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991.
Nucleotide sequence of the leader RNA of the New Jersey serotype of vesicular stomatitis virus. 总被引:8,自引:0,他引:8 下载免费PDF全文
Sequence for the leader RNA Synthesized by the New Jersey serotype of vesicular stomatitis virus is presented and its complementary sequence representing the 3'-terminal sequence of the genome RNA is deduced. Comparison with the leader RNA sequence of the serologically distinct Indiana strain reveals that the 3'-terminal region of the genomes of two viruses is highly conserved. 相似文献
992.
In addition to an RNA-dependent RNA polymerase, purified vesicular stomatitis virus contains a methyltransferase activity which transfers the methyl group from the methyl donor, S-adenosyl-L-methionine, to two positions in the 5'-terminal capped structure of the nascent mRNA's synthesized in vitro as 7mG-(5)'ppp(5')Apm... In the present study it is shown that two distinct methyltransferase activities are discernible in the purified virus. The in vitro concentrations of the methyl donor specify the number and location of the methyl groups transferred to the capped 5'-termini of VSV mRNA's. Limited concentrations of the methyl donor result in a single methylation of the penultimate base in the 2'-hydroxyl position, that is, G(5')ppp(5')Apm..., whereas saturating concentrations of the methyl donor methylate the blocking guanosine residue at the 7-position, resulting in the dimethylated cap, 7mG(5')ppp(5')Apm... Pulse-chase experiments demonstrate that the monomethylated cap structure is the precursor substrate for the dimethylated cap. In this respect, vesicular stomatitis virus system is quite distinct from the vaccinia and reovirus systems. Virus purified from different host cells including hamster, mouse, and human contain both methyltransferase activities. The mRNA's containing monomethylated capped structures are poor templates for protein synthesis in vitro. 相似文献
993.
The temporal dimensions of anticonvulsant action of some newer benzodiazepines against metrazol induced seizures in mice and rats 总被引:2,自引:0,他引:2
In a time-distribution study, the anticonvulsant effects of four benzodiazepine compounds were compared with those of three standard antiepileptics against metrazol-induced seizures in mice and rats. Ethosuximide and trimethadione had the shortest duration of action in mice, but protected the rats up to 6 hr. Phenobarbitone, diazepam, flurazepam and nitrazepam protected the mice up to 12 hr, but the rats were effectively protected only up to 3-4 hr. Clonazepam, the most potent and effective agent, protected the mice from clonic-tonic seizures up to 18-20 hr and the rats up to 6-7 hr. Comparison of the PD50 from clonic seizure at the peak-effect hours revealed that the benzodiazepines were 16 to 96 times more potent than phenobarbitone on a molar basis, while phenobarbitone itself was 12 to 26 times more potent than ethosuximide and trimethadione. Tonic seizures and mortality were largely suppressed by all drugs until 18-20 hr in mice and 6-7 hr in rats. Seizure latency and mortality patterns varied from drug to drug but not in a dose-dependent manner. 相似文献
994.
Effects of undecanoic acid (UDA) on germination of microconidia and elongation of germ tubes in UDA sensitive (uda
s) wild type Trichophyton rubrum and UDA resistant (uda
r) mutant derived from it, were studied. UDA inhibited conidial germination of uda
s and uda
r strains at 30 g/ml and 120 g/ml respectively which were minimum inhibitory concentrations of UDA for these two strains. When spores from both uda
s and uda
r were germinated in presence of subinhibitory concentration of UDA, germ tube growth was short. The elongation of germ tubes of spores pregerminated in absence of UDA was also inhibited by dose of UDA not sufficient to inhibit germination. 相似文献
995.
Thyroid hormones may participate in the regulation of beta-adrenergic receptors in skeletal muscle sarcolemmal membrane. Since skeletal muscles are not innervated by sympathetic nerve endings, the biochemical mechanism involved in the control of beta-adrenergic receptors by thyroid hormones appears to be mediated by thyroid-induced regulation of serum levels of catecholamines. 相似文献
996.
The M-line protein component of molecular weight 165 000 was isolated and purified from rabbit skeletal muscle using ion exchange chromatography. Gel electrophoresis, in the presence and absence of sodium dodecyl sulfate, revealed the protein to be homogeneous. Sodium dodecyl sulfate gel electrophoresis and low speed sedimentation equilibrium studies in 0.5 M KCl, 50 mM potassium phosphate gave a molecular weight of 165 000 suggesting the protein to be made up of a single polypeptide chain. Circular dichroism spectra revealed the presence of two negative dichroic bands located at 216 and 208 nm, indicative of the presence of some beta-structure. Ellipticity values at these two wavelengths were --6500 +/- 400 and --7500 +/- 400 deg . cm2 . dmol-1, respectively. Addition of 165 000 component lowered the enzymatic activity of creatine kinase M-line protein and the nature of the inhibition was found to be a competitive one. When the protein was mixed with creatine kinase in a 1 : 1 mole ratio in a medium consisting of 0.2 M KCl, 25 mM Tris, 1 mM dithiothreitol (pH 8.0), low speed sedimentation equilibrium studies gave a molecular weight of 260 000 +/- 10 000 for the complex, indicative of an interaction of the two components of the M-line. 相似文献
997.
A fast method for preparing Ca2+-ATPase from rabbit muscle sarcoplasmic reticulum was devised. The method involves extracting extrinsic membrane proteins with the non-ionic detergent octylglucoside at high salt concentration. A Ca2+-ATPase of consistently high specific activity (about 25 mumoles/mg.min) is found in the insoluble residue. The method was optimized with respect to the concentrations of detergent and salt, pH, and other extraction conditions. By the criteria of the protein pattern in SDS-polyacrylamide gel electrophoresis, dependence of the hydrolytic activity on the presence of Ca2+, and the phosphoprotein formation, the preparation is identical with the Ca2+-ATPase isolated previously by MacLennan [10] and other authors. The main advantages of the new method are its rapidity, its reliability, and the high specific activity of the purified enzyme. 相似文献
998.
999.
A strain ofBacillus cereus var.mycoides isolated from Burdwan soil producesl-glutamate in the medium. The strain is able to grow and produce in a synthetic medium but supplementation with casamino acid
or yeast extract improves the yield. Maintenance of pH of the fermentation medium near neutrality prolongs the active growth
period and improves the yield. Glucose and ammonium nitrate were found to be most suitable carbon and nitrogen sources, respectively.
Cane sugar molasses (as a substitute for glucose) significantly stimulated the growth but glutamate production was less. Various
B vitamins stimulate the growth and glutamate yield. The yield of glutamate under optimal condition is 5.2 g/l. 相似文献
1000.
Four tertiary trisomic plants are reported here, two of them (Nos. Tr11 and Tr13) from selfed progeny of a triploid Pearl millet and the other two (Nos. 3/12 and 16/7) from the progenies of radiation induced interchange heterozygotes. The extra chromosome in Tr13 and 3/12 was the nucleolus organizing chromosome. In No. 16/7 an extra chromosome enters into an association chromosomes were also involved. Meiotic behaviour in these four trisomics indicates that Tr11 and 3/12 are tertiary trisomics. It is suggested that two reciprocal translocations have occurred between two sets of chromosomes in the triploid parent and that syngamy has taken place in such a way that four interchange chromosomes and one non-interchange nucleolus organizing chromosome have come together in the offspring. The extra chromosome in No. 16/7 is an interchange chromosome which is homologous to one of the chromosomes of an interchange complex of six chromosomes. 相似文献