Availability of phenylisothiocyanate for the amino acid sequence/configuration determination of peptides containing D/L-amino acids.
A potential use for phenylisothiocyanate (PITC), the most popular Edman reagent, is presented for analysis of the amino acid sequence and configuration in peptides containing D/L-amino acids. After derivatization with PITC of the N-terminal amino acid (L-Tyr) of an enkephalin analogue, [D-Ala2, D-Leu5]-enkephalin, followed by cleavage/cyclization with trifluoroacetic acid at 50 degrees C for 5 min, the liberated 2-anilino-5-thiazolinone-L-Tyr (ATZ-L-Tyr) was further treated with 20% aqueous trifluoroacetic acid at 50 degrees C for 10 min. The resultant phenylthiohydantoin (PTH)-L-Tyr was then separated on a chiral stationary phase (a penylcarbamoylated cyclodextrin column), retaining its configuration. The residual sequence and configurations of the peptide (D-Ala-Gly-L-Phe-D-Leu) were also determined by separating the corresponding PTH-D- or L-amino acids on chiral columns. This method may be applicable to an automatic Edman sequence analyzer for the configuration determination of peptides containing D/L-amino acids.
Faculty of Pharmaceutical Sciences, University of Tokyo, Japan.
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Imai
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Matsunaga
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Santa
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Homma
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D016308:Enkephalin, Leucine-2-Alanine / Q000031:analogs & derivatives* / Q000737:chemistry; D007202:Indicators and Reagents; D017879:Isothiocyanates; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry*; D011487:Protein Conformation; D017421:Sequence Analysis / Q000379:methods*; D013237:Stereoisomerism; D013861:Thiocyanates; D014269:Trifluoroacetic Acid
D000596:Amino Acids; D007202:Indicators and Reagents; D017879:Isothiocyanates; D010446:Peptide Fragments; D013861:Thiocyanates; C005441:phenylisothiocyanate; D016308:Enkephalin, Leucine-2-Alanine; C030279:enkephalinamide-Leu, Ala(2)-; D014269:Trifluoroacetic Acid