Table 2.

Identification of the receptor CNBr cleavage fragment containing the site of labeling using CCK1R mutants.

CNBr fragment # (diagram in Figure 5F)	CNBr fragment sequence	M.W. (Da)	Calculated M.W. of fragment with probe	Candidates after cleavage of WT receptor	Eliminated fragment #6 after cleavage of M121L	Eliminated fragment #8 after cleavage of M195L	Eliminated fragment #4 after cleavage of M72L	Confirmed fragment #10 containing site of labeling after cleavage of M205L	Further confirmed fragment #10 containing site of labeling after cleavage of M225L
1	M1	149	820
2	D2-M9	891	1,562
3	N10-M72	7,087+	7,758+
4	R73-M89	1,893	2,564	Y	Y	Y	Expected: 9,651+ Observed: ~3,000 (see Figure 5D )
5	L90-M95	729	1,400
6	P96-M121	2,982	3,653	Y	Expected: 9,396 Observed: ~3,000
7	G122-M173	5,743	6,414
8	T174-M195	2,528+	3,199+	Y	Y	Expected: 4,351+ Observed: ~3,000
9	C196-M205	1,152	1,823
10	Q206-M225	2,361	3,032	Y	Y	Y	Y	Expected: 4,182 Observed: ~4,200 (see Figure 5E )	Expected: 12,940 Observed: ~13,000 (see Figure 5E )
11	V226-M315	9,908	10,579
12	L316-M328	1,596	2,267
13	P229-M374	5,129	5,800
14	N375-M383	1,168	1,839
15	A384-M422	4,251	4,922
16	S423-P429	656	1,327