Dai Zhenyu, Nemet Ina, Shen Wei, Monnier Vincent M
Department of Biochemistry, Case Western Reserve University, Cleveland, OH 44106, USA.
Arch Biochem Biophys. 2007 Jul 1;463(1):78-88. doi: 10.1016/j.abb.2007.03.007. Epub 2007 Apr 2.
We isolated a novel acid-labile yellow chromophore from the incubation of lysine, histidine and d-threose and identified its chemical structure by one and two-dimensional NMR spectroscopy combined with LC-tandem mass spectrometry. This new cross-link exhibits a UV absorbance maximum at 305 nm and a molecular mass of 451 Da. The proposed structure is 2-amino-5-(3-((4-(2-amino-2-carboxyethyl)-1H-imidazol-1-yl)methyl)-4-(1,2-dihydroxyethyl)-2-formyl-1H-pyrrol-1-yl)pentatonic acid, a cross-link between lysine and histidine with addition of two threose molecules. It was in part deduced and confirmed through synthesis of the analogous compound from n-butylamine, imidazole and d-threose. We assigned the compound the trivial name histidino-threosidine. Systemic incubation revealed that histidino-threosidine can be formed in low amounts from fructose, glyceraldehyde, methylglyoxal, glycolaldehyde, ascorbic acid, and dehydroascorbic acid, but at a much higher yield with degradation products of ascorbic acid, i.e. threose, erythrose, and erythrulose. Bovine lens protein incubated with 10 and 50 mM threose for two weeks yielded 560 and 2840 pmol/mg histidino-threosidine. Histidino-threosidine is to our knowledge the first Maillard reaction product known to involve histidine in a crosslink.
我们从赖氨酸、组氨酸和d - 苏糖的孵育产物中分离出一种新型的酸不稳定黄色发色团，并通过一维和二维核磁共振光谱结合液相色谱 - 串联质谱法确定了其化学结构。这种新的交联物在305 nm处有最大紫外吸收，分子量为451 Da。推测的结构为2 - 氨基 - 5 - (3 - ((4 - (2 - 氨基 - 2 - 羧乙基)-1H - 咪唑 - 1 - 基)甲基)-4 - (1,2 - 二羟基乙基)-2 - 甲酰基 - 1H - 吡咯 - 1 - 基)戊糖酸，是赖氨酸和组氨酸之间的交联物，并额外添加了两个苏糖分子。部分结构通过由正丁胺、咪唑和d - 苏糖合成类似化合物得到推导和证实。我们将该化合物命名为组氨酸 - 苏糖苷。全身孵育实验表明，组氨酸 - 苏糖苷可由果糖、甘油醛、甲基乙二醛、乙醇醛、抗坏血酸和脱氢抗坏血酸少量生成，但由抗坏血酸的降解产物（即苏糖、赤藓糖和赤藓酮糖）生成的产率要高得多。用10 mM和50 mM苏糖孵育两周的牛晶状体蛋白分别产生了560和2840 pmol/mg的组氨酸 - 苏糖苷。据我们所知，组氨酸 - 苏糖苷是第一个已知的涉及组氨酸交联的美拉德反应产物。
