Histidine-mediated pH-sensitive regulation of M-ficolin:GlcNAc binding activity in innate immunity examined by molecular dynamics simulations.

ABSTRACT:

Background

M-ficolin, a pathogen recognition molecule in the innate immune system, binds sugar residues including N-acetyl-D-glucosamine (GlcNAc), which is displayed on invading microbes and on apoptotic cells. The cis and trans Asp282-Cys283 peptide bond in the M-ficolin, which was found to occur at neutral and acidic pH in crystal structures, has been suggested to represent binding and non-binding activity, respectively. A detailed understanding of the pH-dependent conformational changes in M-ficolin and pH-mediated discrimination mechanism of GlcNAc-binding activity are crucial to both immune-surveillance and clearance of apoptotic cells.

Methodology/principal findings

By immunodetection analysis, we found that the pH-sensitive binding of GlcNAc is regulated by a conforma

SUBMITTER: Yang L 

PROVIDER: S-EPMC3088710 | biostudies-literature | 2011 May

REPOSITORIES: biostudies-literature