Collagen V Is a Potential Substrate for Clostridial Collagenase G in Pancreatic Islet Isolation

Table 1

Peptide numbers detected by ESI-MS.

		# pep	# tryp	# semitryp		# nontryp		% col. pep
				Gxx-G	non-Gxx-G	Gxx-G	non-Gxx-G
V	α1	29, 31	20, 33	1, 2	8, 6	0, 0	0, 0	3, 6
	α2	45, 38	30, 25	4, 6	11, 7	0, 0	0, 0	9, 16
	α3	17, 17	15, 15	0, 0	2, 2	0, 0	0, 0	0, 0
V + H	α1	39, 33	21, 20	9, 6	4, 6	3, 0	0, 0	31, 27
	α2	46, 47	26, 30	9, 7	10, 9	1, 1	0, 0	22, 17
	α3	21, 18	15, 16	4, 1	2, 1	0, 0	0, 0	19, 6
V + G	α1	64, 56	17, 15	17, 16	8, 5	22, 20	0, 0	61, 64
	α2	71, 62	22, 19	28, 26	7, 2	14, 15	0, 0	59, 66
	α3	34, 24	10, 7	12, 9	1, 1	11, 7	0, 0	68, 67

# pep, # tryp, # semitryp, and # nontryp indicate the number of total peptides, number of tryptic peptides (R/K)↓xxx⋯xxx(R/K)↓xxx⋯, number of semitryptic peptides (R/K)↓xxx⋯ or ⋯xxx(R/K)↓xxx⋯, and number of nontryptic peptides, respectively.
Gxx-G is the preferred substrate sequence for collagenase at position P3-P2-P1-P1′.
Type V collagen was digested by trypsin (V), trypsin + collagenase H (V + H), and trypsin + collagenase G (V + G).
The percentage of collagenolytic peptides was calculated by the following equation: % col. pep = (number of semitryptic Gxx-G + number of nontryptic Gxx-G)/(number of total peptides).