Monoclonal antibodies to Escherichia coli ribosomal proteins L9 and L10. Effects on ribosome function and localization of L9 on the surface of the 50 S ribosomal subunit

Monoclonal antibodies against Escherichia coli ribosomal proteins L9 and L10 were obtained and their specificity confirmed by Western blot analysis of total ribosomal protein. This was particularly important for the L9 antibody, since the immunizing antigen mixture contained predominantly L11. Each antibody recognized both 70 S ribosomes and 50 S subunits. Affinity-purified antibodies were tested for their effect on in vitro assays of ribosome function. Anti-L10 and anti-L9 inhibited poly(U)-directed polyphenylalanine synthesis almost completely. The antibodies had no effect on subunit association or dissociation and neither antibody inhibited peptidyltransferase activity. Both antibodies inhibited the binding of the ternary complex that consisted of aminoacyl-tRNA, guanylyl beta, gamma-methylenediphosphonate, and elongation factor Tu, and the binding of elongation factor G to the ribosome. The intact antibodies were more potent inhibitors than the Fab fragments. In contrast to the previously established location of L10 at the base of the L7/L12 stalk near the factor-binding site, the site of anti-L9 binding to 50 S subunits was shown by immune electron microscopy to be on the L1 lateral protuberance opposite the L7/L12 stalk as viewed in the quasisymmetric projection. The inhibition of factor binding by both antibodies, although consistent with established properties of L10 in the ribosome, suggests a long range effect on subunit structure that is triggered by the binding of anti-L9.     

A comparative study on the distribution of non-specific esterase amongst the various constituents of retinas of some vertebrates

A wide coverage of the retinae of a large number of animals (Calotes, Varanus, Naja, Athene, Passer, Streptopelia, Psittacula and Funambulus) from the point of view of the histoenzymological distribution of non-specific esterase amongst the various constituents reveals mostly identical patterns. They are as follows: 1. Outer segments - positive in all cases. 2. Outer plexiform layer - equipped with enzymatic activity in all the instances. 3. Inner nuclear layer - thin cytoplasmic rim of the neurons characterized by positive activity; the nuclei of the neurons are completely negative. 4. Inner plexiform layer - this layer is endowed with the enzymatic activity. 5. Ganglion cells - negative in all cases. 6. Nerve fibres of the layer of nerve fibres, situated adjasent to ganglion cells are positive in all the animals; in case of squirrel oligodandroglial cells present in the region have demonstrated activity of a high order. On of the high-lights of the present contribution is demarcation of the inner plexiform layer into three stratified zones, equipped with enzymatic activity in Calotes, Streptopelia, Naja and Funambulus. Such stratifications are not seen in Varanus, Passer and Psittacula. The significance of the various patterns and the equipment of the enzyme in various constituents at various locals have been discussed in relation to the metabolic functions, zone-wise and interzone-wise in visual processes of various animals.     

In vitro iodination of plant ribonucleic acids

The optimum conditions for in vitro iodination of RNAs have been established which yield specific radioactivities ranging from 10 × 10⁴ to 10 × 10⁶ cpm/μg. A nomogram has been constructed by correlating specific radioactivities of RNA with concentration of KI, RNA, and ¹²⁵I. This nomogram can be used to determine the conditions for the desired specific radioactivities for any unknown RNA. The in vitro iodinated RNA has been compared with in vivo labeled RNA for hybridization characteristics. Competition hybridization between ¹²⁵I-labeled chloroplast-rRNA and unlabeled pea (Pisum sativum) chloroplast-rRNA was identical to that found using [³²P]chloroplast-rRNA. Thermal stability of DNA-¹²⁵I-rRNA hybrids was similar to the thermal stability of DNA-[³²P]rRNA hybrids. The iodinated RNA was not found to have undergone any changes in its hydrogen-bonding properties.     

