Sequence determination and resonance assignments of an Azomonas siderophore using 13C natural abundance 13C–1H HNCA experiment

Abstract

The determination of the amino acid sequence of small peptides as siderophores is commonly performed using long-range HMBC correlation experiments. However, this type of experiment can lead to ambiguities in the assignment resulting in erroneous primary sequence determination. In this paper, we propose to use an HNCA type experiment on a ¹⁵N-labelled sample in order to avoid these ambiguities. This experiment was successfully used to determine the primary sequence of azoverdin, a siderophore produced by Azomonas.