Sulfur protection with the 3-nitro-2-pyridine sulfenyl group in solid-phase peptide synthesis.
The 3-nitro-2-pyridinesulfenyl (Npys) group has been used successfully for side chain protection of cysteine during the stepwise solid-phase synthesis of Lys8-vasopressin (LVP) on benzhydrylamine resin. The versatility and limitations of this group have been evaluated by comparison of this synthesis with a parallel control synthesis using the 3,4-dimethylbenzyl (DMB) group and with a synthesis utilizing a combination of both groups. The Npys group was found to be stable to TFA as reported and, in addition, was found to be stable to HF: anisole (9:1) for 45 min at 0 degree, but not when thiol was present in either reagent. Furthermore, compatibility of the Npys group with the Boc-benzyl synthetic tactic in solid-phase peptide synthesis was demonstrated. LVP with full biological activity was obtained after purification by gel filtration and reverse-phase HPLC.
D000595:Amino Acid Sequence; D007202:Indicators and Reagents; D008236:Lypressin / Q000138:chemical synthesis*; D008722:Methods; D010455:Peptides / Q000138:chemical synthesis*; D011725:Pyridines; D013434:Sulfenic Acids
D007202:Indicators and Reagents; D010455:Peptides; D011725:Pyridines; D013434:Sulfenic Acids; D008236:Lypressin