Table 1. Identification of CgA and ProSAAS Protein Forms by N-Terminal Peptide Sequencing.

Protein spots from 2-D gel separation of the soluble fraction of purified chromaffin granules were transferred to PVDF membranes, and membrane regions corresponding to designated protein spots were excised for N-terminal peptide sequencing by Edman degradation. The determined N-terminal amino acid sequences for each protein spot is indicated. If more than one protein sequence was identified, their deduced primary sequences are indicated. The properties of each protein spot are illustrated for apparent molecular weight (on 2-D gels), apparent isoelectric point (pI), identification of the N-terminal sequences as CgA (or ProSAAS for spot #37), and relative protein staining by amido black on PVDF membranes of the 2-D gel proteins.

Spot #s	N-terminal Sequences by Edman Degradation	Ratios	Apparent MW range (kD)	Apparent pI	CgA/ Fragment ID	Relative Protein Staining
1	LPVNSPMNKG		153	4.65	CgA	Low
2,3	LPVNSPMNKG		66	4.55 – 4.62	CgA	Very High
4	1°: HSSYEDELSE 2°: LPVNSPMNK	4 to 1	59	4.39	CgA	Medium
5	1°: HSSYEDELSE 2°: LPVNSPMNKG	1 to 1	56	4.39	CgA	Low
6	1°: DDFKEVEKSD 2°: LPVNSPMNKG	3 to 1	50	4.39	CgA	Medium to Low
7	LPVNSPMNKG		45	4.39	CgA	Medium to Low
8,9,10,11	AAPGWPEDGA		27 – 28	4.68 – 4.79	CgA	Medium
12	LPVNSPMNKG		16	4.81	CgA	Medium to Low
13	LPVNSPMNKG		15.5	4.95	CgA	Medium to Low
14,15,16,17	LEGEEEEEED		14.5 – 15	4.60 – 4.81	CgA	Medium
18	GWRPNNNRED		Below 14.4	4.47	CgA	Medium to Low
36	1°: ERGEVG_EER 2°: LPVNSPMNKG	ND	24	4.88	CgB & CgA	Low
37	1°: LPVNSPMNKG 2°: AAPRGEAAGA	1 to 1	18	4.79	CgA & ProSAAS (PC1 inhibitor)	Low Low