The Binding Affinity and Molecular Basis of the Structure-Binding Relationship between Urinary Tamm-Horsfall Glycoprotein and Tumor Necrosis Factor-α

Molecules

Cheng-Han Wu⁴  Ko-Jen Li²  Sue-Cien Siao¹  Yu-Hsuan Chen¹  Tsai-Hung Wu³  Chang-Youh Tsai⁵ 

[1] Institute of Molecular Medicine, National Taiwan University College of Medicine, No.7 Chung-Shan South Road, Taipei 100, Taiwan;Institute of Clinical medicine, National Yang-Ming University College of Medicine, No.155 Li-Nong Street, Shih-Pai, Taipei 11217, Taiwan;Section of Nephrology, Taipei Veterans General Hospital, No.201 Section 2, Shih-Pai Road, Taipei 11217, Taiwan;Institute of Clinical Medicine, National Taiwan University College of Medicine and National Taiwan University Hospital, No.7 Chung-Shan South Road, Taipei 100, Taiwan;Section of Allergy, Immunology and Rheumatology, Taipei Veterans General Hospital, No.201 Section 2, Shih-Pai Road, Taipei 11217, Taiwan

关键词: Tamm-Horsfall glycoprotein;    tumor necrosis factor-α;    binding affinity;    structure-binding relationship;    glucosamine-containing mannose;   

DOI  :  10.3390/molecules171011978

来源: mdpi

【 摘 要 】

In a previous study we noted significant THP binding to TNF-α, but did not explore the molecular basis of the structure-binding relationship. In this study, we used lectin-binding ELISA to assess the carbohydrate compositions of THP, BSA, IgG, TNF-α, and IFN-γ. We identified β(1,4)-N-acetylglucosamine oligomers (GlcNAc) and GlcNAc/branched mannose in BSA, IgG, TNF-α, and THP, but not in IFN-γ. These carbohydrate moieties mediated binding with THP. Small amounts of Siaα(2,3)Gal/ GalNAc, Sia(2,6)Gal/GalNAc, and mannose residues were also present in THP and TNF-α. Binding affinity (K_d) between THP and TNF-α by Scatchard plot analysis was 1.4–1.7 × 10⁻⁶ M, lower than antigen-antibody or ligand-receptor binding affinities. To elucidate the structure-binding relationship of THP-TNF-α, THP was digested with neuraminidase, β-galactosidase, O-sialoglycoprotein endopeptidase, carboxypeptidase Y, or proteinase K. β-galactosidase increased binding capacity of THP for TNF-α. Monosaccharide inhibition suggested that α-methyl-D-mannoside, GlcNAc, and GalNAc, but not sialic acid, suppress THP-TNF-α binding as detected by ELISA. We conclude that sugar-lectin and sugar-protein interactions between cognate sites in THP and TNF-α mediate their binding.

【 授权许可】

CC BY   
© 2012 by the authors; licensee MDPI, Basel, Switzerland.