AndrewAlexanderSandbox1: Difference between revisions

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Pyruvate kinase is primarily allosterically regulated <ref>{{article |author=Valentini, Giovanni; Chiarelli, Laurent.|title=The Allosteric Regulation of Pyruvate Kinase|volume=275|pages=18145-18152|}}</ref>. Allosteric regulation of enzyme activity is a mechanism for finely tuning biochemical reaction pathways in order to maintain an appropriate balance of intracellular substrate and product concentrations. Allosteric processes also allow an enzyme's activity to be coordinated with other cellular reactions and signaling pathways.Through site directed mutagenisis studies, Lys382 is suggested to be involved in both activator binding and in the allosteric transition mechanism. These domain interfaces are critical for the trasnition. Tey couple changes in the tertiary and quaternary structures in fructose 1,6 biphosphate binding sites for pyruvate kinase.

The allosteric site is located 40 å from the active site and is entirely located in the enzyme regulatory (C) domain. A phosphate-binding site for the allosteric activator is created by residues encoded by a region of the gene that corresponds to spliced exons of mammalian isozymes<ref>{{article |author=Jurrica, Mellisa.; Mesecar, Andrew.|title=The allosteric regulation of pyruvate kinase by fructose-1,6-bisphosphatevolume=6|pages=195-210|}}</ref>. FBP activation induces several conformational changes among active-site sidechains through a mechanism that is most likely to involve significant domain motions. The conformational differences observed between the active sites of inactive and fully active Pyruvate Kinase enzymes is in agreement with the ~~rhermodynamic~~ mechanism of allosteric activation through a metal relay that increases the affinity of the enzyme for its phosphoenolpyruvate substrate.

The allosteric site is located 40 å from the active site and is entirely located in the enzyme regulatory (C) domain. A phosphate-binding site for the allosteric activator is created by residues encoded by a region of the gene that corresponds to spliced exons of mammalian isozymes<ref>{{article |author=Jurrica, Mellisa.; Mesecar, Andrew.|title=The allosteric regulation of pyruvate kinase by fructose-1,6-bisphosphatevolume=6|pages=195-210|}}</ref>. FBP activation induces several conformational changes among active-site sidechains through a mechanism that is most likely to involve significant domain motions. The conformational differences observed between the active sites of inactive and fully active Pyruvate Kinase enzymes is in agreement with the thermodynamic mechanism of allosteric activation through a metal relay that increases the affinity of the enzyme for its phosphoenolpyruvate substrate.

AndrewAlexanderSandbox1: Difference between revisions

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Revision as of 03:22, 18 April 2011 view source Andrew Alexander (talk \| contribs) 49 edits →Kinetics and Regulation ← Older edit		Revision as of 03:24, 18 April 2011 view source Andrew Alexander (talk \| contribs) 49 edits →Kinetics and Regulation Newer edit →
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	Pyruvate kinase is primarily allosterically regulated <ref>{{article \|author=Valentini, Giovanni; Chiarelli, Laurent.\|title=The Allosteric Regulation of Pyruvate Kinase\|volume=275\|pages=18145-18152\|}}</ref>. Allosteric regulation of enzyme activity is a mechanism for finely tuning biochemical reaction pathways in order to maintain an appropriate balance of intracellular substrate and product concentrations. Allosteric processes also allow an enzyme's activity to be coordinated with other cellular reactions and signaling pathways.Through site directed mutagenisis studies, Lys382 is suggested to be involved in both activator binding and in the allosteric transition mechanism. These domain interfaces are critical for the trasnition. Tey couple changes in the tertiary and quaternary structures in fructose 1,6 biphosphate binding sites for pyruvate kinase.		Pyruvate kinase is primarily allosterically regulated <ref>{{article \|author=Valentini, Giovanni; Chiarelli, Laurent.\|title=The Allosteric Regulation of Pyruvate Kinase\|volume=275\|pages=18145-18152\|}}</ref>. Allosteric regulation of enzyme activity is a mechanism for finely tuning biochemical reaction pathways in order to maintain an appropriate balance of intracellular substrate and product concentrations. Allosteric processes also allow an enzyme's activity to be coordinated with other cellular reactions and signaling pathways.Through site directed mutagenisis studies, Lys382 is suggested to be involved in both activator binding and in the allosteric transition mechanism. These domain interfaces are critical for the trasnition. Tey couple changes in the tertiary and quaternary structures in fructose 1,6 biphosphate binding sites for pyruvate kinase.

	The allosteric site is located 40 å from the active site and is entirely located in the enzyme regulatory (C) domain. A phosphate-binding site for the allosteric activator is created by residues encoded by a region of the gene that corresponds to spliced exons of mammalian isozymes<ref>{{article \|author=Jurrica, Mellisa.; Mesecar, Andrew.\|title=The allosteric regulation of pyruvate kinase by fructose-1,6-bisphosphatevolume=6\|pages=195-210\|}}</ref>. FBP activation induces several conformational changes among active-site sidechains through a mechanism that is most likely to involve significant domain motions. The conformational differences observed between the active sites of inactive and fully active Pyruvate Kinase enzymes is in agreement with the ~~rhermodynamic~~ mechanism of allosteric activation through a metal relay that increases the affinity of the enzyme for its phosphoenolpyruvate substrate.		The allosteric site is located 40 å from the active site and is entirely located in the enzyme regulatory (C) domain. A phosphate-binding site for the allosteric activator is created by residues encoded by a region of the gene that corresponds to spliced exons of mammalian isozymes<ref>{{article \|author=Jurrica, Mellisa.; Mesecar, Andrew.\|title=The allosteric regulation of pyruvate kinase by fructose-1,6-bisphosphatevolume=6\|pages=195-210\|}}</ref>. FBP activation induces several conformational changes among active-site sidechains through a mechanism that is most likely to involve significant domain motions. The conformational differences observed between the active sites of inactive and fully active Pyruvate Kinase enzymes is in agreement with the thermodynamic mechanism of allosteric activation through a metal relay that increases the affinity of the enzyme for its phosphoenolpyruvate substrate.