Difference between experimental and control organizations was assessed using one-way ANOVA

Difference between experimental and control organizations was assessed using one-way ANOVA. the depletion of l-orn, the precursor of polyamines (PA), led to a significant and long-term decrease in the concentration of polyamines, which are responsible for regulation of many processes including cell proliferation. Therefore, LO may be used to reduce levels of l-lys and PA in the brain. administration at a dose of 1 1.5 mg/kg. (b) l-lysine -oxidase concentration in the brain tissue after solitary administration at a dose of 1 1.5 mg/kg. Quantity of animals = 5 at each time point. The values shown are mean of three determinations. Results are offered as mean SEM. As the study aimed to investigate the LO effect on the metabolism of AA and PA in the brain, we decided the pharmacokinetics of this enzyme in the brain by enzyme immunoassay (Physique 1b). Intravenously injected LO quite quickly appeared in the brain of mice; after 15 min, its concentration was 87.2 6.1 ng/g of tissue. As the total dose of LO was 1.5 mg/kg, Delsoline it was possible to determine that approximately 0.15% of administered LO was found in the brain. 2.2. LO Showed Resistance to Proteolysis It can be assumed that this long-term preservation of LO in the brain is associated with the absence of degrading enzymes, as well as the possible high resistance of LO to proteolysis. To Delsoline confirm this assumption, LO was incubated at 37 C in the presence of the two most prominent proteolytic enzymes, trypsin and chymotrypsin, under optimal conditions for their action. It turned out that these proteinases, which have an affinity for peptide bonds created by different AAs, did not cleave LO to reduce its activity (Physique 2). Open in a separate window Physique 2 The resistance of l-lysine -oxidase (LO) to proteolysis. LO (0.17 M) incubation at 37 C in 0.2 M Tris-HCl buffer (pH 7.8) in the presence of 21.7 M chymotrypsin (), 20 M trypsin (), without additivescontrol (). 2.3. Delsoline Concentrations of Target Amino Acids Are Decreased in the Brain LO catalyzes the oxidative deamination of l-lys and its structural analogues, albeit at a much lower rate. Accordingly, the concentration of these LO substrates in the brain decreased, although to a much smaller extent (Physique 3). Open in a separate window Physique 3 Dynamics of l-lysine structural analogs concentrations in the brain after a single l-lysine -oxidase injection at a dose of 1 1 mg/kg. The results are offered as mean SEM, as a ratio to the control group. Difference between experimental and control groups was assessed using one-way ANOVA. Statistically significant difference designated as ** for 0.05 or * for 0.01. 2.4. Concentrations of Amino Acids, Which Are Directly Associated with the Tricarboxylic Acid Cycle (l-asp and l-glu), Are Significantly Changed in the Brain In addition, the enzyme significantly affected the redistribution of AAs directly associated with the tricarboxylic acid (TCA) cycle (l-asp and l-glu). The study of the dynamics of other l-AA concentrations: (valine, glycine, alanine, proline, tryptophan, isoleucine, methionine, asparagine, glutamine, phenylalanine, tyrosine) in the brain after LO injection did not reveal significant changes in most cases, except for l-glu, l-asp (Physique 4), and l-val. Open in a separate Rabbit polyclonal to YSA1H window Physique 4 Dynamics of amino acid concentrations in the brain after a single l-lysine -oxidase injection at a dose of 1 1 mg/kg. The results are offered as mean SEM, as a ratio to the control group. Difference between experimental and control groups was assessed using one-way ANOVA. Statistically significant difference designated as ** for 0.05 or * for 0.01. 2.5. LO Caused a Significant and Long-Term Decrease of the Polyamines Concentrations As LO degrades l-orn, a precursor of PA, it was of interest to investigate the possibility of by using this enzyme to impact the content of PA in the brain. LO significantly reduced the concentration of PA in.