| 摘要 |
#CMT# #/CMT# Procedure for facilitating an analysis of a peptide, which shows a N-end and a C-end, in a mass spectrometer, comprises: derivatizing the C-end of the peptide with an amino acid residue over a reaction with a carbodiimide-reagent to produce a peptide derivative; ionizing the peptide derivative with a dual charge; and fragmenting the ionized peptide derivative in a mass spectrometer, where binary fragments of the ionized derivatives respectively comprises a charge, which facilitates a sequence analysis of the peptide. #CMT#USE : #/CMT# The procedure deals with facilitating an analysis of a peptide. #CMT#ADVANTAGE : #/CMT# The peptide that is modified by ionization shows a favorable fragmentation behavior, which enables the recovery of strong b- and y-ions frequency that appears in fragment spectrum, from these informative data, the amino acid sequence of the peptide can be easily identified. #CMT#BIOTECHNOLOGY : #/CMT# Preferred Method: The N-end and the C-end of the peptide derivative are charged by ionization. The fragmentation of the peptide derivative generates a considerable y-ions-series and b-ions-series. The fragmentation is carried out by a collision induced dissociation (CID), an electron capture dissociation (ECD) and an electron transfer dissociation. Preferred Components: The amino acid residue comprises at least a lysine or arginine. The peptide is hydrophobic before the derivatization. The peptide comprises no lysine- or arginine residues before the derivatization. The peptide shows a membrane protein. #CMT#EXAMPLE : #/CMT# A pentapeptide, methionine-enkephalin was used as hydrophobic peptide, which contained no basic or acidic groups apart from a C- and N-end. Arginine was derivatized and arginine-methyl-ester was formed by adding a carbodiimide reagents. The arginine-methyl-ester was then coupled with the methionine-enkephalin to form a peptide with six residues. The spectrum of the hexa-peptide was measured before fragmentation. This spectrum showed both dually charged ions and singly charged ions. The ionized peptide was fragmented in a mass spectrometer to facilitate a sequence analysis of the peptide. |
