Table 1.
Composition of standard pool used for quantification of apolipoproteins in sample cohort.
Fig 1.
A) Visualization of the homology of apo(a) to other human proteins plotted as identity based on HsID50 and the transcript ENSP00000321334 (red = high, green = low). T1-T10 is used to denote the K4 domains and PD designates the plasminogen domain. Three different SIS PrEST peptides are mapped to the sequence at the top. B) A schematic visualization of how the SIS PrESTs are used to determine the number of K4 domains following quantification of total apo(a) and the K4 domain upon proteolytic digestion. One SIS PrEST is used to determine the molar concentration of peptides mapping to the K4 domains and one SIS PrEST is used to determine the molar concentration of apo(a). The ratio between the concentration from the K4 domain and the molar concentration of apo(a) corresponds to the number of K4 repeats.
Table 2.
Quantitative performance of EAQLLVIENEVCNHYK across a range between 490 fM to 1,000 nM in human plasma.
Fig 2.
A) Repeatability data indicating the intraday variation during each day of the five-day period and the overall inter-day variation of the proteotypic peptide. B) Stability freeze-thaw data of three cycles for the proteotypic peptides. In both figures 2 times standard deviation interval is visualized with error bars.
Fig 3.
Comparison between CE-IVD approved immuno-assay and the targeted proteomics method.
The ELISA result has been transformed to a molar concentration (from U/l) after quantifying calibrator no. 4 using LC-SRM/MS in triplicate measurements.
Table 3.
Quantification results of apo(a) from ELISA and LC-SRM/MS.
Fig 4.
Apolipoprotein plasma profiling of 90 individuals.
A) Beeswarm plot visualizing the total apo(a) levels among the 90 profiled subjects determined by the peptide EAQLLVIENEVCNHYK. B) Histogram of the average number of K4 domains present in the profiled samples, determined by the peptide GTYSTTVTGR. C) The average number of K4 repeats plotted against the total plasma concentration of apo(a).