scholarly journals The effect of hypermethylation on the functional properties of transfer ribonucleic acid. Formation of aminoacyl-transfer-ribonucleic acid

1969 ◽  
Vol 114 (2) ◽  
pp. 429-435 ◽  
Author(s):  
David J. Pillinger ◽  
John Hay ◽  
Ernest Borek
Keyword(s):  
Amino Acids ◽  
Ribonucleic Acid ◽  
Control Sample ◽  
Transfer Rna ◽  
E Coli ◽  
Functional Sites ◽  
The Individual ◽  
Almost All ◽  
Aminoacyl Transfer ◽  
Kinetics Of

1. The ability of chemically hypermethylated Escherichia coli B transfer RNA to accept 19 amino acids was studied and the results were compared with those obtained with a control sample of E. coli B transfer RNA incubated under similar conditions in the absence of methylating agent. 2. There is a marked decrease in the ability of the modified transfer RNA to accept amino acids in almost all instances. 3. The acceptance of cysteine appears to be unique in that it is enhanced in the hypermethylated transfer RNA. 4. More detailed studies on the kinetics of acceptance for six amino acids is presented, emphasizing the variation in response of the individual amino acids. 5. Increasing hypermethylation causes a progressive decrease in the amino acid acceptance. 6. The results are discussed in terms of methylation at functional sites within the transfer RNA and possible conformational alterations to the structure of the macromolecule.

scholarly journals Rates of aminoacyl-transfer-ribonucleic acid synthesis in vivo and in vitro by bean leaves

1970 ◽  
Vol 117 (5) ◽  
pp. 853-859 ◽  
Author(s):  
T. C. Hall ◽  
K. L. Tao
Keyword(s):  
Amino Acids ◽  
Ribonucleic Acid ◽  
Acid Synthesis ◽  
Leaf Discs ◽  
Endogenous Amino Acids ◽  
Intact Leaves ◽  
Aminoacyl Transfer ◽  
Bean Leaves

1. A procedure for measuring rates of aminoacyl-tRNA synthesis in vitro and in intact leaves is presented. 2. Leaf discs showed rates close to those of intact leaves. 3. Cell-free preparations showed similar rates when assayed by pyrophosphate exchange, but actual aminoacyl-tRNA formation rates appeared to be much lower. Evidence is presented that dilution of supplied labelled amino acids was a major factor causing the low apparent rates. 4. Attempts to strip endogenous amino acids from plant tRNA resulted in low acceptor capability of the tRNA.

scholarly journals Bioprospecting Novel Bioactive Molecules from the Seaweeds in Oman

2018 ◽  
pp. 1-12
Author(s):  
Louay Labban ◽  
Amal Al Yaaqoubi ◽  
Ibrar Al Saadi ◽  
Aisha Al Kazrooni ◽  
Amira Al Jafari ◽  
...  
Keyword(s):  
Marine Algae ◽  
Human Life ◽  
Control Sample ◽  
Analytical Techniques ◽  
Bioactive Molecules ◽  
E Coli ◽  
Spectrophotometric Methods ◽  
The Difference ◽  
Almost All ◽  
Indirect Source

Seaweeds or marine macro-algae form the base for the marine ecosystems and considered as direct or indirect source of food for people across the world. Today, algae have made their way to almost all the areas of human life like food, feed, fuel, medicines etc. Marine algae provide exceptional diverse storage of bioactive compounds such as antimicrobial elements. 5 different varieties of seaweeds were collected from Salalah and they were: Ulva fasciata, Asparagopsis taxiform, Rhizoids of Jolyna laminarioide, Jolyna laminarioides and Laminaria brasiliensis. The biochemical composition of these seaweeds were determined by using several analytical techniques such as gas chromatography coupled with mass spectrometry and spectrophotometric methods. The phenolic content, antioxidant of TPC, DPPH (2,2-Diphenyl-1-Picrylhydrazyl) and FRAP analysis were measured. The results have shown a higher antioxidant activity in Brown (Rhizoids of Jolyna laminarioides) comparing with the other varieties. The antimicrobial activity of Ulva fasciataon on E. coli (G-) and Rhizoids of Jolyna laminarioides) on S. aureus (G+) was higher comparing with the control sample and the difference was significant (p < 0.05). In conclusion, this study points out the possibility of seaweeds to be used in making different products that can be employed in biotechnological, nutraceutical and pharmaceutical applications even though more investigations are required for separating, purifying and characterizing the varieties of seaweeds in Oman.

scholarly journals More benign random peptides in E. coli are enriched for similar amino acids as young animal but not plant genes

2020 ◽  
Author(s):  
Luke Kosinski ◽  
Nathan Raul Aviles ◽  
Kevin Gomez ◽  
Joanna Masel
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Composition ◽  
Acid Composition ◽  
De Novo ◽  
Young Animal ◽  
Structural Disorder ◽  
E Coli ◽  
Random Peptide ◽  
Almost All

Proteins are the workhorses of the cell, yet they carry great potential for harm via misfolding and aggregation. Despite the dangers, proteins are sometimes born de novo from non-coding DNA. Proteins are more likely to be born from non-coding regions that produce peptides that do little to no harm when translated than from regions that produce harmful peptides. To investigate which newborn proteins are most likely to "first, do no harm", we estimate fitnesses from an experiment that competed Escherichia coli lineages that each expressed a unique random peptide. A variety of peptide metrics significantly predict lineage fitness, but almost all this predictive power stems from simple amino acid composition. Amino acids that are smaller and that promote intrinsic structural disorder have more benign fitness effects. Our amino acid composition-based predictions also have validity for an independent dataset using small random N-terminal tags. The same amino acids that predict high fitness in E. coli are enriched in young Pfams in animals, but not in plants. To modify Jacques Monod's famous quote, what makes peptides benign in E.coli also makes them benign in elephants, but not in eucalyptus.

scholarly journals Preparation of polyribosome aminoacyl-transfer ribonucleic acid from the muscle of chick embryos.

