NOVEL FRAGMENTATION PROCESS OF PEPTIDES BY COLLISION-INDUCED DECOMPOSITION IN A TANDEM MASS-SPECTROMETER - DIFFERENTIATION OF LEUCINE AND ISOLEUCINE
NOVEL FRAGMENTATION PROCESS OF PEPTIDES BY COLLISION-INDUCED DECOMPOSITION IN A TANDEM MASS-SPECTROMETER - DIFFERENTIATION OF LEUCINE AND ISOLEUCINE
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DOI：
10.1021/ac00148a019
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发表时间：
1987-11-01
影响因子：
7.4
通讯作者：
WATSON, JT
中科院分区：
文献类型：
--
作者：
JOHNSON, RS;MARTIN, SA;WATSON, JT
肽的质子化分子碰撞诱导的分解产生的质谱通常表现出峰，这些峰通常与通过沿肽链的-n-Cr-键裂解形成的离子相对应，然后裂解.beta。 。键如果r具有一般结构-c.beta.-c.gamma.-r''。以这种方式产生的离子被分配为符号WN，并有助于在该位置表征氨基酸。最重要的是氨基酸亮氨酸和异亮氨酸的分化，质谱法通常很难或不可能。芳香族氨基酸不会经历这种碎片化，因为它会涉及C-AR键的裂解，丙氨酸也不会涉及氢自由基的损失，也没有缺乏.beta。gam的甘氨酸。纽带。通过精确的质量测量和前体产物离子研究证明了这种破碎过程的性质。
The mass spectra produced upon collision-induced decomposition of the protonated molecules of peptides often exhibit peaks that correspond to ions that are formed by cleavage of the -N-CR- bond along the peptide chain followed by cleavage of the .beta.,.gamma. bond if R has the general structure -C.beta.-C.gamma.-R''. Ions produced in this manner are assigned the notation Wn and are helpful in the characterization of the amino acid at that position. Most important is the differentiation of the amino acids leucine and isoleucine, which is generally difficult or impossible by mass spectrometry. Aromatic amino acids do not undergo this fragmentation because it would involve cleavage of a C-Ar bond, neither does alanine, which would involve loss of a hydrogen radical, nor does glycine, which lacks a .beta.,.gamma. bond. The nature of this fragmentation process is demonstrated by exact mass measurements and precursor-product ion studies.