Ultra fast trypsin digestion of proteins by high intensity focused ultrasound

Proteolytic digestion of proteins in seconds under an ultrasonic field provided by high-intensity focused ultrasound (HIFU) has been achieved. Successful in-solution and in-gel tryptic digestion of proteins in 60 s or less was demonstrated by either MALDI-TOF mass spectrometry or liquid chromatography-electrospray ion trap mass spectrometry (RP-HPLC-ESI-IT-MS/MS). The efficiency of this new procedure for protein digestion compared favorably with those attained using conventional overnight incubation methods. The performance of the method was also demonstrated by the specific identification of three proteins in a whole proteome in less than 1 h. The method greatly reduces the time needed for protein digestion, is of easy implementation, environmental friendly, and economic. Adaptation of this method to on-line procedures and robotic platforms could have promising applications in the proteomics field.