Purification of Recombinant DHHC Proteins Using an Insect Cell Expression System

Area of Science:

• Biochemistry
• Molecular Biology
• Enzymology

Background:

• DHHC enzymes catalyze protein palmitoylation, a key post-translational modification.
• Purifying DHHC enzymes for study is challenging due to their integral membrane nature and low abundance.
• Understanding DHHC enzyme mechanisms requires robust methods for protein preparation.

Purpose of the Study:

• To establish a reliable protocol for the large-scale purification of recombinant DHHC enzymes.
• To generate tagged DHHC proteins suitable for biochemical and mechanistic investigations.
• To provide a reproducible method for obtaining homogeneous and monodisperse DHHC protein preparations.

Main Methods:

• Recombinant expression of DHHC proteins with hexahistidine and FLAG tags in Sf9 insect cells.
• Extraction of tagged proteins from cell lysates using dodecylmaltoside (DDM).
• Two-column chromatography purification followed by size exclusion chromatography (SEC) for homogeneity assessment.

Main Results:

• Successful purification of DHHC3 and a catalytically inactive mutant (DHHS3).
• Typical yields of 0.5 mg DHHC3 and 1.0 mg DHHS3 per 400 mL Sf9 cell culture.
• Purified proteins demonstrated monodispersity up to 1 mg/mL concentration by SEC.

Conclusions:

• The described protocol effectively yields purified, functional DHHC enzymes for research.
• This method overcomes previous limitations in obtaining sufficient quantities of DHHC proteins.
• The availability of purified DHHC proteins will facilitate further biochemical and mechanistic studies.