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Enolase, also known as phosphopyruvate hydratase, is a metalloenzyme responsible for the catalysis of the conversion of 2-phosphoglycerate (2-PG) to phosphoenolpyruvate (PEP), the ninth and penultimate step of glycolysis. The chemical reaction catalyzed by enolase is: :2-phospho-D-glycerate phosphoenolpyruvate + H2O Enolase belongs to the family of lyases, specifically the hydro-lyases, which cleave carbon-oxygen bonds. The systematic name of this enzyme is 2-phospho-D-glycerate hydro-lyase (phosphoenolpyruvate-forming). The reaction is reversible, depending on environmental concentrations of substrates. The optimum pH for the human enzyme is 6.5. Enolase is present in all tissues and organisms capable of glycolysis or fermentation. The enzyme was discovered by Lohmann and Meyerhof in 1934,〔Lohman K & Meyerhof O (1934) Über die enzymatische umwandlung von phosphoglyzerinsäure in brenztraubensäure und phosphorsäure (Enzymatic transformation of phosphoglyceric acid into pyruvic and phosphoric acid). Biochem Z 273, 60–72.〕 == Isozymes == In humans there are three subunits of enolase, α, β, and γ, each encoded by a separate gene that can combine to form five different isoenzymes: αα, αβ, αγ, ββ, and γγ.〔 Three of these isoenzymes (all homodimers) are more commonly found in adult human cells than the others: * αα or non-neuronal enolase (NNE), which is found in a variety of tissues, including liver, brain, kidney, spleen, adipose. It is present at some level in all normal human cells. Also known as enolase 1 * ββ or muscle specific enolase (MSE). Also known as enolase 3. This enzyme is largely restricted to muscle where it is present at very high levels in muscle * γγ or neuron-specific enolase (NSE). Also known as enolase 2. Expressed at very high levels in neurons and neural tissues, where it can account for as much as 3% of total soluble protein. It is expressed at much lower levels in most mammalian cells. When present in the same cell, different isozymes readily form heterodimers. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「enolase」の詳細全文を読む スポンサード リンク
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