Engineering of a 3'-sulpho-Gal{beta}1-4GlcNAc-specific probe by a single amino acid substitution of a fungal galectin

Among sulphated glycans, little is known about 3'-sulphation because of the lack of useful probes. In the course of molecular engineering of a fungal galectin from Agrocybe cylindracea, we found that a single substitution of Glu86 with alanine resulted in acquisition of specific binding for the 3'-sulpho-Galβ1-4GlcNAc structure. Extensive glyco-technological analysis revealed that this property was obtained in a ‘loss-of-function’ manner. Though this mutant (E86A) had low total affinity, it showed substantial binding to a naturally occurring N-glycan, of which the terminal galactose is 3-sulphated. Moreover, E86A specifically bound to HeLa cells, in which galactose-3-O-sulfotransferases (Gal3ST2 or Gal3ST3) were over-expressed.

Source: Journal of Biochemistry - March 27, 2015 Category: Biochemistry Authors: Hu, D., Huang, H., Tateno, H., Nakakita, S.-i., Sato, T., Narimatsu, H., Yao, X., Hirabayashi, J. Tags: Rapid Communication Source Type: research