earticle

영어

It has been becoming clear that cell-surface glycans are involved in a variety of important physiological events, such as cell-cell recognition, adhesion, signal transduction, quality control, and circulatory residence of proteins. However, their physiological roles have not been well understood. In this conference, we report two strategies for investigating the physiological role of glycans, i.e., bio-imaging of glycans in a whole body system and synthesis of biologically relevant glycans. Positron emission tomography (PET) is a non-invasive method that quantitatively visualizes the locations and levels of radiotracer accumulation with high imaging contrast. A new DOTA probe 1 was developed for facile labeling of peptides and proteins for PET imaging. The high reactivity of 1 enabled the labeling of lysine residues in peptides and proteins at very low concentration (~10-8 M) within a short reaction time (10~30 min). The labeled glycoproteins and glycoclusters were then subjected to PET imaging in order to examine their in vivo dynamics. MicroPET of the glycoproteins, [68Ga]DOTA-orosomucoid and asialoorosomucoid thus successfully visualized the differences in the circulatory residence of glycoproteins in rabbit, in the presence or absence of the sialic acids in glycans on glycoproteins [1,2]. Synthetic study of glycans including solid-phase synthesis will be also reported.