Biochemistry (Moscow), Supplement Series B: Biomedical Chemistry (v.4, #4)

ACE inhibitors as activators of kinin receptors by E. V. Kugaevskaya; Yu. E. Elisseeva (309-320).
Angiotensin converting enzyme (ACE) inhibitors are widely used for treatment of cardiovascular diseases. Studies of interaction of ACE inhibitors with bradykinin receptors have shown that ACE inhibitors potentiate bradykinin effects not only by blocking its inactivation but also by activation of its receptors. The mechanism of activation and also structural features of the kinin B2R and B1R receptors by ACE inhibitors have been characterized and amino acid residues involved into kinin receptor coupling to G proteins have been identified. Kinins and their receptors are involved into positive therapeutic effect of ACE inhibitors.
Keywords: kinin receptors; angiotensin converting enzyme inhibitors; cardiovascular protection

Synthetic peptide vaccines by A. A. Moisa; E. F. Kolesanova (321-332).
The review considers the stages of the development of synthetic peptide vaccines against infectious agents, novel approaches and technologies employed in this process, including bioinformatics, genomics, proteomics, large-scale peptide synthesis, high-throughput screening methods, the use of transgenic animals for modeling of human infections. An important role for the development and selection of efficient adjuvants for peptide immunogens is noted. The review contains examples of the developments of synthetic peptide vaccines against three infectious diseases (malaria, hepatitis C, and foot-and-mouth disease).
Keywords: vaccine; peptides; B-epitopes; T-epitopes; immune response; malaria; hepatitis C virus

The model of the structural complex of cyclophilin B belonging to the immunophilins family with the HIV-1 subtype A V3 loop presenting the principal neutralizing determinant of the virus gp120 envelope protein as well as determinants of cell tropism and syncytium formation was generated by molecular docking methods. Based on the conformational and energy characteristics of the built complex, computer-aided design of the polypeptide able to block effectively the functionally crucial V3 segments was implemented. Analysis of the results obtained in this study and literature data suggests that the generated molecule represents a promising pharmacological substance, which may be used as the basis structure for realization of the protein engineering projects aimed to develop effective drugs for anti-AIDS therapy.
Keywords: human immunodeficiency virus type 1; protein gp120; V3 loop; cyclophilin B; computer modeling; molecular docking; drugs

Three-dimensional (3D) Quantitative Structure-Activity Relationship models were designed for irreversible and reversible acetylcholinesterase inhibitors by molecular modeling methods. In the case of irreversible inhibitors CoMFA (comparative molecular fields analysis) or CoMSIA (comparative molecular similarity indices analysis) descriptors in combination with HYBOT 3D fields provide more statistically valid 3D-QSAR models. This indicates importance of donor-acceptor interactions for irreversible acetylcholinesterase inhibition. In the case of reversible organophosphorous inhibitors a good quality model for structure-activity relationships was developed using CoMFA fields. The obtained models have good predictive power and can be used for estimation of inhibitory activity of new organophosphorous compounds that in turn correlates with toxicity of these compounds.
Keywords: acetylcholinesterase; molecular modeling; 3D-QSAR; HYBOT-3D; reversible and irreversible inhibitors

The development of a novel vector for construction of a full-length cDNA library by V. I. Fedchenko; A. A. Kaloshin; A. E. Medvedev (353-361).
A new original vector pEM-(dT)40(f+) has been prepared. It can be used for cDNA library construction from polyadenylated mRNA, isolated from various sources. The vector pGEM-(dT)40f(+) is initially transformed into single stranded and then into a linear form and its (dT)40 tail at the 3′-end is used as the vector-primer for synthesis of the first strand cDNA. The use of a synthetic oligonucleotide complementary to the vector and recombinant DNA results in vector circularization and synthesis of the second strand cDNA. This approach has the following advantages: (1) it significantly simplifies cDNA library construction, which includes three steps; (2) full-length cDNA library construction is achieved by adding a (dC)n homopolymer tail to the 5′end; (3) preparation of a clone library requires a few milligrams of total RNA; (4) it is possible to obtain cDNA clones up to 10 kbp; (5) it does not require PCR reaction (which can induce artifact mutations in cDNA sequences); (6) this approach does not employ restrictase treatment and chimeric cDNA products are not formed.
Keywords: cDNA library; vector-primer; full size cDNA; cDNA synthesis

The analysis of interaction of lipoproteins and steroid hormones by L. M. Polyakov; D. V. Sumenkova; R. A. Knyazev; L. E. Panin (362-365).
Using the methods of gel-filtration and fluorescence quenching, it has been demonstrated that plasma lipoproteins bind steroid hormones and can therefore play a role in their active transport in the body. High density lipoproteins demonstrate the highest affinity for steroids.The lipoprotein-steroid complex formation involves the protein components of lipoproteins with the apolipoprotein A-I as one the protein components responsible for binding of steroid hormones. The calculated constants of the complex formation between lipoproteins and steroid hormones suggest specificity of this binding. The data obtained suggest a real possibility of penetration of steroid hormones into cells by a receptor-mediated endocytosis using the lipoprotein complexes as a vehicle.
Keywords: lipoproteins; apolipoproteins; steroid hormones

