The soybean-Phytophthora resistance locus <Emphasis Type="Italic">Rps1</Emphasis>-k encompasses coiled coil-nucleotide binding-leucine rich repeat-like genes and repetitive sequences

Background  

A series of Rps (resistance to P ytophthora s ojae) genes have been protecting soybean from the root and stem rot disease caused by the Oomycete pathogen, Phytophthora sojae. Five Rps genes were mapped to the Rps1 locus located near the 28 cM map position on molecular linkage group N of the composite genetic soybean map. Among these five genes, Rps1-k was introgressed from the cultivar, Kingwa. Rps1-k has been providing stable and broad-spectrum Phytophthora resistance in the major soybean-producing regions of the United States. Rps1-k has been mapped and isolated. More than one functional Rps1-k gene was identified from the Rps1-k locus. The clustering feature at the Rps1-k locus might have facilitated the expansion of Rps1-k gene numbers and the generation of new recognition specificities. The Rps1-k region was sequenced to understand the possible evolutionary steps that shaped the generation of Phytophthora resistance genes in soybean.     

In vitro studies demonstrate anticancer activity of an alkaloid of the plant Gelsemium sempervirens

The chemical structure of the main fluorescenting compound in the ethanolic extract (mother tincture) of the American yellow jasmine, Gelsemium sempervirens, was determined by employing (1)H nuclear magnetic resonance (NMR), (13)C NMR, mass spectroscopy, high-performance liquid chromatography (HPLC), correlation spectroscopy (COSY), and Fourier transform infrared (FTIR) spectroscopy analyses. Spectrofluorometric analysis has been made of the mother tincture and its agitated serial dilutions (up to 12th potency) prepared according to a homeopathic procedure in which serial, agitated dilutions were made separately in glass and polypropylene containers. The succussions were made by employing three different modes: hand jerk, sonication, and vortexing. The chemical formula of scopoletin, the main fluorescent compound, was determined to be C(10)H(8)O(4) having a molecular weight of 192.17. Significant differences were noted between the remedies prepared in the two types of containers. Further, a comparison between any two methods of agitation revealed significant differences in fluorometric data of remedies at certain potency levels. The biological (anticancer) action of the crude extract, the alkaloid scopoletin, and 2C potency of Gelsemium sp were tested in vitro on the HeLa cell line through fluorescence microscopy, the 3(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay, and fluorescent activated cell sorting (FACS). The role of nanoparticles presumably derived from the containers, their orientation, and their interaction with the starting substance during the dynamization process initiated by different modes of agitation could possibly be attributed to the differences noted in the fluorometric data of potencies prepared in the two types of containers and among the three different means of succussion tested.     

Huntington's disease: roles of huntingtin-interacting protein 1 (HIP-1) and its molecular partner HIPPI in the regulation of apoptosis and transcription

Huntingtin protein (Htt), whose mutation causes Huntington's disease (HD), interacts with large numbers of proteins that participate in diverse cellular pathways. This observation indicates that wild-type Htt is involved in various cellular processes and that the mutated Htt alters these processes in HD. The roles of these interacting proteins in HD pathogenesis remain largely unknown. In the present review, we present evidence that Htt-interacting protein 1 (HIP-1), an endocytic protein, together with its interacting partner HIPPI, regulates apoptosis and gene expression, both processes being implicated in HD. Further studies are necessary to establish whether the HIPPI-HIP-1 complex or other interacting partners of HIPPI regulate apoptosis and gene expression that are relevant to HD.     

Conformational properties of alpha-tubulin tail peptide: implications for tail-body interaction.

