Effect of 3-deazaadenosine on methionine metabolism in isolated perfused livers

1988 ◽  
Vol 66 (10) ◽  
pp. 1032-1039 ◽  
Author(s):  
John A. Duerre
Keyword(s):  
Protein Synthesis ◽  
Specific Radioactivity ◽  
Carbon Chain ◽  
Methionine Metabolism ◽  
Equivalent Amount ◽  
Purine Analog ◽  
Inhibition Of Protein Synthesis ◽  
Hydrolysis Of ◽  
Sulfur Containing ◽  
Sulfur Containing Compounds

The effect of the purine analog 3-deazaadenosine (dzAdo) on the metabolism of sulfur-containing compounds was examined in hepatocytes. The uptake of exogenous methionine by the liver was not affected by the addition of dzAdo to the perfusate, while the intracellular concentrations of S-adenosyl-L-methionine (AdoMet) and S-adenosyl-L-homocysteine (AdoHcy) continued to increase as long as exogenous methionine was available. In addition, large amounts of 3-deazaadenosyl-L-homocysteine (dzAdoHcy) accumulated in the cell. The specific radioactivity of the carbon chain of dzAdoHcy was the same as that of AdoMet and AdoHcy. Consequently, an equivalent amount of homocysteine (Hey) must have been generated via hydrolysis of AdoHcy. Free Hey could not be detected either in the tissue or perfusate when dzAdo was present, while Hey was excreted into the perfusate by control livers. Consequently, the AdoHcy and DzAdoHcy that accumulate in the cell not only function as inhibitors of methylation reactions, but serve as a trap for Hey. This could result in methionine starvation and hence, inhibition of protein synthesis.

scholarly journals Inhibition of protein synthesis in frog (Xenopus laevis) egg extracts by an antibody against phosphatidylinositol 4,5-bisphosphate

1996 ◽  
Vol 317 (3) ◽  
pp. 643-646
Author(s):  
Thomas J. KEATING ◽  
Kiyoko FUKAMI ◽  
Kenneth R. ROBINSON
Keyword(s):  
Protein Synthesis ◽  
Xenopus Laevis ◽  
Similar Reduction ◽  
Inhibition Of Protein Synthesis ◽  
Egg Extracts ◽  
Hydrolysis Of

The antibody kt10, which is directed against the phospholipid PtdIns(4,5)P2, inhibits protein synthesis when added to cytosolic extracts prepared from frog eggs. Addition of stable analogues of diacylglycerol and Ins(1,4,5)P3 failed to rescue the inhibition of translation, suggesting that the effect of the antibody was not to block hydrolysis of PtdIns(4,5)P2. Neomycin, which also binds PtdIns(4,5)P2, produced a similar reduction in protein-synthesis levels in the extract system, supporting the idea that it is the interaction of the antibody with PtdIns(4,5)P2 that is producing the effect.

Volatile Sulfur-Containing Compounds from Methionine Metabolism in Genetically ModifiedLactobacillus helveticusCNRZ32 Strains

2007 ◽  
pp. 205-213
Author(s):  
Scott A. Rankin ◽  
Dattatreya S. Banavara ◽  
Ed S. Mooberry ◽  
James L. Steele ◽  
Jeffery R. Broadbent ◽  
...  
Keyword(s):  
Methionine Metabolism ◽  
Sulfur Containing ◽  
Sulfur Containing Compounds ◽  
Volatile Sulfur

scholarly journals Reversible inhibition of protein synthesis in lung by halothane

1983 ◽  
Vol 210 (2) ◽  
pp. 379-387 ◽  
Author(s):  
D E Rannels ◽  
R Christopherson ◽  
C A Watkins
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Plasma Concentrations ◽  
Specific Radioactivity ◽  
Bicarbonate Buffer ◽  
Inhibition Of Protein Synthesis ◽  
Glucose Plasma ◽  
Dose Dependent ◽  
Synthesis And Degradation

