scholarly journals Structural aspects of the dye-linked alcohol dehydrogenase of Rhodopseudomonas acidophila

1979 ◽  
Vol 181 (3) ◽  
pp. 517-524 ◽  
Author(s):  
C W Bamforth ◽  
J R Quayle

1. A dye-linked alcohol dehydrogenase was purified 60-fold from extracts of Rhodopseudomonas acidophila 10050 grown aerobically on ethanol. 2. The properties of this enzyme were identical with those of the alcohol dehydrogenase synthesized by this organism during growth on methanol anaerobically in the light, and they are judged to be the same enzyme. 3. The enzyme gave a single protein band, coincident with alcohol dehydrogenase activity, during electrophoresis on polyacrylamide gel. 4. The amino acid composition, ioselectric point, u.v. and visible absorption spectra of the enzyme were determined and compared with those of other similar enzymes. 5. The presence of 0.7–1.0 g-atom of non-haem, acidlabile iron/mol of enzyme was shown by atomic absorption spectrophotometry and colorimetric assay. The iron could not be dissociated from the enzyme by dialysis against chelating agents. 6. E.p.r. spectroscopy of the enzyme did not indicate any redox function for the iron during alcohol dehydrogenation, but showed a signal at g = 2.00 consistent with the presence of a protein-bound organic free radical. 8. Antisera were raised against alcohol (methanol) dehydrogenases purified from Rhodopseudomonas acidophila, Paracoccus denitrificans and Methylophilus methylotrophus. 9. The antiserum to the Rhodopseudomonas acidophila enzyme cross-reacted with neither of the two other antisera, nor with crude extracts of methanol-grown Hyphomicrobium X and Pseudomonas AM1, thus emphasizing its singular biochemical properties.

Tsitologiya ◽  
2018 ◽  
Vol 60 (6) ◽  
pp. 469-475
Author(s):  
O. D. Nimaeva ◽  
◽  
E. V. Pradedova ◽  
A. B. Karpova ◽  
R. K. Salyaev ◽  
...  

AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Najme Gord Noshahri ◽  
Jamshid Fooladi ◽  
Ulrike Engel ◽  
Delphine Muller ◽  
Michaela Kugel ◽  
...  

Abstractω-Transaminases’ (ω-TAs) importance for synthesizing chiral amines led to the development of different methods to quickly identify and characterize new sources of these enzymes. Here we describe the optimization of growth and induction of such an enzyme in a wild type strain of Bacillus sp. strain BaH (IBRC-M 11337) isolated from Iranian soil in shaking flasks by the response surface methodology (RSM). Optimum conditions were set in a multiplexed bench-top bioreactor system (Sixfors). ω-TA activity of obtained biomass was checked by an innovative efficient colorimetric assay for localizing ω-TAs in crude extracts on acrylamide gel by using ortho-xylylenediamine (OXD) as amino donor. The application of the established OXD assay is thereby expanded from high-throughput activity screenings and colony-based screenings of heterologously expressed mutants to a direct identification of ω-TAs in wild-type strains: This assay can be used to detect the protein band of the respective enzyme in crude extracts of novel isolates by visual inspection of native PAGEs without any upstream protein purification, thus enabling subsequent further investigations of a newly discovered enzyme directly from the crude extract.


1972 ◽  
Vol 42 (6) ◽  
pp. 781-784 ◽  
Author(s):  
Maureen O'keane ◽  
M. R. Moore ◽  
A. Goldberg

1. Because it has been shown that a majority of alcoholics are subclinically scorbutic, the metabolism of ethanol was studied in subclinically-scorbutic guinea-pigs. 2. Hepatic alcohol dehydrogenase activity was raised maximally by ethanol within 2 days. 3. In twenty-three subclinically-scorbutic guinea-pigs fed ethanol for 2 weeks, the alcohol dehydrogenase activity (±SD) was 11·5 ± 1·2 units/g of liver protein compared with 8·6 ± 0·6 units/g of liver protein in twenty-three healthy animals fed ethanol. 4. The NAD+/NADH ratio in subclinically-scorbutic guinea-pigs and healthy guinea-pigs fed ethanol, shows that there is more NAD+ available for oxidation of alcohol in subclinically-scorbutic guinea-pigs. These results may explain the increased tolerance of alcoholics to alcohol.


1971 ◽  
Vol 17 (10) ◽  
pp. 1047-1049 ◽  
Author(s):  
S Raymond Gambino ◽  
Ivelice Fonseca

Abstract Comparable results are obtained when serum calcium is measured by a colorimetric cresolpthalein method on the Technicon SMA 12/60 and by atomic absorption spectrophotometry (Instrumentation Laboratory Model 153 instrument), with strontium as an internal standard. Sera from 250 patients with abnormal calcium concentrations, ranging from 4.9 mg/100 ml to 9.0 mg/100 ml, were measured by each method; the difference between the means for each method was only 0.04 mg/100 ml. The standard deviation of the difference between paired results was ±0.16 mg/100 ml. We were unable to discover any effect of drug or disease on the colorimetric assay, which therefore is suitable for use in large-scale surveys. On the other hand, the more precise atomic absorption spectrophotometry is suitable for use as a reference method. In addition, with an internal standard it is fast and simple, making it suitable for emergency assays of calcium 24 h a day.


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