The first step in the marine sponge cell recognition and adhesion operates via a Ca2+-dependent carbohydrate-carbohydrate interaction. For the species Microciona prolifera the 200 kDa N-glycan (g-200) involved in the self-recognition is part of a proteoglycan-like macromolecular complex, the aggregation factor, with a molecular mass of 2×104 kDa. The complex has a sunburst-like shape. One of the carbohydrate epitopes involved in the self-interaction is a sulfated disaccharide fragment, β-D-GlcpNAc3S-(1→3)-α-L-Fucp. In an attempt to mimick the polyvalent g-200 glycan-g-200 glycan self-recognition on the disaccharide level, the disaccharide epitope was synthesized and conjugated with bovine serum albumin, gold nanoparticles, and gold layers. The protein conjugates were used in UV and SPR experiments, the gold glyconanoparticles in TEM experiments, and the gold glycolayers in AFM experiments. It turned out that in the presence of 10 mM CaCl2 the various disaccharide results match completely those obtained on the polymer level for M. prolifera cells and aggregation-factor-coated beads.
The first question asked by a researcher who would like to use glycochip technologies is ‘what benefits will I get in exchange for potentially large investments?’ Our brief answer to this question is: the achievable application possibilities are unlimited, whereas the primary expenses depend largely on the task, or a range of tasks to be approached. Even today, at the early stage of development, arraying of glycans is flexible, offering to a researcher a choice of technological niche optimal as a solution to his practical task with respect to an effort and expenses. In other words, several rather different approaches to glycoarray design are being currently developed, that are offering several other glycoarray types besides the most advanced and well known ‘printed glycan array’ (PGA). In this review we will describe what technical solutions have been used, or are under development in the area of glycochip design, what immobilization chemistries are best suited for the glycan structures, and wherefrom glycan libraries originate. We will also provide examples of glycochip applications to demonstrate unlimited research possibilities and teethed practical applications of this outstanding instrument.