Über die Lactosegärung und die Lokalisation der Enzyme in der Hefezelle

Myrbäck, Karl; Vasseur, Erich

doi:10.1515/bchm2.1943.277.4-6.171

Cited by 24 publications

(3 citation statements)

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“…Since Fisher (1895) first proposed that maltose is metabolized initially by the action of a-glucosidase, there have been conflicting observations indicating that maltose is not metabolized under conditions in which a-glucosidase would be expected to operate in vivo (Willstaitter and Bamann, 1926;Leibowitz and Hestrin, 1945). These observations have led to the suggestion that a-glucosidase may exist on the cell wall of yeast (Myrback and Vasseur, 1943), or that the cell wall may represent an impermeable membrane for maltose (Gottschalk, 1950), or that specific permeases may be absent or rate-limiting for substrate entry in yeast (Monod, 1956). The present finding of a specific glucoside permeation mechanism, whose loss of activity during deadaptation leads to an increase in the crypticity factor, is in support of the latter hypothesis.…”

Section: Discussionmentioning

confidence: 99%

The Components of Maltozymase in Yeast, and Their Behavior During Deadaptation

1957

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The term maltozymase designates the enzyme system involved in the production of carbon dioxide from maltose in yeast. The discovery of a hydrolytic a-glucosidase led Fisher (1895) to propose that the following reactions represent the action of maltozymase: maltose ki > glucose k2 4 C02, etc. (1) Recent studies on the induced synthesis of a-glucosidase (Halvorson and Spiegelman, 1957) support Fisher's hypothesis. During the early stages of induction, the rate of the a-glucosidase reaction (k1) limits the overall activity of maltozymase. However, the observation that maltose is not metabolized, while glucose is, under conditions in which a-glucosidase would be expected to operate in vivo (Willstatter and Bamann, 1926; Leibowitz and Hestrin, 1945) suggests that maltozymase may contain other enzyme reactions. Since the reactions produced by maltozymase include all those involved in glucose metabolism, it is clear that the appropriate method for searching for other components of maltozymase is to establish conditions in which its activity can be varied independently from glucose metabolism. Such conditions are provided when yeast cells grown in maltose are incubated aerobically with glucose in nitrogen-free medium (Spiegelman and Reiner, 1947). The resulting loss of maltozymase activity has been termed deadaptation. Although the phenomenon of deadaptation has led to speculation about the existence of competitive reac-I Supported in part by a research grant from Division of Research Grants of the U. S. Public Health Service and while one of us (H. 0. H.) was a Merck Fellow in the National Sciences of the National Research Council. Part of the work reported here was taken from a thesis submitted to the Graduate School of the University of Michigan in partial fulfillment of the requirements for a Ph.D. degree by J. J. Robertson, June 1955.

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Section: Discussionmentioning

confidence: 99%

The Components of Maltozymase in Yeast, and Their Behavior During Deadaptation

1957

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“…Their kinetic findings have since been extended and confirmed for the case of a yeast strain isolated from Palestine "leben" (41), as well as for Saccharomyces fragilis and S. cremoris (85). The superior fermentation rate frequently found when lactose, rather than monose constituents of this sugar, served as the fermentation carbohydrate, and the low lactase values found in extracts of the same yeast samples, led Willstatter and Oppenheimer to suppose for lactose fermentation a mechanism, "lactoeymase,'7 distinct from, but analogous to, the mechanism, "maltoeymase," of direct maltose fermentation.…”

Section: Lactosementioning

confidence: 79%

Alcoholic Fermentation of the Oligosaccharides

Leibowitz¹,

Hestrin²

1945

Advances in Enzymology - And Related Areas of Molecular Biology

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“…Invertase activity, as well as other carbohydrases (26) have previously been reported to be associated with the external cell surface of yeast (5,10,27) and other fungi (21). It has also been reported as a cellwall enzyme of higher plants (11,17,1).…”

Section: Discussionmentioning

confidence: 96%

Exocellular Enzymes of Corn Roots

Chang

Bandurski

1964

Plant Physiol.

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Little attention has been given to the occurrence of exocellular hydrolytic enzymes associated with the roots of higher plants. Such enzymes, if present, could solubilize macromolecular constituents of organic soils, permitting uptake and utilization by the plant of the resultant low molecular weight organic compounds. The present work supports this concept by demonstrating that several exocellular hydrolytic enzymes are associated with the roots of intact corn seedlings. Distinction has been made between exocellular enzymes released into the culture media and enzymes apparently bound to the root surface.A previous paper from this laboratory (17) reviewedl earlier studies and presented evidence for the occurrence of exocellular enzymnes associated with the primary cell w all of corn coleoptiles. Of particular relevance to the present work is a report (36) of the secretion of peroxi(lase, aci(l phosphatase, indolylacetic aci(l oxidase, and amylase into the culture media bathing plant tissue cultures. In addition, reports have appeared (2, 6, 14) of the occurrence of an exocellular invertase, possibly involved in sucrose metabolism by roots.In the present work it is reporte(I that invertase, cellobiase, adenosine tri phosphatase, pyrophosphatase, ancl nuclease activity is observed when appropriate substrates are added to nutrient solution bathing the roots of intact seedling corn plants. In addition, invertase and nuclease are (letectecl as soluble enzymes in the nutrient solution. Materials and MethodsCorn seeds (Zea ways L. var. Michigan hybrid 350) were soaked in running water overnight, then surface sterilized by soaking in 1% sodium p-toluenesulfonchloramide (chlorazenie) for 5 minutes and finally, washed thoroughly wxith sterile glass distilled water. The soaked seeds were germinate(l between sterilized paper towels in a moist chamber at room temperature an(l used at an age of 4 to 5 days.Two incubation methods were used, A) the substrate was addle(l to the nutrient in which the seedling roots were growing, an(l B) the seedlings were removed from the nutrient and the substrate then added. MWethod A measured total enzymatic activity of the roots while method BP measure(l activity of enzymes present in solution. 60For procedure A, 8 intact seedlings, each 80 mml in length, were washed with glass distilled water, then incubated at room temperature in 15 X 100 mm tubes. The tubes contained seedlings, substrate, and necessary cofactors, in 13 nml of inorganic nutrient solution (37). Aseptic air was supplied at the bottom of the tube by means of a fine glass tube. At intervals, 1 nl of reaction mixture was removed an(l the amount of substrate hydrolyzed(l determined by standard methods with minor modifications.For procedure BP 8 seedlings were suspended in tubes containing 13 nml of inorganic nutrient solution. Samples of 1 nml of the nutrient were removed from the tubes, at varying time intervals, and incubated with the appropriate substrate and cofactors. Rates of reaction were determined as for B above.No(direct...

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Über die Lactosegärung und die Lokalisation der Enzyme in der Hefezelle

Cited by 24 publications

References 0 publications

The Components of Maltozymase in Yeast, and Their Behavior During Deadaptation

The Components of Maltozymase in Yeast, and Their Behavior During Deadaptation

Alcoholic Fermentation of the Oligosaccharides

Exocellular Enzymes of Corn Roots

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