X-ray crystallography is a discipline to study the arrangement of atoms in crystals by using X-ray
technique. Crystal structure could provide visualized answers for following scientific issues: pro-tein folding mechanism, the binding of substrate and ligand, functional atoms or residues.
X-ray crystallography is applied to determine the structure and study the function of biomacro-molecules, such as protein and DNA. Nowadays, X-ray crystallography is widely used in molecular
biology and drug development.
From crystallization screening, data collection, to data analysis, standard experimental procedures and rigorous data analysis ensure
high quality research results.
The Novogene Advantage
- Project evaluation for free.
- High throughput automated crystallization screening.
- Relying on Shanghai synchrotron radiation source.
- The deliverable data conforms to the PDB data submission standard.
- Within 3~6 months from crystallization to data analysis.
- The protein sequence can be directly provided.
- Target protein in solution for 20 mg and the purity of protein should be more than 90%.
1. Protein crystallization and optimization.
Through the high-throughput automated screening method, more than 1,000 buffer conditions were screened. After the crystal
growth was observed, the crystallization conditions of the protein were optimized to obtain high quality single crystal finally.
2. Protein diffraction data collection and refinement statistics.
||105.361 109.653 134.130
||90.00 99.41 99.00
|No. of observations
|No. of unique reflections
HKL 3000 was used to process the diffraction data, thus a series of parametric data such as crystal cell parameters, angle units, integri-ty, effective signal strength and signal-to-noise ratio were obtained.
3.Protein 3D structure
The protein 3D structure data conforms to the Protein Date Bank (PDB) data submission standard, and meets the article publication
standard: R free is lower than 0.3, R work is lower than 0.25.
Q：What materials should be provided for project evaluation?
A: Because the physical and chemical properties of proteins and biochemical properties are very different, please offer the name,
molecular weight, source species and amino acid sequence of your intention protein. If you pay attention to the structure of protein
complex, please provide the affinity data to us.
Q：What the effect does the homologous structure on the structure analysis have?
A: With homologous structure (homology >30%), the phase problem can be solved by molecular replacement method and the pro-tein structure is resolved consequently. Only a set of diffraction data needs to be collected, and the calculation method is simple.
Without homologous structure, the phase problem needs to be solved by multi-wavelength anomalous scattering and then deter-mined the protein structure. Two sets of diffraction data need to be collected, and the calculation method is much complicated. The
diffraction data of SeMet-labeled protein and native protein should be collected respectively. Generally speaking, structure analysis
is relatively difficult without homologous structure
Q：How do I send the protein solution?
First of all, ensure that protein was not treated by freeze-thaw cycle, because freeze-thaw cycle will cause protein denaturation. 4℃
ice pack or -80℃ dry ice pack is recommended.
Q：What is the protein concentration during transport?
A: The protein can be delivered in any concentration, just adding a tube of protein buffer.