Polyvalan Crystallophore Pre-Screening and Experimental Phasing Agents
Polyvalan new generation Crystallophores are Lanthanide based complexes that will help you to get more structures.
1) WHEN USED AS PRE-SCREENING AGENTS
Crystallophores unique nucleating properties are related to versatile protein binding sites and supramolecular interactions.
TbXo4-02-N and LuXo4-01-N are two different generations of Lanthanide complexes (Terbium or Lutetium) presenting complementary nucleation enhancement mainly adapted to soluble proteins and complexes.
As pre-screening agents, Crystallophores shall be directly dissolved first with the protein solution at a concentration of 10 mM before running crystallization screening. Every vial is adapted to 25 µL of protein solution.
They can be useful for:
- Generating new crystallization conditions
- Inducing different crystal forms
- Improving crystal quality and reproducibility
Moreover, Crystallophores are designed to improve phasing properties of obtained co-crystals using SAD or MAD methods
- Llll absorption edge of LuXo4-01, at 1.34 Å, is easily accessed with most synchrotron-radiation sources leading to an anomalous contribution of about 30 e-
- TbXo4-02 is a straightforward PHASING AGENT thanks to the exceptional anomalous properties of f-block elements
- Both also works well with X-ray home source
2) WHEN USED AS PHASING AGENTS
TbXo4-02-P and LuXo4-01-P are powerful phasing agents for native crystals using SAD or MAD methods.
The soft incorporation of Crystallophore lanthanide atoms in macromolecular crystals allows to exploit information from anomalous diffraction data, including, when unoptimized or partial, for the validation of MR solutions and reduction of model/phase bias.
Soak your crystals with Crystallophore P vials (higher concentration required when compared to nucleation) during the cryoprotection step.
Important Notice – 30 seconds to 5 minutes are enough No back soak, it’s ready to use !
Each Polyvalan Crystallophore products can be used both as pre-screening agents and phasing agents.
The difference is how they are used depends on how they are packaged.
When used as pre-screening agents (for getting protein crystals), the aim is to enable users to limit their costly protein consumption. This is why the pre-screening agents are provided in small packaging adapted to 25 µL protein solution. The quantities of products are different (0,15mg and 0,17mg) because of their respective molar mass. We consider LuXo4-01 and TbXo4-02 as complementary nucleating agents. These agents are offered in batches of 5.
When used as phasing agents (for soaking protein crystals), a high concentration of the Crystallophore is required (100mM : 10 times more than for nucleation) : according to their respective molar mass, the packaging allow users to prepare 10 µl of soaking liquor (≈ 10 trials). The phasing properties are due to the Lanthanide atom “trapped” in the agents: Tb=Terbium and Lu=Lutetium. Each one has its own characteristics: the user can go to the one that seems the most suitable to their needs.