Bioorganicheskaia khimiia最新文献

A prototype of test-system for simultaneous quantitative assay of nine tumor markers in blood serum was developed. The main constituent of the test-system is OM-9 biochip containing immobilized antibodies against nine oncomarkers: α-fetoprotein (AFP), carcinoembryonic antigen (CEA), human chorionic gonadotropin (HCG), cancer antigen 15-3 (CA 15-3), cancer antigen 125 (CA 125), cancer antigen 19-9 (CA 19-9), prostate-specific antigen, total (PSAtot) and free (PSAfree) forms, neuron-specific enolase (NSE). The biochip-based assay procedure for carrying out simultaneous quantitative determination of nine tumor markers in patient's blood serum: two-steps sandwich-immunoassay, was proposed. The main analytical characteristics of the method were obtained. The results permit to consider the prototype of the test-system as a promising instrument for clinical application. The test-system prototype was tested using blood serum samples of oncological patients (252 samples) and healthy donors (185 samples). Increased concentrations of one or more tumor markers above the normal level were found in 76.6% cases of oncological patients and only in 6% cases of healthy donors. For colorectal cancer patients group, application of modern statistical methods of data-processing in medical researchers, i.e. ROC-analysis and logistic regression, indicted that the simultaneous assay of nine tumor markers on biochips showed much more diagnostic significance (area under the ROC-curve (AUC) reached 0.84) than traditional assay of 2 tumor markers, CEA and CA 19-9 (AUC = 0.59). The developed biochip-based test-system can be recommended both for the estimation of people's health, e.g., for standard medical examination, and for tracking of tumoral process in postsurgical period or after specific tumor treatment.

Based on the computer model of active center of bacteriophage T5 deoxyribonucleoside monophosphate kinase amino acid residues essential for the enzyme activity were determined. As the result of site-directed mutagenesis, cloning and expression of the gene in E. coli series of proteins were obtained with single amino acid substitutions of conservative active center residues--S13A, D16N, T17N, T17S, R130K, K131E, Q134A, G137A, T138A, W150F, W150A, D170N, R172I, E176Q. Electrophoretically homogeneous preparations of mutant forms were purified using ion exchange and affinity chromatographic steps. Measuring of the specific enzyme activities of these enzymes for the natural acceptors of phosphoryl group (dAMP, dCMP, dGMP, dTMP) revealed that substitutions of charged residues of NMP-binding domain-namely, R130, R172, D170 and E176-lead to almost complete loss of enzyme activity. It was shown that presence of OH-group at position 17 is also important for catalytic activity. Based on the changes in specific activities we suppose that arginine residues at positions 130 and 172 participate in binding of γ-phosphoryl of donor and α-phosphoryl of acceptor. Also, aspartic acid at 16 position of ATP-binding site (P-loop) probably assists in the binding of acceptor, first of all dTMP. Unequal decrease in enzyme activities for different substrates of partially active mutants--G137A, T138A, T17N, Q134A, S13A, D16N--indicate that in the binding of various substrates different amino acid residues take part.

Since discovery and development of effective as well as safe drugs has brought a progressive era in human healthcare that is accompanied by the appearance of drug resistant bacterial strains, there is constant need of new antibacterial agent having novel mechanisms of action to act against the harmful pathogens. In the present study, several N-terminal substituted urea/thiourea derivatives were synthesized by the reaction of glutamic acid and 3-(1-piperazinyl)-1,2-benzisothiazole with various substituted phenyl isocyanates/isothiocyanates. Elemental analysis, IR, 1H NMR, 13C NMR and mass spectral data confirmed the structure of the newly synthesized compounds. The derivatives were investigated for their antibacterial and antifungal activities against various pathogens of human origin by agar well diffusion method and microdilution method. The preliminary antimicrobial bioassay reveals that the compounds containing fluoro and bromo as substituents showed promising antimicrobial activity.

Methionine sulfoxide reductase plays a regulatory role in plant growth and development, especially in scavenging reactive oxygen species by restoration of the oxidation of methionine in protein. A full-length cDNA sequence encoding methionine sulfoxide reductase (MSR) from mulberry, which we designated MMSR, was cloned based on mulberry expressed sequence tags (ESTs). Sequence analysis showed that the MMSR is 810 bp long, encoding 194 amino acids with a predicted molecular weight of 21.6 kDa and an isoelectric point of 6.78. The expression level of the MMSR gene under conditions of drought and salt stresses was quantified by qRT-PCR. The results show that the expression level changed significantly under the stress conditions compared to the normal growth environment. It helps us to get a better understanding of the molecular basis for signal transduction mechanisms underlying the stress response in mulberry.

