should be changed before each use while the other parts of an inhalator and aerosol preparation may be changed once per 15 inhalations. It was also noted that disinfection of different parts of the device by a 2% aqueous glutaric aldehyde (30 minutes at room temperature) is efficient in about 95%.

Air Microbiology↗
PubMed1989

Studies on gamma-aminobutyric acid production by immobilized Escherichia coli cells.

E. coli cells with glutamate decarboxylase activity were immobilized by entrapment in calcium alginate gel lattices, followed by cross-linking with glutaric dialdehyde to increase mechanical strength. A large number of cells was immobilized in the gel, resulting in high enzyme activity. Optimum conditions for gamma-aminobutyric acid production were investigated. A comparative study of three reactor modes, i.e., batch, continuously stirred, and continuous column, found the optimal pH and temperature for -aminobutyric acid production to be 4.4 and 37 degrees C respectively. The batch process was run on a shaker at 120 r/min, the continuously stirred reaction (in a flask reactor) at 6 ml/h, and column production (in a special column reactor) at 12 ml/h. Conversion of the L-glutamate to gamma-aminobutyric acid was about 85-100% under these conditions. The immobilized cells could be regenerated by incubation in phosphopyridoxal coenzyme solution when enzyme activity and immobilized-cell throughput declined. The column-type process had some advantages over the others.

Alginates↗
PubMed1989

Substitution of a lysyl residue for arginine 386 of Escherichia coli aspartate aminotransferase.

Substitution of a lysyl residue for Arg-386 of Escherichia coli aspartate aminotransferase resulted in an extensive decrease in Vmax values (0.8% with the aspartate-2-oxoglutarate pair and 0.2% with the glutamate-oxalacetate pair, compared with the corresponding values for the wild-type enzyme). Kinetic analysis of the four sets of half-reactions, the pyridoxal form of the enzyme with aspartate or glutamate and the pyridoxamine form with 2-oxoglutarate or oxalacetate, allowed us to define the independent effect of the mutation on the reactivity of each substrate. Decrease in the first order rate constant (kmax) was more pronounced in the reactions with five-carbon substrates (glutamate and 2-oxoglutarate) than in those with four-carbon substrates (aspartate and oxalacetate), while the increase in the apparent dissociation constant (Kd) was greater for four-carbon substrates than for five-carbon substrates. The decrease of overall catalytic efficiency as judged by the values, kmax/Kd, was more pronounced in the reactions with five-carbon substrates than in those with four-carbon substrates. Affinities for substrate analogs such as succinate, glutarate, 2-methylaspartate, and erythro-3-hydroxyaspartate, were also considerably decreased by the mutation of the enzyme. These findings indicate that the side chain of the lysyl residue, although it bears a positive charge similar to that of the arginyl residue, is not structurally adequate for the productive binding of a substrate during catalysis.

Amino Acid Sequence↗
PubMed1989

Significance of antigen, drug, and tumor cell targets in the preclinical evaluation of doxorubicin, daunorubicin, methotrexate, and mitomycin-C monoclonal antibody immunoconjugates.

We tested drug monoclonal antibody immunoconjugates in vitro in 72 h 3H-thymidine assays and in vivo in athymic mice bearing human tumor xenografts of the same target cells. Experimental arms included control, monoclonal antibody, drug, drug + antibody, the test immunoconjugate, and a negative control immunoconjugate with an equivalent molar amount of drug for in vitro experiments, and the amount of drug conjugated to 500 micrograms of antibody in the animal experiments. Monoclonal antibodies included T101, an IgG2a that reacts with a rapidly modulating antigen, 9.2.27, an IgG2a that reacts with a slowly modulating antigen, and ME7, an IgG1 that reacts with a slowly modulating antigen. Cells used in testing included MOLT-4 (T lymphoma), 8392 (B lymphoma), and M21 (melanoma). Drugs tested were doxorubicin, daunorubicin, methotrexate, and mitomycin-C. M21 cells were resistant to daunorubicin in vitro but were inhibited by the 9.2.27 daunorubicin immunoconjugate. T101, 9.2.27, and ME7 cis-aconitate anthracycline immunoconjugates and mitomycin-C-glutarate immunoconjugates were specifically cytotoxic only for antigen positive cells in vitro and were superior to free drug in vivo. These results confirm that antigen specific-cytotoxic drug immunoconjugates can be produced that are superior to the same dose of free drug. However, each monoclonal antibody drug target system is unique and must be well-characterized for appropriate interpretation of data.

Animals↗
PubMed1989

[Inborn errors of metabolism: lessons from a clinical case].

