Table 2.

Primary Sequences of Model Peptides

Peptide	Sequence	Calculated m/z	Observed m/z
1	CPWRATNPFC	1235.45	1234.91
2	pa-VCNATCHIWH	1262.47	1262.42
3	VCNATCHIWH	1224.43	1224.57
4	VCNATHCIWH	1224.43	1223.26
5	VCNATIHCWH	1224.43	1223.26
6	VCNATSHIWH	1208.36	1208.54
7	VCNATMHIWH	1252.48	1252.59
8	VMNATMHIWH	1280.53	1280.73

All peptides were prepared with C-terminal amides and N-terminal acetyl groups, except for peptide 2 which was prepared with an N-terminal pentynyl group (denoted pa-) as shown in Fig. 5. Sulfur-containing amino acids capable of participating in macrocyclization reactions are shown in bold. Observed m/z are reported as major peaks from MALDI mass spectra.