Cui Weidong, Thompson Matthew S, Reilly James P
Department of Chemistry, Indiana University, Bloomington, Indiana 47505-4001, USA.
J Am Soc Mass Spectrom. 2005 Aug;16(8):1384-98. doi: 10.1016/j.jasms.2005.03.050.
One Hundred Fifty-Seven nm photodissociation of singly protonated peptides generates unusual distributions of fragment ions. When the charge is localized at the C-terminus of the peptide, spectra are dominated by x-, v-, and w-type fragments. When it is sequestered at the N-terminus, a- and d-type ions are overwhelmingly abundant. Evidence is presented suggesting that the fragmentation occurs via photolytic radical cleavage of the peptide backbone at the bond between the alpha- and carbonyl-carbons followed by radical elimination to form the observed daughter ions.
单质子化肽的157纳米光解离产生异常的碎片离子分布。当电荷定位于肽的C末端时，光谱以x-、v-和w-型碎片为主。当电荷被隔离在N末端时，a-和d-型离子大量存在。有证据表明，碎片化是通过肽主链在α-碳和羰基碳之间的键处进行光解自由基裂解，然后通过自由基消除形成观察到的子离子。
