The proline effect and the tryptophan immonium ion assist in de novo sequencing of adipokinetic hormones.

ABSTRACT: Adipokinetic hormones (AKHs) in Arthopoda are characterized by special sequence features including limited choices of amino acid residues in certain positions, such as Trp in position 8. Over 100 different AKHs have been described, but de novo sequencing of novel peptide hormones can be a challenge. In a project of analyzing corpora cardiaca extracts from two fly species, two different moths, a termite and a beetle for their AKHs, we noted specific patterns in the fragmentation spectra of octapeptides in electrospray Q-TOF experiments resulting from the presence of Pro in position 6. The preference for cleavage N-terminal to Pro residues created an abundant y₃″-ion, which, in conjunction with the two b-ions resulting from the fragmentation before and after Pro, provided a marker

SUBMITTER: Konig S 

PROVIDER: S-EPMC10322821 | biostudies-literature | 2023 Jul

REPOSITORIES: biostudies-literature