Antioxidant activity of vegetable oils with different omega-6/omega-3 fatty acids ratio by D. A. Guseva; N. N. Prozorovskaya; A. V. Shironin; M. A. Sanzhakov; N. M. Evteeva; I. F. Rusina; O. T. Kasaikina (366-371).
The antioxidant activity and the oxidative stability of flax, sesame, silybum oils and seed blend oils with different ω-6/ω-3 fatty acid ratios have been investigated. The antioxidant content (AO) in crude oils and their reactivity towards peroxyl radicals were studied using the kinetic method based on oil addition to the model reaction of cumene oxidation. There were correlations between the ratio polyunsaturated fatty acids (PUFA)/ω-9 and thermal stability (50°C); between the effect of γ-tocopherol content and oil resistance to oxidative changes during long-term storage at (10 ± 2)°C.
Keywords: flax oil; sesame oil; silybum oil; seed blend oils; antioxidant content; antiradical activity; oxidative stability

The influence of α-lipoic acid (LA) on the hepatic glutathione system of mice with transplanted Ehrlich ascites carcinoma (EAC) has been investigated. LA caused multidirectional influence on the glutathione system of healthy mice. EAC transformed the LA influence, by strengthening prooxidant effects, which were more expressed on early terms after inoculation of the tumor. The mechanism explaining realization of the LA prooxidant effects as a result of interaction with the glutathione system is suggested.
Keywords: glutathione system; α-lipoic acid; Ehrlich ascites carcinoma; lipid peroxidation

Evaluation of cytotoxicity and efficiency of antioxidant protection of hydrophilic derivatives of 2,4,6-trialkylphenols in Escherichia coli cells by U. N. Rotskaya; L. P. Ovchinnikova; E. A. Vasunina; O. I. Sinitsina; N. V. Kandalintseva; E. A. Prosenko; G. A. Nevinsky (377-382).
The effects of five new derivatives of 2,6-dialkyl-4-propylphenol containing different ionogenic groups (-SO3Na, -S-SO3Na, -S-(NH2)2Cl) in the para position on survival of the E. coli AB1157 strain and its isogenic strain deficient in repair enzyme genes have been investigated in the presence and in the absence of hydrogen peroxide. Survival of cells treated with hydrogen peroxide was markedly increased in the presence of sodium (3-(3,5-dimethyl-4-hydroxyphenyl)propyl)-1-sulphonate (C1). Replacement of methyl substituents at ortho-position of C1 for tert-butyl or cyclohexyl groups decreased cell protection against exogenous hydrogen peroxide. Among 2,6-di-tert-buthylphenol the compound with the thiosulphonate group demonstrated properties similar to its sulphonate analog, whereas 3 mM isothiuronium chloride completely suppressed cell growth both in the absence and in the presence of hydrogen peroxide. Thus, among the tested compounds C1 may be considered as the most promising antioxidant.
Keywords: oxidative stress; sulfur-containing phenolic antioxidants; hydrophilic antioxidants; 2,4,6-trisubstituted phenols

The content of basic fibroblast growth factor (bFGF) and also interleukins 1β and 6 (IL-1β and IL-6) has been investigated in rat buccal mucosa after its surgical injury by an erbium laser (Er:YAG laser) and a scalpel. The laser emission caused a sharp increase in the content of these regulators on the second day after treatment followed by decrease observed on the seventh day. These results may reflect synergistic effect of these peptide regulators in the wound defect. Changes in time-course of bFGF, IL-1β and IL-6 release in the wound formed by the laser beam compared with the wound induced by the cutting instrument may promote earlier appearance of the proliferation phase.
Keywords: basic fibroblast growth factor; interleukins; Er:YAG laser; wound; oral mucosa

