Peptide Analytes

A set of imidazole dipeptides (camosine, anserine, balenine, histidine, 1-methylhis-tidlne, 3-methylhistldlne, homocamosine) were isolated fix)m equine muscle, deri-vatized with o-phthaladehyde immediately prior to analysis, and separated on a C g column (A == 340 nm, ex 450 nm, em). A complex 45-min 100/0 - 0/100(995/5 water [12.5 mM sodium acetate at pH 7.2]/THF)/(55/35/15 water [12.5 mM sodium acetate at pH 7.2]/methanol/acetonitrile) gradient was used. Note that the buffer preparation uses the addition of isomolar amounts of sodium acetate (1.026g/L) to acetic acid (0.751 g/L). The resulting pH of the aqueous solution should be the pA, of acetic acid (4.76). Peak shapes were excellent and only 1-methyl-and 3-methylhistidine peaks lacked baseline resolution. Working standards were 

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Hakansson, K., Emmett, M.R., Hendrickson, C.L. and Marshall, A.G. (2001) High-sensitivity electron capture dissociation tandem FTICR mass spectrometry of microelectrosprayed peptides, Analytical Chemistry 73,... 

Monton M R N, Terabe S (2005). Recent development in capillary electrophoresis-mass spectrometry of proteins and peptides. Analyt. Sci. 21 5-13. 

Michalski W P, Shiell B J (1999). Strategies for analysis of electrophoretically separated proteins and peptides. Analyt. Chim. Acta. 383 27-46. 

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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