Familial amyotrophic lateral sclerosis-associated mutations decrease the thermal stability of distinctly metallated species of human copper/zinc superoxide dismutase

We report the thermal stability of wild type (WT) and 14 different variants of human copper/zinc superoxide dismutase (SOD1) associated with familial amyotrophic lateral sclerosis (FALS). Multiple endothermic unfolding transitions were observed by differential scanning calorimetry for partially metallated SOD1 enzymes isolated from a baculovirus system. We correlated the metal ion contents of SOD1 variants with the occurrence of distinct melting transitions. Altered thermal stability upon reduction of copper with dithionite identified transitions resulting from the unfolding of copper-containing SOD1 species. We demonstrated that copper or zinc binding to a subset of "WT-like" FALS mutants (A4V, L38V, G41S, G72S, D76Y, D90A, G93A, and E133Delta) conferred a similar degree of incremental stabilization as did metal ion binding to WT SOD1. However, these mutants were all destabilized by approximately 1-6 degrees C compared with the corresponding WT SOD1 species. Most of the "metal binding region" FALS mutants (H46R, G85R, D124V, D125H, and S134N) exhibited transitions that probably resulted from unfolding of metal-free species at approximately 4-12 degrees C below the observed melting of the least stable WT species. We conclude that decreased conformational stability shared by all of these mutant SOD1s may contribute to SOD1 toxicity in FALS.     

In vitro propagation of Lagerstromia parviflora Roxb. from adult tree

A micropropagation protocol based on axillary bud proliferation has been developed from mature Lagerstromia parviflora adult tree. Nodal segments cultured on woody plant medium supplemented with 5.0 microl. BAP and 0.25 microm IAA gave maximum (86.9%) morphogenetic response. Proliferated shoots (10.7 per explants) were elongated to 3.9 cm within 6 weeks. In vitro produced micro-shoots were subjected to an IBA treatment (500 ppm for 2 min. dip) and placed under misting conditions for rooting. Misting beds were prepared with sand: soil (3:1) for 80.6% rooting and was acclimatized. Shoot length seems to be important to induce adventitious roots. The highest (91.7%) rooting was recorded on shoots ranging a length between 3.1-4.0 cm. Rooted and hardened plants were later transferred to poly bags and maintained in shadenet house. The protocol has the realizes capacity to produce 260 plants from a single explants within 10 months multiplication cycle.     

The OxyS regulatory RNA represses rpoS translation and binds the Hfq (HF-I) protein.

The OxyS regulatory RNA integrates the adaptive response to hydrogen peroxide with other cellular stress responses and protects against DNA damage. Among the OxyS targets is the rpoS-encoded sigma(s) subunit of RNA polymerase. Sigma(s) is a central regulator of genes induced by osmotic stress, starvation and entry into stationary phase. We examined the mechanism whereby OxyS represses rpoS expression and found that the OxyS RNA inhibits translation of the rpoS message. This repression is dependent on the hfq-encoded RNA-binding protein (also denoted host factor I, HF-I). Co-immunoprecipitation and gel mobility shift experiments revealed that the OxyS RNA binds Hfq, suggesting that OxyS represses rpoS translation by altering Hfq activity.     

Obtusilobinin and obtusilobin,two new triterpene saponins from Anemone obtusiloba

Obtusilobinin and obtusilobin, two new saponins, have been isolated from the ethanolic extract of Anemone obtusiloba (Ranunculaceae). The structural elucidation of obtusilobinin and obtusilobin have showed them to be olean-12-ene-28-oic-3-O-(α-l-arabinofuranosyl 1→2) (α-l-rhamnopyranosyl 1→4)-β-d-glucopyranoside and olean-12-ene-28-oic-3-O-α-l-rhamnopyranosyl 2→1-O-α-l-arabinofuranoside, respectively.     

The treatment of skin carcinoma, induced by UV B radiation, using 1-oxo-5beta, 6beta-epoxy-witha-2-enolide, isolated from the roots of Withania somnifera, in a rat model.

