Unfused heterobicycles as amplifiers of phleomycin. III. Thiazolylpyridines and bipyrimidines with strongly basic side chains

1981 ◽  
Vol 34 (11) ◽  
pp. 2423 ◽  
Author(s):  
DJ Brown ◽  
BB Buttler ◽  
WB Cowden ◽  
GW Grigg ◽  
D Kavulak ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Side Chain ◽  
Side Chains ◽  
Escherichia Coli B

Syntheses are described for 4-(thiazol-4'-yl)pyridines, each 2'-substituted by a dialkylaminoalkyl, dialkylaminoalkylthio or dialkylaminoalkylamino side chain; for 2- and 3-(thiazol-4'-yl)pyridines with a 2'-dimethylaminoethylthio substituent; for 4-(thiazol-2'-yl)pyridines with either a 4'- or a 5'-dialkylaminoalkylcarbamoyl substituent; and for some analogous compounds. The above and similarly substituted 2,4'-, 4,5'- and 5,5'-bipyrimidines have been screened for activity as amplifiers of phleomycin-G against Escherichia coli B by an improved in vitro procedure. The results are tabulated and discussed.

Unfused heterobicycles as amplifiers of phleomycin. VII. Some triazolyl-, thiadiazolyl- and oxadiazolyl-pyridines and related pyrimidines

1983 ◽  
Vol 36 (7) ◽  
pp. 1469 ◽  
Author(s):  
DJ Brown ◽  
WB Cowden
Keyword(s):  
Escherichia Coli ◽  
In Vitro Culture ◽  
Membered Ring ◽  
Side Chain ◽  
Escherichia Coli B

Syntheses are described for several 4-(1',2',4'-triazol-3'yl)pyridines, 3-and 4-(1',3',4'-thiadiazol-2'-yl)-pyridines, 3- and 4-(1',3',4'-oxadiazol-2'-yl)pyridines, 5-(1',3',4'-thiadiazol-2'-yl)pyrimidines and 5-(1',3',4'-oxadiazol-2'-yl)pyrimidines, all provided with a β-dimethylaminoethylthio side chain at the 5-position of the five-membered ring. The activities of these compounds as amplifiers of phleomycin-G against an in vitro culture of Escherichia coli B are tabulated and discussed.

scholarly journals Binding Site of the Bridged Macrolides in the Escherichia coli Ribosome

2005 ◽  
Vol 49 (1) ◽  
pp. 281-288 ◽  
Author(s):  
Liqun Xiong ◽  
Yakov Korkhin ◽  
Alexander S. Mankin
Keyword(s):  
Escherichia Coli ◽  
Tight Binding ◽  
Dimethyl Sulfate ◽  
23S Rrna ◽  
Side Chain ◽  
Macrolide Antibiotics ◽  
Side Chains ◽  
Alkyl Aryl ◽  
E Coli ◽  
Exit Tunnel

ABSTRACT Ketolides represent the latest group of macrolide antibiotics. Tight binding of ketolides to the ribosome appears to correlate with the presence of an extended alkyl-aryl side chain. Recently developed 6,11-bridged bicyclic ketolides extend the spectrum of platforms used to generate new potent macrolides with extended alkyl-aryl side chains. The purpose of the present study was to characterize the site of binding and the action of bridged macrolides in the ribosomes of Escherichia coli. All the bridged macrolides investigated efficiently protected A2058 and A2059 in domain V of 23S rRNA from modification by dimethyl sulfate and U2609 from modification by carbodiimide. In addition, bridged macrolides that carry extended alkyl-aryl side chains protruding from the 6,11 bridge protected A752 in helix 35 of domain II of 23S rRNA from modification by dimethyl sulfate. Bridged macrolides efficiently displaced erythromycin from the ribosome in a competition binding assay. The A2058G mutation in 23S rRNA conferred resistance to the bridged macrolides. The U2609C mutation, which renders E. coli resistant to the previously studied ketolides telithromycin and cethromycin, barely affected cell susceptibility to the bridged macrolides used in this study. The results of the biochemical and genetic studies indicate that in the E. coli ribosome, bridged macrolides bind in the nascent peptide exit tunnel at the site previously described for other macrolide antibiotics. The presence of the side chain promotes the formation of specific interactions with the helix 35 of 23S rRNA.

scholarly journals Acyl-CoA oxidase complexes control the chemical message produced by Caenorhabditis elegans

2015 ◽  
Vol 112 (13) ◽  
pp. 3955-3960 ◽  
Author(s):  
Xinxing Zhang ◽  
Likui Feng ◽  
Satya Chinta ◽  
Prashant Singh ◽  
Yuting Wang ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Environmental Conditions ◽  
Side Chain ◽  
Side Chains ◽  
Activity Assay ◽  
C Elegans ◽  
Substrate Preferences ◽  
Acyl Coa Oxidase ◽  
Coa Thioesters

