Probing higher order multimers of pyruvate kinase with charge detection mass spectrometry
Probing higher order multimers of pyruvate kinase with charge detection mass spectrometry
复制标题
DOI：
10.1016/j.ijms.2013.01.002
复制
发表时间：
2013-03-01
影响因子：
1.8
通讯作者：
Jarrold, Martin F.
中科院分区：
文献类型：
--
作者：
Pierson, Elizabeth E.;Keifer, David Z.;Jarrold, Martin F.
丙酮酸激酶多聚体已经通过电荷检测质谱（CDMS）进行了研究。在CDMS中，同时测量每个离子的m/z和z，因此可以直接确定质量。测量是使用一个修改后的锥形陷阱，它结合了图像电荷探测器与低温冷却的电子束。在非变性溶液条件下，观察到丙酮酸激酶的四聚体形式沿着四聚体的聚集体。飞行时间m/z光谱显示八聚体和十二聚体。然而，电荷状态分辨率的缺乏阻止了更大的多聚体的鉴定。CDMS显示了高达40-met的多聚体。它们的强度随体积呈指数下降。证据支持一个非特定的，基于解决方案的聚合机制。多聚体的m/z和质量之间的关系与电荷残留模型的预测一致。丙酮酸激酶离子在锥阱中保持长达129 ms。有了这么长的捕获时间，电荷测定的均方根偏差减少到1.3个基本电荷。(C)2013爱思唯尔有限公司版权所有。
Pyruvate kinase multimers have been investigated by charge detection mass spectrometry (CDMS). In CDMS, the m/z and z are simultaneously measured for each ion, so the mass is determined directly. The measurements were made using a modified cone trap that incorporates an image charge detector with a cryogenically cooled preamplifier. With non-denaturing solution conditions, the tetrameric form of pyruvate kinase is observed along with aggregates of the tetramer. The time-of-flight m/z spectrum shows octamers and dodecamers. However, the lack of charge state resolution prevents identification of larger multimers. Multimers up to the 40-met are revealed by CDMS. Their intensities fall-off exponentially with size. Evidence supporting a non-specific, solution-based aggregation mechanism is presented. The relationship between the m/z and mass of the multimers is consistent with the predictions of the charge residue model. Pyruvate kinase ions are held in the cone trap for up to 129 ms. With this long trapping time the root mean square deviation in the charge determination is reduced to 1.3 elementary charges. (C) 2013 Elsevier B.V. All rights reserved.