Assessment of ultrasonic-assisted enzymatic digestion of complex protein mixtures by high-resolution mass spectrometry

Background & Objectives Large-scale proteome analysis by mass spectrometry is commonly preceded by enzymatic digestion of proteins. The conventional protocol for in-solution digest of complex protein mixtures includes trypsin and is performed at room temperature for at least 12h. To improve this time-consuming method we assessed the efficiency of focused ultrasound-assisted enzymatic digest. It has previously been shown that ultrasonication can dramatically reduce digestion time. However, it is not known how this affects protein identification and quantification when applied to complex protein mixtures such as whole cell lysates. Here, we explore in-depth the proteome of embryonic stem cells comparing trypsin-digestion methods with and without ultrasound support side-by-side. Methods In-solution protein digest Protein extracts were digested with sequencing-grade trypsin (Promega) for 1, 5, 10, 20, 30, 40min and 1h in the presence or absence of focused ultrasonication (Covaris). A conventional digestion ov...