Here we introduce the Protein Cutter (http:// biochemie.upol.cz/software/proteincutter), a web application for the prediction of results of protein digestion by proteolytic enzymes, which is accessible over the Internet network. In the beginning, previous and current approaches for protein sequencing are summarized. This includes the use of dinitrofluorobenzene and substituted isothiocyanate reagents as well as mass-spectrometry-based strategies and translation of genomic sequences. The following text characterizes bioinformatics as a modern scientific discipline, which solves problems arising from the management and analysis of biological data. The most important nucleotide and amino acid sequence databases are described together with the databases of DNA and protein structures. The program Protein Cutter, which is described in detail with respect to its design and technology, allows predicting peptide sequences generated by proteolytic digestion of a protein (represented by a user-entered amino acid or coding nucleotide sequence). In addition to other comparable applications, Protein Cutter offers more complex information calculated from amino acid sequences (i.e. molecular mass, amino acid composition, isoelectric point, hydropathicity index etc.), it works with nucleotide sequences upon automatic translation, it is open and friendly for user-entered cutting rules and provides more options for the filtration and sorting of results.

Katedra biochemie a Centrum regionu Haná pro biotechnologický a zemědělský výzkum Přírodovědecká fakulta Univerzita Palackého Šlechtitelů 11 783 71 Olomouc

Program application for the prediction of results of protein digestion by proteolytic enzymes