TY  - JOUR
AU  - Psurek, A.
AU  - Feuerstein, S.E.
AU  - Willbold, D.
AU  - Scriba, G. K. E.
TI  - Nonaqueous versus aqueous capillary electrophoresis of alpha-helical polypeptides: Effect of secondary structure on separation selectivity
JO  - Electrophoresis
VL  - 27
SN  - 0173-0835
CY  - Weinheim
PB  - Wiley-Blackwell
M1  - PreJuSER-55022
SP  - 1768 - 1775
PY  - 2006
N1  - Record converted from VDB: 12.11.2012
AB  - The CE separation of alpha-helical polypeptides composed of 14-31 amino acid residues has been investigated using aqueous and nonaqueous BGEs. The running buffers were optimized with respect to pH. Generally, higher separation selectivities were observed in nonaqueous electrolytes. This may be explained by a change in the secondary structure when changing from water to organic solvents. Circular dichroism spectra revealed a significant increase in helical structures in methanol-based buffers compared to aqueous buffers. This change in secondary structure of the polypeptides contributed primarily to the different separation selectivity observed in aqueous CE and NACE. For small oligopeptides of two to five amino acid residues no significant effect of the solvent was observed in some cases while in other cases a reversal of the migration order occurred when changing from aqueous to nonaqueous buffers. As these peptides cannot adopt secondary structures the effect may be attributed to a shift of the pKa values in organic solvents compared to water.
KW  - Amino Acid Sequence
KW  - Circular Dichroism
KW  - Electrophoresis, Capillary: methods
KW  - Molecular Sequence Data
KW  - Peptides: chemistry
KW  - Peptides: isolation & purification
KW  - Protein Structure, Secondary
KW  - Water: chemistry
KW  - Peptides (NLM Chemicals)
KW  - Water (NLM Chemicals)
KW  - J (WoSType)
LB  - PUB:(DE-HGF)16
C6  - pmid:16645940
UR  - <Go to ISI:>//WOS:000237685600011
DO  - DOI:10.1002/elps.200500673
UR  - https://juser.fz-juelich.de/record/55022
ER  -