神秘果素的研究进展

神秘果素(miraculin,MIR)是在神秘果中(Synsepalum dulcificum)发现的一种变味糖蛋白,又称为变味魔术师。神秘果素由191个氨基酸组成,其主要活性形式为二聚体和四聚体,His-30和His-60是这个糖蛋白的活性中心位点,Asn-42和Asn-186是神秘果素的糖基化位点,Cys对蛋白的结构和折叠也有一定的影响。神秘果素本身并没有甜味,在中性条件下不表现出活性,但是在酸性条件下能够产生让酸的食物变甜的活性,并且这种影响能够持续一段时间(1～ 2 h);另一方面,神秘果素能够在一定程度上提高糖尿病动物对胰岛素的敏感性。最新的制备方法是通过从神秘果中直接提取、转基因到植物中和在微生物中进行表达等方法。综述了神秘果素的结构、功能和制备方法等方面的研究进展。

Summarized on function and preparation of miraculin

Miraculin,a taste-modify glycoprotein,is first discovered in the miracle fruit(Synsepalum dulcificum).Miraculin is made up of 191 amino acids,and the main active forms of it are dimmers and tetramers,in which His-30 and His-60 are the active centers.Cys also plays a role in its structure forming and folding to some degree.The glycosylation sites of miraculin are Asn-42 and Asn-186.Miraculin itself does not taste sweet,and in the neutral pH condition it does not show any activity either.But under acidic condition,it can bring about an activity of changing food from sour to sweet,which may last for 1~2 h.On the side,miraculin can increase the sensitivity of diabetic animals to insulin.The latest preparation methods of miraculin are direct extraction from Synsepalum dulcificum and expressing in transgenic plants or microbiology.In this paper,we summarized the miraculin structure,function and preparation methods in many latest researches.