Allen sandbox 1: Difference between revisions
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'''Step 2''': Lys 345 then deprotonates the alpha hydrogen, a reaction which is stabilized by resonance between the carboxyl oxygens and the two Mg ions and Glu 211 bonded to the hydroxyl group. This creates a carbanion intermediate. | '''Step 2''': Lys 345 then deprotonates the alpha hydrogen, a reaction which is stabilized by resonance between the carboxyl oxygens and the two Mg ions and Glu 211 bonded to the hydroxyl group. This creates a carbanion intermediate. | ||
'''Step 3''': An electron transfer reaction then occurs from the C'1 carboxyl oxygen to form a ketone. This removes electrons from the alkene bond between C'1 and C'2 to create an alkene between C'2 and C'3 instead. This allows the C'3 hydroxyl group to deprotonate Glu 211, resulting in the ejection of a water molecule and formation of the product PEP. PEP is then dephosphorylated in the next step of glycolysis to create pyruvate. | '''Step 3''': An electron transfer reaction then occurs from the C'1 carboxyl oxygen to form a ketone. This removes electrons from the alkene bond between C'1 and C'2 to create an alkene between C'2 and C'3 instead. This allows the C'3 hydroxyl group to deprotonate Glu 211, resulting in the ejection of a water molecule and formation of the product PEP. PEP is then dephosphorylated in the next step of glycolysis to create pyruvate. | ||
Studies have shown that mutating the residues within the active site can have serious effects on the activity of the enzyme. For example, mutation in either Glu 168, Glu 211, Lys 345, or Lys 396 of the active site results in a reduction in the reaction activity by 10^4 to 10^5 of wild type levels. Clearly, these residues play critical roles in maintaining enolase's activity.<ref></ref> | |||
Additionally, this mechanism can be inhibited by addition of Fluoride ions, which bond to Mg 2+, thus blocking the substrate (2PG) from binding to the active site of enolase.<ref>{{textbook |author=Voet, Donald; Voet, Judith C.; Pratt, Charlotte W.|title=Fundamentals of Biochemistry: Life at the Molecular Level|edition= 3|pages=500|}}</ref> | Additionally, this mechanism can be inhibited by addition of Fluoride ions, which bond to Mg 2+, thus blocking the substrate (2PG) from binding to the active site of enolase.<ref>{{textbook |author=Voet, Donald; Voet, Judith C.; Pratt, Charlotte W.|title=Fundamentals of Biochemistry: Life at the Molecular Level|edition= 3|pages=500|}}</ref> | ||
==Kinetics== | ==Kinetics== | ||