A synthesis for fluorescent analogs of ceramide-1-phosphate bearing 9-anthrylvinyl or 4,4-difluoro-3a,4a- diaza-s-indacene-8-yl (Me4-BODIPY) fluorophore at o-position of fatty acid residue was carried out. The key stage of the synthesis is hydrolysis of corresponding sphingomyelins catalyzed by phospholipase D from Streptomyces chromofuscus; the enzymatic yield has been raised to 50-70% by appliance of organic solvent in the incubation medium.

Reaction of 4-chlorocoumarin-3-carbonitrile with ethyl thioglycolate and ethyl glycinate hydrochloride leads to a series of title products. Hydrazinolysis of amino thienocoumarin carboxylate afforded the hydrazine derivative which underwent various reactions to build new heterocyclic rings containing thienocoumarin moiety. Chloro acetylation of aminoester compound afforded the chloro acetyl amino which underwent nucleophilic substitution reactions various amines. The following treatment with formaldehyde under Mannich conditions afforded the corresponding imidazo derivatives. Reaction of Ghloroacetylamino with potassium thiocyanate yielded ethylpyrimidothieno coumarin sulfanylacetate which was used as a versatile precursor for synthesis of other heterocycles. On the other hand, reaction of chloro coumarin carbo nitrile with hydrazine gave the aminopyrazolocoumaine which reacted with bifunctionally compounds to give the substituted pyrimido derivatives. Diazotization and coupling of aminopyrazole with ethylcyanoacetate yielded ethylaminotriazinopyrazolocoumarine carboxylate. Several of the compounds obtained demonstrated considerable antifungal and antibacterial activity in the in vitro test systems.

In this study, glutathione S-transferase (GST) was isolated from the liver of pike Esox lucius, which was homogenous according to SDS-PAGE and isoelectrofocusing. It is a homodimer with subunits mass 25235.36 Da (according to HPLC-MS/MS) and pI about 6.4. Substrate specificity, thermostability, some kinetic characteristics and optimum pH were determined. The enzyme was identified as Alpha class GST.

Linear hepta-peptide Cys-Lys-Gly-Asp-Trp-Asp-Cys was synthesized first and then disulfide bond was formed between the Cys1 and Cys7 to develop cyclo-heptapeptide containing Lys-Gly-Asp-sequence. Structural simulation showed that Lys-Gly-Asp-motif (KDG) displayed functional conformation. The cyclo-heptapeptide exhibited potent anti-platelet aggregation activity based on specific recognition and interaction with the GPIIb-IIIa receptor on platelet cell membrane. The specific and potent anti-platelet activity makes the KGD-containing cyclo-heptapeptide a possible therapeutic agent.

Colchicine site binders--blockers of tubulin polymerization--are potential antimitotic agents for anticancer therapy. To reduce their systemic toxicity and improve biodistribution, encapsulation in nanosized liposomes may be employed. Liposomes present a convenient means for preparation of injectable formulations of hydrophobic compounds, however colchicine as such is known to leak through the lipid bilayer. In this study, newly synthesized triazole-containing analogues of colchicine and allocolchicine, and their palmitic and oleic esters (lipophilic prodrugs) were tested for anti-proliferative activity and apoptosis-inducing potential. In contrast to colchicine conjugates, whose activities ranged with those of colchicine, allocolchicine derivatives exhibited drastically lower effects and were discarded. Liposomes of about 100 nm in diameter composed of egg phosphatidylcholine--yeast phosphatidylinositol--palmitic or oleic prodrug, 8 : 1: 1, by mol, were prepared by standard extrusion technique and tested in a panel of four human tumor cell lines. Liposome formulations preserved the biological activities of the parent colchicinoid the most towards human epithelial tumor cells. Moreover, liposomal form of the oleoyl bearing colchicinoid inhibited cell proliferation more efficiently than free lipophilic prodrug. Due to substantial loading capacity of the liposomes, the dispersions contain sufficient concentration of the active agent to test wide dose range in experiments on systemic administration to animals.

Synthesis of benzofuran-1,3-thiazolidinone derivatives is described herein. These compounds were prepared via a concise and short route by condensation reaction of khellinone with aromatic/aliphatic amines followed by cyclization using thioglycolic acid. The newly synthesized compounds were characterized using the well known spectroscopic tools (IR, 1H NMR, and mass spectroscopy), as well as microanalysis. In frames of biological screening of the compounds, antioxidant activity was assessed in vitro.