Isolation of two novel mannan- and L-fucose-binding lectins from the green alga Enteromorpha prolifera: biochemical characterization of EPL-2

Arch Biochem Biophys. 2003 Jul 15;415(2):245-50. doi: 10.1016/s0003-9861(03)00232-7.

Abstract

EPL-1 and EPL-2 represent lectins isolated from the green alga Enteromorpha prolifera. Both lectins are 20- to 22-kDa single-chain, nonglycosylated proteins. N-terminal sequence analysis of peptides representing over 70% of their primary structures shows that EPL-1 and EPL-2 represent novel proteins. Sedimentation-diffusion equilibrium experiments showed that EPL-1 and EPL-2 had average apparent molecular masses of 60000+/-6000 Da (EPL-1) and 59500+/-3000 Da (EPL-2), indicating that EPL-1 and EPL-2 have a tendency to self-associate into higher order aggregates, possibly homodimers and homotetramers, in equilibrium. The carbohydrate-binding specificity of EPL-2 was studied by enzyme-linked lectin assay and intrinsic fluorescence measurements. The results show that the combining site of EPL-2 is capable of accommodating both D-mannose and L-fucose, which share the conformation of the hydroxyl groups at positions 2 (axial) and 4 (equatorial), and includes subsites for the substituents at O1 and for branched mannose residues.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Chlorophyta / chemistry*
  • Chlorophyta / classification
  • Chlorophyta / metabolism*
  • Fucose / chemistry
  • Mannans / chemistry
  • Mannose / chemistry
  • Molecular Sequence Data
  • Molecular Weight
  • Plant Lectins / chemistry*
  • Plant Lectins / classification
  • Plant Lectins / isolation & purification*
  • Protein Binding
  • Sequence Alignment / methods*
  • Sequence Analysis, Protein
  • Species Specificity

Substances

  • Mannans
  • Plant Lectins
  • Fucose
  • Mannose