List of mathematical jargon: Difference between revisions
Jump to navigation
Jump to search
en>Rgdboer m →Philosophy of mathematics: lk mathematical folklore |
|||
| Line 1: | Line 1: | ||
{{Infobox enzyme | |||
| Name = Phosphorylase | |||
| EC_number = 2.4.1.1 | |||
| CAS_number = 9035-74-9 | |||
| IUBMB_EC_number = 2/4/1/1 | |||
| GO_code = | |||
| image = | |||
| width = | |||
| caption = | |||
}} | |||
'''Phosphorylases''' are enzymes that catalyze the addition of a phosphate group from an inorganic phosphate (phosphate+hydrogen) to an acceptor. | |||
:A-B + P <math>\rightleftharpoons</math> A + P-B | |||
They include [[Allosteric regulation|allosteric]] [[enzyme]]s that [[catalysis|catalyze]] the production of [[glucose-1-phosphate]] from a [[glucan]] such as [[glycogen]], [[starch]] or [[maltodextrin]]. Phosphorylase is also a common name used for [[glycogen phosphorylase]] in honor of Earl W. Sutherland Jr. who in the late 1930s discovered the first phosphorylase.<ref>Lehninger Principles of Biochemistry 5th ed. pg. 603</ref> | |||
== Function == | |||
Not to be confused with phosphotases. | |||
In more general terms, phosphorylases are enzymes that catalyze the addition of a phosphate group from an inorganic phosphate (phosphate+hydrogen) to an acceptor, not to be confused with a [[phosphatase]] (a [[hydrolase]]) or a [[kinase]] (a phosphotransferase). A phosphatase removes a phosphonate group from a donor using water, whereas a kinase transfers a phosphonate group from a donor (usually ATP) to an acceptor. | |||
{| class=wikitable | |||
!Enzyme name | |||
!Enzymes class | |||
!Reaction | |||
!Notes | |||
|- | |||
|Phosphorylase|| Transferase<br>(EC 2.4 and EC 2.7.7) | |||
||A-B + H-'''OP''' <math>\rightleftharpoons</math> A-'''OP''' + H-B | |||
|| transfer group = A = [[glycosyl]]- group or<br> [[nucleotidyl]]- group | |||
|-' | |||
|Phosphatase|| Hydrolase<br>(EC 3) | |||
||'''P'''-B + H-OH <math>\rightleftharpoons</math> '''P'''-OH + H-B | |||
|| | |||
|- | |||
|Kinase|| Transferase<br>(EC 2.7.1-2.7.4) | |||
||'''P'''-B + H-A <math>\rightleftharpoons</math> '''P'''-A + H-B | |||
|| transfer group = '''P''' | |||
|- | |||
|colspan=4|'''P''' = [[phosphonate]] group, '''OP''' = phosphate group, H-'''OP''' or '''P'''-OH = inorganic phosphate | |||
|} | |||
== Types == | |||
The phosphorylases fall into the following categories: | |||
*Glycosyltransferases (EC 2.4) | |||
**Enzymes that break down [[glucan]]s by removing a glucose residue (break ''O''-glycosidic bond) | |||
***[[glycogen phosphorylase]] | |||
***[[starch phosphorylase]] | |||
***[[maltodextrin phosphorylase]] | |||
**Enzymes that break down [[nucleoside]]s into their constituent bases and sugars (break ''N''-glycosidic bond) | |||
***[[Purine nucleoside phosphorylase]] (PNPase) | |||
*Nucleotidyltransferases (EC 2.7.7) | |||
**Enzymes that have phosphorolytic 3' to 5' exoribonuclease activity (break phosphodiester bond) | |||
***[[RNase PH]] | |||
***[[Polynucleotide Phosphorylase]] (PNPase) | |||
All '''known''' phosphorylases share catalytic and structural properties [http://www.expasy.org/cgi-bin/nicedoc.pl?PDOC00095]. | |||
== Activation == | |||
'''Phosphorylase a''' is the active form of glycogen phosphorylase that is derived from the phosphorylation of the inactive form, '''phosphorylase b'''. | |||
== Pathology == | |||
Some disorders are related to phosphorylases: | |||
* [[Glycogen storage disease type V]] - muscle glycogen | |||
* [[Glycogen storage disease type VI]] - liver glycogen | |||
==See also== | |||
*[[Hydrolase]] | |||
== References == | |||
<references/> | |||
== External links == | |||
*[http://mcardlesdisease.org Muscle phosphorylase deficiency - McArdle's Disease Website] | |||
* {{MeshName|Phosphorylases}} | |||
{{Glycosyltransferases}} | |||
{{Kinases}} | |||
[[Category:Transferases]] | |||
[[Category:EC 2.4.1]] | |||
{{transferase-stub}} | |||
Revision as of 14:00, 11 December 2013
Template:Infobox enzyme Phosphorylases are enzymes that catalyze the addition of a phosphate group from an inorganic phosphate (phosphate+hydrogen) to an acceptor.
They include allosteric enzymes that catalyze the production of glucose-1-phosphate from a glucan such as glycogen, starch or maltodextrin. Phosphorylase is also a common name used for glycogen phosphorylase in honor of Earl W. Sutherland Jr. who in the late 1930s discovered the first phosphorylase.[1]
Function
Not to be confused with phosphotases. In more general terms, phosphorylases are enzymes that catalyze the addition of a phosphate group from an inorganic phosphate (phosphate+hydrogen) to an acceptor, not to be confused with a phosphatase (a hydrolase) or a kinase (a phosphotransferase). A phosphatase removes a phosphonate group from a donor using water, whereas a kinase transfers a phosphonate group from a donor (usually ATP) to an acceptor.
| Enzyme name | Enzymes class | Reaction | Notes |
|---|---|---|---|
| Phosphorylase | Transferase (EC 2.4 and EC 2.7.7) |
A-B + H-OP A-OP + H-B | transfer group = A = glycosyl- group or nucleotidyl- group |
| Phosphatase | Hydrolase (EC 3) |
P-B + H-OH P-OH + H-B | |
| Kinase | Transferase (EC 2.7.1-2.7.4) |
P-B + H-A P-A + H-B | transfer group = P |
| P = phosphonate group, OP = phosphate group, H-OP or P-OH = inorganic phosphate | |||
Types
The phosphorylases fall into the following categories:
- Glycosyltransferases (EC 2.4)
- Enzymes that break down glucans by removing a glucose residue (break O-glycosidic bond)
- Enzymes that break down nucleosides into their constituent bases and sugars (break N-glycosidic bond)
- Purine nucleoside phosphorylase (PNPase)
- Nucleotidyltransferases (EC 2.7.7)
- Enzymes that have phosphorolytic 3' to 5' exoribonuclease activity (break phosphodiester bond)
- RNase PH
- Polynucleotide Phosphorylase (PNPase)
- Enzymes that have phosphorolytic 3' to 5' exoribonuclease activity (break phosphodiester bond)
All known phosphorylases share catalytic and structural properties [1].
Activation
Phosphorylase a is the active form of glycogen phosphorylase that is derived from the phosphorylation of the inactive form, phosphorylase b.
Pathology
Some disorders are related to phosphorylases:
- Glycogen storage disease type V - muscle glycogen
- Glycogen storage disease type VI - liver glycogen
See also
References
- ↑ Lehninger Principles of Biochemistry 5th ed. pg. 603