Biochemical changes in the germinating seeds ofTrigonella foenum graecum L. in relation tos-triazine herbicides

Thes-triazine herbicides studied (atrazine and simazine) inhibited the growth of the seedlings ofTrigonella foenum graecum L.(Viciaceae). These herbicides caused a decrease in the contents of total water soluble carbohydrates and reducing sugars. Pentose sugars increased in the cotyledons. The total protein and free amino acid contents were enhanced. The activity of peroxidase was inhibited in the cotyledons, but was enhanced in the seedling axes.     

Functional characterization of types of plasma membranes in cerebral cortex.

The cerebral cortex of normal oxygenated and of asphyxiated mice has been studied by freeze-fracturing technique with a twofold purpose. First, to investigate changes, if any, in the molecular organization of the plasma membrane of any specific cell type(s) that could be correlated with permeability changes thought to take place as a consequence of asphyxiation. Secondly, to attempt characterization of plasma membranes on the basis of the organization of their fractured faces. The decrease in the extracellular material in asphyxiated cerebral cortex seen in electron micrographs of thin sections could not be correlated with change(s), if any, in the molecular organization of the plasma membrane of any particular cell type. Plasma membranes of various types could be characterized on the basis of the arrangement of particles on the fractured faces. Some of these types correspond to identifiable cell processes, while others have not yet been identified with certainty. Fusion of synaptic vesicles with the presynaptic membrane is mediated through clustering of 100-150 A membrane-associated particles.     

Docking Simulation and Anti-Inflammatory Profile of Some Synthesized Heterodimer of Pyrazole

Russian Journal of Bioorganic Chemistry - In the present studies, novel pyrazole derivatives have been synthesized linked through various linkers for the anti-inflammatory evaluation. The...     

Multiple myeloma and occupation: A pooled analysis by the International Multiple Myeloma Consortium

Objective: We investigated occupational risk of multiple myeloma (MM) in a pooled analysis of five international case–control studies. Methods: We calculated the odds ratio and its 95% confidence interval for selected occupations with unconditional regression analysis in 1959 MM cases and 6192 controls, by pooling study-specific risks using random-effects meta-analysis. Exposure to organic solvents was assessed with a job-exposure matrix (JEM). Results: Gardeners and nursery workers combined, most likely exposed to pesticides, showed a 50% increase in risk (OR = 1.50, 95% CI 0.9–2.3), while other farming jobs did not. Metal processors (OR = 1.55, 95% CI 0.9–2.3), female cleaners (OR = 1.32, 95% CI 1.0–1.8), and high level exposure to organic solvents (OR = 1.38, 95% CI 0.96–1.8) also showed moderately increased risks. Conclusions: Additional case–control studies of MM aetiology are warranted to further investigate the nature of the repeatedly reported increase in MM risk in several occupational groups.     

Enhancing the Yield of Active Recombinant Chitobiase by Physico-Chemical and In Vitro Refolding Studies

Chitobiase (CHB) is an important enzyme for the production of N-acetyl-d-glucosamine from the chitin biopolymer in the series of chitinolytic enzymes. Majority of over-expressed CHB (58 %) in E. coli expression system led to formation of inclusion bodies. The production and soluble yield of active CHB was enhanced by co-expression with GroEL/ES chaperonin, optimizing culture conditions and solubilization followed by refolding of remaining inactive chitobiase present in the form of inclusion bodies. The growth of recombinant E. coli produced 42 % CHB in soluble form and the rest (~58 %) as inclusion bodies. The percentage of active CHB was enhanced to 71 % by co-expression with GroEL/ES chaperonin system and optimizing culture conditions (37 °C, 200 rpm, IPTG—0.5 mM, l-arabinose—13.2 mM). Of the remaining inactive CHB present in inclusion bodies, 37 % could be recovered in active form using pulsatile dilution method involving denaturants (2 M urea, pH 12.5) and protein refolding studies (1.0 M l-arginine, 5 % glycerol). Using combinatorial approach, 80 % of the total CHB expressed, could be recovered from cells grown in one litre of LB medium is a step forward in replacing hazardous chemical technology by biotechnological process for the production of NAG from chitinous waste.