Biological Importance of Phosphorylated Peptide and Cyclic Peptide Synthesis.
Phosphorylated peptide One of the most prominent post-translational modification (PTM) is the phosphorylation of Ser, Thr and Tyr (Table 1). These modifications that are easily reversible allow for the in vivo production of a myriad of proteins and thus manifold biological fonctions from a singly translated polypeptide that varies in their phosphorylation patterns. Phosphorylation of serine or threonine - and to a lesser extent tyrosine- residues prompts conformational changes of the protein that modify their biological activity. For example, it has long been recognized that hormones transmit information across the external membrane of the cells by activating transmembrane signalling systems that regulate the production of a fairly small number of chemical mediators, called second messengers. These messengers trigger the activities of protein kinases and phosphatases that modify the phosphorylation states of many intracellular proteins, thu...