Epitope mapping of an uncertain endogenous antigen implies secretogranin II peptide splicing.

ABSTRACT: Background: The search for a tissue-mass reducing reproductive hormone involved a bioassay-guided physicochemical fractionation of sheep blood plasma. This brought forth a candidate protein whose apparent mass on gels and in mass spectrometry (MS) was 7-8 kDa, implying a polypeptide of ~70 residues. Four purification runs gave Edman N-terminal sequences relating to ₁MKPLTGKVKEFNNI ₁₄. This is bioinformatically obscure and has been resistant to molecular biological investigation. The sequence was synthesized as the peptide EPL001, against which was raised a goat polyclonal antiserum, G530. Used in an antigen capture campaign, G530 pointed to the existence of a novel derivative of secretogranin II (SgII), the neuroendocrine secretory vesicle helper protein and pr

SUBMITTER: Howlett DR 

PROVIDER: S-EPMC7194351 | biostudies-literature | 2019

REPOSITORIES: biostudies-literature