Lux Sebastian, Vogt Clara, Voll Milena, Hoffmann Ralf
Institute of Bioanalytical Chemistry, Faculty of Chemistry, Universität Leipzig, Leipzig, Germany.
Center for Biotechnology and Biomedicine, Universität Leipzig, Deutscher Platz 5, 04103, Leipzig, Germany.
Anal Bioanal Chem. 2025 Aug 7. doi: 10.1007/s00216-025-06044-2.
Protein glycation, or non-enzymatic glycosylation, refers to the reaction of reducing sugars with amino groups in proteins to form Amadori and Heyns products for aldoses (e.g., glucose) and ketoses (e.g., fructose), respectively. While Amadori peptides have been well studied after enrichment by boronate affinity chromatography (BAC), it is often assumed that BAC also enriches the isomeric Heyns peptides, although the binding of Heyns rearrangement products seems unlikely due to the very low content of 1,2- and 1,3-cis-diols in their dominant tautomeric forms. For seven different tryptic peptide sequences derived from human plasma digests, we showed that the synthetic glucose-modified Amadori peptides can be enriched by BAC with high recovery rates, while the corresponding fructose-modified Heyns peptides did not bind, independent of the buffers and pH used. Reduction of the carbonyl groups with borohydride, yielding the corresponding hexitol-modified peptides, allowed enrichment of both the former Amadori and, more importantly, Heyns peptides.
蛋白质糖基化，即非酶糖基化，是指还原糖与蛋白质中的氨基反应，分别形成醛糖（如葡萄糖）的Amadori产物和酮糖（如果糖）的Heyns产物。虽然通过硼酸亲和色谱法（BAC）富集后，Amadori肽已得到充分研究，但人们通常认为BAC也能富集异构体Heyns肽，尽管Heyns重排产物的结合似乎不太可能，因为其主要互变异构体形式中1,2-和1,3-顺式二醇的含量非常低。对于源自人血浆消化物的七种不同胰蛋白酶肽序列，我们表明合成的葡萄糖修饰的Amadori肽可以通过BAC以高回收率富集，而相应的果糖修饰的Heyns肽不结合，这与所使用的缓冲液和pH无关。用硼氢化物还原羰基，得到相应的己糖醇修饰的肽，使得先前的Amadori肽以及更重要的Heyns肽都能被富集。
