Definition: In this task, you're given a paragraph from the research paper and your task is to generate a suitable title for the research paper based on the given paper. Under 100 words is a good title length.
Input: The 3C-like protease (3CL pro ) of severe acute respiratory syndrome coronavirus (SARS-CoV) plays key roles in viral replication and is an attractive target for anti-SARS drug discovery. In this report, a fluorescence resonance energy transfer (FRET)-based method was developed to assess the proteolytic activity of SARS-CoV 3CL pro . Two internally quenched fluorogenic peptides, 1NC and 2NC, corresponding to the N-terminal and the C-terminal autocleavage sites of SARS-CoV 3CL pro , respectively, were used as substrates. SARS-CoV 3CL pro seemed to work more efficiently on 1NC than on 2NC in trans-cleavage assay. Mutational analysis demonstrated that the His41 residue, the N-terminal 7 amino acids, and the domain III of SARS-CoV 3CL pro were important for the enzymatic activity. Antibodies recognizing domain III could significantly inhibit the enzymatic activity of SARS-CoV 3CL pro . The effects of class-specific protease inhibitors on the trans-cleavage activity revealed that this enzyme worked more like a serine protease rather than the papain protease.

Mutational and inhibitive analysis of SARS coronavirus 3C-like protease by fluorescence resonance energy transfer-based assays