scholarly journals The lipolytic activities of the isolated cell envelope fractions of baker's yeast

1970 ◽  
Vol 118 (5) ◽  
pp. 759-763 ◽  
Author(s):  
T. Nurminen ◽  
H. Suomalainen
Keyword(s):  
Plasma Membrane ◽  
Adenosine Triphosphatase ◽  
Cell Envelope ◽  
Baker’S Yeast ◽  
Baker's Yeast ◽  
Lipolytic Enzymes ◽  
Enzymic Digestion ◽  
Cell Envelopes ◽  
Isolated Cell ◽  
Lipid Components

1. The existence of phospholipase and lipase activities in the isolated cell envelopes of baker's yeast was demonstrated. 2. The content of phospholipase was found to be markedly higher than that of lipase. 3. After partial enzymic digestion of the isolated cell envelopes, the bulk of the lipolytic activities was recovered in the sedimentable preparations, which consisted of the fragments of the plasma membrane. 4. During repeated washings, the lipase was completely released from the cell envelopes, as were also the bulk of the lipid components and most of the Mg2+-dependent adenosine triphosphatase, an enzyme connected with the plasma membrane. The phospholipase was more firmly bound to the preparation but not so firmly as the external saccharase. 5. These results indicate that the lipolytic enzymes found in the cell envelopes are mostly located in the plasma membrane.

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

1970 ◽  
Vol 116 (1) ◽  
pp. 61-69 ◽  
Author(s):  
T. Nurminen ◽  
E. Oura ◽  
H. Suomalainen
Keyword(s):  
Cell Wall ◽  
Plasma Membrane ◽  
Cell Walls ◽  
Adenosine Triphosphatase ◽  
Baker’S Yeast ◽  
Membrane Preparation ◽  
Baker's Yeast ◽  
Enzymic Digestion ◽  
Plasma Membrane Preparation ◽  
Isolated Cell

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 PPi, with optimum activity at pH3–4, and an activity of Mg2+-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 Mg2+-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 Mg2+-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.

scholarly journals N 1 N 8-bis(γ-glutamyl)spermidine cross-linking in epidermal-cell envelopes. Comparison of cross-link levels in normal and psoriatic cell envelopes

1990 ◽  
Vol 271 (2) ◽  
pp. 305-308 ◽  
Author(s):  
N Martinet ◽  
S Beninati ◽  
T P Nigra ◽  
J E Folk
Keyword(s):  
Epidermal Cell ◽  
Skin Disease ◽  
Envelope Protein ◽  
Cell Envelope ◽  
Human Epidermis ◽  
Cross Linking ◽  
Cross Link ◽  
Gamma Glutamyl ◽  
Cell Envelopes ◽  
Isolated Cell

N1N8-Bis(gamma-glutamyl)spermidine was found in exhaustive proteolytic digests of isolated cell envelopes from human epidermis at levels comparable with those of epsilon-(gamma-glutamyl)lysine. Significantly higher than normal amounts of these compounds, particularly the bis(gamma-glutamyl)polyamine, were observed in envelopes from afflicted areas (scales) of psoriatic patients. These findings support the notions that N1N8-bis(gamma-glutamyl)spermidine, like epsilon-(gamma-glutamyl)lysine, functions in cell envelopes as an enzyme-generated protein cross-link and stabilizing force and that individuals with the chronic, recurrent skin disease, psoriasis, exhibit in involved epidermis abnormal cell-envelope-protein cross-linking.

Penetrability of a marine pseudomonad by inulin, sucrose, and glycerol and its relation to the mechanism of lysis

1970 ◽  
Vol 16 (2) ◽  
pp. 75-81 ◽  
Author(s):  
Francis L. A. Buckmire ◽  
Robert A. MacLeod
Keyword(s):  
Osmotic Pressure ◽  
Exchange Resin ◽  
Sucrose Solution ◽  
Cell Envelope ◽  
Sucrose Concentration ◽  
Ion Exchange Resin ◽  
Cell Preparation ◽  
Cell Envelopes ◽  
Almost All ◽  
Isolated Cell

