Fig 1

Protein distribution in SWAP. a Protein abundance of SWAP determined using the absolute Area Under Curve (AUC) values recorded for each of the 633 proteins identified. Note that a very small number of proteins contributed to the most prominent MS peaks detected. b Protein abundance in SWAP represented as a cumulative frequency plot revealed that only 18 constituents contributed to 50 % of the total mass. c Frequency distribution plotted after Log₂ transformation of the calculated AUC for each protein. Although the distribution superficially appears Gaussian, a Shapiro-Wilk test revealed that it is not (p < 0.05), high abundance proteins being over-represented