Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.7.6 (RNA polymerase)
 34,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Chromatin fragments of the RNA polymerase II-transcriptional complex were purified from the micrococcal nuclease digest of rat liver nuclei in the presence of n-butyrate, a potent histone deacetylase inhibitor. Polyacrylamide gel electrophoretic analysis in Triton acid-urea revealed that the extent of histone acetylation of the complex did not differ markedly from that of the total chromatin.
 ...
PMID:Transcribing chromatin is not preferentially enriched with acetylated histones. 687 81

Influenza viruses, which had lost up to 99.999% infectivity by incubation with antibody (a) specific for the haemagglutinin (HA) or with monoclonal alpha-HA, attached on to and penetrated chick embryo fibroblast (CEF) cells to the same extent as non-neutralized virus. Neutralized virus was also uncoated efficiently as shown by the accumulation of virion RNA in the nucleus and virion envelope in the cytoplasm. Polyacrylamide gel electrophoresis of virion RNA segments recovered from the nucleus or cytoplasm of cells inoculated with neutralized or non-neutralized virus showed that antibody did not potentiate degradation of RNA. However, these RNAs were not expressed since virus-induced proteins were not detected in cells to which neutralized virus had been added. Assay of virion transcriptase of neutralized virus in vitro showed that its activity was reduced up to sevenfold compared with non-neutralized virus, and annealing studies showed that no detectable transcription took place in vivo with neutralized virus. These studies support the conclusion that antibody directed specifically against the HA protein on the outer surface of the influenza virus particle neutralizes infectivity by inactivating virion transcriptase activity and it is suggested that antibody to HA brings about allosteric rearrangements in the HA molecule which are transmitted across the virus envelope to the interior of the particle.
 ...
PMID:Studies on the mechanism of neutralization of influenza virus by antibody: evidence that neutralizing antibody (anti-haemagglutinin) inactivates influenza virus in vivo by inhibiting virion transcriptase activity. 706 92

The effect of 2-[1'-aminoethyl)-bicyclo[2.2.1]heptane chlorohydrate on the accumulation of hemagglutinating activity of chick embryo fibroblasts infected with influenza A/FPV/Rostock/34 (Hav1N1) and A/WSN/33 (H0N1) was studied. The drug inhibited hemagglutinines accumulation when added at various intervals after infection, the maximum effect having been observed upon its addition to the maintenance medium immediately after adsorption. Polyacrylamide gel electrophoresis showed the drug to reduce the synthesis of virus-specific proteins of A/FPV and to inhibit considerably the transcriptase activity of A/FPV and A/WSN viruses in vitro.
 ...
PMID:[Mechanism of action of 2-(1'-aminoethyl)-bicyclo[2.2.1]heptane hydrochloride]. 709 Mar 42

Using mild sonication, nucleoplasmic, nucleolar, and subnucleolar P-3 and S-3 chromatin fractions are isolated from rat liver nuclei. These fractions differ widely (over 80-fold) from each other in transcriptional activity as measured by the chromatin bound engaged RNA polymerases. Chemical analyses indicate that the active chromatin, e.g. P-3 and nucleolar fractions, are rich in RNA and protein as compared to the inactive chromatin, e.g. nucleoplasmic, and S-3 fractions. However, the DNA base content are all the same, showing 40% GC and 60% AT, including P-3 which is enriched in rDNA. Polyacrylamide gel electrophoresis of the 0.25 N HCl extracted proteins shows that all five histones are present in active chromatin. Additionally, the gel reveals two protein bands, one ahead of histone H2B and another ahead of histone H4, that are diminished or missing from the inactive chromatin. On the other hand, there is a fast moving protein band ahead of H4 in the inactive chromatin that is almost absent in the active chromatin. Transcriptional tests using E. coli RNA polymerase and several synthetic DNA templates of known base content and sequence indicate that the 0.25 N HCl soluble protein extracts from active chromatin contain activator proteins which are capable of countering the histone suppressors present in the extracts in a DNA base and sequence specific manner. The data show that although the histone suppressors are able to strongly inhibit the template function of poly[d(A-T)], the protein activators are able to overcome the suppressor activity and stimulate RNA synthesis several-fold when poly(dA).poly(dT) or poly(dT) is used.
 ...
PMID:Studies on the isolated transcriptionally active and inactive chromatin fractions from rat liver nuclei. 760 68