The carboxy-terminal segments of the alpha/beta-tubulins are flexible regions rich in acidic amino acid residues. It is generally believed that these regions play crucial roles in tubulin polymerization and interaction with many ligands, including colchicine. Exactly how these effects are exerted are not known at present. One such interesting aspect is the pH dependence of colchicine-tubulin interaction and the influence of the alpha-tail on the binding interaction. We have investigated the location of the colchicine-binding site on tubulin by docking. It has been located on the alpha/beta interface on the N-terminal side, which is also supported by much of the solution data. This location is too far from the tail regions, suggesting that influence of the tail region is transmitted by a pH-dependent conformational change. Two-dimensional NMR studies indicate that at pH 7 a 13-residue peptide corresponding to alpha-tubulin tail shows little NOE constraints, suggesting extended conformation. On the contrary, at pH 5, a relatively compact structure was deduced from the interproton NOE constraints. Pulsed field gradient measurement of diffusion constant indicates that the peptide at pH 5 is substantially faster diffusing than at pH 7. The Perrin factors calculated from diffusion data indicates that the peptide structure at pH is significantly more compact than at pH 7. Temperature coefficients of several amide protons at pH 5 fall below 5 ppb/(o)K, indicating a degree of protection. A difference is also seen in the CD spectra obtained at different pHs, consistent with the NMR data. We have investigated the probable spatial organization of the tail of the alpha-subunit of tubulin, in the high pH extended form and the low pH compact form. On the basis of correlation of pH dependence of many properties of tubulin and the conformation of the alpha-tail peptide, we propose that the intrinsic conformational preference of the tail-region modulate the tail-body interaction, which in turn has important bearing on colchicine binding properties.     

Regeneration of activated charcoal used in decolorization and purification of crude protease from Rhizopus oryzae

Activated charcoal, used for decolorization and purification of crude protease, was regenerated by treatment six times with acetone/water (40:60 v/v), followed by drying. This multistage leaching followed the leaching equation adapted to multistage leaching. The regenerated charcoal was nearly as effective as fresh charcoal in decolorization and purification of crude protease, but only after drying. List of symbols: c ^*, equilibrium solute concentration (w/v) in liquid; c _s, solute concentration in solid phase (w/w); F, interfacial area between solid and liquid phases; k, rate constant for leaching equation; v, volume of liquid per unit weight of adsorbent (solid phase).     

Antifolate drug resistance: Novel mutations and haplotype distribution in <Emphasis Type="Italic">dhps</Emphasis> and <Emphasis Type="Italic">dhfr</Emphasis> from Northeast India

Malaria is a major public health concern in Northeast India with a preponderance of drug-resistant strains. Until recently the partner drug for artemisinin combination therapy (ACT) was sulphadoxine pyrimethamine (SP). Antifolate drug resistance has been associated with the mutations at dihydropteroate synthase (dhps) and dihydrofolatereductase (dhfr) genes. This study investigated antifolate drug resistance at the molecular level. A total of 249 fever cases from Arunachal Pradesh, NE India, were screened for malaria, and of these, 75 were found to be positive for Plasmodium falciparum. Samples were sequenced and analysed with the help of BioEdit and ClustalW. Three novel point mutations were found in the dhps gene with 10 haplotypes along with the already reported mutations. A single haplotype having quadruple mutation was found in the dhfr gene. The study reports higher degree of antifolate drug resistance as evidenced by the presence of multiple point mutations in dhps and dhfr genes. The findings of this study strongly discourage the use SP as a partner drug in ACT.     

An insight to the binding of ellagic acid with human serum albumin using spectroscopic and isothermal calorimetry studies

Ellagic acid (EA), a natural polyphenol evidence several pharmacological benefits. The binding profile of EA with human serum albumin (HSA) has been explored and investigated by Isothermal titration calorimetry (ITC), circular dichroism (CD) spectroscopy, time-correlated single-photon counting (TCSPC), absorbance spectroscopy, steady-state fluorescence spectroscopy, and modelling studies. The ITC data analysis revealed the binding Constant (K_a), ΔH, ΔS and ΔG values to be 15.5×10⁴M^?1, ?116.2±18.1 Kcal mol^?1, ?366 cal mol^?1K^?1 and ?7.13 Kcal mol^?1 respectively with a unique binding site at HSA. EA effectively quenched the intrinsic fluorescence of HSA by static quenching, whereas TCSPC data also revealed association of dynamic quenching also. Thermodynamic analysis confirmed that hydrophobic and mainly hydrogen bonding interaction played important role in stabilizing the HSA-EA complex. It further dictates the binding reaction to be enthalpy driven. The secondary structure of HSA was altered upon binding with EA. CD spectroscopic data indicated the fraction of alpha helicity to be decreased from 52% to 40% upon binding to EA. This study will provide an insight on evaluation of this bioactive interaction during transport and releasing efficiency at the target site in human physiological system since HSA is the most important carrier protein in blood serum.