Protein Characterization by MALDI In-Source Decay Mass Spectrometry in Support of Safety Assessments of Genetically Modified Crops.
J Agric Food Chem
; 69(35): 10358-10370, 2021 Sep 08.
Article
em En
| MEDLINE
| ID: mdl-34428040
ABSTRACT
The advancement of mass spectrometry provides advantages for transgenic protein characterization in support of safety assessments of genetically modified crops. Here, we describe how matrix-assisted laser desorption ionization in-source decay (ISD) mass spectrometry (MS) in combination with intact mass and bottom-up analyses can be applied to achieve high confidence in the sequences of transgenic proteins expressed in plants and establish the biochemical equivalence of microbially produced protein surrogates. ISD confirmed 40-60 near terminal residues regardless of the protein size, including the improvement of the coverage of cysteine-rich proteins by the reduction/alkylation of disulfide bonds. Negative ISD significantly improved spectral quality and sequence coverage of acidic proteins. Various post-translational modifications, such as terminal truncations and N-terminal methionine excision and acetylation, were identified in plant-produced proteins by top-down MS. Finally, we demonstrated that a combination of top-down and bottom-up analyses provides high confidence in sequence equivalence of plant and microbially produced proteins.
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Base de dados:
MEDLINE
Assunto principal:
Proteínas
/
Produtos Agrícolas
Idioma:
En
Ano de publicação:
2021
Tipo de documento:
Article