Two types of multivalent lectins produced from hemagglutinins of clostridium botulinum: Gg binds to Gal/GalNAc and Rn binds to Neu5Ac

A group from Tokyo University of Agriculture and Technology, Tokyo, 183-8509, Japan, etc. has reported two types of multivalent lectins produced from hemagglutinins of clostridium botulinum.
https://www.nature.com/articles/s41598-021-01501-1

Clostridium botulinum is a gram-positive anaerobic bacterium that produces a neurotoxin. Botulinum bacteria are classified into serotypes A to G depending on the antigenicity of the toxin produced. The type C 16S progenitor toxin is composed of a neurotoxin, non-toxic non-hemagglutinin component and several hemagglutinin proteins (HA) designated as HA1, HA2, HA3a and HA3b.

It has been know that type C HA1 has two binding sites: site I and site II. Site I binds to N-acetylneuraminic acid (Neu5Ac), N-acetylgalactosamine (GalNAc) and galactose (Gal) while site II binds to galactose only.

Authors have developed two new multivalent lectins from the above mentioned hemagglutinins of clostridium botulinum designed to have different binding specificities were produced: namely Gg and Rn:
Gg is an Alexa 488 labeled complex with HA1 WADF -HA2 WT-HA3 WT, which binds to Gal/GalNAc,

and, Rn is an Alexa 594 labeled complex with HA1 NQAA-HA2 WT-HA3 WT, which binds to Neu5Ac only.