Synthesis and optimization of lectin functionalized nanoprobes for the selective recovery of glycoproteins from human body fluids

Anal Chem. 2011 Sep 15;83(18):7035-43. doi: 10.1021/ac200916j. Epub 2011 Aug 26.

Abstract

Biomedical sciences, and in particular biomarker research, demand efficient glycoprotein enrichment platforms. Herein magnetic nanoprobes (MNP), after being coated with three broad-spectrum lectins-concanavalin A (ConA), wheat germ agglutinin (WGA), and Maackia amurensis lectin (MA)-were utilized to selectively capture glycoproteins from human body fluids. Additionally, a new methodology, based on protection of the lectins with their target sugars prior to coupling with MNPs, was proposed to overcome the nonspecific nature of conjugation. This approach contributed to preserve lectin conformation, increasing by 40% and 90% the affinity of ConA and MA for glycoproteins in relation to synthesis with nonprotected lectins. Optimal operating conditions (temperature, time) and maximum binding capacities were further determined for each lectin by use of fetuin as a reference. The enhanced performance of lectin-based nanoplatforms was demonstrated by comparing MNP@ConA with conventional Sepharose@ConA. These experiments have shown that ConA immobilized on MNP exhibited 5 times higher affinity for fetuin and ovalbumin when compared with Sepharose@ConA with the same amount of immobilized lectin. MNP@Lectins were then applied to human serum, saliva, and urine and the recovered proteins were digested with trypsin and analyzed by nano-HPLC MALDI-TOF/TOF. This allowed the identification of 180 proteins, 90% of which were found to be glycosylated by use of bioinformatics tools, therefore revealing low levels of unspecific binding. Thus, MNP@lectins have proved to be a valuable tool for glycoproteomic studies, particularly when dealing with minute amounts of material.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chromatography, High Pressure Liquid / methods*
  • Concanavalin A / chemistry
  • Concanavalin A / metabolism
  • Fetuins / metabolism
  • Glycoproteins / analysis*
  • Glycoproteins / blood
  • Glycoproteins / urine
  • Glycosylation
  • Humans
  • Immobilized Proteins / chemistry
  • Immobilized Proteins / metabolism
  • Lectins / chemistry
  • Lectins / metabolism*
  • Magnetite Nanoparticles / chemistry*
  • Ovalbumin / metabolism
  • Protein Binding
  • Saliva / metabolism
  • Sepharose / analogs & derivatives
  • Sepharose / chemistry
  • Sepharose / metabolism
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / methods*
  • Trypsin / metabolism
  • Wheat Germ Agglutinins / chemistry
  • Wheat Germ Agglutinins / metabolism

Substances

  • Fetuins
  • Glycoproteins
  • Immobilized Proteins
  • Lectins
  • Magnetite Nanoparticles
  • Wheat Germ Agglutinins
  • concanavalin A-sepharose
  • Concanavalin A
  • Ovalbumin
  • Sepharose
  • Trypsin