The Structure of the Yeast Cell Wall
Wilfred Niels Arnold
Journal of Biological Chemistry
Abstract
The autolytic release of β-fructofuranosidase (EC 3.2.1.26) and acid phosphatase (EC 3.1.3.2) from the cell wall of yeast was studied under different organic solvents and with a variety of pH and temperature conditions. β-Fructofuranosidase (but not acid phosphatase) was found to be a convenient marker for studying changes in the wall structure. The ethyl acetate-treated cell was characterized in terms of changes in cell volume, dry weight, total nitrogen, and phospholipid; and it was used as a model of wall structure. The β-fructofuranosidase content is little affected by ethyl acetate treatment, but a 2-day exposure completely inactivates the autolytic enzyme system. Approximately 50% of the marker can then be enzymatically released by incubation with a cell-free extract from fresh yeast. If ethyl acetate-treated cells are previously treated with dithiothreitol, 100% of the marker now becomes accessible and is liberated by cell-free extract. The effect of sulfhydryls was shown to be on a wall component. The cell-free extract was partially purified by heat treatment, ammonium sulfate precipitation, and dialysis with full retention of autolytic activity. Diethylaminoethyl-cellulose chromatography was used to resolve the extract into two active fractions. Fraction I is a β(1 → 6) glucanase, while Fraction II is a β(1 → 3) glucanase; both appear to be endohydrolases in their action pattern. Fractions I and II will account for, at most, 77% release of marker from ethyl acetate-treated cells. A third (or more) fraction(s) was clearly indicated but not identified. In living yeast cells the autolytic enzyme system is located internal to the protoplasmic membrane and, during toluene-induced autolysis, is retained by the cell at least until 20% of the marker has been liberated.
Extracted Claims
5 claims extracted from this paper into the knowledge graph
β-fructofuranosidase is released by incubation with a cell-free extract from fresh yeast
“Approximately 50% of the marker can then be enzymatically released by incubation with a cell-free extract from fresh yeast.”
β-fructofuranosidase is affected by ethyl acetate treatment
“The β-fructofuranosidase content is little affected by ethyl acetate treatment, but a 2-day exposure completely inactivates the autolytic enzyme system.”
β-fructofuranosidase is accessible and liberated by cell-free extract after dithiothreitol treatment
“If ethyl acetate-treated cells are previously treated with dithiothreitol, 100% of the marker now becomes accessible and is liberated by cell-free extract.”