catalyzes
Catalysis () is the increase in rate of a chemical reaction due to an added substance known as a catalyst (). Catalysts are not consumed by the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recycles quick ...
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 hexaphosphate, inositol hexakisphosphate (IP6) or inositol polyphosphate. At physiological pH, the phosphates are partia ...
.
These enzymes belongs to the family of
hydrolase
In biochemistry, hydrolases constitute a class of enzymes that commonly function as biochemical catalysts that use water to break a chemical bond:
:\ce \quad \xrightarrowtext\quad \ce
This typically results in dividing a larger molecule into s ...
s, specifically those acting on phosphoric
monoester
In chemistry, an ester is a compound derived from an acid (either organic or inorganic) in which the hydrogen atom (H) of at least one acidic hydroxyl group () of that acid is replaced by an organyl group (R). These compounds contain a distinct ...
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 semitrivi ...
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 ...
3-phytase
The enzyme 3-phytase (EC 3.1.3.8) catalyzes the reaction
: ''myo''-inositol hexakisphosphate + H2O = 1D-''myo''-inositol 1,2,4,5,6-pentakisphosphate + phosphate
''myo''-Inositol hexakisphosphate is also known as phytic acid.
These enzymes belon ...
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 = ...