Methods for labeling amine-containing compounds
The invention relates to an activated form of procaine, and the use of the activated procaine, or salts or solvates thereof, to label amine-containing compounds, such as N-glycans, amine-containing amino acids, amine-containing peptides, amine-containing proteins, or other amine-containing compounds in a sample. Use of activated procaine as a label allows for sensitive detection of compounds labeled with it by both fluorescence and mass spectrometry.
1. A method for labeling and, optionally, analyzing, a N-glycan, amine-containing amino acid, amine-containing peptide, amine-containing protein, glycosylamine, or other amine-containing compound in a sample, said method comprising: (a) mixing said N-glycan, amine-containing amino acid, amine-containing peptide, amine-containing protein, glycosylamine, or other amine-containing compound in a solution with a labeling compound (“Activated Procaine”) with the structure
or a solvate or a salt of said labeling compound, thereby creating a labeling mixture, and
(b) conducting said labeling at a labeling temperature of between 10° C.±2° C. to 60° C.±2° C.,
thereby creating a labeled, fluorescent, mass spectrometry-active derivative of said N-glycan, of said amine-containing amino acid, of said amine-containing peptide, of said amine-containing protein, of said glycosylamine, or of said other amine-containing compound in said sample.
2. The method of claim 1 , wherein N-hydroxysuccinimide is present during said labeling of said N-glycan, amine-containing amino acid, amine-containing peptide, amine-containing protein, glycosylamine, or other amine-containing compound with said Activated Procaine or solvate or salt thereof.
3. The method of claim 1 , wherein said fluorescent, mass spectrometry-active derivative of said N-glycan, amine-containing amino acid, amine-containing peptide, amine-containing protein, glycosylamine, or other amine-containing compound is a fluorescent, mass spectrometry-active derivative of said N-glycan.
4. The method of claim 1 , wherein said fluorescent, mass spectrometry-active derivative of said N-glycan, amine-containing amino acid, amine-containing peptide, amine-containing protein, glycosylamine, or other amine-containing compound is a fluorescent, mass spectrometry-active derivative of said glycosylamine.
5. The method of claim 1 , wherein said labeling temperature is 45° C. to 55° C.
6. The method of claim 1 , wherein said labeling temperature is 50° C.±2° C.
7. The method of claim 1 , wherein said labeling temperature is 50° C.
8. The method of claim 1 , wherein said labeling is conducted by incubating said labeling mixture at said labeling temperature for 30 seconds to 5 minutes.
9. The method of claim 1 , wherein said labeling is conducted by incubating said labeling mixture at said labeling temperature for 1 minute ±15 seconds to 3 minutes ±15 seconds.
10. The method of claim 1 , wherein said labeling is conducted by incubating said labeling mixture at said labeling temperature for 1 minute ±15 seconds.
11. The method of claim 1 , wherein said labeling is conducted by heating said labeling mixture to a labeling temperature of 50° C.±2° C. and incubating said labeling mixture at said labeling temperature of 50° C.±2° C. for 1 minute ±15 seconds to 3 minutes ±15 seconds.
12. The method of claim 1 , wherein said labeling is conducted by heating said labeling mixture to a labeling temperature of 50° C.±2° C. and incubating said labeling mixture at said labeling temperature of 50° C.±2° C. for 1 minute ±15 seconds.
13. The method of claim 1 , wherein said labeling is conducted by heating said labeling mixture to a labeling temperature of 50° C. and incubating said labeling mixture at said labeling temperature of 50° C. for 1 minute ±15 seconds.
14. The method of claim 1 , wherein said labeling mixture has a pH of 7.5-8.5.
15. The method of claim 1 , wherein said labeling mixture has a pH of 8.0±0.25.
16. The method of claim 1 , wherein said labeling mixture has a pH of 8.0.
17. The method of claim 1 , further comprising analyzing said fluorescent, mass spectrometry-active derivative of said N-glycan, amine-containing amino acid, amine-containing peptide, amine-containing protein, glycosylamine, or other amine-containing compound by subjecting said fluorescent, mass spectrometry-active derivative of N-glycan, amine-containing amino acid, amine-containing peptide, amine-containing protein, glycosylamine, or other amine-containing compound to an analytical method.
18. The method of claim 17 , wherein said analytical method is selected from the group consisting of high-pressure liquid chromatography, capillary electrophoresis, fluorescence analysis, mass spectrometry, and a combination of any of these.
19. The method of claim 18 , wherein said combination is of fluorescence analysis and mass spectrometry.