Caenorhabditis elegans uses ascaroside pheromones to induce development of the stress-resistant dauer larval stage and to coordinate various behaviors. Peroxisomal β-oxidation cycles are required for the biosynthesis of the fatty acid-derived side chains of the ascarosides. Here we show that three acyl-CoA oxidases, which catalyze the first step in these β-oxidation cycles, form different protein homo- and heterodimers with distinct substrate preferences. Mutations in the acyl-CoA oxidase genes acox-1, -2, and -3 led to specific defects in ascaroside production. When the acyl-CoA oxidases were expressed alone or in pairs and purified, the resulting acyl-CoA oxidase homo- and heterodimers displayed different side-chain length preferences in an in vitro activity assay. Specifically, an ACOX-1 homodimer controls the production of ascarosides with side chains with nine or fewer carbons, an ACOX-1/ACOX-3 heterodimer controls the production of those with side chains with seven or fewer carbons, and an ACOX-2 homodimer controls the production of those with ω-side chains with less than five carbons. Our results support a biosynthetic model in which β-oxidation enzymes act directly on the CoA-thioesters of ascaroside biosynthetic precursors. Furthermore, we identify environmental conditions, including high temperature and low food availability, that induce the expression of acox-2 and/or acox-3 and lead to corresponding changes in ascaroside production. Thus, our work uncovers an important mechanism by which C. elegans increases the production of the most potent dauer pheromones, those with the shortest side chains, under specific environmental conditions.

NEAR-ULTRAVIOLET MODIFICATION OF ESCHERICHIA COLI B UBIQUINONE IN VIVO AND IN VITRO

1974 ◽  
Vol 19 (5) ◽  
pp. 321-328 ◽  
Author(s):  
Harold Werbin ◽  
Bala D. Lakchaura ◽  
John Jagger
Keyword(s):  
Escherichia Coli ◽  
Near Ultraviolet ◽  
Escherichia Coli B

Functional Activities of Monoclonal Antibodies to the O Side Chain of Escherichia coli Lipopolysaccharides in Vitro and in Vivo

1988 ◽  
Vol 157 (1) ◽  
pp. 47-53 ◽  
Author(s):  
K. S. Kim ◽  
J. H. Kang ◽  
A. S. Cross ◽  
B. Kaufman ◽  
W. Zollinger ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Monoclonal Antibodies ◽  
Side Chain ◽  
Functional Activities

scholarly journals EcoBLMcrX, a classical modification-dependent restriction enzyme in Escherichia coli B: Characterization in vivo and in vitro with a new approach to cleavage site determination

PLoS ONE ◽  
2017 ◽  
Vol 12 (6) ◽  
pp. e0179853 ◽  
Author(s):  
Alexey Fomenkov ◽  
Zhiyi Sun ◽  
Deborah K. Dila ◽  
Brian P. Anton ◽  
Richard J. Roberts ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Restriction Enzyme ◽  
Cleavage Site ◽  
New Approach ◽  
Escherichia Coli B

scholarly journals Acetolactate Synthase from Bacillus subtilis Serves as a 2-Ketoisovalerate Decarboxylase for Isobutanol Biosynthesis in Escherichia coli

2009 ◽  
Vol 75 (19) ◽  
pp. 6306-6311 ◽  
Author(s):  
Shota Atsumi ◽  
Zhen Li ◽  
James C. Liao
Keyword(s):  
Escherichia Coli ◽  
Amino Acids ◽  
Bacillus Subtilis ◽  
Lactococcus Lactis ◽  
Acetolactate Synthase ◽  
Side Chains ◽  
Decarboxylase Activity ◽  
Small Side

ABSTRACTA pathway toward isobutanol production previously constructed inEscherichia coliinvolves 2-ketoacid decarboxylase (Kdc) fromLactococcus lactisthat decarboxylates 2-ketoisovalerate (KIV) to isobutyraldehyde. Here, we showed that a strain lacking Kdc is still capable of producing isobutanol. We found that acetolactate synthase fromBacillus subtilis(AlsS), which originally catalyzes the condensation of two molecules of pyruvate to form 2-acetolactate, is able to catalyze the decarboxylation of KIV like Kdc both in vivo and in vitro. Mutational studies revealed that the replacement of Q487 with amino acids with small side chains (Ala, Ser, and Gly) diminished only the decarboxylase activity but maintained the synthase activity.

Recent discoveries in the pathways to cobalamin (coenzyme B12) achieved through chemistry and biology

2007 ◽  
Vol 79 (12) ◽  
pp. 2179-2188 ◽  
Author(s):  
A. Ian Scott ◽  
Charles A. Roessner
Keyword(s):  
Escherichia Coli ◽  
Side Chain ◽  
Coenzyme B12 ◽  
Over Expression ◽  
High Resolution Nmr ◽  
In Vitro Biosynthesis ◽  
Transport Complex ◽  
Aerobic And Anaerobic

The genetic engineering of Escherichia coli for the over-expression of enzymes of the aerobic and anaerobic pathways to cobalamin has resulted in the in vivo and in vitro biosynthesis of new intermediates and other products that were isolated and characterized using a combination of bioorganic chemistry and high-resolution NMR. Analyses of these products were used to deduct the functions of the enzymes that catalyze their synthesis. CobZ, another enzyme for the synthesis of precorrin-3B of the aerobic pathway, has recently been described, as has been BluB, the enzyme responsible for the oxygen-dependent biosynthesis of dimethylbenzimidazole. In the anaerobic pathway, functions have recently been experimentally confirmed for or assigned to the CbiMNOQ cobalt transport complex, CbiA (a,c side chain amidation), CbiD (C-1 methylation), CbiF (C-11 methylation), CbiG (lactone opening, deacylation), CbiP (b,d,e,g side chain amidation), and CbiT (C-15 methylation, C-12 side chain decarboxylation). The dephosphorylation of adenosylcobalamin-phosphate, catalyzed by CobC, has been proposed as the final step in the biosynthesis of adenosylcobalamin.

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