Glycosaminoglycan binding studies using chimeric peptides

Liu YJ(劉耀禎), Jayaraman G(賈亞曼), Wu CW(吳丞偉),

Chien KY(簡昆鎰) and Lyu PC(呂平江)

                    Department of Life Sciences, National Tsing Hua University, Hsinchu


Specificity in the interaction of the biomolecules is of importance for the normal functioning of a living cell.  In this regard, a proper understanding of these biological processes is of vital importance in the designing of specific drugs. Among variety of interactions, the molecular basis of the binding of proteins to glycosaminoglycans remains elusive.  We aim at understanding the logistics underlying the binding of proteins to a given glycosaminoglycan using model peptides.  In the current study we have used a chimeric peptide (a chimera of apamin and a de nova designed lysine rice peptide). The binding of the peptide to glycosaminoglycans was followed by circular dichroism and fluorescence anisotropy.  The differences in the binding abilities of these peptides were estimated in the presence and absence of the intramolecular disulfide bridges.  Both forms of the peptide do distinguish the iduronic acid(s) containing glycosaminoglycans from those lodging glucoronic acid(s).  Further studies with enzymatically digested heparin fragments indicate that the binding specificities of these peptides are different, thus signifying the importance of performed structures.