Ice as a matrix for IR-matrix-assisted laser desorption/ionization: Mass spectra from a protein single crystal
Ice as a matrix for IR-matrix-assisted laser desorption/ionization: Mass spectra from a protein single crystal
复制标题
DOI：
10.1073/pnas.93.14.7003
复制
发表时间：
1996-07-09
影响因子：
11.1
通讯作者：
Hillenkamp, F
中科院分区：
文献类型：
--
作者：
Berkenkamp, S;Karas, M;Hillenkamp, F
在260 - 360 nm的紫外波长范围内发射的激光几乎专门用于大分子的基质辅助激光解吸/电离质谱（MALDI-MS）。关于使用红外线激光器的报告首次出现在1990/1991年。与紫外线中的MALDI相反，此后发表的有关IR-MALDI的报告数量非常有限。已经确定了几种红外MALDI基质，产生的光谱质量与紫外线中获得的光谱质量相当。水（冰）由于在3 μ m附近具有很强的O-H伸缩模，很早就被认为是一种潜在的基质。对水作为基质的兴趣主要来自于它是大多数生物组织的主要成分的事实。如果作为基质起作用，它可能允许在冷冻细胞切片中原位分析大分子成分而无需提取或交换水。我们目前的结果表明，IR-MALDI的冻干蛋白质，空气干燥的蛋白质溶液，或蛋白质晶体高达30 kDa的分子量是可能的，而无需添加任何单独的矩阵。样品必须冷冻以在真空中保留足够部分的水合水。有限的电流灵敏度，需要至少10 pmol的蛋白质的成功分析需要进一步提高。
Lasers emitting in the ultraviolet wavelength range of 260-360 nm are almost exclusively used for matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) of macromolecules. Reports about the use of lasers emitting in the infrared first appeared in 1990/1991. In contrast to MALDI in the ultraviolet, a very limited number of reports on IR-MALDI have since been published, Several matrices have been identified for infrared MALDI yielding spectra of a quality comparable to those obtained in the ultraviolet. Water (ice) was recognized early as a potential matrix because of its strong O-H stretching mode near 3 mu m. Interest in water as matrix derives primarily from the fact that it is the major constituent of most biological tissues, If functional as matrix, it might allow the in situ analysis of macromolecular constituents in frozen cell sections without extraction or exchanging the water. We present results that show that IR-MALDI of lyophilized proteins, air dried protein solutions, or protein crystals up to a molecular mass of 30 kDa is possible without the addition of any separate matrix. Samples must be frozen to retain a sufficient fraction of the water of hydration in the vacuum. The limited current sensitivity, requiring at least 10 pmol of protein for a successful analysis needs to be further improved.