茶树花青素还原酶的酶学特性研究

Research on Enzymatic Characteristics of Anthocyanin Reductase of Tea Plant [Camellia sinensis (L.) O. Kuntze]

茶树花青素还原酶(CsANR)作为原花青素生物合成途径中的关键酶,催化花青素为相应的2,3-顺式-黄烷-3-醇。为了研究该酶的酶学特性,本文采用原核表达及钴离子亲和柱纯化技术,表达并纯化出目的蛋白;重点对CsANR1酶学特性进行研究分析。结果表明,CsANR1的最适反应温度为40℃,最适pH值为6.5;对底物矢车菊色素的亲和力高于飞燕草色素。Cu2+、Co2+、Fe2+、Mn2+、Zn2+和Hg2+等金属离子对酶有抑制作用,存放15d后酶活下降50%。

Anthocyanidin reductase （ANR） is a key enzyme in the biosynthetic pathway of proanthocyanidins（PAs）, which catalyzes anthocyanidins into the corresponding 2, 3-cis-flavan-3-ols. For researching enzymatic characteristics of the enzyme, this study was carried out to express and purify the protein by prokaryotic expression and Cobalt ion affinity column purification. The optimal conditions of CsANR1 were observed at 40℃ and pH 6.5. The more substrate preference of CsANR1 was showed on cyanidin over delphinidin. Moreover, Cu^2＋, Co^2＋, Fe^2＋, Mn^2＋, Zn^2＋ and Hg^2＋inhibited the enzyme activity and the enzyme activity decreased 50% after storing 15 days.