Biomimetic processes. IV. Carbocationic polymerization of isoprene initiated by dimethyl allyl alcohol

2009 ◽  
Vol 47 (8) ◽  
pp. 2181-2189 ◽  
Author(s):  
Judit E. Puskas ◽  
Clément Peres ◽  
Frédéric Peruch ◽  
Alain Deffieux ◽  
David E. Dabney ◽  
...  
Genetics ◽  
1999 ◽  
Vol 151 (4) ◽  
pp. 1379-1391
Author(s):  
Monique A Johnson ◽  
Hans R Waterham ◽  
Galyna P Ksheminska ◽  
Liubov R Fayura ◽  
Joan Lin Cereghino ◽  
...  

Abstract We have developed two novel schemes for the direct selection of peroxisome-biogenesis-defective (pex) mutants of the methylotrophic yeast Pichia pastoris. Both schemes take advantage of our observation that methanol-induced pex mutants contain little or no alcohol oxidase (AOX) activity. AOX is a peroxisomal matrix enzyme that catalyzes the first step in the methanol-utilization pathway. One scheme utilizes allyl alcohol, a compound that is not toxic to cells but is oxidized by AOX to acrolein, a compound that is toxic. Exposure of mutagenized populations of AOX-induced cells to allyl alcohol selectively kills AOX-containing cells. However, pex mutants without AOX are able to grow. The second scheme utilizes a P. pastoris strain that is defective in formaldehyde dehydrogenase (FLD), a methanol pathway enzyme required to metabolize formaldehyde, the product of AOX. AOX-induced cells of fld1 strains are sensitive to methanol because of the accumulation of formaldehyde. However, fld1 pex mutants, with little active AOX, do not efficiently oxidize methanol to formaldehyde and therefore are not sensitive to methanol. Using these selections, new pex mutant alleles in previously identified PEX genes have been isolated along with mutants in three previously unidentified PEX groups.


1992 ◽  
Vol 20 (2) ◽  
pp. 266-270
Author(s):  
Jens-Uwe Voss ◽  
Hasso Seibert

The toxicity of allyl alcohol and several glycols (ethylene glycol, 1,2-propanediol, 1,3-propanediol, methoxyethanol, and the glycol ether dioxane) was studied in cultures of 3T3 cells and in co-cultures of 3T3 cells with microcarrier-attached hepatocytes. Metabolism-mediated effects on the cytotoxicity to 3T3 cells were recorded by differences in the growth of the cultures exposed in the presence or absence of hepatocytes. Hepatocyte viability was determined by depletion of intracellular lactate dehydrogenase and effects on the biotransformation ability of hepatocytes were assessed by determination of O-deethylation of 7-ethoxycoumarin (EOD activity). Allyl alcohol was the only substance more toxic to the hepatocytes than to 3T3 cells cultured in the absence of hepatocytes. Toxicity to 3T3 cells of allyl alcohol, ethylene glycol, and 1,3-propanediol, but not of 1,2-propanediol, methoxyethanol and dioxane, was markedly enhanced when the cells were co-cultured with hepatocytes. The results indicate that the toxicity of allyl alcohol, ethylene glycol, and 1,3-propanediol, to 3T3 cells depends on the formation of active metabolites. For ethylene glycol and 1,3-propanediol, growth of 3T3 cells in co-cultures was reduced at concentrations without effects on hepatocyte viability. Co-culture of 3T3 cells with microcarrier-attached rat hepatocytes represents a suitable approach for the in vitro evaluation of metabolism-mediated cytotoxicity.


1978 ◽  
Vol 19 (16) ◽  
pp. 1367-1370 ◽  
Author(s):  
Robert G. Salomon ◽  
Amitabha Sinha
Keyword(s):  

1973 ◽  
Vol 18 (4) ◽  
pp. 561-562 ◽  
Author(s):  
B. Silvi ◽  
F. Froment ◽  
J. Corset ◽  
J.P. Perchard

1967 ◽  
Vol 40 (5) ◽  
pp. 1171-1174 ◽  
Author(s):  
Tetsuya Ogura ◽  
Nobuo Furuno ◽  
Shinichi Kawaguchi

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