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Combining Wet and Dry Lab Techniques to Guide the Crystallization of Large Coiled-coil Containing Proteins
Published on: January 6, 2017
Structural studies on the cobra venom factor: isolation, purification, crystallization and preliminary
Summary
Cobra venom factor (CVF), a complement-activating protein, forms an enzyme that depletes complement in serum. This protein, isolated from Naja naja naja, has potential clinical applications and has been crystallized for structural analysis.
Area of Science:
- Biochemistry
- Immunology
- Structural Biology
Background:
- Cobra venom factor (CVF) is a key protein found in cobra venom.
- It functions as a potent activator of the complement system in mammals.
- CVF is a three-chain glycoprotein with a molecular weight of 149,000 Da.
Purpose of the Study:
- To investigate the structural properties of CVF through crystallization.
- To understand the mechanism of CVF-mediated complement activation.
- To explore the potential therapeutic applications of CVF in complement-related diseases.
Main Methods:
- Isolation of CVF from Indian cobra (Naja naja naja) venom.
- Crystallization of CVF using the sitting-drop vapour-diffusion technique at room temperature.
- X-ray diffraction analysis to determine crystal structure and unit-cell parameters.
Main Results:
- CVF forms a bimolecular enzyme with factor B's Bb subunit in serum.
- This enzyme effectively cleaves C3 and C5, leading to complement consumption.
- Crystallized CVF diffracted X-rays to 2.7 A resolution, belonging to the tetragonal space group P4(1).
Conclusions:
- CVF is a valuable tool for studying complement biology and C3 multifunctionality.
- Its ability to deplete complement suggests potential therapeutic uses in diseases driven by complement activation.
- The determined crystal structure provides a basis for further mechanistic and therapeutic investigations.
