Table 3.

Classification of peptides based on trypsin digestion pattern.

Group	Amino Acids Included	Number of SDA labels a	Number of trypsin cleavage sites	Tryptic Peptides included	Secondary Structure Elements
1	1–16	1	1	Gly1-Lys16	N-terminus, Helix A
2	17–31	2.5	1	Val17-Arg31	AB loop, Helix B
3	32–47	1.5	3	Leu32-Lys42 Leu32-Lys45 Leu32-Lys47	Helix B, BC loop, Helix C, CD loop
4	43–63	2	6	Phe43-Lys45 Phe43-Lys47 Phe43-Lys50 Phe43-Lys56 Phe43-Lys62 Phe46-Lys50 Phe46-Lys56 Phe46-Lys62 His48-Lys56 His48-Lys63 Thr51-Lys56 Thr51-Lys62 Thr51-Lys63 Ala57-Lys62 Ala57-Lys63	CD loop, Helix D, DE loop, Helix E
5	63–79	1.3	4	Lys63-Lys77 Lys63-Lys78 Lys63-Lys79	Helix E, EF loop
6	78–98	1.4	5	Lys78-Lys79 Lys78-Lys87 Lys78-Lys98 Lys79-Lys87 Lys79-Lys96 Gly80-Lys87 Gly80-Lys96 Pro88-Lys98	Helix E, EF loop, Helix F, FG loop
7	97–118	1.2	3	His97-Lys102 His97-Lys118 Ile99-Lys118 Tyr103-Lys118	FG loop, Helix G
8	119–153	2	4	His119-Lys133 His119-Arg139 Ala134-Arg139 Ala134-Lys145 Ala134-Lys147 Asn140-Lys145 Asn140-Lys147 Asn140-Gly153 Tyr146-Gly153 Gln148-Gly153	GH loop, Helix H, C-terminus

^aAverage number of SDA labels per group (n) was calculated as described in Materials and Methods.