Effects of metal ion adduction on the gas-phase conformations of protein ions.
Effects of metal ion adduction on the gas-phase conformations of protein ions.
复制标题
DOI：
10.1007/s13361-013-0664-3
复制
发表时间：
2013-11
影响因子：
3.2
通讯作者：
Williams, Evan R.
中科院分区：
文献类型：
--
作者：
Flick, Tawnya G.;Merenbloom, Samuel I.;Williams, Evan R.
关键词：
采用行波离子迁移谱（TWIMS）研究了水溶液电喷雾电离（ESI）过程中金属离子与蛋白质的非特异性加合作用对蛋白质离子构象的影响。对于所有的蛋白质检查，蛋白质阳离子（和在大多数情况下阴离子）与非特异性金属离子加合物是更紧凑的比完全质子化（或去质子化）的离子具有相同的电荷状态。非特异性金属离子结合时蛋白质阳离子的压实对于中间电荷态离子是最显著的，并且随着金属离子加合物数量的增加和离子价的增加，碰撞截面有更大的减少，这与离子和蛋白质之间的静电相互作用一致。具有最大数量的加合金属离子的蛋白质阳离子并不比从水溶液形成的最低质子化离子更紧凑。这些结果表明，较小的碰撞横截面的金属附着的蛋白质离子是不是一个很好的指标，在溶液中的特定的金属-蛋白质相互作用，因为非特异性金属离子加合也导致在较小的气态蛋白质阳离子横截面。相反，α-乳白蛋白的碰撞截面，它特异性地结合一个Ca 2+，是更大的全息形式相比，apo-形式，与溶液相测量。因为当金属离子加合是非特异性时发生蛋白质阳离子的压缩，蛋白质阳离子的伸长可能是溶液中发生特定金属离子-蛋白质相互作用的更可靠的指标。
Changes in protein ion conformation as a result of nonspecific adduction of metal ions to the protein during electrospray ionization (ESI) from aqueous solutions were investigated using traveling wave ion mobility spectrometry (TWIMS). For all proteins examined, protein cations (and in most cases anions) with nonspecific metal ion adducts are more compact than the fully protonated (or deprotonated) ions with the same charge state. Compaction of protein cations upon nonspecific metal ion binding is most significant for intermediate charge state ions, and there is a greater reduction in collisional cross section with increasing number of metal ion adducts and increasing ion valency, consistent with an electrostatic interaction between the ions and the protein. Protein cations with the greatest number of adducted metal ions are no more compact than the lowest protonated ions formed from aqueous solutions. These results show that smaller collisional cross sections for metal-attached protein ions are not a good indicator of a specific metal-protein interaction in solution, because nonspecific metal ion adduction also results in smaller gaseous protein cation cross sections. In contrast, the collisional cross section of α-lactalbumin, which specifically binds one Ca2+, is larger for the holo-form compared to the apo-form, in agreement with solution-phase measurements. Because compaction of protein cations occurs when metal ion adduction is nonspecific, elongation of a protein cation may be a more reliable indicator that a specific metal ion-protein interaction occurs in solution.
登录
查看更多内容
DOI：
10.1007/s13361-011-0313-7
发表时间：
2012-03
影响因子：
3.2
作者：
Merenbloom, Samuel I.;Flick, Tawnya G.;Williams, Evan R.
通讯作者：
Williams, Evan R.
DOI：
10.1073/pnas.89.21.10124
发表时间：
1992-11-01
影响因子：
11.1
作者：
BRAUN, W;VASAK, M;WUTHRICH, K
通讯作者：
WUTHRICH, K
影响因子：
3.3
作者：
Kohtani, M;Jarrold, MF;O'Hair, RAJ
通讯作者：
O'Hair, RAJ
DOI：
10.1016/s1044-0305(99)00036-7
发表时间：
1999-08-01
影响因子：
3.2
作者：
Nemirovskiy, O;Giblin, DE;Gross, ML
通讯作者：
Gross, ML
影响因子：
7.4
作者：
Badman, ER;Hoaglund-Hyzer, CS;Clemmer, DE
通讯作者：
Clemmer, DE