Proteoform analysis of lipocalin-type prostaglandin D-synthase from human cerebrospinal fluid by isoelectric focusing and superficially porous liquid chromatography with Fourier transform mass spectrometry.
Proteomics
; 14(10): 1223-31, 2014 May.
Article
en En
| MEDLINE
| ID: mdl-24678018
ABSTRACT
Lipocalin-type prostaglandin D-synthase (L-PGDS) in cerebrospinal fluid contributes to the maturation and maintenance of the CNS. L-PGDS PTMs may contribute to pathobiology of different CNS diseases, but methods to monitor its proteoforms are limited. Herein, we combined off-gel IEF and superficially porous LC (SPLC) with Fourier transform MS to characterize common cerebrospinal fluid L-PGDS proteoforms. Across 3D physiochemical space (pI, hydrophobicity, and mass), 217 putative proteoforms were observed from 21 to 24 kDa and pI 5-10. Glycoprotein accurate mass information, combined with MS/MS analysis of peptides generated from 2D-fractionated proteoforms, enabled the putative assignment of 208 proteoforms with varied PTM positional occupants. Fifteen structurally related N-glycans at N29 and N56 were observed, with different N-glycan compositional variants being preferred on each amino acid. We also observed that sialic acid content was a major factor for pI shifts between L-PGDS proteoforms. Other putative PTMs characterized include a core-1 HexHexNAc-O-glycan at S7, acetylation at K16 and K138, sulfonation at S41 and T142, and dioxidation at C43 and C145. The IEF-SPLC-MS platform presented provides 30-40× improved peak capacity versus conventional 2DE and shows potential for repeatable proteoform analysis of surrogate PTM-based biomarkers.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Espectrometría de Masas
/
Cromatografía Liquida
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Oxidorreductasas Intramoleculares
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Lipocalinas
/
Focalización Isoeléctrica
Límite:
Humans
Idioma:
En
Revista:
Proteomics
Asunto de la revista:
BIOQUIMICA
Año:
2014
Tipo del documento:
Article
País de afiliación:
Estados Unidos