title: Tailoring a novel sialic acid-binding lectin from a ricin-B chain-like galactose-binding protein by natural evolution-mimicry.
abstract: Sialic acid (Sia) is a typical terminal sugar, which modifies various types of glycoconjugates commonly found in higher animals. Its regulatory roles in diverse biological phenomena are frequently triggered by interaction with Sia-binding lectins. When using natural Sia-binding lectins as probes, however, there have been practical problems concerning their repertoire and availability. Here, we show a rational creation of a Sia-binding lectin based on the strategy 'natural evolution-mimicry', where Sia-binding lectins are engineered by error-prone PCR from a Gal-binding lectin used as a scaffold protein. After selection with fetuin-agarose using a recently reinforced ribosome display system, one of the evolved mutants SRC showed substantial affinity for alpha2-6Sia, which the parental Gal-binding lectin EW29Ch lacked. SRC was found to have additional practical advantages in productivity and in preservation of affinity for Gal. Thus, the developed novel Sia-recognition protein will contribute as useful tools to sialoglycomics.
authors.affiliation: Research Center for Glycoscience, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568, Japan.
authors.forename: Rikio
authors.initials: R
authors.lastname: Yabe
authors.forename: Ryuichiro
authors.initials: R
authors.lastname: Suzuki
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kuno
authors.forename: Zui
authors.initials: Z
authors.lastname: Fujimoto
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Jigami
authors.forename: Jun
authors.initials: J
authors.lastname: Hirabayashi
mesh_terms: D000595:Amino Acid Sequence; D018360:Crystallography, X-Ray; D019020:Directed Molecular Evolution; D037161:Galectins / Q000235:genetics*; D037102:Lectins / Q000235:genetics*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009844:Oligosaccharides / Q000737:chemistry; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012276:Ricin / Q000737:chemistry*; D016415:Sequence Alignment; D063265:Sialic Acid Binding Immunoglobulin-like Lectins
chemical_list: D037161:Galectins; D037102:Lectins; D009844:Oligosaccharides; D063265:Sialic Acid Binding Immunoglobulin-like Lectins; D012276:Ricin