Über die enzymatische Oxydation des Carotins

Süllmann, H.

doi:10.1002/hlca.19410240186

Cited by 10 publications

(2 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Unsaturated fatty acids.-The oxidation of compounds of the oleic acid type by lipoxidase from soy beans was investigated independently by Sumner (143) and Siillmann (144,145). In many respects these investigations complement each other and may be reported jointly.…”

Section: Fatty Acid Oxidationmentioning

confidence: 99%

“…It seems from the oxygen uptake that only one of the two double bonds in linoleic acid and two of the three in linolenic acid were oxidized. Indications were found that carbonyl compounds were among the oxidation products(145) . The coupled oxidation of carotene occurs only concomitantly with fatty acid oxi dation although large amounts of peroxide may accumulate.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Biological Oxidations and Reductions

Lipmann¹

1943

Annu. Rev. Biochem.

View full text Add to dashboard Cite

Correlation between metabolism and phosphate turnover.Through a subtle analysis of the metabolism of an autotrophic sulfur oxidizing organism, Thiobacillus thiooxidans, Vogler, Umbreh and their collaborators (1, 2, 3, 4) have disclosed a new and striking ex ample of the general occurrence in nature of a linking between oxida tion and phosphate turnover. The processes of energy release through oxidation, in this case of sulfur, and of energy utilization could be separated. The oxidative phase was found to be accompanied by phos phate fixation, and the reductive phase of carbon dioxide fixation by a release of phosphate. O'Kane & Umbreit (5) also studied in some detail the more familiar coupling of glucose fermentation with phos phate fixation, using resting cells of Streptococcus fecalis. It may be emphasized that, parallel with the fermentative phosphate shift, an accumulation of potassium has been observed in several microorgan isms, e.g., in yeast (6) and in Escherichia coli.With radioactive phosphorus as indicator, Taurog, Chaikoff & Perlman (8) demonstrated a dependence of the synthesis of phospho lipids on oxidative metabolism in experiments with liver and kidney slices. Likewise, with brain slices (9), glucose increased the turnover four to five times. The permeation of phosphate into brain cells was followed and found largely dependent on carbohydrate metabolism. Analogous results with yeast are reported by Mullins (10).Efficiency of energy conversion.-The equivalent per mole of carbohydrate oxidized of energy-rich phosphate bonds, designated with ---'P h (11), had been determined by Belitzer & Tsibakova (12) and by Ochoa (13) to about 24 ---'P h, or 2 '--ph per atom of oxygen consumed. In such determinations fluoride is used to stabilize, more or less effectively, the generated phosphate esters; due to the unavoid able loss through dephosphorylation, these figures are to be considered minimum values. In a new series of experiments Ochoa (14) has determined now, rather reliably, the extent of the loss through dephos-1 Annu. Rev. Biochem. 1943.12:1-26. Downloaded from www.annualreviews.org Access provided by University of California -Davis on 02/03/15. For personal use only. Quick links to online content Further ANNUAL REVIEWS LIPMANNphorylation to be 30 to 40 per cent; he arrives at an average of 3 """' ph per atom of respired oxygen, or 36 �h per mole of carbohydrate.With 11 kca!. per bond (11) this makes an efficiency of 60 per cent for the conversion of available oxidation energy into utilizable phos-, phate bond energy. The question then arises how such a high yield of phosphate bonds can be explained in terms of a mechanism. Fol lowing the metabolic pathway of one half of the glucose passing from pyruvate tbrough the citric acid cycle, five energy-rich phosphate bonds may be derived as :follows : Two �h on the fermentation path way from glucose to pyruvate; two ,·-ph as acylphosphates, with the oxidation of the two a-keto acids, py:ruvic and ketoglutaric acids; and one �h, with Kalckar's enolphosphate...

show abstract

Section: Fatty Acid Oxidationmentioning

confidence: 99%

mentioning

confidence: 99%