Anionic and zwitterionic moieties as widespread glycan modifications in non-vertebrates

Area of Science:

• Biochemistry
• Evolutionary Biology
• Glycobiology

Background:

• Glycan structures in non-vertebrates exhibit high variability, suggesting evolutionary and speciation-driven origins.
• Eukaryotes utilize a limited set of monosaccharide building blocks, mostly neutral, with anionic hexuronic and sialic acids being exceptions.

Purpose of the Study:

• To investigate the prevalence and significance of anionic and zwitterionic modifications in N-glycans of protists and invertebrates.
• To highlight the impact of these charged moieties on physicochemical properties and biological interactions.

Main Methods:

• Focus on N-glycans with anionic and zwitterionic modifications in protists and invertebrates.
• Briefly reference O-glycans, glycolipids, and glycosaminoglycans containing similar charged moieties.

Main Results:

• Anionic and zwitterionic modifications, including sulfate and phosphate groups, are widespread in lower organisms.
• These modifications alter glycan ionization during mass spectrometry and influence protein receptor interactions.

Conclusions:

• Charged glycoconjugates are a pervasive, yet frequently underestimated, characteristic of protists and invertebrates.
• Understanding these charged structures is crucial for comprehending glycan diversity and function in these organisms.