Datensatz

Zusammenfassung

Because of their key position in signal transduction cascades, passing chemical signals across the cell membrane and beyond to the cell nucleus, protein conjugates such as glyco-, lipo-, phospho- and nucleoproteins are at the focal point of intense biochemical research. They are involved, for instance, in the regulation of cell growth and, in consequence, also in malignant proliferation processes which can lead to cancer. This biological importance has created a high demand for these complex macromolecules and for fragments thereof carrying characteristic structural features, especially the linkage region of the peptide backbone with the carbohydrate, the lipid or the phosphoric acid ester. However, the synthesis of peptide conjugates by means of classical chemical methods has come up against difficulties and limitations, prompting the development of new synthetic techniques and strategies. Thus, in recent years, combinations of enzymatic and classical methods proved to offer rewarding alternatives. This chapter highlights the potential of hydrolytic enzymes for the mild and selective introduction of protecting groups as well as for the cleavage of such groups, and later presents examples of their application as central steps in synthetic routes for the preparation of peptide conjugates.