Effects Of Tripeptide Research Articles

Interaction mechanism of three egg protein derived ACE inhibitory tri-peptides and DPPC membrane using FS, FTIR, and DSC studies.

Understanding the interaction of food derived angiotensin converting enzyme (ACE) inhibitory peptides and intestinal epithelial cell membrane may help to improve their absorption. This research aimed to study the molecular interaction of ACE inhibitory tri-peptides ADF, FGR, and MIR with DPPC membrane during absorption process. The DPPC liposome was prepared and characterized, then used as a model membrane. The permeability of tri-peptides across the membrane was investigated using Fluorescence spectroscopy. The effect of tri-peptides on the structure and dynamics of DPPC bilayers was determined using Fourier transform infrared spectroscopy. The effect of tri-peptides on the phase transition temperature in the DPPC membrane was also analyzed using Differential scanning calorimetry. The results showed that ACE inhibitory tri-peptides ADF, FGR, and MIR can penetrate into both the membrane-water interface and hydrophobic region of DPPC bilayer, and the tri-peptide FGR have higher permeability across the membrane.

Nephroprotective Effect of Leu-Ile-Lys Tripeptide in Experimental Diabetes Mellitus.

We studied the effect of tripeptide Leu-Ile-Lys on kidney function in rats with experimental diabetes mellitus modeled by single intraperitoneal administration of streptozotocin (65 mg/kg). The tripeptide was intragastrically administrated in a dose of 11.5 mg/kg from week 5 to week 8 of the pathological process. The concentrations of glucose, protein, and creatinine in the urine were measured before and then weekly throughout the experiment. In 8 weeks, the markers of activity of the free radical oxidation process (concentration of TBA-reactive substances, total prooxidant activity, and total antioxidant activity, as well as activities of catalase, superoxide dismutase, and glutathione peroxidase) were assayed and a morphological study was conducted. After administration of the tripeptide Leu-Ile-Lys for 4 weeks, glucose concentration in the urine decreases by 3-44 times (p<0.001) and protein concentration by 2.3-3.7 times (p=0.007). The concentration of TBA-reactive substances decreased by 1.3 times (p<0.001), and the total antioxidant activity increased by 2.3 times (p<0.001). Administration of the tripeptide Leu-Ile-Lys to animals with experimental diabetes mellitus led to significant improvement of the renal function against the background of significant alleviation of oxidative damage and an increase in the antioxidant protection of the renal tissues. Improvement of the morphofunctional state of tissues and cells of the renal glomerulus was confirmed histologically, in particular, an increase in the number of podocytes by 1.5 times was observed.

Experience of Using Tripeptide Leu-Ile-Lys for Experimental Therapy of Chronic 16-Week Oxalate Nephrolithiasis in Rats.

We studied the effect of tripeptide Leu-Ile-Lys on the course of chronic 16-week oxalate nephrolithiasis in rats modeled by administration of 1% ethylene glycol solution in drinking water for 16 weeks. The tripeptide Leu-Ile-Lys obtained by chemical synthesis (sample purity ≥98%) was administered intragastrically through a probe in a dose of 11.5 mg/kg in 1 ml saline. It was found that during tripeptide Leu-Ile-Lys significantly alleviated the course of experimental pathology, which was confirmed by characteristic biochemical and morphological indicators. We observed a decrease in the concentration of calcium ions by 4.4 times, weakening of oxidative stress in the renal tissue due to a decrease in the total prooxidant activity by 1.2 times, normalization of increased catalase activity, and reduction of superoxide dismutase activity by 2.4 times relative to disease control. Histological signs of nephrolithiasis were recorded in 9% cases (vs. 75% cases in disease control).

Effect of three-day Glutathione introduction on hydrogen sulfide metabolism in liver of rats under experimental nephropathy conditions

Topicality. Scientists are becoming more interested in the exchange of sulfur-containing amino acids and hydrogen sulfide (H 2 S) metabolism and glutathione. But the effect of tripeptide on the H 2 S metabolism by nephropathy is not studied enough. Aim. To study the effect of tree-day glutathione introduction on the system of H 2 S-producing enzymes, concentration and production in the liver of rats under conditions of experimental nephropathy. Materials and methods. The experiment was conducted on albino mature male rats. The animals in experimental group were administered a single intraperitoneal dose of folic acid (250 mg/kg). Glutathione was introduced intragastral (100 mg/kg) during 3 days after intoxication. Results and discussion. Under conditions of experimental nephropathy, there was a decrease in concentration of hydrogen sulfide by 37.92 % and the production of hydrogen sulfide by 34.84 % compared with the control group. The introduction of glutathione led to an increase in these indicators by 36.32 % and 48.4 % compared with the animals with nephropathy. The activity of cystathionine-γ-lyase (CSE), cystathionine-β-synthase (CBS) and cysteinaminotransferase (CAT) in the liver of rats with nephropathy was reduced by 38.98 %, 33.73 % and 26.76 % compared with animal control group. Glutathione increased the activity of CSE and CBS by 31 % and 33.55 % compared with a group of animals with nephropathy. The activity of cystathionine aminotransferase in the conditions of tripeptide increased by 49.3 % introduction and exceeded the date of the control group. Conclusions. The activity of H 2 S-producing enzymes in experimental nephropathy in the liver of rats is decreased. The introduction of glutathione increased the content of hydrogen sulfide and promoted the growth of the activity of H 2 S-producing enzymes in the liver of rats with nephropathy. As reasons for this effect, the possibility of including tripeptide as a source of cysteine in the synthesis of hydrogen sulfide is considered.