Dramatic advances in recent years in the diagnosis and treatment of inborn errors of metabolism (IEM) make it imperative for the physician to be both aware of their occurrence and acquainted with their clinical presentations. Many may present with symptoms and signs common to sick infants, such as refusal to feed, vomiting and convulsions. Failure to include IEM in the differential diagnosis may have grave consequences, because only prompt recognition and appropriate treatment of a metabolic crisis can help prevent irreversible brain damage or death. We describe a 3-week-old female infant, eventually diagnosed as having an IEM (3-hydroxy-3-methyl-glutaric aciduria), who was admitted to various hospitals and died during her last admission. We focused on the clinical and laboratory findings of each of the first 2 admissions which might have provided clues to the true nature of the illness had the clinicians been aware of the possibility of IEM. Patients with IEM are generally managed in specialized centers; however, the responsibility for initial recognition and immediate treatment of a metabolic emergency lies with the primary physician. The purpose of our case presentation and the discussion of the lessons derived from it, is to prompt the clinician to an awareness and understanding of a subject that used to be considered reserved for specialists. In fact, all that is needed is clinical alertness and the performance of certain well-focused, simple laboratory tests for IEM.

Amino Acid Metabolism, Inborn Errors↗
PubMed1989

[Vimentin-positive epithelial cells in aggregated lymphoid nodules (Peyer's patches) in rabbits].

Peculiarities of cytoskeleton in membranous cells and disposition of the latter in the cupola epithelium in aggregated lymphoid nodules++ (ALN) have been studied in the ileum of 5 rabbits. The material has been fixed in liquid nitrogen and in the mixture of paraformaldehyde and glutar aldehyde. Methods of immunomorphology, high resolving light and transmissive electron microscopy have been used. Monoclonal antibodies to vimentin are selectively bind with a specific population of the ALN cupola epithelial cells. These cells are regularly arranged in the epithelium of the cupola lateral part and they are absent in the epithelium of the intestinal crypts, villi and apex of the cupolas. In the lateral epithelium of the cupolas surface, nearer to their base vimentin-positive++ epitheliocytes make contacts with single interepitheliocytic lymphocytes, and nearer to the apex they surround compact groups of the interepitheliocytic lymphocytes. The vimentin-positive++ epitheliocytic cells are identified as M-cells.

Animals↗
PubMedDate not supplied

[Immobilized form of Streptomyces griseus proteases complex].

The immobilized form of proteases complex of Str. griseus actinomycete is obtained by means of glutaric aldehyde with aminoethyl cellulose. Hydrolysis of synthetic substrates showed that the system of peptide hydrolases is bound, but the ratio of activities as compared to the initial proteolytic complex changes, pH-optimum of the total proteolytic activity, pH- and temperature optima of stability are not changed with immobilization. On the whole no essential stabilization of the complex was observed. After five repeated cycles of the immobilized form utilization of the activity loss accounts for 40-60%.

Enzymes, Immobilized↗
PubMedDate not supplied

[Changes in the brain GABA system after repeated injections of pyridoxal-5'-phosphate and its Schiff base with GABA].

A state of the gamma-aminobutyric acid (GABA) system (glutamate, glutamate decarboxylase, GABA, GABA-alpha-ketoglutarate aminotransferase) and the coupled reactions (alpha-ketoglutarate dehydrogenase complex, aspartate- and alanine aminotransferases) was studied in three brain structures (cerebellum, brain cortex and truncus cerebri) after multiple administration of pyridoxal-5'-phosphate (PALP) and its Shiff base with GABA (5 injections at doses 10.0 and 15.0 mg/kg of body mass, respectively). Non-coenzymatic effects of PALP were found to prevail within 1 hr after its last administration: inhibition of PALP-dependent aminotransferases and activation of the alpha-keto-glutarate oxidative decarboxylation were observed. The opposite effects were detected after addition of PALP to brain homogenates in vitro. Administration of the PALP-GABA complex exhibited qualitatively similar to those of PALP effects on the reactions studied in brain. The data obtained suggest that parenteral administration of the coenzyme preparation caused a number of metabolic effects, which are sometimes far from unambigously predicted theoretical considerations. The similarity of PALP and PALP-GABA effects appears to demonstrate ready biotransformation of the Shiff base with liberation of PALP and GABA.

Animals↗
PubMed1989

[Cells-boosters as the modulators of immunogenesis].

In the course of mouse immune response to ram erythrocytes, cells capable of enhancing immune and proliferative response (enhancing cells, or EC) are shown to appear in the spleen. The EC effect is antigen-unspecific. Cycloheximide (CH), an inhibitor of protein synthesis, speeds up EC development, which is associated with a greater immune response. In vitro CH treatment of mouse spleen cells (SC), for 3 hours at 37 degrees C, CH taken in a concentration of 1-3 micrograms/ml, resulted in in vitro induction of EC, capable of enhancing proliferative response to PHA and recombinant IL-2 in normal SC and increasing immune response to ram erythrocytes. Glutaric aldehyde fixation of EC was not reflected in their immunostimulating activity, either in vivo, or in vitro. The data obtained point to the significance of CH-induced changes in membrane-associated structures in mediating EC effect. It is assumed that the agents, altering the expression of functionally-significant structures (membrane-linked mediators and auxiliary intercellular interaction molecules) on cell surface, may be used for extracorporeal treatment of lymphoid cells to be eventually re-introduced into the body to control immunologic disorders.

Adjuvants, Immunologic↗