Separation of amino acid and peptide stereoisomers by nonionic micelle-mediated capillary electrophoresis after chiral derivatization.
Enantiomers of amino acids and peptides were derivatized with a fluorescent chiral reagent, 4-(3-isothiocyanatopyrrolidinl-yl)-7-nitro-2,1,3-benzoxadiazole [R-(-)- or S-(+)-NBD-PyNCS] and the resulting diastereomeric derivatives separated by capillary electrophoresis (CE). The CE running buffer consisted of 25 mM acetate buffer (pH 4) and 10 mM of the nonionic surfactant Triton X-100. The excitation maximum of NBD-PyNCS at 480 nm matches the major Ar-ion emission line at 488 nm allowing sensitive laser-induced fluorescence detection with limits of detection around 50 nM. D-Proline and D-aspartate spiked (at 10(-4) M and 10(-5) M concentrations, respectively) into complex biological matrices (rabbit serum and homogenate of Aplysia californica buccal ganglion) are detected without matrix interferences. This method has also been applied to the determination of D- and L-amino acid residues in peptides after acid hydrolysis. Results from the chiral analysis of the naturally-occurring peptide, gramicidin D, are shown.
Liu
Y M
YM
Department of Chemistry, University of Illinois at Urbana-Champaign 61801, USA.
Schneider
M
M
Sticha
C M
CM
Toyooka
T
T
Sweedler
J V
JV
D000596:Amino Acids / Q000032:analysis* / Q000737:chemistry; D000818:Animals; D000900:Anti-Bacterial Agents / Q000032:analysis* / Q000737:chemistry; D019075:Electrophoresis, Capillary / Q000379:methods*; D005456:Fluorescent Dyes / Q000737:chemistry*; D006096:Gramicidin / Q000032:analysis* / Q000737:chemistry; D007106:Immune Sera / Q000276:immunology; D017879:Isothiocyanates / Q000737:chemistry*; D008823:Micelles; D010069:Oxadiazoles / Q000737:chemistry*; D011817:Rabbits; D013237:Stereoisomerism
C107817:4-(3-isothiocyanatopyrrolidin-1-yl)-7-(N,N-dimethylaminosulfonyl)-2,1,3-benzoxadiazole; D000596:Amino Acids; D000900:Anti-Bacterial Agents; D005456:Fluorescent Dyes; D007106:Immune Sera; D017879:Isothiocyanates; D008823:Micelles; D010069:Oxadiazoles; D006096:Gramicidin