PLUNC in human nasal lavage fluid: multiple isoforms that bind to lipopolysaccharide

Biochim Biophys Acta. 2004 Jun 1;1699(1-2):57-63. doi: 10.1016/j.bbapap.2004.01.001.


Here, we demonstrate the presence of multiple isoforms of palate lung nasal epithelial clone (PLUNC) in human nasal lavage fluid (NLF). Eight isoforms were separated by two-dimensional gel electrophoresis (2-DE), and peptide mapping of the proteins was performed using MALDI-TOF MS (matrix assisted laser desorption/ionization time of flight mass spectrometry) of tryptic and asparginase cleavages. The identification was verified by amino acid sequencing after analysis of collision-induced dissociation (CID) fragmentation spectra with nanoelectrospray MS/MS. One isoform showed an electrophoretic mobility shift after N-glycosidase treatment, indicating that at least one of the PLUNC isoforms is glycosylated. We also demonstrate that PLUNC in NLF binds to lipopolysaccharide (LPS) in vitro; indeed, out of all proteins present in NLF only the PLUNC isoforms were found to adsorb to an LPS-coated surface. These results show that PLUNC is expressed as multiple LPS-binding isoforms in human NLF. The possibility that PLUNC may play a role in the innate immune response of the upper airways is inferred.

MeSH terms

  • Electrophoresis, Gel, Two-Dimensional
  • Electrophoretic Mobility Shift Assay
  • Glycoproteins / analysis*
  • Glycoproteins / metabolism
  • Humans
  • Leucine Zippers
  • Lipopolysaccharides / metabolism*
  • Nasal Lavage Fluid / chemistry*
  • Peptide Mapping
  • Phosphoproteins / analysis*
  • Phosphoproteins / metabolism
  • Protein Binding
  • Protein Isoforms / metabolism
  • Respiratory Mucosa / metabolism*
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization


  • BPIFA1 protein, human
  • Glycoproteins
  • Lipopolysaccharides
  • Phosphoproteins
  • Protein Isoforms