There are two types of infection caused by pathogenic microorganisms, intracellular infection and intercellular infection. Infection of pathogenic leptospira is an intercellular infection. The immunological reaction of host to intercellular infection is unique. The potential immunogen of an expressed protein should meet three criteria: it can be degraded (by antigen-present cells in the host); it should have antigenic epitope which can be recognized by specific antibodies and have at least one epitope that can be recognized by an MHC II protein and T cell receptor. In this study we report the cloning of an L. interrogans protein in plasmid rpDJt and the immunogencity of the expressed protein derivative. A genomic library of L. interrogans serovar lai strain 017 was constructed with the plasmid vector pUC18. Recombinant plasmids, designated pDJH2 and pDJ8 were screened from the bank. EcoRI-inserted fragment of 1. 9 kb recombinant DNA of pDJH2 was ligated into T7 RNA polymerase/promoter vectors (pT7-7). Then they were transformed into E. coli JM109 (De3), one of subclones, designated rpDJt was achieved. SDS-PAGE showed that the molecular weights of expression proteins were 68 kd and 23 kd respectively, designated p68 and p23. Purifying and isolating p68 and p23, we separated them from SDS-Polyacrylamide gels by using Side-Strip method. After fragmenting and electroeluting, p68 and p23 were injected into guinea pigs and rabbits. An extremely strong immune response to p68 was obtained since an anti-p68 antibody response could be detected to a dilution 1:524,288 (guinea pigs) and 1:262,144 (rabbits) by ELISA while anti-P23 antibody being 1:1024 (the same to guinea pigs and rabbits). The results of improved MTT and conA 3HTdR transformation methods showed the activities and proliferation of Th-cells were increased in guinea pigs after p68 immunization (IL-6, 83.25 IU/ml, IL-2, 28.75 IU/ml; RPI, 2.04, SI, 65.62%) Thlymphocyte existed in two subclasses, the Th1- and Th2-cells. A major role of Th2-cells is to "help" B-cells differentiate, replicate, and secrete antibody. The properties of these interactions explain why p68 makes good antigen and p23 does not. The antigens responsible for eliciting the production of protective antibodies are not known; however, several outer membrane proteins on L. interrogans are candidates for vaccine. Our results suggest that expresion protein p68 from recombinants (rpDJt) may be a candidate for gene engineered subunit vaccine for Leptospirosis.
 ...
PMID:[Immunogenecity of expressed protein p68 from recombinant plasmid rpDJt in L. interrogans serovar lai]. 1068 17

In this paper, we borrow the idea of the receiver operating characteristic (ROC) from clinical medicine and demonstrate its application to sequence comparison. The ROC includes elements of both sensitivity and specificity, and is a quantitative measure of the usefulness of a diagnostic. The ROC is used in this work to investigate the effects of scoring table and gap penalties on database searches. Studies on three families of proteins, 4Fe-4S ferredoxins, lysR bacterial regulatory proteins, and bacterial RNA polymerase sigma-factors lead to the following conclusions: sequence families are quite idiosyncratic, but the best PAM distance for database searches using the Smith-Waterman method is somewhat larger than predicted by theoretical methods, about 200 PAM. The length independent gap penalty (gap initiation penalty) is quite important, but shows a broad peak at values of about 20-24. The length dependent gap penalty (gap extension penalty) is almost irrelevant suggesting that successful database searches rely only to a limited degree on gapped alignments. Taken together, these observations lead to the conclusion that the optimal conditions for alignments and database searches are not, and should not be expected to be, the same.
 ...
PMID:Use of receiver operating characteristic (ROC) analysis to evaluate sequence matching. 1671 63


<< Previous 1 2 3