Efficient chymotryptic proteolysis enhanced by infrared radiation for peptide mapping

Infrared (IR) radiation was employed to enhance the efficiency of chymotryptic proteolysis for peptide mapping in this work. Protein solutions containing chymotrypsin in sealed transparent Eppendorf tubes were allowed to digest under an IR lamp at 37 degrees C. BSA and cytochrome c (Cyt- c) were digested by IR-assisted chymotryptic proteolysis to demonstrate the feasibility and performance of the novel digestion approach and the digestion time was significantly reduced to 5 min. The obtained digests were further identified by MALDI-TOF MS with the sequence coverages that were comparable to those obtained by using conventional in-solution digestion. The suitability of IR-assisted chymotryptic proteolysis to complex proteins was demonstrated by digesting human serum. The present proteolysis strategy is simple and efficient, offering great promise for high-throughput protein identification.