Species-Related Differences in the Proteome of Rat and Human Pancreatic Beta Cells

Table 1

Overview of proteome coverage by LC-MS/MS.

	Rat		Human
	Beta	Alpha	Endocrine	Exocrine
Number of proteins identified
	506	417	462	372
Number of proteins quantified
	465	353	413	300
GEO-normalized molar amount
Highest	3.61	8.22	8.95	14.74
Lowest	0.02	0.02	0.01	0.06
Dynamic range	226	548	746	246
Biological replicates ()	3	3	4	1
Technical replicates ()	3	3	3	3

Unfractionated protein extracts of FACS-purified pancreatic beta and alpha cells () and FACS-enriched human islet endocrine cells () were analyzed by alternate-scanning LC-MS/MS. As additional quality control, one pancreatic exocrine cell-enriched human sample was also measured. All samples were injected in triplicate, yielding 372 (300) to 506 (465) proteins that met the criteria for identification (quantification, if detected in of 3 technical replicates) as specified in Methods, with dynamic ranges (difference between the lowest and the highest quantifiable concentration) ranging from 226 to 746 as listed.