Reactivity and Applications of New Amine Reactive Cross-Linkers for Mass Spectrometric Detection of Protein−Protein Complexes
作者:Claudia Bich、Stefanie Maedler、Katja Chiesa、Fabio DeGiacomo、Nicolas Bogliotti、Renato Zenobi
DOI:10.1021/ac901651r
日期:2010.1.1
Chemical cross-linking of proteins permits the stabilization of noncovalent complexes through introduction of covalent bonds. A crucial challenge is to find the fastest and most efficient cross-linkers in order to minimize reaction times and to handle delicate complexes. New cross-linkers were synthesized by introducing N-hydroxyphthalimide, hydroxybenzotriazole, and 1-hydroxy-7-azabenzotriazole as leaving groups instead of the commonly used N-hydroxysuccimidyl moiety. With the use of matrix-assisted laser desorption ionization (MALDI) mass spectrometry, these new cross-linkers were then compared with the commercially available disuccinimidyl suberate (DSS) for covalent stabilization of the gluthatione-S-transferase (GST) dimer and of an antibody−antigen complex. They showed a better efficiency, generated about 30% more cross-linked complex, and reacted about 10 times faster than DSS. The reaction with the GST dimer was utilized to get information about their reaction efficiency and kinetics. Their ability to stabilize only specific protein complexes was verified by incubating them with a mixture of the proteins GST and ubiquitin. Finally, the cross-linkers were incubated with synthetic peptides to study the selectivity of the binding with various amino acid side chains. Not only lysine but also tyrosine was found to react with the newly synthesized cross-linker containing 1-hydroxy-7-azabenzotriazole as the reactive group.
蛋白质的化学交联可以通过引入共价键来稳定非共价复合物。如何找到最快、最有效的交联剂,以最大限度地缩短反应时间并处理微妙的复合物,是一项严峻的挑战。通过引入 N-羟基邻苯二甲酰亚胺、羟基苯并三唑和 1-羟基-7-氮杂苯并三唑作为离去基团,而不是常用的 N-羟基琥珀酰亚胺基团,合成了新的交联剂。然后,利用基质辅助激光解吸电离(MALDI)质谱法,将这些新型交联剂与市售的丁二酰亚胺基辛二酸二酯(DSS)进行了比较,以对谷氨酰化-S-转移酶(GST)二聚体和抗体-抗原复合物进行共价稳定。它们显示出更高的效率,产生的交联复合物比 DSS 多约 30%,反应速度比 DSS 快约 10 倍。利用与 GST 二聚体的反应来了解它们的反应效率和动力学。通过将它们与 GST 和泛素的混合物一起培养,验证了它们只稳定特定蛋白质复合物的能力。最后,交联剂与合成肽进行了孵育,以研究与各种氨基酸侧链结合的选择性。结果发现,不仅赖氨酸,酪氨酸也能与新合成的以 1-hydroxy-7-azabenzotriazole 为活性基团的交联剂发生反应。