Antidiabetic properties of Hibiscus rosa sinensis L. leaf extract fractions on nonobese diabetic (NOD) mouse

On fractionation the ethanolic extract of H. rosa sinensis leaves, 5 fractions were obtained. Of these, fraction-3 (F3) and fraction-5 (F5) were chosen for detailed investigation on non obese diabetic (NOD) mouse to study anti-diabetic properties because they were more active than others. Serum glucose, glycosylated hemoglobin, triglyceride, cholesterol, blood urea, insulin, LDL, VLDL, and HDL were estimated. Both fractions F3 and F5 on oral feeding (100 and 200 mg/kg body weight) demonstrated insulinotropic nature and protective effect in NOD mice. These fractions may contain potential oral hypoglycemic agent.     

Sterol biosynthesis by a cell free extract of Dioscorea floribunda

The biosynthesis of sterols from mevalonate by a cell free extract prepared from actively growing tuber portions and leader shoots with young leaves of Dioscorea floribunda has been demonstrated. The preparation was capable of synthesizing 86.4 μg and 34.0 1£g of sterols from leader shoots with young leaves and actively growing tuber portions respectively. The cofactor requirement for the above system was also studied.     

iPSC-derived myelinoids to study myelin biology of humans

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A bifunctional fusion between beta-glucuronidase and neomycin phosphotransferase: a broad-spectrum marker enzyme for plants.

We have used an in vivo selection approach to isolate a gene encoding a bifunctional fusion peptide between Escherichia coli beta-glucuronidase (GUS) and neomycin phosphotransferase II (NPT-II) from transposon Tn5 in the NH2-GUS::NPT-II-COOH configuration. The fused gene is predicted to encode a fusion peptide 885 amino acids long, and was shown in E. coli to synthesize a 97-kDa GUS+ NPT-II+ gene product. Gel-filtration chromatography suggested that, while the native GUS may be active as a dimer and NPT-II as a monomer, the elution profile of the fusion protein is consistent with that of a trimer. The fusion marker has been produced and defined in transgenic Nicotiana tabacum plants, where both the chimeric gene and the gene product were stable. The bifunctional gene enabled direct KmR selection at the callus stage and enzymatic or histochemical assessment of the steady-state production of GUS activity in regenerated plants. In addition to allowing structure-function determination for the GUS and NPT-II domains of the fusion peptide, the gus::npt-II gene simplifies vector constructs where both marker domains are desired.     

Stimulated release of arachidonate and prostaglandins is vectorial in MDCK epithelial cells.

The receptor mediated activation of phospholipase A2 by appropriate ligands results in the synthesis and release of eicosanoids, a class of potent bioregulatory molecules. Madin-Darby canine kidney cells (MDCK) are polarized epithelial cells, with structurally and functionally distinct plasma membrane domains separated by tight junctions. Using MDCK cells grown in dual sided chambers, we show in this report, that a) the receptor mediated release of prostaglandins and arachidonate into the extracellular medium is predominantly unidirectional, b) the direction of release is agonist specific, and c) the magnitude of the response due to a given agonist is cell-domain specific. These characteristics, if operative in vivo, would contribute towards the optimal function of trans-cellular metabolism of eicosanoids already demonstrated.     

An Analysis of the Amino Acid Clustering Pattern in (α/β)8 Barrel Proteins

The (α/β)₈ barrel proteins, in spite of having a common fold, do not show any sequence similarity. In order to understand the factors which are responsible for maintaining the common fold, the three-dimensional structures of 36 (α/β)₈ barrel proteins are analyzed for the presence of identical amino acid clusters or physicochemically similar clusters. The results reveal 14 identical amino acid clusters and a large number of physicochemically similar clusters. Further analysis of the similar clusters points to the conservation of secondary structures, the presence of pairs of residues occupying topologically equivalent secondary structures, and the presence of certain key residues which may play a vital role in directing and stabilizing the (α/β)₈ barrel fold.