Sialic acids as link to Japanese scientists

Area of Science:

• Biochemistry
• Marine Biology
• Glycobiology

Background:

• Sialic acids are crucial glycans involved in various biological processes.
• O-acetylation of sialic acids can significantly alter their biological functions and interactions.
• N-glycolylneuraminic acid (Neu5Gc) is a prominent sialic acid found in various species, with implications for health and disease.

Purpose of the Study:

• To review 40 years of research on sialic acids and their derivatives, focusing on cooperations with Japanese scientists.
• To investigate the presence and characteristics of sialic acids, including O-acetylated forms and Neu5Gc, in diverse biological sources.
• To explore the impact of sialic acid modifications on enzyme activity and develop novel inhibitors.

Main Methods:

• Analysis of sialic acids in sea urchins (Pseudocentrotus depressus) and tunicates (Halocynthia species).
• Quantification of sialic acids in human and bovine milk.
• Use of synthetic substrates to study the effect of O-acetylation on sialidase activity.
• Literature review on Neu5Gc biosynthesis, distribution in dogs, and edible bird nest mucin.

Main Results:

• Sialic acid O-acetylation at C-4 was found to inhibit sialidase activity, except for viral enzymes.
• N-glycolylneuraminic acid was identified as a key focus in seafood research.
• Edible bird nest substance (Collocalia mucin) was utilized for synthesizing sialylation inhibitors.

Conclusions:

• Sialic acid O-acetylation represents a significant regulatory mechanism affecting enzyme interactions.
• Understanding Neu5Gc distribution and biosynthesis is important for various biological contexts.
• The study highlights the potential of natural sources like edible bird nests for developing therapeutic agents targeting sialylation pathways.