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Updated: Aug 23, 2026
ABCG5/G8 Crystallization in a Lipidic Bicelle Environment for X-Ray Crystallography
Published on: August 25, 2023
Crystallization of microsomal triglyceride transfer protein from bovine liver
S L Ohringer1, H Jamil, C H Chu
1Bristol-Myers Squibb Pharmaceutical Research Institute, Princeton, New Jersey 08543, USA.
Abstract:
The microsomal triglyceride transfer protein (MTP) is a heterodimeric lipid transfer protein required for the assembly of plasma very low density lipoproteins in the liver and chylomicrons in the intestine. Bovine MTP was purified by a modification of a previously published procedure and crystals of MTP were grown reproducibly with polyethylene glycol as a precipitant at pH 7.0. MTP crystals, which diffract to Bragg spacings of better than 3.2 A, have the symmetry of space group P2(1)2(1)2(1) with refined lattice constants of a = 88.7, b = 100.9 and c = 201.1 A, with one heterodimer per asymmetric unit.
Insights
Researchers purified bovine microsomal triglyceride transfer protein (MTP), a key enzyme in lipoprotein assembly. They successfully crystallized MTP, enabling structural analysis for understanding lipid transport mechanisms.
Area of Science:
- Biochemistry
- Structural Biology
- Lipid Metabolism
Background:
- Microsomal triglyceride transfer protein (MTP) is essential for assembling very low density lipoproteins (VLDL) in the liver and chylomicrons in the intestine.
- MTP facilitates the transfer of triglycerides and other lipids, crucial for lipoprotein biogenesis and plasma lipid transport.
Purpose of the Study:
- To purify bovine MTP using an optimized protocol.
- To obtain well-diffracting crystals of MTP suitable for structural determination.
- To characterize the crystallographic properties of MTP.
Main Methods:
- Purification of bovine MTP via a modified established procedure.
- Crystallization of MTP using polyethylene glycol as a precipitant at pH 7.0.
- X-ray diffraction analysis of MTP crystals to determine space group and lattice constants.
Main Results:
- Bovine MTP was successfully purified.
- Reproducible growth of MTP crystals was achieved.
- MTP crystals diffracted to Bragg spacings better than 3.2 Å.
- The crystals belong to space group P2(1)2(1)2(1) with one heterodimer per asymmetric unit.
Conclusions:
- The successful crystallization of bovine MTP provides a foundation for high-resolution structural studies.
- Understanding MTP structure is critical for elucidating its mechanism in lipoprotein assembly.
- These findings pave the way for potential therapeutic strategies targeting MTP in lipid-related disorders.
