Malonate: a versatile cryoprotectant and stabilizing solution for salt-grown macromolecular crystals

Area of Science:

• Crystallography
• Structural Biology
• Biophysics

Background:

• High-quality data collection at synchrotron sources necessitates effective cryoprotectants.
• Protein crystals require cryocooling to prevent radiation damage during data acquisition.
• Ice formation during cryocooling can damage protein crystals, compromising data quality.

Purpose of the Study:

• To introduce sodium malonate as a cryoprotectant for protein crystals.
• To evaluate the efficacy of sodium malonate in preventing ice formation and crystal damage during cryocooling.
• To explore the utility of sodium malonate as a stabilizing solution for crystal manipulation.

Main Methods:

• Cryocooling of protein crystals using sodium malonate solutions.
• Assessment of crystal integrity post-cryocooling.
• Evaluation of sodium malonate's performance as a stabilizing solution for derivatization and ligand soaking.

Main Results:

• Sodium malonate effectively cryoprotects protein crystals, preventing ice formation and damage.
• The compound facilitates manipulation, derivatization, and ligand soaking of salt-grown crystals.
• These processes may not be feasible using the crystal's native mother liquor.

Conclusions:

• Sodium malonate is a versatile cryoprotectant for protein crystallography.
• It offers additional benefits as a stabilizing solution, enhancing experimental possibilities.
• This expands the toolkit for obtaining high-quality diffraction data from challenging crystal systems.