Linamarase
Encyclopedia
Linamarase, or beta-D-glucosidase , is an enzyme
found in many plants including cassava
and the butter bean.
In cassava it is found in the cell wall
s. When the plant is chewed or ground, it exposes the enzyme to compounds like linamarin
and lotaustralin
which release cyanide
compounds that can be lethal to the eater. In human
s, chronic toxicity is more likely than death.
This action of the enzyme is used by many cultures to process cassava into an edible substance. The enzyme converts the cyanide containing compounds into acetone cyanohydrin
, which spontaneously decomposes to hydrogen cyanide (HCN). The HCN then either dissolves readily in water or is released into the air. Not all cyanide can be removed during processing.
Linamarase can be inhibited by low pH
via a dilute acid
.
Enzyme
Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...
found in many plants including cassava
Cassava
Cassava , also called yuca or manioc, a woody shrub of the Euphorbiaceae native to South America, is extensively cultivated as an annual crop in tropical and subtropical regions for its edible starchy tuberous root, a major source of carbohydrates...
and the butter bean.
In cassava it is found in the cell wall
Cell wall
The cell wall is the tough, usually flexible but sometimes fairly rigid layer that surrounds some types of cells. It is located outside the cell membrane and provides these cells with structural support and protection, and also acts as a filtering mechanism. A major function of the cell wall is to...
s. When the plant is chewed or ground, it exposes the enzyme to compounds like linamarin
Linamarin
Linamarin is a cyanogenic glucoside found in the leaves and roots of plants such as cassava, lima beans, and flax. It is a glucoside of acetone cyanohydrin...
and lotaustralin
Lotaustralin
Lotaustralin is a cyanogenic glucoside found in small amounts in Fabaceae Austral Trefoil , cassava , lima bean , roseroot and white clover , among other plants...
which release cyanide
Cyanide
A cyanide is a chemical compound that contains the cyano group, -C≡N, which consists of a carbon atom triple-bonded to a nitrogen atom. Cyanides most commonly refer to salts of the anion CN−. Most cyanides are highly toxic....
compounds that can be lethal to the eater. In human
Human
Humans are the only living species in the Homo genus...
s, chronic toxicity is more likely than death.
This action of the enzyme is used by many cultures to process cassava into an edible substance. The enzyme converts the cyanide containing compounds into acetone cyanohydrin
Acetone cyanohydrin
Acetone cyanohydrin is an organic compound used in the production of methyl methacrylate, the monomer of the transparent plastic polymethyl methacrylate , also known as acrylic.-Preparation:...
, which spontaneously decomposes to hydrogen cyanide (HCN). The HCN then either dissolves readily in water or is released into the air. Not all cyanide can be removed during processing.
Linamarase can be inhibited by low pH
PH
In chemistry, pH is a measure of the acidity or basicity of an aqueous solution. Pure water is said to be neutral, with a pH close to 7.0 at . Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline...
via a dilute acid
Acid
An acid is a substance which reacts with a base. Commonly, acids can be identified as tasting sour, reacting with metals such as calcium, and bases like sodium carbonate. Aqueous acids have a pH of less than 7, where an acid of lower pH is typically stronger, and turn blue litmus paper red...
.