Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, United States.
Anal Chem. 2011 Nov 15;83(22):8391-5. doi: 10.1021/ac202429c. Epub 2011 Oct 20.
Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS) provides the highest mass resolving power and mass measurement accuracy for unambiguous identification of biomolecules. Previously, the highest-mass protein for which FTICR unit mass resolution had been obtained was 115 kDa at 7 T. Here, we present baseline resolution for an intact 147.7 kDa monoclonal antibody (mAb), by prior dissociation of noncovalent adducts, optimization of detected total ion number, and optimization of ICR cell parameters to minimize space charge shifts, peak coalescence, and destructive ion cloud Coulombic interactions. The resultant long ICR transient lifetime (as high as 20 s) results in magnitude-mode mass resolving power of ~420,000 at m/z 2,593 for the 57+ charge state (the highest mass for which baseline unit mass resolution has been achieved), auguring for future characterization of even larger intact proteins and protein complexes by FTICR MS. We also demonstrate up to 80% higher resolving power by phase correction to yield an absorption-mode mass spectrum.
傅里叶变换离子回旋共振质谱（FTICR MS）为生物分子的明确鉴定提供了最高的质量分辨率和质量测量精度。此前，在 7 T 下获得 FTICR 单位质量分辨率的最高质量蛋白质为 115 kDa。在这里，我们通过预先解离非共价加合物、优化检测到的总离子数以及优化 ICR 单元参数以最小化空间电荷漂移、峰合并和破坏性离子云库仑相互作用，为完整的 147.7 kDa 单克隆抗体（mAb）提供了基线分辨率。由此产生的长 ICR 瞬态寿命（高达 20 秒）导致在 m/z 2,593 处的 57+电荷状态下的质量分辨率高达~420,000（实现了基线单位质量分辨率的最高质量），预示着未来通过 FTICR MS 对更大的完整蛋白质和蛋白质复合物进行表征。我们还通过相位校正证明了高达 80%的更高分辨率，从而产生吸收模式质谱。
