During the last three decades or so, many efforts have been made to study the protein cleavage sites by some disease-causing enzyme, such as HIV (human immunodeficiency virus) protease and SARS (severe acute respiratory syndrome) coronavirus main proteinase. It has become increasingly clear via this minireview that the motivation driving the aforementioned studies is quite wise, and that the results acquired through these studies are very rewarding, particularly for developing peptide drugs.
Running Title: Recollection of distorted key theoryJournal Pre-proof J o u r n a l P r e -p r o o f Furthermore, a web-server called "HIVcleave" [21] has been established for predicting HIV protease cleavage sites in proteins. Its website address is at Just like the pseudo amino acid components [51-54] and the 5-steps rule [55], which have been stimulated by the development of the sequence bioinformatics, widely and increasingly used in proteome and genome analysis and , it is anticipated that the "distorted key theory" that was stimulated from the structural bioinformatics [187] as well as some pioneering studies [188][189][190][191][192][193][194][195] and their follow-up studies , will be also widely and increasingly used in drug development, particularly for developing peptide drugs [217] and multi-target drugs [218]. Journal Pre-proof J o u r n a l P r e -p r o o f Journal Pre-proof J o u r n a l P r e -p r o o f 5 Figure 1 Journal Pre-proof J o u r n a l P r e -p r o o f 6 Figure 2. A schematic illustration to show a peptide in good fitting and tightly binding with the enzyme's active site before it is cleaved by the latter. Adapted from [42] with permission.