Residue packing in globular and intrinsically disordered proteins

Intrinsically disordered proteins (IDPs)/regions do not have well‐defined secondary and tertiary structures, however, they are functional and it is critical to gain a deep understanding of their residue packing. The shape distributions methodology, which is usually utilized in pattern recognition, clustering, and classification studies in computer science, may be adopted to study the residue packing of the proteins. In this study, shape distributions of the globular proteins and IDPs were obtained to shed light on the residue packing of their structures. The shape feature that was used is the sphericity of tetrahedra obtained by Delaunay Tessellation of points of Cα coordinates. Then the sphericity probability distributions were compared by using Principal Component Analysis. This computational structural study shows that the set of IDPs constitute a more diverse set than the set of globular proteins in terms of the geometrical properties of their network structures.     

Antiproliferative effects of some N-benzylideneanilines

A series of Schiff bases including N-benzylideneaniline (NBA) nuclei were prepared. The chemical products obtained were characterized by mass spectometry (APCI), 1H NMR, and IR spectroscopy in order to seek their cytotoxic and proliferation effects on human small lung (A549) and cervical (HeLa) cancer cell lines with biochemical assays. All of the synthesized compounds showed antiproliferative effects to different extents.     

Determination of HER-2/Neu status in hepatocellular carcinoma cases

Specific chromosome abnormalities and genetic changes in hepatocellular carcinoma (HCC) have been demonstrated by conventional cytogenetic studies or molecular cytogenetic approaches like comparative genomic hybridization and loss of heterozygosity analyses. HER-2/Neu amplification and expression has been studied as a molecular target for treatment of HCC, and there are conflicting results. We aimed to determine HER-2/Neu status in archive materials of HCC patients by fluorescence in situ hybridization (FISH). Among the 35 patients, 2 had HER-2/Neu amplification and 3 had increased chromosome 17 copy number. All these patients had grade 2 or 3 tumor with a diameter of 3-12 cm. We conclude that although HER-2/Neu amplification is not the primary mechanism in the development of liver tumors, it might play a role in one of the steps of multistage carcinogenesis.     

Thalictricoside, a new phenolic compound from Thalictrum orientale

From the underground parts of Thalictrum orientale Boiss., a new phenolic compound 1 was isolated in addition to one known cyanoglycoside, lithospermoside (2). For the structure elucidation of all compounds, 1D- and 2D-NMR techniques (DEPT, COSY, HMBC, HSQC) and MS (HR-MALDI) were used. The structure of the new compound was established as 2-(4'-hydroxyphenyl)-nitroethane-4'-O-[beta-xylopyranosyl-(1 --> 6)-beta-glucopyranoside] (1).     

Synthesis and cytotoxic and analgesic activities of some 1, 5-diaryl-3-ethoxycarbonylpyrrole derivatives

Some 1,5-diaryl-3-ethoxycarbonyl-2-methylpyrrole derivatives were obtained by reacting 1-aryl-3-ethoxycarbonylpent-1,4-diones and a suitable aniline derivative or sulfanilamide under Paal-Knorr pyrrole synthesis conditions. The cytotoxicity of the compounds was tested and all compounds, except for compound 2 h, showed a time-dependent increase in cytotoxic activity. Analgesic activities of the compounds were determined by using the tail-flick and tail-immersion methods; some of the compounds showed potent analgesic activity.     

Formation of human immunoreactive LMW and HMW-kininogens during coagulation. Comparison with bradykinin activity

Variations of the levels of human HMW and LMW kininogens have been studied in serum and in plasma incubated in vitro during 30 hours, at three different temperatures: 4 degrees, 22 degrees and 37 degrees C. There is a small difference between the level of LMW kininogen in plasma and in serum, but the serum and plasma level of LMW kininogen are almost stable during the time of incubation at the three temperatures. However, HMW kininogen is reduced in serum to about fifty percent of its plasma level. It decreases in plasma and in serum during incubation, overall at 4 degrees C. A strict parallelism stays between the radioimmunoassay and the bioassay.     

Nutritional relationships between hemi-parasitic mistletoe and some of its deciduous hosts in different habitats

Parasitism of plants by other plants provides an exceptional opportunity for investigating correlative nutritional relationships. Because of lacking a usual plant-root sytem capable of active uptake, the best correlation for predicting the concentrations of elements in parasitic plants is often those in the host plants. This study, therefore, mainly focuses on determination of i) mineral nutrient partitioning between hemi-parasitic white berry mistletoe (Viscum album L. subsp. album) and four of its deciduous hosts growing in different habitats namely wetland and semi-arid and ii) effects of these habitat types on nutrient absorption. During the research, leaf samples of both hemi-parasites and their host plants were chemically analysed, mistletoes on each host plants were counted and the results were considered statistically. Concentrations of some elements (N, P, K, Na, S, Cu, Zn) were higher in mistletoe whereas some others (Ca, Mg, Fe, Mn and B) were higher in the hosts (p< 0.05). Habitat type was also determined to be effective in host-parasite systems. Revealing information about nutritional interactions between multi-host hemi-parasites and their host plants is a useful tool to understand their functions in ecosystems, population-community dynamics and their co-evolution process.     

Cytotoxic and apoptotic effects of boron compounds on leukemia cell line

In this study we investigated the effects of boric acid and sodium tetraborate on an acute leukemia cell line and healthy human lymphocytes. We evaluated the effects of boric acid and sodium tetraborate on the HL-60 cell line and healthy human lymphocytes by using the methods of MTT, Neutral Red, AO (flow cytometry) and transmission electron microscope. We found that there were dead cells at a concentration of 500 µM boric acid and sodium tetraborate (50 % and 40 %, respectively). An apoptotic effect was found at a concentration of 1,000 µM concentration in normal lymphocytes and HL-60 (acute leukemia cells) cells (2.5 % and 8.8 % respectively). We observed that boric acid at a concentration of 500 µM caused double nucleus and micronucleus formation in both HL-60 cells and lymphocytes. An expansion in mitochondrial dimension and deformation in cristas also appeared. Our findings suggest that boric acid is more effective than sodium tetraborate on the HL-60, and boric acid in particular showed a cytotoxic effect on HL-60 in comparison to healthy lymphocytes and it also affected the mitochondrial pathway.