scholarly journals Isolation, characterization and possible mode of action of antiseminalplasmin, a new protein that inhibits the antimicrobial activity of seminalplasmin

1985 ◽  
Vol 227 (2) ◽  
pp. 609-619 ◽  
Author(s):  
V N Rao ◽  
P M Bhargava

The isolation from bovine seminal plasma and purification of a new protein called ‘antiseminalplasmin’, which reverses the inhibition of the growth of, and RNA synthesis in, Escherichia coli by seminalplasmin (another protein of bovine seminal plasma), is described. Antiseminalplasmin, a weakly acidic protein, has a minimum Mr of about 39 000 and appears to consist of three acidic peptide chains that move close to each other on electrophoresis on cellulose acetate strips or on sodium dodecyl sulphate/18%-(w/v)-polyacrylamide gels. Antiseminalplasmin has a tendency to oligomerize at slightly alkaline pH values; it does not bind to seminalplasmin or to DNA, and does not reverse the inhibition by seminalplasmin of transcription in vitro by purified E. coli RNA polymerase. It appears that antiseminalplasmin may act by binding to the cell surface and preventing the entry of seminalplasmin into the cells. By itself, antiseminalplasmin has no effect on the growth of E. coli.

1982 ◽  
Vol 152 (3) ◽  
pp. 1117-1125
Author(s):  
J M Leventhal ◽  
G H Chambliss

The major acid-soluble spore proteins (ASSPs) of Bacillus subtilis were detected by immunoprecipitation of radioactively labeled in vitro- and in vivo-synthesized proteins. ASSP synthesis in vivo began 2 h after the initiation of sporulation (t2) and reached its maximum rate at t7. This corresponded to the time of synthesis of mRNA that stimulated the maximum rate of ASSP synthesis in vitro. Under the set of conditions used in these experiments, protease synthesis began near t0, alkaline phosphatase synthesis began at about t2, and refractile spores were first observed between t7 and t8. In vivo- and in vitro-synthesized ASSPs comigrated in sodium dodecyl sulfate-polyacrylamide gels. Their molecular weights were 4,600 (alpha and beta) and 11,000 (gamma). The average half-life of the ASSP messages was 11 min when either rifampin (10 micrograms/ml) or actinomycin D (1 microgram/ml) was used to inhibit RNA synthesis.


2013 ◽  
Vol 24 (5) ◽  
pp. 474-476 ◽  
Author(s):  
Paulo Henrique Weckwerth ◽  
Ronald Ordinola Zapata ◽  
Rodrigo Ricci Vivan ◽  
Mário Tanomaru Filho ◽  
Amanda Garcia Alves Maliza ◽  
...  

Enterococcus faecalis is a bacterial species often found in root canals with failed endodontic treatment. Alkaline pastes are widely used in Endodontics because of their biocompatibility and antimicrobial activity, but this microorganism can resist alkalinity. The purpose of this study was to evaluate in vitro the alkaline pH resistance of E. faecalis for different periods up to 14 days. Samples were obtained from the oral cavity of 150 patients from the Endodontic clinic. The pH of the experimental tubes (n=84) was first adjusted with 6M NaOH to pH values of 9.5, 10.5, 11.5 and 12.5 (21 tubes per pH). Twenty clinical isolates and the ATCC 29212 strain were tested. The 5 positive controls and experimental tubes of each pH were inoculated with 10 µL of bacterial suspension and incubated at 36 °C for 24, 48 and 72 h, 7 and 14 days. For each period, the turbidity of the medium was visually compared with a 0.5 McFarland standard. The presence of the microorganism was confirmed by seeding on M-Enterococcus agar. Four tubes containing BHI broth adjusted to the tested pHs were incubated for 14 days to verify if pH changes occurred. The pH of inoculated BHI broth was also measured on day 14 to determine if the microorganism acidified the medium. The growth of all E. faecalis strains occurred at pH 9.5 to 11.5 in all periods. Although turbidity was not observed at pH 12.5, there was growth of 13 and 2 strains at 24 and 48 h, respectively, on M-Enterococcus agar. No tube showed growth at pH 12.5 after 72 h. It was concluded that E. faecalis can survive in highly alkaline pH, and some clinical isolates require 72 h at pH 12.5 to be killed.


1978 ◽  
Vol 174 (1) ◽  
pp. 95-102 ◽  
Author(s):  
E Di Mauro ◽  
F Pedone ◽  
M Pomponi

Non-histone chromosomal proteins prepared from chromosomal material of the sea-urchin Paracentrotus lividus affect RNA synthesis in vitro. 1. The extent of transcription can be radically changed from inhibition to stimulation, depending on the DNA/non-histone chromosomal proteins ratio. 2. A correlation exists between stage of development and influence on transcription. 3. Non-histone chromosomal proteins exert their action by intervening directly on some initiation step of RNA synthesis, as shown by the numbers of initiation events that take place in their presence or absence. 4. Stimulatory activity is observed only in restrictive conditions of ionic strength and temperature. These observations are in agreement with models that predict for non-histone chromosomal proteins a regulatory role on the transcription process exerted through a modulation of promoter availability.


