Structural characterization of glycoprotein NGAL, an early predictive biomarker for acute kidney injury.
Neutrophil gelatinase-associated lipocalin (NGAL) is a promising new renal biomarker that can reduce the time to diagnose acute kidney injury (AKI). There is little information available about complex glycans on NGAL. Detailed structural characterization of NGAL is necessary to understand the structural variability of NGAL used as a standard in the NGAL immunoassay. This study demonstrated that 7-9% of mutant (C87S) recombinant NGAL was N-glycosylated and no O-glycosylation was detected. The NGAL sequence was confirmed by nanoLC/MS/MS following in gel and in solution trypsin digestion, and the N-glycosylation site was localized by MS/MS. Six different mutant recombinant NGAL samples (samples A-F) were analyzed in this study; however, these samples demonstrated two different glycan patterns. Forty-one N-glycans were detected in sample A and the more abundant N-glycans were unsialylated. Forty-three N-glycans were detected in sample F and the more abundant N-glycans were sialylated. Each of the other four samples (B-E) had a similar N-glycan pattern as sample F.
Zhao
Cheng
C
Diagnostic Research Analytical Chemistry, Abbott Diagnostics Division, Abbott Laboratories, Abbott Park, IL 60064, United States. cheng.zhao@abbott.com
Ozaeta
Panfilo
P
Fishpaugh
Jeffrey
J
Rupprecht
Kevin
K
Workman
Ryan
R
Grenier
Frank
F
Ramsay
Carol
C
D058186:Acute Kidney Injury / Q000175:diagnosis* / Q000652:urine; D000595:Amino Acid Sequence; D000818:Animals; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D006023:Glycoproteins / Q000737:chemistry* / Q000652:urine; D006801:Humans; D008969:Molecular Sequence Data; D053719:Tandem Mass Spectrometry
D006023:Glycoproteins