Quantification of carnosine-related peptides by microchip electrophoresis with chemiluminescence detection.
A microchip electrophoresis (MCE) method with chemiluminescence (CL) detection was developed for the determination of carnosine-related peptides, including carnosine, homocarnosine, and anserine, in biological samples. A simple integrated MCE-CL system was built to perform the assays. The highly sensitive CL detection was achieved by means of the CL reaction between hydrogen peroxide and N-(4-aminobutyl)-N-ethylisoluminol-tagged peptides in the presence of adenine as a CL enhancer and Co(2+) as a catalyst. Experimental conditions for analyte labeling, MCE separation, and CL detection were studied. MCE separation of the above-mentioned three peptides took less than 120 s. Detection limits (signal/noise ratio [S/N]=3) of 3.0x10(-8), 2.8x10(-8), and 3.4x10(-8) M were obtained for carnosine, anserine, and homocarnosine, respectively. The current MCE-CL method was applied for the determination of carnosine, anserine, and homocarnosine in human cerebrospinal fluid (CSF) and canine plasma. Homocarnosine was detected at the micromolar (microM) level in the CSF samples analyzed, whereas the levels of carnosine and anserine in these samples were below the detection limit of the assay. Interestingly, both carnosine and anserine were detected in the canine plasma samples, whereas homocarnosine was not.
Zhao
Shulin
S
College of Chemistry and Chemical Engineering, Guangxi Normal University, Guilin 51004, People's Republic of China.
Huang
Yong
Y
Shi
Ming
M
Huang
Junming
J
Liu
Yi-Ming
YM
D000818:Animals; D002336:Carnosine / Q000032:analysis*; D002555:Cerebrospinal Fluid / Q000737:chemistry; D004285:Dogs; D046209:Electrophoresis, Microchip / Q000379:methods*; D006801:Humans; D008163:Luminescent Measurements / Q000379:methods*; D008165:Luminol / Q000031:analogs & derivatives; D015203:Reproducibility of Results
D008165:Luminol; C031912:6-(N-(4-aminobutyl)-N-ethyl)amino-2,3-dihydrophthalazine-1,4-dione; D002336:Carnosine