1975 ◽  
Vol 147 (3) ◽  
pp. 473-477 ◽  
Author(s):  
M Nwagwu
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Sodium Dodecyl Sulphate ◽  
Ribonucleic Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Sodium Dodecyl ◽  
Specific Radioactivity ◽  
Chick Embryos ◽  
Aminoacyl Transfer

A procedure for preparing polyribosome aminoacyl-tRNA free from contamination by supernatant aminoacyl-tRNA and free amino acids is described. Important features of the procedure are the use of acidic buffers to help protect the amino acid-tRNA linkage and the inclusion of sodium dodecyl sulphate, to inhibit ribonuclease activity. The specific radioactivity of polyribosome aminoacyl-tRNA is high within 30s and reaches a maximum in 2 1/2 min, well ahead of polyribosome peptides which, as described by Herrmann et al. (1971), attain maximum specific radioactivity in about 10 min.

Oligoribonucleotide synthesis. X. An improved synthesis of the anticodon loop region of methionine transfer ribonucleic acid from E. coli

1976 ◽  
Vol 54 (17) ◽  
pp. 2689-2696 ◽  
Author(s):  
E. S. Werstiuk ◽  
Thomas Neilson
Keyword(s):  
Ribonucleic Acid ◽  
Coupling Efficiency ◽  
Transfer Rna ◽  
Its Sequence ◽  
Anticodon Loop ◽  
E Coli ◽  
Loop Region ◽  
Phosphotriester Method

Nonaribonucleotide, GpCmpUpCpApUpApApC, was synthesized using a block phosphotriester method. Its sequence corresponds to that of the anticodon loop of transfer RNAfMet (E. coli). Protected tetramer, GCmUC and pentamer nucleotides, AUAAC, assembled stepwise from nucleoside derivatives, were joined together to give protected nonamer which on deblocking, gave the free nonaribonucleotide in milligram amounts. The superior internucleotide coupling efficiency of mesitylenesulfonyl triazolide (MST) over triisopropylbenzenesulfonyl chloride (TPS) is demonstrated.

scholarly journals The control of ribonucleic acid synthesis in bacteria. The synthesis and stability of ribonucleic acid in rifampicin-inhibited cultures of Escherichia coli

1971 ◽  
Vol 122 (2) ◽  
pp. 161-169 ◽  
Author(s):  
W. J. H. Gray ◽  
J. E. M. Midgley
Keyword(s):  
Escherichia Coli ◽  
Ribonucleic Acid ◽  
Acid Synthesis ◽  
Polymerization Rate ◽  
23S Rrna ◽  
Considerable Proportion ◽  
Bacterial Growth Rate ◽  
Ribonucleic Acids ◽  
E Coli ◽  
Kinetics Of

A study was made of the kinetics of labelling of the stable ribonucleic acids (rRNA+tRNA) and the unstable mRNA fraction in cultures of Escherichia coli M.R.E.600, inhibited by the addition of 0.1g of rifampicin/l. Labelling was carried out by adding either [2-14C]- or [5-3H]-uracil as an exogenous precursor of the cellular nucleic acids. From studies using DNA RNA hybridization, the kinetics of the synthesis and degradation of mRNA was followed in the inhibited cultures. Although a considerable proportion of the mRNA labelled in the presence of rifampicin decayed to non-hybridizable products, about 25% was stabilized beyond the point where protein synthesis had finally ceased. It therefore seems unwise to extrapolate the results of studies on mRNA stability in rifampicin-inhibited cultures to the situation existing in the rate of steady growth, where there appears to be little, if any, stable messenger. The kinetics of labelling of RNA in inhibited cultures indicated that the clapsed time from the addition of rifampicin to the point at which radioactivity no longer enters the total cellular ribonucleic acids is a measure of the time required to polymerize a molecule of rRNA. At 37°C, in culture grown in broth, glucose–salts or lactate salts media, exogenous [2-14C]uracil entered rifampicin-inhibited cells and was incorporated into RNA for 2 3min after the antibiotic was added. Taking this time as that required to polymerize a complete chain of 23S rRNA, the polymerization rate of this fraction in the three media was 25, 22 and 19 nucleotides added/s to the growing chains. Similar experiments in cultures previously inhibited by 0.2g of chloramphenicol/l showed virtually identical behaviour. This confirmed the work of Midgley & Gray (1971), who, by a different approach, showed that the polymerization rate of rRNA in steadily growing and chloramphenicol-inhibited cultures of E. coli at 37°C was essentially constant at about 22 nucleotides added/s. It was thus confirmed that the rate of polymerization of at least the rRNA fraction in E. coli is virtually unaffected by the nature of the growth medium and therefore by bacterial growth rate.

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