Invertase Content of Yeast Protoplasts

Burger, M.; Bacon, E. Elizabeth; Bacon, J. S. D.; Millbank, J. W.

doi:10.1038/205622b0

Cited by 5 publications

(2 citation statements)

References 8 publications

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“…On preparation of yeast protoplasts, the bulk of the saccharase is released into the surrounding medium (Sutton & Lampen, 1962;Islam & Lampen, 3 1962;Millbank, 1963;Burger, Bacon, Bacon & Millbank, 1965; Suomalainen, Nurminen & Oura, 1967a), although there is some disagreement on the extent to whichprotoplastsretain saccharase activity. Nevertheless.…”

Section: Total Activitymentioning

confidence: 99%

The enzymic composition of the isolated cell wall and plasma membrane of baker's yeast

Nurminen

Oura

Suomalainen

1970

Biochemical Journal

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A study was made of the enzyme content of the isolated cell walls and of a plasma-membrane preparation obtained by centrifugation after enzymic digestion of the cell walls of baker's yeast. The isolated cell walls showed no hexokinase, alkaline phosphatase, esterase or NADH oxidase activity. It was concluded that these enzymes exist only in the interior of the cell. Further, only a negligible activity of deamidase was detectable in the cell walls. Noticeable amounts of saccharase, phosphatases hydrolysing p-nitrophenyl phosphate, ATP, ADP, thiamin pyrophosphate and PP(i), with optimum activity at pH3-4, and an activity of Mg(2+)-dependent adenosine triphosphatase at neutral pH, were found in the isolated cell walls. During enzymic digestion, the other activities appearing in the cell walls were mostly released into the medium, but the bulk of the Mg(2+)-dependent adenosine triphosphatase remained in the plasma-membrane preparation. Accordingly, it may be assumed that the enzymes released into the medium during digestion are located in the cell wall outside the plasma membrane, whereas the Mg(2+)-dependent adenosine triphosphatase is an enzyme of the plasma membrane. This enzyme differs from the phosphatases with pH optima in the range pH3-4 with regard to location, pH optimum, substrate specificity and different requirement of activators.

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Section: Total Activitymentioning

confidence: 99%

The enzymic composition of the isolated cell wall and plasma membrane of baker's yeast

Nurminen

Oura

Suomalainen

1970

Biochemical Journal

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“…An electron micrograph of material from the main phospholipid peak is shown in Plate la. At the heavy end of the gradient, there was a minor peak of protein, phospholipid, sterol, Mg-ATPases and ,B-fructofuranosidase at p= 1.26-1.28. fJ-Fructofuranosidase (Sutton & Lampen, 1962;Islam & Lampen, 1962;Millbank, 1963;Burger et al, 1965;Suomalainen et al, 1967) and acid phosphatase (McLellan & Lampen, 1963;Tonino & Steyn-Parve, 1963;Suomalainen et al, 1967) are mainly located outside the plasma membrane, for they are released into the surrounding medium during the preparation of yeast spheroplasts. These exoenzymes are synthesized inside the yeast cell (e.g.…”

Section: Distribution (%)mentioning

confidence: 99%

Distribution of membranes, especially of plasma-membrane fragments, during zonal centrifugations of homogenates from glucose-repressed Saccharomyces Cerevisiae

Nurminen

Taskinen

Suomalainen

1976

Biochemical Journal

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1. The distributions of several enzymes and other marker components were examined after zonal centrifugations of whole homogenates from glucose-repressed Saccharomyces cerevisiae on sucrose and iso-osmotic Ficoll, and the composition and morphology of the fractions were investigated. 2. After high-speed zonal centrifugation most of the protein, acid and alkaline phosphatases, alkaline pyrophosphatase, adenosine monophosphatase, beta-fructofuranosidase, alpha-mannosidase, NADPH-cytochrome c oxidoreductase and an appreciable amount of phospholipid and sterol were non-sedimentable, i.e. were at densities below 1.09 (g/cm3). Most of the RNA was at p=1.06-1.08 in Ficoll and at p=1.09-1.11 in sucrose. 3. The bulk of the Mg2+-dependent adenosine triphosphatase (Mg-ATPase) was coincident with the main peak of phospholipid and sterol, at median density 1.10, which was also rich in smooth-membrane vesicles. In Ficoll, a minor peak of phospholipid and sterol at p-1.12-1.15 contained a smaller part of the oligomycin-insensitive Mg-ATPase and heavy membrane fragments. In sucrose, several minor peaks of Mg-ATPase were in the mitochondrial density range, and a peak of oligomycin-insensitive Mg-ATPase coincident with a minor peak of phospholipid and sterol at around p-1.25 contained heavy membrane fragments of high carbohydrate content, especially mannose. 4. Further purification of the oligomycin-insensitive Mg-ATPase containing membrane preparations was performed on Urografin gradients. 5. It is argued that the oligomycin-insensitive Mg-ATPase containing membranes are fragments of the plasma membrane, but have different densities because they contain different amounts of glycoprotein particles.

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Release of enzymes from bakers' yeast by disruption in an industrial homogenizer

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Hetherington

Dunnill

et al. 1971

Biotech & Bioengineering

120

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SummaryThe rates of release of 7 enzymes from bakers' yeast have been measured. The disruption process did not cause loss of activity of these enzymes. The various operating pressures, temperatures, and initial yeast concentrations used did not affect the rates of enzyme release relative to protein release. The release of acid phosphatase and invertase was faster than the overall protein release. Alcohol, glucose-&phosphate, and 6-phosphogluconate dehydrogenases were released slightly faster or at the same rate as the overall protein and alkaline phosphatase and fumarase were released more slowly. These observations correlate well with the reported locations of these enzymes in the yeast cell.

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Invertase Content of Yeast Protoplasts

Cited by 5 publications

References 8 publications

The enzymic composition of the isolated cell wall and plasma membrane of baker's yeast

The enzymic composition of the isolated cell wall and plasma membrane of baker's yeast

Distribution of membranes, especially of plasma-membrane fragments, during zonal centrifugations of homogenates from glucose-repressed Saccharomyces Cerevisiae

Release of enzymes from bakers' yeast by disruption in an industrial homogenizer

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