Precise protein quantification based on peptide quantification using iTRAQ™

BMC Bioinformatics

Table 4 Quantification results of the sample 1:1 mix.

Protein Id	Protein name	Quant						EE	Mascot™ 2.2
								1.4126
		Ratio	n	IQR	RMS	LSE	μ	σ	Ratio	σ
P00722	Beta-galactosidase BGAL_ECOLI	1.0508	5	0.4003	0.0104	0.9106	-0.1207	0.2656	0.9600	NN
P02787	Serotransferrin precursor TRFE_HUMAN	0.9984	15	0.2522	0.0076	0.9673	-0.0500	0.1902	1.1660	NN

The quantification results of the sample 1:1 mix are shown that include all unique peptides of each identified protein. Listed are the Protein Id, the protein name, and the protein ratio (ratio) with the experiment error (EE) estimate of Quant. The number of MS/MS spectra is listed in column n. Several quality factors calculated by Quant are shown: the least squares estimator (LSE), interquartile range (IQR), root-mean-square value (RMS), mean value (μ) and standard deviation (σ). μ and σ of Quant results were calculated from the log-transformed data. For comparison, results of Mascot™ 2.2 are listed. The protein ratios of the results are normalized.

ISSN: 1471-2105