PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “PIMELIC ACID”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 307 records · Page 17Linked to original sources

Mode of action of primaquine: preferential inhibition of protein biosynthesis in Bacillus megaterium.

The growth of a strain of Bacillus megaterium was prevented by a minimal inhibitory concentration of primaquine of 52 mug/ml or 2 x 10(-4)m. When exponentially growing cultures received the drug at 6 x 10(-4)m, the rate of growth was drastically reduced and no further growth occurred after 15 min of exposure. At this concentration, primaquine was bactericidal, causing a 50% reduction in the viable population after one doubling time of 45 min. Supplying primaquine to cultures 30 min after adding radioactive-labeled phenylalanine, thymidine, uracil, or diaminopimelic acid produced an immediate and complete inhibition of protein biosynthesis but no inhibition of deoxyribonucleic acid biosynthesis for at least 15 min, and caused the formation of ribonucleic acid and cell wall polymer to proceed linearly at rates similar to those established prior to the addition of drug. This pattern of inhibition of macromolecular biosyntheses suggests that the major in vivo action of primaquine in B. megaterium is to block protein synthesis.

Amino Acids↗

Laboratory identification of clinically important aerobic actinomycetes.

A battery of morphological, physiological, and biochemical tests, including paper chromatographic analysis of whole cell hydrolysates, was used to study 177 cultures of aerobic actinomycetes. One hundred thirty-five of the 177 were submitted as diagnostic laboratory specimens; of these, 129 were identified as belonging to 1 of 10 genus or species groups. The tests and procedures used were found to be relatively easy to perform and interpret. On the basis of the results, a flow chart was devised to permit the step by step identification of unknown clinical isolates of these organisms.

Acids↗

Effects of penicillin and glycine on cell wall glycopeptides of the two varieties of Vibrio fetus.

Actively growing strains of Vibrio fetus venerealis and V. fetus intestinalis, none of which produced penicillinase, were treated with inhibitory levels of penicillin or glycine, primarily to gain insight into the differential sensitivities of the two varieties to both of these compounds. Treatments induced the accumulation of uridine nucleotide glycopeptide precursors which contained amino sugars and amino acids in various molar ratios. Penicillin-induced nucleotides all contained muramic acid and sometimes glucosamine; they generally contained alanine, glutamic acid, diaminopimelic acid, and glycine. Approximately equimolar ratios of these components were observed in some compounds, but ratios varied considerably in others. Glycine-induced nucleotides contained muramic acid and, in some instances, glucosamine. Amino acids were detected only infrequently and usually in low molar ratios. The data suggest that penicillinase production, differences in the chemical composition of glycopeptide, and variations in modes of action of penicillin and glycine cannot individually account for the differential sensitivities of venereal and intestinal strains of V. fetus to these substances.

Alanine↗

Wax D from different bovine strains of Mycobacterium.

Wax D(P), a peptido-glycolipid found in extracts of Mycobacterium tuberculosis var. hominis, was not found in extracts of three strains of still-grown M. tuberculosis var. bovis (BCG, Marmorek and Dupray). However, extracts from three other bovine strains (Behring, LA and BB) did yield waxes D(P), and these did not differ as to their molar ratios of alanine/glutamic acid/diaminopimelic acid from human waxes D(P).

Alanine↗

Temperature-sensitive mutants of Escherichia coli K-12 with low activity of the diaminopimelic acid adding enzyme.

Five temperature-sensitive lysis mutants were found to possess very low diaminopimelic acid (Dpm) adding enzyme activity in vitro. Murein synthesis at 42 C was impaired, and uridine-5'-diphosphate-N-acetyl-muramyl-l-Ala- d-Glu (UDP-MurNAc-dipeptide) was accumulated. In the presence of NaCl, the mutants could grow at 42 C. NaCl had no influence on the Dpm adding enzyme activity in vitro. The growth rate of most temperature-resistant revertants was decreased, but their Dpm adding enzyme activity remained very low. Two revertants had a rather normal growth rate. Their Dpm adding enzyme activity was significantly increased, but much lower than in the wild type. The influence of growth rate on the viability of the mutants is discussed.

Alanine↗

Coordinative binding of divalent cations with ligands related to bacterial spores. Equilibrium studies.

It has been repeatedly postulated that the high heat resistance of bacterial spores is due to stabilization of biopolymers in the spore interior by a solid deposit of protective cement consisting of coordination complexes of ligands with divalent metal ions. This report presents data on metal-binding characteristics of some of the ligands related to spores as determined by means of potentiometric equilibrium measurements under conditions of temperature and ionic strength (t = 25.0 degrees C; mu = 1.0 KNO(3)) identical with those reported earlier by the authors in order to facilitate correlation by using comparable data. The spore ligands investigated in this study included 2,6-pyridinedicarboxylic acid (DPA), alpha,epsilon-diaminopimelic acid, D-glutamic acid, and D-alanine in a ratio of 1:1 with metal ions which are known to play a role in heat resistance of spores. Stability constants of the chelates of these spore ligands with metal ions such as Ca(II), Mg(II), Cu(II), Ni(II), Zn(II), Co(II), and Mn(II) have been determined. In general the metal chelates of DPA exhibited the greatest stability. On the basis of a consideration of the stability data together with the known configurations of the ligand and the coordination requirements of the metal ions, possible structures indicating the coordinate binding of the spore ligands with the metal ions are presented. All the metal chelates except those of Ca(II) were found to undergo hydrolysis and separation of solid phase in the pH range 7-8.5. The relatively greater hydrolytic stability of Ca(II) chelates and the high affinity of DPA for metal ions appear to be of biological significance insofar as these two spore components are more widely associated with the heat resistance of bacterial spores.

Alanine↗