The 'O-acyl isopeptide method' for the synthesis of difficult sequence-containing peptides:: application to the synthesis of Alzheimer's disease-related amyloid β peptide (Aβ) 1-42
The 'O-acyl isopeptide method' for the synthesis of difficult sequence-containing peptides:: application to the synthesis of Alzheimer's disease-related amyloid β peptide (Aβ) 1-42
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DOI：
10.1002/psc.649
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发表时间：
2005-07-01
影响因子：
2.1
通讯作者：
Kiso, Y
中科院分区：
文献类型：
--
作者：
Sohma, Y;Hayashi, Y;Kiso, Y
将合成困难序列多肽的“O-酰基异肽法”成功地应用于合成淀粉样β蛋白(A-β)1-42，即‘26-O-酰基异构体1-42’(6)。本文详细介绍了Aβ1-42的合成方法，重点介绍了树脂选择的重要性以及0-酰基异肽法中副反应的分析。用2-氯三丁基氯树脂合成了受保护的‘26-O-酰基异构体β1-42’肽树脂，与其他树脂相比副反应最少，去保护的粗品26-O-酰基异构体β1-42纯度较好，洗脱范围窄，具有较好的水溶性，易于用高效液相色谱分离纯化。这表明，在42个残基的多肽序列中只插入一次异肽结构就可以抑制其困难序列的不利性质。在生理条件下(pH 7.4)，O-酰基异肽通过O-N分子内酰基迁移反应快速迁移到完整的Aβ1-42，未观察到其他副产物的形成，而6在储存条件下是稳定的。这些结果表明，我们的策略不仅克服了合成Aβ1-42的溶解性问题，而且可以有效地提供完整的Aβ1-42，而且还适用于合成至少50个氨基酸以上的大的困难序列多肽。这种合成方法将为阿尔茨海默病的研究提供一种生物学评价系统，其中26-O-酰基异构体β1-42可以在使用前以溶解的形式储存，然后在生物实验中在原位快速产生完整的Aβ1-42。版权所有(C)2005欧洲肽协会和John Wiley&Sons，Ltd.
An efficient 'O-acyl isopeptide method' for the synthesis of difficult sequence-containing peptides was applied successfully to the synthesis of amyloid beta peptide (A beta) 1-42 via a water-soluble O-acyl isopeptide of A beta 1-42, i.e. '26-O-acyl isoA beta 1-42' (6). This paper describes the detailed synthesis of A beta 1-42 focusing on the importance of resin selection and the analysis of side reactions in the 0-acyl isopeptide method. Protected '26-O-acyl isoA beta 1-42' peptide resin was synthesized using 2-chlorotrityl chloride resin with minimum side reactions in comparison with other resins and deprotected crude 26-O-acyl isoA beta 1-42 was easily purified by HPLC due to its relatively good purity and narrow elution with reasonable water solubility. This suggests that only one insertion of the isopeptide structure into the sequence of the 42-residue peptide can suppress the unfavourable nature of its difficult sequence. The migration of O-acyl isopeptide to intact A beta 1-42 under physiological conditions (pH 7.4) via O-N intramolecular acyl migration reaction was very rapid and no other by-product formation was observed while 6 was stable under storage conditions. These results concluded that our strategy not only overcomes the solubility problem in the synthesis of A beta 1-42 and can provide intact A beta 1-42 efficiently, but is also applicable in the synthesis of large difficult sequence-containing peptides at least up to 50 amino acids. This synthesis method would provide a biological evaluation system in Alzheimer's disease research, in which 26-O-acyl isoA beta 1-42 can be stored in a solubilized form before use and then rapidly produces intact A beta 1-42 in situ during biological experiments. Copyright (c) 2005 European Peptide Society and John Wiley & Sons, Ltd.