Spontaneous Glycan Reattachment Following N-Glycanase Treatment of Influenza and HIV Vaccine Antigens.
J Proteome Res
; 19(2): 733-743, 2020 02 07.
Article
em En
| MEDLINE
| ID: mdl-31913636
ABSTRACT
In cells, asparagine/N-linked glycans are added to glycoproteins cotranslationally, in an attachment process that supports proper folding of the nascent polypeptide. We found that following pruning of N-glycan by the amidase PNGase F, the principal influenza vaccine antigen and major viral spike protein hemagglutinin (HA) spontaneously reattached N-glycan to its de-N-glycosylated positions when the amidase was removed from solution. This reaction, which we term N-glycanation, was confirmed by site-specific analysis of HA glycoforms by mass spectrometry prior to PNGase F exposure, during exposure to PNGase F, and after amidase removal. Iterative rounds of de-N-glycosylation followed by N-glycanation could be repeated at least three times and were observed for other viral glycoproteins/vaccine antigens, including the envelope glycoprotein (Env) from HIV. Covalent N-glycan reattachment was nonenzymatic as it occurred in the presence of metal ions that inhibit PNGase F activity. Rather, N-glycanation relied on a noncovalent assembly between protein and glycan, formed in the presence of the amidase, where linearization of the glycoprotein prevented this retention and subsequent N-glycanation. This reaction suggests that under certain experimental conditions, some glycoproteins can organize self-glycan addition, highlighting a remarkable self-assembly principle that may prove useful for re-engineering therapeutic glycoproteins such as influenza HA or HIV Env, where glycan sequence and structure can markedly affect bioactivity and vaccine efficacy.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Vacinas contra Influenza
/
Vacinas contra a AIDS
/
Influenza Humana
Limite:
Humans
Idioma:
En
Revista:
J Proteome Res
Assunto da revista:
BIOQUIMICA
Ano de publicação:
2020
Tipo de documento:
Article
País de afiliação:
Estados Unidos