Method and apparatus for pyrolysis-induced cleavage in peptides and proteins
A method and apparatus for conducting the rapid pyrolysis of peptides, proteins, polymers, and biological materials. The method can be carried out at atmospheric pressures and takes only about 5 to 30 seconds. The samples are cleaved at the C-terminus of aspartic acid. The apparatus employs a probe on which the sample is heated and digested components analyzed.
1. A method of analyzing a peptide sample containing aspartic acid and cysteine, comprising the steps of:
(a) heating the peptide sample to between about 180° C. and about 250° C., in a period of between about 5 seconds and about 30 seconds to cleave the peptide at both the aspartic acid and cysteine site-specific locations;
(b) electrospraying the digested sample with a solvent to produce desorbed ions of components of the digested sample; and
(c) detecting the desorbed ions.
2. A method as described in claim 1 , wherein the step of detecting the desorbed ions is by mass spectrometry.
3. A method as described in claim 1 , wherein the solvent is free of cationizing agents.
4. A method as described claim 1 , wherein the method is performed at atmospheric pressure.
5. Apparatus for analyzing a peptide sample containing aspartic acid and cysteine, comprising:
(a) a heating element having a surface on which the sample is deposited and which heats the peptide sample to between about 180° C. and about 250° C., in a period of between about 5 seconds and about 30 seconds to cleave the peptide at both the aspartic acid and cysteine site-specific locations;
(b) an electrospray device that subjects the digested sample to a solvent spray to produce desorbed ions of components of the digested sample; and
(c) a detector for detecting the desorbed ions.