Matrix-assisted laser desorption/ionization time-of-flight
(MALDI-TOF) mass spectrometric analysis was performed using
the Voyager DE PRO (AB Biosystems, Framingham, Mass.) with
an acceleration voltage of 20 kV and an N2 laser at 337 nm.
Sinapinic acid was used as the matrix for protein analysis, while acyano-4-hydroxycinnamic
acid was used for peptides