1,721,029 research outputs found
Lysis of plasma cell membrane by reactive oxygen species and protection by nitric oxide and chondroitin sulfate
No full textLysis of plasma cell membrane by reactive oxygen species and protection by nitric oxide and chondroitin sulfate
Transamidinase of Hog Kidney V Kinetic studies
No full textTransamidinase of hog kidney V kinetic studies
ALKYLATION OF ADENOSINE DEAMINASE BY BENZYLBROMOACETATE AND 9-(PARA-BROMOACETAMIDOBENZYL)ADENINE
No full textAdenosine deaminase (adenosine aminohydrolase, EC 3.5.4.4) from calf intestinal mucosa is not affected at pH 8 by haloacetate and haloacetamide, while benzylbromoacetate and 9-(p-bromoacetamidobenzyl)adenine inactivate the enzyme. Substrate analogs protect against inactivation by these reagents. 2. 2. One mole of reagent is bound per mole of inactivated enzyme. The alkylated amino acid has been identified as lysine. 3. 3. The reaction of alkylation consists of two stages: binding of the alkylating agent (fast reaction) and alkylation of the ε-amino group of lysine (slow reaction). 4. 4. Bromoacetate, which does not inactivate the enzyme, does not alkylate the reactive lysine. 5. 5. The difference in reactivity is explained on the basis of a selectivity of the alkylation site on the enzyme towards the alkylating reagents
Transamidinase of Hog kidney IV Effect of dinitrophenylation
No full textTransamidinase of hog kidney IV effect of dinitrophenylation
L-PROPIONYL CARNITINE PROTECTS ERYTHROCYTES AND LOW-DENSITY LIPOPROTEINS AGAINST PEROXIDATION
No full textThe effects of peroxidation on the erythrocytes of rats orally treated with L-propionyl carnitine for 15 day) (50 mg/kg/day/ were investigated. Peroxidation was produced by incubating the cells in the presence of the cytotoxic system: lactoperoxidase-hydrogen peroxide and iodide ions. Lysis of erythrocytes was evaluated by measuring the turbidity following the decrease in absorbance at 600 nm. The 50% of erythrocyte lysis of untreated animals was observed after 16 min and in about 30 min all the cells were lysed. With L-propionyl carnitine-treated rat erythrocytes the time at which 50% of lysis was observed increased to 23 min. L-propionyl carnitine also exerted its protective effect in vitro when incubated with untreated rat erythrocytes or human erythrocytes in the presence of the cytolytic system. The presence of L-propionyl carnitine in the incubation mixture markedly decreased the malonaldehyde formation. The protection was concentration-dependent. To establish if L-propionyl carnitine protects from oxygen reactive species or is able to stabilize the damaged membranes, a latent damage was produced by incubating the erythrocytes with the cytolytic system for a few minutes. The cells were then removed and suspended in buffered saline in the absence or in the presence of different L-propionyl carnitine concentrations L-propionyl carnitine decreased the velocity of lysis of damaged erythrocytes. These data suggest that L-propionyl carnitine protects erythrocytes from oxygen reactive species and also stabilizes the damaged membrane probably by specific binding with protein and/or phospholipid domains. Low density lipoproteins (LDLs) from human blood were peroxidized by exposure to Cu2+ ions in the presence of various L-propionyl carnitine concentrations. The formation of malonaldehyde decreased in the presence of L-propionyl carnitine, These findings provide evidence that L-propionyl carnitine protects cell membrane and circulating lipoproteins from peroxidation and stabilizes the cell membrane damaged by oxygen reactive species
NEW APPLICATION OF AFFINITY CHROMATOGRAPHY - IDENTIFICATION AND STUDY OF SPECIFIC CARRIER PROTEINS
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