Effects of Tripeptide Gly-His-Lys in Pain-Induced Aggressive-Defensive Behavior in Rats.

We studied the effect of Gly-His -Lys tripeptide administered intraperitoneally in doses of 5, 15, 50 and 150 μg/kg on pain-induced aggressive-defensive behavior. A foot-shock model of aggression in rats grouped in pairs in an electrified chamber was used. Analgesic and antiaggresiogenic effects of the peptide were demonstrated. It was found the L-lysine residue plays the key role in these effects, because they were observed under the influence of L-lysine administration in doses close to its equimolar content in the studied tripeptide.

Screening milk-derived antihypertensive peptides using quantitative structure activity relationship (QSAR) modelling and in vitro/in vivo studies on their bioactivity

In this study, we constructed a quantitative structure activity relationship (QSAR) model of angiotensin I-converting enzyme (ACE) inhibitory tripeptides from published data (R2 = 0.8437; Q2 = 0.649) and applied the model to screen 27 tripeptides derived from cow milk protein sequences. Potential ACE inhibitory tripeptides were synthesised and evaluated in in vitro/in vivo studies. Results showed that ACE inhibitory activities of tripeptides followed the order (p < 0.05): isoleucine-proline-proline (IPP, commercial) > valine-isoleucine-proline (VIP) > isoleucine-valine-proline (IVP) based on concentrations (7.57–49.72 μm) that decreased 50% of ACE activity. Lowering systolic blood pressure (SBP) effect of tripeptides in rats (1.5 mg kg−1 body weight dosage) followed the order according to relative lowering SBP rates: IVP (24%) > IPP (17%) > VIP (12%), consistent with results on mRNA levels of sarcoplasmic reticulum Ca2+, Mg2+ -ATPase gene in rat hearts (p < 0.05). IPP and IVP showed no negative effects on blood glycometabolism.

Effect of Tripeptides on Lymphoid and Stem Cells

Tripeptides T-36 and, particularly, T-38 in concentrations of 0.1, 1, and 10 ng/ml inhibited proliferation of primary trypsinized embryonic mesenchymal stem cells, rat transplantable KF-1 fibroblasts, and human erythromyelosis K-562 cells. Inhibition of proliferation in embryonic and immortalized cells under the influence of tripeptides probably reflects antitumor activity of these substances. Tripeptides had no effect on lymphocyte survival and their adhesive, cytotoxic, and induced proliferative activities. T-36 did not modulate the proliferative properties of erythromyelosis K-562 cells. Tripeptides did not change engulfment activity and spontaneous and induced bactericidal activities of granulocytes. T-36 in a concentration of 0.1 ng/ml increased spontaneous proliferation of normal lymphocytes. These data suggest that tripeptides stimulate nontumor immune cells in adult people.

Effects of Tripeptides on the Amidolytic Activities of Urokinase, Thrombin, Plasmin and Trypsin

Eight peptides of the general formula X-d-Ser-AA-Arg-Y where X = H, Ac; AA = Ala, Gly and Y = OH, NH2 were obtained and tested for their effect on the amidolytic activities of urokinase, thrombin, plasmin, and trypsin.

Protective effect of tripeptide in the presence of cyclophosphamide on the growth of cultured lymphoid tissue from rats of different age

We studied the effect of tripeptide T-38 (Lys-Glu-Asp) in the presence of cyclophosphamide on cell proliferation and apoptosis in explants of splenic lymphoid tissue from young and old rats. Peptide T-38 in a concentration of 0.05 ng/ml produced a stimulatory effect on the growth zone of the explants. Addition of 1 mg/ml cyclophosphamide to the culture medium suppressed cell proliferation, which was associated with enhanced expression of proapoptotic p53 protein. Under conditions of combined treatment with cyclophosphamide and T-38 no inhibiting effect of the cytostatics was observed. Thus, tripeptide T-38 in the presence of cytostatics produces a protective effect on cell proliferation in lymphoid tissue explants.

Central activity of peptide Gly-Pro-Hyp - the main component of collagen degradation products mixture

The effect of tripeptide Gly-Pro-Hyp on the central nervous system was studied. The peptide Gly-Pro-Hyp is a main component of the mixture of collagen type I degradation products obtained by 6-h digestion with bacterial collagenase. The investigated peptide in the doses 1 microgram, 2 micrograms, and 5 micrograms significantly reduces the psychomotor activity of animals, intensifies haloperidol-induced catalepsy and enhances stereotypy behaviour after apomorphine administration. The central activity of Gly-Pro-Hyp is similar to the action of collagen degradation products mixture. This suggests that this peptide may be the active substance responsible for the effects of degradation products of collagen type I.

Tripeptide, Arg-Gly-Asp, inhibits the transfection of protein-linked DNA of bacteriophage M2.

The effect of tripeptide, Arg-Gly-Asp (RGD), on the transfection activity of Bacillus phage M2 DNA was examined. The transfection activity decreased when M2 DNA was preincubated with RGD before it was added to competent cells.