Generation of monoclonal antibody fragments binding the native γ-secretase complex for use in structural studies

Biochemistry. 2012 Nov 6;51(44):8779-90. doi: 10.1021/bi300997e. Epub 2012 Oct 25.

Abstract

A detailed understanding of γ-secretase structure is crucially needed to elucidate its unique properties of intramembrane protein cleavage and to design therapeutic compounds for the safe treatment of Alzheimer's disease. γ-Secretase is an enzyme complex composed of four membrane proteins, and the scarcity of its supply associated with the challenges of crystallizing membrane proteins is a major hurdle for the determination of its high-resolution structure. This study addresses some of these issues, first by adapting CHO cells overexpressing γ-secretase to growth in suspension, thus yielding multiliter cultures and milligram quantities of highly purified, active γ-secretase. Next, the amounts of γ-secretase were sufficient for immunization of mice and allowed generation of Nicastrin- and Aph-1-specific monoclonal antibodies, from which Fab fragments were proteolytically prepared and subsequently purified. The amounts of γ-secretase produced are compatible with robot-assisted crystallogenesis using nanoliter technologies. In addition, our Fab fragments bind exposed regions of native γ-secretase in a dose-dependent manner without interfering with its catalytic properties and can therefore be used as specific tools to facilitate crystal formation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amyloid Precursor Protein Secretases / chemistry*
  • Amyloid Precursor Protein Secretases / immunology
  • Amyloid Precursor Protein Secretases / isolation & purification
  • Animals
  • Antibodies, Monoclonal
  • CHO Cells
  • Cholic Acids
  • Cricetinae
  • Cricetulus
  • Crystallization
  • Humans
  • Immunoglobulin Fab Fragments
  • Membrane Proteins / metabolism*
  • Mice
  • Presenilin-1

Substances

  • Antibodies, Monoclonal
  • Cholic Acids
  • Immunoglobulin Fab Fragments
  • Membrane Proteins
  • Presenilin-1
  • chapso
  • Amyloid Precursor Protein Secretases