Serum amyloid A protein in humans and four animal species: a comparison by two dimensional electrophoresis

Cf, Bruun; Nordstoga, K.; Sletten, K; Husby, Gunnar; Marhaug, G.

doi:10.1016/0305-0491(95)00074-7

Cited by 8 publications

(8 citation statements)

References 25 publications

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“…The higher p l of protein in spot 4, relative to spots 4A and 5(Fig. l), was compatible with spot 4 being the Arg-form of SAAla as suggested by N-terminal sequencing[25]. We did not, however, observe the peptide with the N-terminal Arg.…”

supporting

confidence: 82%

“…Direct N-terminal amino acid sequence analysis of three spots revealed SAA sequence in position 1-8 [25]. Two major spots were characterized further and were found to rep-resent SAAlu and SAAlu des-Arg.…”

Section: -D Electrophoresis Of Saa Isoformsmentioning

confidence: 96%

“…In a prwious study, comparative analysis of 2-D gel patterns of acute-phase serum proteins separated by IPGbased linear pH gradients, followed by a SDS-PAGE size separation, identified eight spots of interest within the p l and molecular mass range of known SAA [25]. Direct N-terminal amino acid sequence analysis of three spots revealed SAA sequence in position 1-8 [25].…”

Section: -D Electrophoresis Of Saa Isoformsmentioning

confidence: 99%

“…1. Based on visual comparison with previous 2-D electrophoretograms [18,25], nine spots of interest were designated. All the spots were in the typical mass range or SAA: spots 1-5 had a molecular mass of approximately 14 kDa while spot 0 had an estimated molecular mass of about 20 kDa.…”

Section: -D Electrophoresis Of Saa Isoformsmentioning

confidence: 99%

“…The use of a nonlinear pH gradient complicated the exact determination of p l values, and as the presented 2-D electrophoretogram was not subjected to image software evaluation, calculation of experimental p l values was not performed. However, the four major species, labeled 2, 3, 4 and 5, were assumed to correspond to the four major spots measured to focus at pH 8.7, 7.6, 6.6 and 6.0, respectively [25]. Spots 1 and 0 were of particular interest since they were focusing at pH values that were atypical for acute-phase SAA, suggesting that they were either a previously undescribed SAA isoform or C-SAA, which is known to focus at a relatively high pH [18].…”

Section: -D Electrophoresis Of Saa Isoformsmentioning

confidence: 99%

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Characterization of human serum amyloid A protein isoforms separated by two‐dimensional electrophoresis by liquid chromatography/electrospray ionization tandem mass spectrometry

et al. 1996

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A detailed structural analysis of the serum amyloid A proteins (SAA) of an individual with highly active, chronic rheumatoid arthritis is reported. SAA isoforms were separated by high-resolution two dimensional (2-D) gel electrophoresis. Peptide mapping by reverse-phase chromatography/electrospray ionization tandem mass spectrometry was applied to correlate the protein(s) contained in each spot with their respective coding gene and to study the post-translational processing and modification events which might result in differential electrophoretic mobility. Nine protein spots were analyzed. The six major spots corresponded to the Arg and des-Arg forms of SAA1 alpha and SAA2 alpha, respectively, and to the glycosylated and nonglycosylated form of constitutive serum amyloid A protein (C-SAA). Two minor spots were identified as SAA1 alpha isoforms containing post-translational modifications. We suggest that these variants contained a gamma-N, N'-dimethylasparagine residue at position 83 and that one of them was additionally oxidized at Trp53 and Trp85. The ninth spot was shown to contain a mixture of SAA1 alpha and SAA2 alpha. To our knowledge, this is the first report in which analysis of peptides has been used to verify the presence of C-SAA in acute-phase serum. Furthermore, the data illustrate that extensive post-translational processing results in a structurally diverse class of acute-phase SAA proteins, which are derived from a small number of genes. Finally, the fast and conclusive technology used in this study promises to be generally useful for the comprehensive investigation of proteins at the level of the primary structure.

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supporting

confidence: 82%

Section: -D Electrophoresis Of Saa Isoformsmentioning

confidence: 96%