The Epstein-Barr virus (EBV) latent membrane protein 1 (LMP1) encoded by the LMP1 gene is a transmembrane protein, which can activate a number of cellular signal cascades and transcriptional factors leading to cell transformation. In the present study the sequencing of full-length LMP1 variants isolated from Russian patients with Hodgkin’s lymphoma (HL), non-Hodgkin’s lymphomas (NHL) and infectious mononucleosis (IM) has been carried out. The phylogenetic analysis of the obtained sequences revealed dominance of the LMP1 variants belonging to proteins of the low-divergent group LMP1-B95.8b characterized by minimal set of mutations. Investigation of biological properties in the Russian representatives of this group revealed that expression of the studied LMP1 variants in embryonic kidney (HEK) 293 cells was accompanied by an insignificant increase in activation of the transcriptional factor NF-κB and had minor influence on activation of the transcriptional factor AP-1. It was also detected that all investigated low-divergent LMP1 variants expressed in Rat-1 cells caused activation of inducible NO-synthase (iNOS) and intracellular production of nitric oxide (NO). At the same time the level of NO accumulation was lower than that induced by the low-transforming prototype variant LMP1-B95.8. The data obtained indicate that the LMP1 variants, which are the most common among Russian patients with EBV-associated lymphoproliferative diseases, are characterized by minimum number of mutations and rather low ability to activate basic cellular signaling pathways regardless the nature of pathological process, benign (IM) or malignant (HL, NHL). It is suggested that in addition to the modest activation of NF-κB and iNOS induction by LMP1 other factors are involved in the cell transformation process.
Keywords: Epstein-Barr virus; LMP1 protein; NF-κB; NO; iNOS

Statins and angiotensin-converting enzyme (ACE) inhibitors have beneficial impact on the serum cholesterol and blood pressure. It is supposed that statins and ACE inhibitors may modify the antioxidative status in erythrocytes. The study objective was to compare the effects of two treatments, lisinopril alone versus lisinopril plus simvastatin, on erythrocyte antioxidant enzyme activities. The study involved 32 patients with arterial hypertension, their initial serum total cholesterol, LDL-cholesterol and triglycerides were within the normal range. Patients of two groups, each of 16 subjects, were treated with lisinopril (10 mg/day) or with lisinopril (10 mg/day) plus simvastatin (20 mg/day). Before and after the ambulatory therapy for 3 and 6 months, activities of superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx), glutathione reductase (GR) were determined in purified erythrocytes. All treated patients had significantly higher catalase activity (by 79.3–106.5%, p < 0.0001) and significantly lower GPx activity (by 20.7–30.6%, p < 0.001) as compared to the baselines. The same results were obtained in both groups (lisinopril and lisinopril + simvastatin), after both periods (3 and 6 month) of treatments. SOD activity increased only in the lisinopril group and only after 6 months (p = 0.0345). No changes of GR activity were observed under all conditions studied. Thus, the lisinopril monotherapy and combined lisinopril plus simvastatin therapy exhibit specific, pronounced and equipotent effects on antioxidant enzymes in human erythrocytes. Peroral administration of lisinopril or lisinopril plus simvastatin may protect erythrocytes and other tissues against oxidative damage.
Keywords: erythrocyte; antioxidant enzymes; lisinopril; simvastatin; catalase; glutathione peroxidase

The antioxidant status of patients with thyrotoxicosis during combined therapy with epifamin by S. S. Popov; A. N. Pashkov; V. I. Zoloedov; T. N. Popova; T. I. Rakhmanova (400-403).
The aim of this study was to investigate intensity of free radical processes and catalase activity in serum of patients with thyrotoxicosis during traditional therapy and combined therapy with epifamin. Patients (n = 25) were subdivided into two groups: the first group of patients (n = 12) received traditional therapy (antithyroid drugs, β-adrenoblockers, and the second group of patients (n = 13) received additionally epifamin (1 tablet of 10 mg 3 times a day, 10–15 minutes before meal for 7 days). The thyrotoxic patients were characterized by intensification of free radical oxidation evaluated in blood serum by biochemiluminescence parameters. During the combined therapy with epifamin there was less expressed intensity of free-radical processes and the increase in total antioxidant activity of the body, which was not observed during traditional therapy. The standard therapy of thyrotoxicosis by thyrostatics and β-adrenoblockers decreased catalase activity and thus exhibited a negative effect on the antioxidant status of the body. On the contrary, combined therapy with epifamin increased catalase activity and this could positively influence the antioxidant protection of the body.
Keywords: thyrotoxicosis; free-radical oxidation; catalase; epifamin

ATP-Dependent Lon-proteases are components of the protein quality control system, which maintains cellular proteome. The Lon family consists of two subfamilies A and B, differing in subunit architecture and intracellular location. We propose here a reinterpretation of the domain organization of the non-catalytic N-terminal region of LonA proteases. Using Escherichia coli LonA protease (EcLon) as an example, it has been shown that a fragment (αN domain) located between the N-terminal domain and the AAA+ module is similar to the α1 domain of the first AAA+ module of chaperone-disaggregase ClpB. A coiled-coil (CC) region included in the αN domain of LonA is similar to the M domain of ClpB chaperones, which is inserted into the α1 domain. This region is suggested to adopt the structure similar to the propeller-like (PL) domain. The typical architecture of the N-terminal region of LonA proteases is postulated to be characterized by the obligatory presence of a PL domain, included in the αN domain, but may vary in the length and topology of the preceding N-terminal domain, which can have in some cases a more complex structure than in EcLon.
Keywords: AAA+ proteins; ATP-dependent proteolysis; Lon protease; ClpB chaperones; propeller-like domain; coiled-coil region