Primary structure of hemoglobin β-chain fromColumba livia (gray wild pigeon)

Primary structure of -chain of pigeon is presented. It was determined by amino acid sequence analysis of intact -chain and its peptides obtained by the enzymatic and chemical cleavage. Comparison of amino acid sequence of the chain with other available data shows 14 Ile, 61 Lys, and 113 Ile as residues specific to pigeon. One important replacement at ₁₁ contact is 55 MetSer.     

Increase in nitrate reductase activity in the presence of sucrose in bean leaf segments

The supply of sucrose to leaf segments from light-grown bean seedlings caused a substantial increase in substrate inducibility of in vivo and in vitro nitrate reductase activity but only a small increase in total protein. Cycloheximide and chloramphenicol inhibited the increase in enzyme activity by nitrate and sucrose. The in vivo decline in enzyme activity in nitrate-induced leaf segments in light and dark was protected by sucrose and nitrate. The supply of NADH also protected the decline in enzyme activity, but only in the light. In vitro stability of the extracted enzyme was, however, unaffected by sucrose. The size of the metabolic nitrate pool was also enhanced by sucrose. The experiments demonstrate that sucrose has a stimulatory effect on activity or in vivo stability ' of nitrate reductase in bean leaf segments, which is perhaps mediated through increased NADH level and/or mobilization of nitrate to the metabolic pool.     

Primary structure of hemoglobin β-chain fromColumba livia (gray wild pigeon)

Primary structure of β-chain of pigeon is presented. It was determined by amino acid sequence analysis of intact β-chain and its peptides obtained by the enzymatic and chemical cleavage. Comparison of amino acid sequence of the chain with other available data shows β 14 Ile, β61 Lys, and β113 Ile as residues specific to pigeon. One important replacement at α₁β₁ contact is β55 Met→Ser.     

Three-Dimensional Self-Gravito-Acoustic Solitary Waves in a Degenerate Quantum Plasma System

Plasma Physics Reports - Three-dimensional self-gravito-acoustic solitary waves (SGASWs) in a general (but realistic) self-gravitating degenerate quantum plasma media consisting of heavy...     

Morphological and molecular screening of rice germplasm lines for low soil P tolerance

Phosphorus (P) is an essential macronutrient to all crops including rice and it plays a key role in various plant activities and development. Low availability of P in the soils negatively, influences rice crop growth and causes significant yield loss. In the present study, we characterized a set of 56 germplasm lines for their tolerance to low soil P by screening them at low soil P and optimum soil P levels along with low soil P tolerant and sensitive check varieties. These lines were genotyped for the presence/absence of tolerant allele with respect to the major low soil P tolerance QTL, Pup1, using a set of locus specific PCR-based markers, viz., K46-1, K46-2, K52 and K46CG-1. High genetic variability was observed for various traits associated with low soil P tolerance. The yield parameters from normal and low soil P conditions were used to calculate stress tolerance indices and classify the genotypes according to their tolerance level. Out of the total germplasm lines screened, 15 lines were found to be tolerant to low soil P condition based on the yield reduction in comparison to the tolerant check, but most of them harbored the complete or partial Pup1 locus. Interestingly, two tolerant germplasm lines, IC216831 and IC216903 were observed to be completely devoid of Pup1 and hence they can be explored for new loci underlying low soil P tolerance.

     

STATISTICAL APPROACH FOR THE ENHANCED PRODUCTION OF COLD-ACTIVE β-GALACTOSIDASE FROM Thalassospira frigidphilosprofundus: A NOVEL MARINE PSYCHROPHILE FROM DEEP WATERS OF BAY OF BENGAL

In the present investigation Thalassospira frigidphilosprofundus, a novel species from the deep waters of the Bay of Bengal, was explored for the production of cold-active β-galactosidase by submerged fermentation using marine broth medium as the basal medium. Effects of various medium constituents, namely, carbon, nitrogen source, pH, and temperature, were investigated using a conventional one-factor-at-a-time method. It was found that lactose, yeast extract, and bactopeptones are the most influential components for β-galactosidase production. Under optimal conditions, the production of β-galactosidase was found to be 3,864 U/mL at 20 ± 2°C, pH 6.5 ± 0.2, after 48 hr of incubation. β-Galactosidase production was further optimized by the Taguchi orthogonal array design of experiments and the central composite rotatable design (CCRD) of response surface methodology. Under optimal experimental conditions the cold-active β-galactosidase enzyme production from Thalassospira frigidphilosprofundus was enhanced from 3,864 U/mL to 10,657 U/mL, which is almost three times higher than the cold-active β-galactosidase production from the well-reported psychrophile Pseudoalteromonas haloplanktis.     

Nature of KaiB-KaiC binding in the cyanobacterial circadian oscillator

In the cyanobacteria Synechococcus elongatus and Thermosynechococcus elongatus, the KaiA, KaiB and KaiC proteins in the presence of ATP generate a post-translational oscillator (PTO) that can be reconstituted in vitro. KaiC is the result of a gene duplication and resembles a double doughnut with N-terminal CI and C-terminal CII hexameric rings. Six ATPs are bound between subunits in both the CI and CII ring. CI harbors ATPase activity, and CII catalyzes phosphorylation and dephosphorylation at T432 and S431 with a ca. 24-h period. KaiA stimulates KaiC phosphorylation, and KaiB promotes KaiC subunit exchange and sequesters KaiA on the KaiB-KaiC interface in the final stage of the clock cycle. Studies of the PTO protein-protein interactions are convergent in terms of KaiA binding to CII but have led to two opposing models of the KaiB-KaiC interaction. Electron microscopy (EM) and small angle X-ray scattering (SAXS), together with native PAGE using full-length proteins and separate CI and CII rings, are consistent with binding of KaiB to CII. Conversely, NMR together with gel filtration chromatography and denatured PAGE using monomeric CI and CII domains support KaiB binding to CI. To resolve the existing controversy, we studied complexes between KaiB and gold-labeled, full-length KaiC with negative stain EM. The EM data clearly demonstrate that KaiB contacts the CII ring. Together with the outcomes of previous analyses, our work establishes that only CII participates in interactions with KaiA and KaiB as well as with the His kinase SasA involved in the clock output pathway.