Chemoselective one-step purification method for peptides synthesized by the solid-phase technique.
The specific reaction between SH and iodoacetamide groups has been explored as the basis of an affinity-type purification procedure for peptides synthesized by the solid-phase technique. For this affinity-type purification procedure, we synthesized an SH precursor reagent bearing an acid-labile S-protecting group, pMB-SCH2CONHCH2CH2-SO2CH2CH2OCO2pNP (compound I), in which pMB is p-methoxybenzyl and pNP is p-nitrophenyl. Using this reagent, the procedure involves the following sequence of four reactions: (i) attachment of the SH function of compound I to the alpha-amino group of a peptide-resin through a base-labile sulfonylethoxycarbonyl linkage in the final step of solid-phase peptide synthesis, (ii) acid treatment to remove the S-pMB and side-chain-protecting groups employed and cleave the modified peptide from the resin, (iii) immobilization of the derived SH-peptide on an iodoacetamide-resin column, and (iv) base (5% NH4OH) treatment to release the desired peptide from the resin in nearly pure form. To facilitate this purification procedure, unreacted amino groups were acetylated in each step during solid-phase synthesis. The usefulness of this method was demonstrated by the purification of several peptides (18 to approximately 44 amino acids in length) synthesized by the 9-fluorenylmethoxycarbonyl (Fmoc)-based solid-phase technique. The principle of this affinity-type purification procedure may also be applied to the tert-butoxycarbonyl (Boc)-based solid-phase technique.
Funakoshi
S
S
Kyoto University, Japan.
Fukuda
H
H
Fujii
N
N
D002851:Chromatography, High Pressure Liquid / Q000379:methods; D003432:Cross-Linking Reagents; D007202:Indicators and Reagents; D009842:Oligopeptides / Q000138:chemical synthesis / Q000302:isolation & purification; D010455:Peptides / Q000138:chemical synthesis / Q000302:isolation & purification*; D016339:Spectrometry, Mass, Fast Atom Bombardment; D013439:Sulfhydryl Reagents / Q000138:chemical synthesis / Q000302:isolation & purification*; D013450:Sulfones / Q000138:chemical synthesis* / Q000302:isolation & purification; D013864:Thioglycolates / Q000138:chemical synthesis* / Q000302:isolation & purification
D003432:Cross-Linking Reagents; D007202:Indicators and Reagents; D009842:Oligopeptides; D010455:Peptides; D013439:Sulfhydryl Reagents; D013450:Sulfones; D013864:Thioglycolates; C070390:S-(4-methoxybenzyl)thioglycolylaminoethylsulfonylethyl-4-nitrophenyl carbonate