Center of Mass Calculation in Combination with MS/MS Allows Robust Identification of Single Amino Acid Polymorphisms in Clinical Measurements of Insulin-Like Growth Factor-1.
J Proteome Res
; 19(1): 186-193, 2020 01 03.
Article
em En
| MEDLINE
| ID: mdl-31736316
ABSTRACT
Insulin-like growth factor-1 (IGF-1) measurement by high-resolution accurate mass-mass spectrometry (HRAM-MS) is replacing IGF-1 immunoassays and allows for identification of single amino acid variants; by contrast, both normal and deleterious sequence variants might be missed by immunoassays or non-HRAM-MS methods. We have developed an intact molecule HRAM-MS method to identify IGF-1 variants, distinguishing them by a center of mass (COM) calculation, followed by various tandem-MS activation techniques (HCD, ETD, ETciD, EThcD, UVPD). We found single amino acid variants in 841 of 146â¯620 patient samples (0.57%). Most were benign (A67T, A70T). We also observed a pathogenic variant (V44M), likely pathogenic variants (A38V, V17M), and a likely benign variant (A67V). For 207 samples from unique patients with residual serum, the MS variant results were confirmed by cell-free DNA sequencing. Our approach allows accurate quantitative reporting of functional IGF-1 in the presence of single amino acid variants. The COM approach potentially enables omission of tandem-MS for known, common variants, while the combination of COM and tandem-MS allows accurate identification in all cases we encountered. This approach should be applicable to qualitative and quantitative analyses of other peptides/proteins in clinical and research settings and might lend itself to the characterization of other protein variations.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fator de Crescimento Insulin-Like I
/
Espectrometria de Massas em Tandem
Tipo de estudo:
Diagnostic_studies
/
Prognostic_studies
/
Qualitative_research
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