Cross-linking of proteins by Maillard processes: Characterization and detection of lysine-arginine cross-links derived from glyoxal and methylglyoxal
Cross-linking of proteins by Maillard processes: Characterization and detection of lysine-arginine cross-links derived from glyoxal and methylglyoxal
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DOI：
10.1016/s0968-0896(99)00212-6
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发表时间：
1999-11-01
影响因子：
3.5
通讯作者：
Klaiber, RG
中科院分区：
文献类型：
--
作者：
Lederer, MO;Klaiber, RG
-二羰基化合物，如乙二醛和甲基乙二醛，是美拉德反应过程中通过还原糖使蛋白质褐变和交联的关键中间体。从乙二醛/甲基乙二醛-牛血清白蛋白（BSA）培养中，鉴定并定量了2-氨-6-（{2-[（4-氨-5-氧化-5-氧戊基）氨基]-4,5-二氢- 1h -咪唑-5-氧戊基）氨基)己酸酯（9)和2-氨-6-（{2-[（4-氨-5-氧化-5-氧戊基）氨基]-4-甲基-4,5-二氢- 1h -咪唑-5-氧戊基）氨基）己酸酯（10）的交联单元GODIC和MODIC。给出了9和10的独立合成和明确的结构表征。建立了电喷雾电离（ESI）液相色谱-质谱联用测定方法。将牛血清白蛋白与α -二羰基化合物分别在37℃、pH 7.4条件下培养1周，观察9和10的形成随时间的变化。在含有50g /L BSA和2mM乙二醛或甲基乙二醛的溶液中，经过7天的孵育，得到的最大值对应于精氨酸衍生配额为13.0 +/- 0.32 mmol 9；或3.0 +/- 0.12 mmol 10/mol Arg。在d -葡萄糖-牛血清白蛋白孵育中也检测到交联9和10。从这些结果来看，似乎有理由认为9和10在体内和食品中蛋白质的交联中都起着重要作用。在另一个模型研究中，9和10的形成与咪唑交联物GOLD 3和MOLD 3的形成进行了比较。1999爱思唯尔科学有限公司版权所有。
alpha-Dicarbonyl compounds, such as glyoxal and methylglyoxal, are crucial intermediates in the browning and cross-linking of proteins by reducing sugars in the course of the Maillard reaction. The cross linking units 2-ammonio-6-({2-[(4-ammonio-5-oxido-5-oxopentyl)amino]-4,5-dihydro-1H-imidazol-5-ylidene}amino)hexanoate (9) and 2-ammonio-6-({2-[(4-ammonio-5-oxido-5-oxopentyl)amino]-4-methyl-4,5-dihydro-1H-imidazol-5-ylidene}amino)hexanoate (10), designated as GODIC and MODIC, are identified and quantified from glyoxal/methylglyoxal-bovine serum albumin (BSA) incubations. Independent syntheses and unequivocal structural characterization are given for 9 and 10. A protocol was established for their determination by liquid chromatography-mass spectrometry (LC-MS) with electrospray ionization (ESI). BSA and the respective alpha-dicarbonyl compound were incubated at 37 degrees C, pH 7.4 for 1 week, and the time-dependent formation of 9 and 10 was observed. The maximum value obtained from a solution containing 50 g/L BSA and 2mM glyoxal or methylglyoxal after a 7-day incubation period corresponds to an arginine derivatization quota of 13.0 +/- 0.32 mmol 9;mol Arg or 3.0 +/- 0.12 mmol 10/mol Arg. The cross-links 9 and 10 were also detected in a D-glucose-BSA incubation. From these results, it seems justified to assign an important role to 9 and 10 in the cross-linking of proteins in vivo as well as in foodstuffs. In an additional model study, formation of 9 and 10 was compared to that of the imidazolium cross-links GOLD 3 and MOLD 3. (C) 1999 Elsevier Science Ltd. All rights reserved.