Dass C
Charles B. Stout Neuroscience Mass Spectrometry Laboratory, University of Tennessee-Memphis 38163.
Rapid Commun Mass Spectrom. 1989 Aug;3(8):264-6. doi: 10.1002/rcm.1290030805.
Positive- and negative-ion fast-atom bombardment (FAB) mass spectrometry and linked-field scan techniques at constant B/E are used to characterize phosphorylated serine, threonine, and tyrosine amino acids. Abundant molecular ions are formed for all three amino acids in both modes of ionization. The dominant fragmentation is cleavage of the phosphate ester bond with charge retention in positive-ion FAB by the amino acid backbone and in the negative-ion mode by the phosphate group. The unique feature of positive-ion FAB mass spectra of phosphoserine and -threonine is the loss, from the ion [M + H]+, of a molecule of phosphoric acid (98 Da), whereas the corresponding tyrosine expels a HPO4 (96 Da) moiety to yield a stable phenylalanine ion.
采用正离子和负离子快原子轰击（FAB）质谱法以及在恒定B/E下的联动场扫描技术来表征磷酸化的丝氨酸、苏氨酸和酪氨酸氨基酸。在两种电离模式下，所有这三种氨基酸均形成了丰富的分子离子。主要的碎片化过程是磷酸酯键的断裂，在正离子FAB中电荷保留在氨基酸主链上，而在负离子模式下电荷保留在磷酸基团上。磷酸丝氨酸和磷酸苏氨酸的正离子FAB质谱的独特特征是离子[M + H]+损失一分子磷酸（98 Da），而相应的酪氨酸则排出一个HPO4（96 Da）部分，生成一个稳定的苯丙氨酸离子。
