Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States.
J Mass Spectrom. 2011 Oct;46(10):1011-5. doi: 10.1002/jms.1982.
Infrared multiple photon dissociation spectroscopy and hydrogen/deuterium exchange methods are used to confirm the macrocylic structure of a b(6) peptide fragment by direct comparison with a synthetically made cyclic peptide. The acetylation of the peptide N-terminus results in the inhibition of the macrocyclic formation, supporting the "head-to-tail" cyclization mechanism. Differences in hydrogen/deuterium exchange rates for macrocyclic and oxazalone structure peptide fragments are interpreted to be a result of the complex interplay of multiple basic sites in the peptide fragment, supporting the relay mechanism for deuterium exchange with CH(3)OD.
利用红外多光子解离光谱和氢/氘交换方法，通过与合成的环状肽直接比较，确认 b(6) 肽片段的大环结构。肽 N-末端的乙酰化导致大环形成受到抑制，支持“头到尾”的环化机制。大环和噁唑烷酮结构肽片段的氢/氘交换速率的差异解释为肽片段中多个碱性位点的复杂相互作用的结果，支持与 CH(3)OD 进行氘交换的接力机制。
