Kraunsoe J A, Aplin R T, Green B, Lowe G
Dyson Perrins Laboratory and Oxford Centre for Molecular Sciences, University of Oxford, UK.
FEBS Lett. 1996 Oct 28;396(1):108-12. doi: 10.1016/0014-5793(96)01081-2.
The binding of BPTI and SBTI with trypsin has been investigated by ESI MS, using the mutant K15V-BPTI and the chemically modified RcamBPTI as controls. Although high cone voltages (+80 V) produce sharp spectra of BPTI, RcamBPTI, SBTI and trypsin alone, the complexes of BPTI, RcamBPTI and SBTI with trypsin undergo partial dissociation due to collisional activation. At lower cone voltages (+40 V) these non-covalent complexes are stable. The charge distribution on the trypsin and the inhibitors produced by gas phase dissociation of the complexes are markedly different from those of the components alone, indicating that ESI MS provides a novel probe for exploring the ionic interactions at the contact surface of proteins. Moreover, by determining the cone voltage at which the gas phase dissociation of complexes occurs it may be possible to use ESI MS to compare the binding energies of closely related complexes.
通过电喷雾电离质谱法（ESI MS），以突变体K15V - BPTI和化学修饰的RcamBPTI作为对照，研究了BPTI和SBTI与胰蛋白酶的结合情况。尽管高锥电压（+80 V）能产生单独的BPTI、RcamBPTI、SBTI和胰蛋白酶的尖锐光谱，但由于碰撞激活，BPTI、RcamBPTI和SBTI与胰蛋白酶的复合物会发生部分解离。在较低锥电压（+40 V）下，这些非共价复合物是稳定的。复合物气相解离产生的胰蛋白酶和抑制剂上的电荷分布与单独组分的电荷分布明显不同，这表明ESI MS为探索蛋白质接触表面的离子相互作用提供了一种新探针。此外，通过确定复合物发生气相解离的锥电压，有可能利用ESI MS比较密切相关复合物的结合能。