Histopathological studies of the cutaneous tissues of Wistar rats exposed to UV B radiation (294 nm) for 20 days and rats exposed to UV B radiation for 20 days, followed by topical treatment with benzoyl peroxide, a tumor promoter (20 mg/animal/0.2 ml acetone) twice a week for 1 month, and kept under observation for 12 weeks, demonstrate the development of malignancy. Pretreatment of the animals with 1-oxo-5beta, 6beta-epoxy-witha-2-enolide (20 mg/kg bwt.), isolated from the roots of Withania somnifera, prior to exposing the animals to UV B radiation, prevents the incidence of skin carcinoma. The administration of 1-oxo-5beta, 6beta-epoxy-witha-2-enolide, to the animals after exposing them to UV B radiation/UV B radiation and benzoyl peroxide also prevents the occurrence of malignancy in the cutaneous tissue. Immunohistochemical staining of the cutaneous tissues of rats exposed to UV B radiation show the presence of p53 + foci (clusters of cells containing the mutated p53 protein), whereas an absence of p53 + foci is observed in animals pretreated with 1-oxo-5beta, 6beta-epoxy-witha-2-enolide. These results prove that 1-oxo-5beta, 6beta-epoxy-witha-2-enolide has the potential for acting as an effective agent to prevent the incidence of skin carcinoma induced by UV B radiation.     

Sequence analysis of VP7 gene of Indian bluetongue virus serotype-23 shows its close phylogenetic relationship to Australian and Chinese serotypes.

Bluetongue, an arthropod borne viral disease of wild and domestic ruminants, causes heavy economic losses throughout the world. In the present study, full-length VP7 gene of Indian bluetongue virus (BTV) serotype 23 was sequenced and compared with prototype strains of BTV reported from different countries. Nucleotide sequence analysis of VP7 gene revealed Indian BTV serotype 23 to have 1154 nucleotides with the deletion of two nucleotides at 3' non-coding region and a unique amino acid change 211S-N. The Indian virus also demonstrated a maximum similarity of 94.2% with Australian serotype 1 and a minimum similarity of 67.4% with Australian serotype 15. However, at deduced amino acid level, it had maximum similarity of 99.7% and a minimum of 82.5% with Chinese serotypes 1, 2 and 4 and Australian serotype 15, respectively. Deduced amino acid sequence analysis of putative receptor binding domain (121-249) revealed all the nine hydrophilic domains to be conserved across the serotypes. Functional motifs present in VP7 protein were also conserved in almost all the BTV serotypes including Indian serotype 23. Phylogenetic analysis based on VP7 gene sequence revealed Indian BTV serotype 23 segregating into a monophyletic group along with Australian serotype 1 and Chinese serotypes 1, 2 and 4, indicating its close evolutionary relationship with these Australian and Chinese serotypes.     

A zinc (II) complex comprising an aminoethyl-nitropyridine-derived N,N,O-donor Schiff base ligand serves as an efficient ON–OFF probe for Cu(II)

A new fluorescent zinc (II) complex-based probe 1 encompassing a Schiff's base (E)-2-methoxy-6-((2-[5-nitropyridin-2-ylamino]ethylimino)methyl)phenol ( HL ) was designed, synthesized, and used for the highly selective detection of Cu²⁺. Ligand HL and complex 1 were characterized using various spectroscopic techniques such as ¹H, ¹³C-NMR, and FTIR spectroscopy, high-resolution mass spectronomy (HRMS), UV/visible light spectroscopy, and fluorescence studies. Ligand HL did not exhibit any considerable change in fluorescence in the presence of various cations. Notably, its Zn(II) complex 1 exhibited highly selective ‘TURN-OFF’ fluorescence signalling towards Cu²⁺ that remained uninterrupted with competing analytes. Probe 1 interacted with Cu²⁺ in 1:2 (1:Cu²⁺) stoichiometry as estimated through a Job's plot. Moreover, the selectivity of 1 was further confirmed through the interaction of the 1 + Cu²⁺ complex with some possible interfering metal ions inducing an insignificant response. Additionally, the association and quenching constant were determined to be 3.30 × 10⁴ M⁻¹ and 0.21 × 10⁵ M⁻¹ through the Benesi–Hildebrand method and Stern–Volmer plot, respectively.