A Study of Formation and Fragmentation of Ionic Complexes of α-Amino Acids and Peptides with Al(III)–Glycerol by Fast Atom Bombardment Mass Spectrometry

✍ Scribed by Mandapati Saraswathi; Jack M. Miller

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 921 KB
• Volume: 10
• Category: Article
• ISSN: 0951-4198
• DOI: 10.1002/(sici)1097-0231(199610)10:13<1706::aid-rcm723>3.0.co;2-p

✦ Synopsis

Complexation of aluminum ions {AI(III) in glycerol} with a-amino acids has been studied by FAB mass spectrometry. Twelve a-amino acids and cysteine methyl ester interact with different Al(II1)-containing ions and form several cluster ions such as [M+117]', [117={Al(LII)+glycerol-2H}]; [M+231]+, [231={AI(III)+glycerol+ trifluoroacetic acid -2H)I; [M+233]', [233={2AI(III)+2glycerol-5H)I; [2M+A1-2H]' and [2M+117]'. Fragmentation of these adduct ions led to the formation of mainly metal-containing product ions. Fragmentation pathways were demonstrated with the help of the dissociation of Leu-d,, His-d,, Tyr-d,, Ser-d,, Cys-d, and Cys methyl ester-d, ion complexes in glycerol-d,. Aliphatic, aromatic and a-amino acids possessing functional side chains show differences in the fragmentation of [M+117]' ions. Fourteen peptides of different chain lengths (two through six amino acids) also form adducts with A1(III)-glycerol. Dissociation of these complex ions, especially [M+ Al -2Hl' ions provides information about side-chain functional groups and some sequence information.

The site of the metal-ion interaction is mostly at the amide nitrogens.