Ueki Masaaki, Yamaguchi Miyuki
Department of Applied Chemistry, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601, Japan.
Rapid Commun Mass Spectrom. 2006;20(11):1615-20. doi: 10.1002/rcm.2480.
A new two-component system, consisting of a matrix and an onium salt as comatrix, is described for detection of sulfo-peptides in the positive mode by matrix-assisted desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS). Binary iodonium salts were superior to quaternary phosphonium salts in terms of suppression of desulfation and salt formation with the carboxyl group. Of the iodonium salts examined, bis(4-tert-butylphenyl)iodonium (BTI) hexafluorophosphate and bromide were most effective in giving intensive molecular ion signals in the form of M(BTI)+BTI. The conditions optimized for O-sulfated tyrosine-containing peptides could be applicable for O-sulfated serine- and threonine-containing peptides. In the case of a phospho-peptide, a molecular ion appeared more intensively as a proton adduct than as a BTI adduct.
本文描述了一种新的双组分体系，该体系由一种基质和作为共基质的鎓盐组成，用于通过基质辅助激光解吸/电离飞行时间质谱（MALDI-TOFMS）在正模式下检测磺基肽。就抑制脱硫和与羧基形成盐而言，二元碘鎓盐优于季鏻盐。在所研究的碘鎓盐中，双（4-叔丁基苯基）碘鎓（BTI）六氟磷酸盐和溴化物在以M(BTI)+BTI形式给出强分子离子信号方面最为有效。针对含O-硫酸化酪氨酸的肽优化的条件可适用于含O-硫酸化丝氨酸和苏氨酸的肽。对于磷酸肽，分子离子以质子加合物形式出现的强度比以BTI加合物形式出现的强度更高。
