catalyzes
Catalysis () is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst (). Catalysts are not consumed in the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recyc ...
the reaction
:''myo''-inositol hexakisphosphate + H2O = 1L-''myo''-inositol 1,2,3,4,6-pentakisphosphate + phosphate
''myo''-Inositol hexakisphosphate is also known as
phytic acid
Phytic acid is a six-fold dihydrogenphosphate ester of inositol (specifically, of the ''myo'' isomer), also called inositol hexakisphosphate (IP6) or inositol polyphosphate. At physiological pH, the phosphates are partially ionized, resulting ...
.
These enzymes belongs to the family of
hydrolase
Hydrolase is a class of enzyme that commonly perform as biochemical catalysts that use water to break a chemical bond, which typically results in dividing a larger molecule into smaller molecules. Some common examples of hydrolase enzymes are este ...
s, specifically those acting on phosphoric
monoester
In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides are fa ...
bonds. The
systematic name A systematic name is a name given in a systematic way to one unique group, organism, object or chemical substance, out of a specific population or collection. Systematic names are usually part of a nomenclature.
A semisystematic name or semitrivial ...
of this enzyme class is ''myo''-inositol-hexakisphosphate 5-phosphohydrolase.
Prevalence
Of the hundreds of phytase enzymes that have been characterized in the literature, only two have been characterized as 5-phytases. A histidine acid phosphatases purified from lily pollen and a protein tyrosine phosphatase-like phytase from ''Selenomonas ruminantium'' subsp. ''lactilytica'' were both found to have specificity for the 5-phosphate position of ''myo''-inositol hexakisphosphate.
Structural studies
As of late 2007, only the phytase purified from lily pollen had its
structure
A structure is an arrangement and organization of interrelated elements in a material object or system, or the object or system so organized. Material structures include man-made objects such as buildings and machines and natural objects such as ...
Protein tyrosine phosphatase
Protein tyrosine phosphatases (EC 3.1.3.48, systematic name protein-tyrosine-phosphate phosphohydrolase) are a group of enzymes that remove phosphate groups from phosphorylated tyrosine residues on proteins:
: proteintyrosine phosphate + H2O = ...