Modification of capillary electrophoresis selectivity in hydro-organic solutions - Dissociation constants and Stokes radius measurements of peptides in water-2,2,2-trifluoroethanol mixtures

被引:18
作者
Castagnola, M
Rossetti, DV
Misiti, F
Cassiano, L
Giardina, B
Messana, I
机构
[1] Univ Cagliari, Ist Chim Biol, I-09126 Cagliari, Italy
[2] CNR, Ctr Studio Chim Recettori & Mol Biologicamente At, Rome, Italy
[3] Catholic Univ Rome, Fac Med & Chirurg, Ist Chim & Chim Clin, Rome, Italy
关键词
selectivity; dissociation constants; Stokes radius; buffer composition; peptides; trifluoroethanol;
D O I
10.1016/S0021-9673(97)00920-5
中图分类号
Q5 [生物化学];
学科分类号
071010 ; 081704 ;
摘要
Peptide electrophoretic mobilities were measured at different acidic pH in water-2,2,2-trifluoroethanol mixtures. Fit of experimental mobilities according to binding equations allowed the calculation of peptide C-terminus dissociation constants and the Stokes radius of the differently protonated forms. Analysis of the data showed that the use of hydro-organic solvents in capillary electrophoresis offers the following principal advantages: (a) a modification of dissociation constants and Stokes radii that are strongly dependent upon peptide sequence and that can be conveniently utilised for selectivity manipulation; (b) an increase of separation performance arising from the stabilisation of particular peptide conformations; (c) a solubility of large apolar peptides with respect to aqueous solutions. (C) 1997 Published by Elsevier Science B.V.
引用
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页码:57 / 65
页数:9
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