Hinton D J S, Ames J M
Hugh Sinclair Unit of Human Nutrition, School of Food Biosciences, University of Reading, Whiteknights, Reading, UK.
Amino Acids. 2006 Jun;30(4):425-34. doi: 10.1007/s00726-006-0269-2. Epub 2006 Apr 4.
We report an investigation of the site specificity, extent and nature of modification of bovine serum albumin (BSA) incubated with fructose or glucose at physiological temperature and pH. Sites of early glycation (Heyns rearrangement products (HRP) from fructose; fructoselysine (FL) from glucose) as well as advanced glycation (N(epsilon)-(carboxymethyl)lysine; CML) were analyzed by liquid chromatography-mass spectrometry. The major site of modification by fructose, like glucose, is Lysine-524 and this results in, respectively, 31 and 76% loss of the corresponding unmodified tryptic peptide, Gln525-Lys533. In addition, total lysine, HRP, FL, CML and N(epsilon)-(carboxyethyl)lysine in the incubations, was quantified. Almost all of the loss of lysine in the fructose-modified BSA was attributed to the formation of CML, with the yield of CML being up to 17-fold higher than glucose-modified BSA. A mechanism for the formation of CML from the HRP is proposed.
我们报告了一项关于牛血清白蛋白（BSA）在生理温度和pH条件下与果糖或葡萄糖孵育时修饰的位点特异性、程度和性质的研究。通过液相色谱-质谱法分析了早期糖基化位点（果糖产生的海因斯重排产物（HRP）；葡萄糖产生的果糖赖氨酸（FL））以及晚期糖基化位点（N（ε）-（羧甲基）赖氨酸；CML）。与葡萄糖一样，果糖修饰的主要位点是赖氨酸-524，这分别导致相应未修饰的胰蛋白酶肽Gln525-Lys533损失31%和76%。此外，还对孵育物中的总赖氨酸、HRP、FL、CML和N（ε）-（羧乙基）赖氨酸进行了定量。果糖修饰的BSA中赖氨酸的几乎所有损失都归因于CML的形成，CML的产量比葡萄糖修饰的BSA高17倍。提出了一种由HRP形成CML的机制。