Alterations in the synthesis and degradation of proteins were investigated in intact lungs exposed to the volatile anaesthetic halothane. In rat lungs perfused in situ with Krebs-Henseleit bicarbonate buffer containing 4.5% (w/v) bovine serum albumin, 5.6 mM-glucose, plasma concentrations of 19 amino acids and 690 microM-[U-14C]-phenylalanine and equilibrated with O2/N2/CO2 (4:15:1), protein synthesis, calculated based on the specific radioactivity of aminoacyl-tRNA, was inhibited by halothane. The anaesthetic did not affect degradation of lung proteins. The inhibition of protein synthesis was rapid in onset, dose-dependent, and quickly reversible. It did not appear to be associated with overall energy depletion, with non-specific changes in cellular permeability, or with decreased availability of amino acids as substrates for protein synthesis.

scholarly journals Inhibition of protein synthesis in Krebs 2 ascites cells and cell-free systems by phenylalanine and its effect on leucine and lysine in the amino acid pool

1968 ◽  
Vol 109 (4) ◽  
pp. 507-515 ◽  
Author(s):  
Joan P. Roscoe ◽  
M. D. Eaton ◽  
Gladys Chin Choy
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Specific Radioactivity ◽  
Transfer Rna ◽  
Free System ◽  
Cell Free System ◽  
Whole Cells ◽  
System L ◽  
Inhibition Of Protein Synthesis ◽  
A Cell

1. The inhibition of incorporation of 14C-labelled amino acids into protein of whole cells by phenylalanine has been reproduced in a cell-free system. In both cases only the l-isomer was inhibitory. 2. The effect of phenylalanine on incorporation of [14C]leucine and [14C]lysine into protein was different in both whole cells and cell-free systems. 3. In whole cells inhibition of incorporation of leucine at 2·5μg./ml. was very rapid, but when the concentration was increased to 100μg./ml. the inhibition was not apparent for about 1hr. The kinetics of inhibition of lysine was the same at both these concentrations and was similar to that found with leucine at 100μg./ml. 4. Neither a lower specific radioactivity of the two amino acids in the pool nor a decrease in their pool size could be consistently related with inhibition of protein synthesis. 5. In the cell-free system l-phenylalanine inhibited the incorporation of leucine but not of lysine. 6. Charging of transfer RNA by leucine was markedly decreased in the presence of phenylalanine, whereas charging of transfer RNA by lysine was not.

Analysis of Volatile Compounds from Wheat Flour in the Heating Process

2019 ◽  
Vol 15 (10) ◽  
Author(s):  
Duo Chai ◽  
Chongwei Li ◽  
Xinxin Zhang ◽  
Jingfeng Yang ◽  
Longze Liu ◽  
...  
Keyword(s):  
Volatile Compounds ◽  
Solid Phase ◽  
Formation Rate ◽  
Carbon Chain ◽  
Gas Chromatography Mass Spectrometry ◽  
Heating Process ◽  
Forming Mechanism ◽  
Volatile Aldehydes ◽  
Sulfur Containing ◽  
Sulfur Containing Compounds

AbstractVolatile profiling was carried out during heating through vacuum-assisted headspace solid-phase microextraction combined with gas chromatography-mass spectrometry to better understand the flavor forming mechanism of flour products. Ninety-two volatile compounds were detected and identified, including aldehydes (25), ketones (15), alcohols (9), nitrogen- and sulfur-containing compounds (6), benzene derivatives (15), furans (10), and acids and esters (12). The formation temperature of each volatile was also determined. Results showed that temperature played an important role in the formation and content of volatile compounds. In the low-temperature range (60 °C–100 °C), the flavor composition of flour was mainly composed of C6–C10 volatile aldehydes and alcohols. At temperatures exceeding 100 °C, especially at 120 °C, many long carbon chain aldehydes and alcohols, furans, acids, esters, nitrogen- and sulfur-containing compounds were formed. The formation rate of most identified volatile compounds increased during heating, especially from 90 °C to 130 °C.

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