Author(s):  
M Karunakaran ◽  
Vivek C Gajare ◽  
Ajoy Mandal ◽  
Mohan Mondal ◽  
S K Das ◽  
...  

This experiment was conducted to study the electrophoretic characters of heparin binding proteins (HBP) of Black Bengal buck semen and their correlation with sperm characters and cryo-survivability. Semen ejaculates (n=20/buck) were collected from nine bucks and in vitro sperm characters were evaluated at collection, after equilibration and after freeze - thawing. HBP were isolated through heparin column and discontinuous Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoresis (SDS-PAGE) was performed to assess molecular weight. Significant difference (plessthan0.01) were observed among the bucks in sperm characters and freezability. Eight protein bands of 17 to 180 kDa in seminal plasma and 7 bands in sperm were found. 180 -136 kDa HBP of seminal plasma and 134-101 kDa HBP of sperm had showed high correlation with in vitro sperm characters. Further studies on identification of these proteins and their correlation with in vivo pregnancy are needed to find their role as marker for buck selection.


1998 ◽  
Vol 330 (1) ◽  
pp. 55-59 ◽  
Author(s):  
Chien-Yun HSIANG ◽  
Tin-Yun HO ◽  
Chin-Hui HSIANG ◽  
Tien-Jye CHANG

The pseudorabies virus (PRV) DNase gene has previously been mapped within the PRV genome. To characterize further the enzymic properties of PRV DNase, this enzyme was expressed in Escherichia coli with the use of a pET expression vector. The protein was purified to homogeneity and assayed for nuclease activity in vitro. Recombinant PRV DNase exhibited an alkaline pH preference and an absolute requirement for Mg2+ ions that could not be replaced by Ca2+ and Na+ ions. Further studies showed that PRV DNase exhibited endonuclease, 5ʹ-exonuclease and 3ʹ-exonuclease activities in both single-stranded and double-stranded DNA. This activity occurred randomly and no significant base preference was demonstrated. The multiple biochemical activities of PRV DNase are similar to the activities of Neurospora crassa endo-exonuclease and E. coli RecBCD, two additional enzymes that are involved in recombination. Taken together, the similarity of action between N. crassa endo-exonuclease, E. coli RecBCD, and PRV DNase suggests that PRV DNase might have a role in the process of recombination that occurs during PRV infection.


1969 ◽  
Vol 115 (3) ◽  
pp. 353-361 ◽  
Author(s):  
John O. Bishop ◽  
Forbes W. Robertson

1. RNA was synthesized in vitro from a template of bacteriophage T4 DNA, in the presence of Mn2+. A comparison was made of the RNA synthesized by purified RNA polymerase from two sources, Micrococcus lysodeikticus and Escherichia coli; these are referred to as Micrococcus cRNA and E. coli cRNA respectively (where cRNA indicates RNA synthesized in vitro by using purified RNA polymerase and a DNA primer). 2. Both types of RNA were self-complementary as judged by resistance to digestion with ribonuclease after self-annealing, Micrococcus cRNA being more self-complementary (40%) than was E. coli cRNA (30%). The cRNA was found to be much less self-complementary if Mg2+ was present during RNA synthesis instead of Mn2+. 3. Micrococcus cRNA hybridized with a larger part of bacteriophage T4 DNA than did E. coli cRNA. The E. coli cRNA competed with only part (70%) of the Micrococcus cRNA in hybridization-competition experiments. It is concluded that more sequences of bacteriophage T4 DNA are transcribed by Micrococcus polymerase than by E. coli polymerase. 4. The RNA sequences synthesized by Micrococcus RNA polymerase but not by E. coli RNA polymerase are shown by hybridization competition to compete with specifically late bacteriophage T4 messenger RNA sequences. The relevance of this finding to the control of transcription is discussed. 5. In an Appendix, new methods are described for the analysis of hybridization-saturation and -competition experiments. Particular attention is paid to the effects produced if different RNA sequences are present at different relative concentrations. 6. By using cRNA isolated from an enzymically synthesized DNA–RNA hybrid, it is estimated that, of the DNA that is complementary to cRNA, only about half can become hybridized with cRNA under the experimental conditions used.


1998 ◽  
Vol 180 (9) ◽  
pp. 2359-2366 ◽  
Author(s):  
Ming Tan ◽  
Tamas Gaal ◽  
Richard L. Gourse ◽  
Joanne N. Engel

ABSTRACT We have characterized the Chlamydia trachomatisribosomal promoter, rRNA P1, by measuring the effect of substitutions and deletions on in vitro transcription with partially purifiedC. trachomatis RNA polymerase. Our analyses indicate that rRNA P1 contains potential −10 and −35 elements, analogous toEscherichia coli promoters recognized by E-ς70. We identified a novel AT-rich region immediately downstream of the −35 region. The effect of this region was specific for C. trachomatis RNA polymerase and strongly attenuated by single G or C substitutions. Upstream of the −35 region was an AT-rich sequence that enhanced transcription by C. trachomatis and E. coli RNA polymerases. We propose that this region functions as an UP element.


