Journal article
Gas-phase fragmentations of anionic complexes between peptides and alkaline earth metal ions: structure-specific side-chain interactions
Journal of the American Chemical Society, Vol.115(7), pp.2854-2863
04/01/1993
DOI: 10.1021/ja00060a037
Abstract
The first study of gas-phase anionic (M + Cat2+ − 3 H)− complexes between 59 peptides and Mg2+, Ca2+, and Ba2+ is reported. Formation of the complexes requires deprotonation of three sites. Peptide complexes that contain aprotic (hydrocarbon) amino acid side chains decompose primarily to give (xn−m + Cat2+ − 2 H)−, (yn−m + Cat2+ − 2 H)−, and other ions that contain the C-terminus. Molecular mechanical calculations reveal that these product ions arise from complexes that contain Cat2+ nonspecifically bound to deprotonated amides and/or the C-terminus. In sharp contrast, peptide complexes that contain the protic amino acids Asp, Glu, Tyr, His, or Trp decompose to give unique N-terminal (cn−m + Cat2+ − 2 H)− ions that instead contain the alkaline earth metal ion bound to the deprotonated side chain and to two deprotonated amides. The experimental data and molecular mechanical calculations support formation of structurally specific precursor ion complexes that involve specific side-chain binding interactions. Other evidence for specific side-chain binding interactions is provided in a comparison of the chemistry of the alkaline earth metal ions to that of some transition metal(II) ions
Details
- Title: Subtitle
- Gas-phase fragmentations of anionic complexes between peptides and alkaline earth metal ions: structure-specific side-chain interactions
- Creators
- Hong ZhaoAlex ReiterLynn M TeeschJeanette Adams
- Resource Type
- Journal article
- Publication Details
- Journal of the American Chemical Society, Vol.115(7), pp.2854-2863
- Publisher
- American Chemical Society
- DOI
- 10.1021/ja00060a037
- ISSN
- 0002-7863
- eISSN
- 1520-5126
- Language
- English
- Date published
- 04/01/1993
- Academic Unit
- Medicine Administration; Core Research Facilities
- Record Identifier
- 9984622052902771
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