Cells of a marine pseudomonad were prevented from lysing when suspended in a 0.15 M sucrose solution even after treatment of the sucrose with an ion exchange resin to remove contaminating trace elements. Isolated cell envelopes of the organism in concentrations of sucrose able to prevent lysis of the cells released non-dialyzable hexosamine-containing material into the suspending medium. This did not occur when the envelopes were suspended in concentrations of NaCl able to prevent cell lysis. Glycerol was found to occupy almost all the available fluid space in a packed cell preparation of the organism. Sucrose occupied less space than glycerol, and inulin the least. When the sucrose concentration was increased from 3 mM to 0.2 M, both the sucrose and inulin spaces increased. The results have been interpreted as indicating that sucrose prevents lysis by balancing the internal osmotic pressure of the cells, that the various layers of the cell envelope of the organism differ in their permeability to various solutes, and that the whole cell shrinks in solutions of high osmotic pressure.

scholarly journals Native Cell Wall Organization Shown by Cryo-Electron Microscopy Confirms the Existence of a Periplasmic Space in Staphylococcus aureus

2006 ◽  
Vol 188 (3) ◽  
pp. 1011-1021 ◽  
Author(s):  
Valério R. F. Matias ◽  
Terry J. Beveridge
Keyword(s):  
Electron Microscopy ◽  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Plasma Membrane ◽  
Cell Envelope ◽  
High Density ◽  
Low Density ◽  
Periplasmic Space ◽  
Wall Zone ◽  
Cell Envelopes

ABSTRACT The current perception of the ultrastructure of gram-positive cell envelopes relies mainly on electron microscopy of thin sections and on sample preparation. Freezing of cells into a matrix of amorphous ice (i.e., vitrification) results in optimal specimen preservation and allows the observation of cell envelope boundary layers in their (frozen) hydrated state. In this report, cryo-transmission electron microscopy of frozen-hydrated sections of Staphylococcus aureus D2C was used to examine cell envelope organization. A bipartite wall was positioned above the plasma membrane and consisted of a 16-nm low-density inner wall zone (IWZ), followed by a 19-nm high-density outer wall zone (OWZ). Observation of plasmolyzed cells, which were used to artificially separate the membrane from the wall, showed membrane vesicles within the space associated with the IWZ in native cells and a large gap between the membrane and OWZ, suggesting that the IWZ was devoid of a cross-linked polymeric cell wall network. Isolated wall fragments possessed only one zone of high density, with a constant level of density throughout their thickness, as was previously seen with the OWZs of intact cells. These results strongly indicate that the IWZ represents a periplasmic space, composed mostly of soluble low-density constituents confined between the plasma membrane and OWZ, and that the OWZ represents the peptidoglycan-teichoic acid cell wall network with its associated proteins. Cell wall differentiation was also seen at the septum of dividing cells. Here, two high-density zones were sandwiched between three low-density zones. It appeared that the septum consisted of an extension of the IWZ and OWZ from the outside peripheral wall, plus a low-density middle zone that separated adjacent septal cross walls, which could contribute to cell separation during division.

scholarly journals Changes in trehalose content of baker's yeast as affected by octanoic acid

1993 ◽  
Vol 50 (3) ◽  
pp. 460-463 ◽  
Author(s):  
L.E. Gutierrez
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Plasma Membrane ◽  
Octanoic Acid ◽  
Baker’S Yeast ◽  
Baker's Yeast ◽  
Ethanolic Fermentation ◽  
Trehalose Content ◽  
Trehalose Accumulation

Octanoic acid inhibited ethanolic fermentation by Saccharomyces cerevisiae (bakers yeast) and the trehalose accumulation, however did not affect the endogenous degradation of trehalose. This inhibition may be explained by the binding of octanoic acid to hexokinase or other proteins of plasma membrane because they are not necessary for endogenous fermentation. The degradation of trehalose may be due to an activation of trehalase.

scholarly journals Antigenicities of Several Cell Wall Mannan Preparations and Cell Envelope Preparations from Baker’s Yeast

1980 ◽  
Vol 44 (1) ◽  
pp. 49-53
Author(s):  
Youichi Tamai ◽  
Takahiro Nakashima ◽  
Masayoshi Takakuwa ◽  
Akira Misaki
Keyword(s):  
Cell Wall ◽  
Cell Envelope ◽  
Baker’S Yeast ◽  
Baker's Yeast ◽  
Cell Wall Mannan
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