1978 ◽  
Vol 176 (1) ◽  
pp. 305-318 ◽  
Author(s):  
Julia Hughes ◽  
Graham Mellows

The mode of action of the antibiotic pseudomonic acid has been studied in Escherichia coli. Pseudomonic acid strongly inhibits protein and RNA synthesis in vivo. The antibiotic had no effect on highly purified DNA-dependent RNA polymerase and showed only a weak inhibitory effect on a poly(U)-directed polyphenylalanine-forming ribosomal preparation. Chloramphenicol reversed inhibition of RNA synthesis in vivo. Pseudomonic acid had little effect on RNA synthesis in a regulatory mutant, E. coli B AS19 RCrel, whereas protein synthesis was strongly inhibited. In pseudomonic acid-treated cells, increased concentrations of ppGpp, pppGpp and ATP were observed, but the GTP pool size decreased, suggesting that inhibition of RNA synthesis is a consequence of the stringent control mechanism imposed by pseudomonic acid-induced deprivation of an amino acid. Of the 20 common amino acids, only isoleucine reversed the inhibitory effect in vivo. The antibiotic was found to be a powerful inhibitor of isoleucyl-tRNA synthetase both in vivo and in vitro. Of seven other tRNA synthetases assayed, only a weak inhibitory effect on phenylalanyl-tRNA synthetase was observed; this presumably accounted for the weak effect on polyphenylalanine formation in a ribosomal preparation. Pseudomonic acid also significantly de-repressed threonine deaminase and transaminase B activity, but not dihydroxyacid dehydratase (isoleucine-biosynthetic enzymes) by decreasing the supply of aminoacylated tRNAIle. Pseudomonic acid is the second naturally occurring inhibitor of bacterial isoleucyl-tRNA synthetase to be discovered, furanomycin being the first.


2009 ◽  
Vol 191 (12) ◽  
pp. 3763-3771 ◽  
Author(s):  
Mohammed Dehbi ◽  
Gregory Moeck ◽  
Francis F. Arhin ◽  
Pascale Bauda ◽  
Dominique Bergeron ◽  
...  

ABSTRACT The primary sigma factor of Staphylococcus aureus, σSA, regulates the transcription of many genes, including several essential genes, in this bacterium via specific recognition of exponential growth phase promoters. In this study, we report the existence of a novel staphylococcal phage G1-derived growth inhibitory polypeptide, referred to as G1ORF67, that interacts with σSA both in vivo and in vitro and regulates its activity. Delineation of the minimal domain of σSA that is required for its interaction with G1ORF67 as amino acids 294 to 360 near the carboxy terminus suggests that the G1 phage-encoded anti-σ factor may occlude the −35 element recognition domain of σSA. As would be predicted by this hypothesis, the G1ORF67 polypeptide abolished both RNA polymerase core-dependent binding of σSA to DNA and σSA-dependent transcription in vitro. While G1ORF67 profoundly inhibits transcription when expressed in S. aureus cells in mode of action studies, our finding that G1ORF67 was unable to inhibit transcription when expressed in Escherichia coli concurs with its inability to inhibit transcription by the E. coli holoenzyme in vitro. These features demonstrate the selectivity of G1ORF67 for S. aureus RNA polymerase. We predict that G1ORF67 is one of the central polypeptides in the phage G1 strategy to appropriate host RNA polymerase and redirect it to phage reproduction.


1984 ◽  
Vol 72 (1) ◽  
pp. 1-13
Author(s):  
H.R. Petty ◽  
W. Hermann ◽  
W. Dereski ◽  
T. Frey ◽  
H.M. McConnell

Natural killer (NK) cells have been obtained from mouse spleens and grown in vitro. These cells: retained cytotoxicity against YAC targets; and were homogeneous as judged by morphology and surface markers. The alpha-naphthol acetate esterases (ANAE) and diisopropyl-fluorophosphate (DFP)-binding proteins of NK cells, YAC cells and NK-YAC conjugates have been examined. Ultrastructural cytochemistry indicates that NK cells have two types of ANAE: an enzyme primarily associated with the granule externum and an activatable ANAE associated with the granule internum. Both of these activities are inhibited by DFP. The activatable ANAE appears during incubation of NK cells with YAC cells. DFP-binding proteins were examined by sodium dodecyl sulphate/polyacrylamide gel electrophoresis and autofluorography. NK cells and YAC cells have major DFP-binding proteins of 35 X 10(3) and 20 X 10(3) Mr, respectively. NK-YAC conjugates had a new band at 55 X 10(3) Mr. This new protein may be identical to the activatable ANAE described above. Our studies provide evidence for an NK cell esterase that becomes activated when incubated in the presence of tumour cells. This esterase may be related to the cytolytic mechanism.


Sign in / Sign up

Export Citation Format

Share Document