title: Binding Specificity of Philyra pisum Lectin to Pathogen-Associated Molecular Patterns, and Its Secondary Structure.
abstract: We recently reported a Philyra pisum lectin (PPL) that exerts mitogenic effects on human lymphocytes, and its molecular characterization. The present study provides a more detailed characterization of PPL based on the results from a monosaccharide analysis indicating that PPL is a glycoprotein, and circular dichroism spectra revealing its estimated α-helix, β-sheet, β-turn, and random coil contents to be 14.0%, 39.6%, 15.8%, and 30.6%, respectively. These contents are quite similar to those of deglycosylated PPL, indicating that glycans do not affect its intact structure. The binding properties to different pathogen-associated molecular patterns were investigated with hemagglutination inhibition assays using lipoteichoic acid from Gram-positive bacteria, lipopolysaccharide from Gram-negative bacteria, and both mannan and β-1,3-glucan from fungi. PPL binds to lipoteichoic acids and mannan, but not to lipopolysaccharides or β-1,3-glucan. PPL exerted no significant antiproliferative effects against human breast or bladder cancer cells. These results indicate that PPL is a glycoprotein with a lipoteichoic acid or mannan-binding specificity and which contains low and high proportions of α-helix and β-structures, respectively. These properties are inherent to the innate immune system of P. pisum and indicate that PPL could be involved in signal transmission into Gram-positive bacteria or fungi.
authors.affiliation: Physical Pharmacy Laboratory, College of Pharmacy, Chung-Ang University, Seoul 156-756, Korea.
authors.forename: Byung Tae
authors.initials: BT
authors.lastname: Park
authors.affiliation: Physical Pharmacy Laboratory, College of Pharmacy, Chung-Ang University, Seoul 156-756, Korea.
authors.forename: Byung Sun
authors.initials: BS
authors.lastname: Kim
authors.affiliation: Physical Pharmacy Laboratory, College of Pharmacy, Chung-Ang University, Seoul 156-756, Korea.
authors.forename: Heajin
authors.initials: H
authors.lastname: Park
authors.affiliation: Physical Pharmacy Laboratory, College of Pharmacy, Chung-Ang University, Seoul 156-756, Korea.
authors.forename: Jaehoon
authors.initials: J
authors.lastname: Jeong
authors.affiliation: Physical Pharmacy Laboratory, College of Pharmacy, Chung-Ang University, Seoul 156-756, Korea.
authors.forename: Hanbit
authors.initials: H
authors.lastname: Hyun
authors.affiliation: Physical Pharmacy Laboratory, College of Pharmacy, Chung-Ang University, Seoul 156-756, Korea.
authors.forename: Hye Seong
authors.initials: HS
authors.lastname: Hwang
authors.affiliation: Physical Pharmacy Laboratory, College of Pharmacy, Chung-Ang University, Seoul 156-756, Korea.
authors.forename: Ha Hyung
authors.initials: HH
authors.lastname: Kim
keywords: Antiproliferative activity; Deglycosylation; Lectin; Pathogen-associated molecular patterns; Secondary structure