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| Note: Silanols normally found on capillary walls are substituted with Si-H (hydride) in our CelerityCE™
capillaries. Basic neuropeptides are therefore not adsorbed by the capillary assuring intraday and interday
repeatability of migration times. To achieve lower detection limits coupling with MS is recommended. |
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CelerityCE™ Application Sheet
Enkephalins by CE
Reproducible & Robust Technique for the Analysis of Neuropeptides
Endogenous peptides, called enkephalins, are located in the spinal cord and other key regions of the nervous
system involved in pain transmission and analgesia. Activating opioid receptors to reduce pain, enkephalins are
neurotransmitters and a disturbance in their synthesis can cause serious illnesses. These peptides are studied in
connection with autism, Alzheimer and Parkinson diseases.
Method Conditions:
Voltage: 20kV
Capillary: CelerityCE™ C18, High Surface Area Capillary for CE, i.d. 50µm, total length 32cm, effective length 23.5cm
Catalog No: 04918-50
Injection: 3 seconds @ 50 mbar
Stock Buffer: 0.03 M Lactic acid, 0.136M B-alanine, pH=3.7
Run Buffer: Stock buffer diluted to 1:10k, pH=3.7
Sample: Mixture of
- D-ala-met-5-enkephalin
- D-ala-leu-5-enkaphalin
- met-enkephalin
10 µg/mL of each enkephalin peptide in 50µL total volume
Detection: UV @ 210nm
Instrument: Agilent 3D HPCE |
Discussion:
This developed separation method measures the enkephalins in a small volume (50µL) sample, which is similar to
in-vivo samples. These biologically active peptides have “basic” functional groups which makes their analysis
non-reproducible when using bare fused silica capillaries. The usefulness of the C18 bonded capillaries for the
analysis of positively charged peptides is demonstrated by the fast and efficient separation of closely related
enkephalins shown in this application note.
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