Capillary electrophoresis, free solution peptides

Jorgenson reported the use of glass capillaries for free solution electrophoresis 25 years ago (Jorgenson andLukacs, 1981,1983). Aplug of analyte was introduced into a buffer-filled capillary and separated at high electric fields. Capillaries of 75 im inner diameter were employed, and detection of labeled amino acids and peptides was based on fluorescence. 

P. D. Grossman, J. C. Colburn, H. H. Lauer, R. G. Nielsen, R. M. Riggin, G. S. Sittampalam and E. C. Rickard, Application of free-solution capillary electrophoresis to the analytical scale separation of proteins and peptides . Anal. Chem. 61 1186-1194 (1989). 

Karim, M.R., Shinagawa, S., Takagi, T. (1994). Electrophoretic mobilities of the complexes between sodium dodecyl sulfate and various peptides or proteins determined by free solution electrophoresis using coated capillaries. Electrophoresis 15, 1141-1146. 

YH Chu, DP Kirby, BL Karger. Free-solution identification of candidate peptides from combinatorial libraries by affinity capillary electrophoresis/mass spectrometry. J Am Chem Soc 117 5419-5420, 1995. 

The key operational parameter in free-solution capillary electrophoresis is the pH of the running buffer, as the electroosmotic flow and ionization of the analyte can be regulated by this variable. The role of buffers in capillary electrophoresis has been discussed in detail, with emphasis on buffer concentration, buffer type, and pH effects [10]. The effect of organic solvents on separation and migration behavior has been studied for dipeptides [11] and somatostatin analog peptides [12]. The order of migration as well as the selectivity may be manipulated by organic modifiers in... 

Other methodologies. Desportes et al. (2000) isolated several small wine peptides (Mr <3000) using RP-HPLC on a porous graphite carbon Hypercarb column. The purity of the fractions collected was confirmed by free-solution capillary electrophoresis (FSCE). In a later study, Desportes et al. (2001) determined the peptide sequence of some isolated peptides by Edman degradation. 

Chu, Y-H. Kirby, D.P Karger, B.L. Free Solution Identification of Candidate Peptides from Combinatorial Libraries by Affinity Capillary Electrophoresis/ Mass Spectrometry, J. Am. Chem. Soc. 117, 5419-5420 (1995). 

Grossman, P.D. et al. Application of free-solution capillary electrophoresis to the analytical scale separation of proteins and peptides, AnaZ. Chem., 61, 1186, 1989. 

Figure 7 CZE separation of hGH and its derivatives. CZE performed in FS capiiiary (i.d. 50 pm, totai iength 105cm, effective iength (to detector) 81.5cm BGE lOmmoii" Tricine, 5.8mmoii morphoiine, 20mmoii NaCi, pH8.0 eiectric fieid intensity 300Vcm current 20pA, temperature 24°C. 1, hGH 2, (desamido-149)- and (desamido-152)-hGH 3, (didesamido-149-152)-hGH. Mesityl oxide, electroosmotic fiow marker. (Reprinted with permission from Grossman PD, Coiburn JC, Lauer HH, et al. (1989) Application of free-solution capillary electrophoresis to the anaiyticai scaie separation of proteins and peptides. Analytical Chemistry 61(11) 1186-1194 American Chemical Society.)...

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