Loo R R, Loo J A, Udseth H R, Fulton J L, Smith R D
Chemical Sciences Department, Pacific Northwest Laboratory, Richland, WA 99352.
Rapid Commun Mass Spectrom. 1992 Mar;6(3):159-65. doi: 10.1002/rcm.1290060302.
The relationship between gas-phase protein structure and ion/molecule reactivity is explored in comparisons between native and disulfide-reduced aprotinin, lysozyme, and albumin. Reactions are performed in the atmospheric-pressure inlet to a quadrupole mass spectrometer employing a novel capillary interface-reactor. In reactions with equal concentrations of diethylamine, multiply protonated molecules generated by electrospray ionization (ESI) of 'native' proteins shifted to lower charge states than did multiply protonated molecules from ESI of the disulfide-reduced counterparts, suggesting that the disulfide-reduced protein ions are less reactive than native protein ions of the same charge state. Differences in reactivity may arise from protonation of different amino acid residues and/or differences in the proximities of charge sites in the two molecules. These results suggest that the reactivity of multiply charged proteins can be significantly affected by their gas-phase structure.
通过对天然型和二硫键还原型抑肽酶、溶菌酶及白蛋白进行比较，探究了气相蛋白质结构与离子/分子反应活性之间的关系。反应在采用新型毛细管接口反应器的四极杆质谱仪的大气压进样口中进行。在与等浓度二乙胺的反应中，“天然”蛋白质经电喷雾电离（ESI）产生的多质子化分子比二硫键还原型对应物经ESI产生的多质子化分子向更低电荷态移动，这表明二硫键还原型蛋白质离子的反应活性低于相同电荷态的天然蛋白质离子。反应活性的差异可能源于不同氨基酸残基的质子化和/或两种分子中电荷位点的接近程度差异。这些结果表明，多电荷蛋白质的反应活性会受到其气相结构的显著影响。
