My lab had done protein crystallography with lysozyme. Two solutions were used to prepare the crystallization: lysosome solution and the precipitate solution.
1) There was a distinct amount of starting material in a well. what would that do to the size of the crystals if the crystal number increases? Why? The size will decrease?
2) What would be a negative consequence of thoroughly mixing the lysosome and precipitate solutions? Why? No crystals will appear?
Thank you for the help!
1) In protein crystallography, the size of the crystals can be influenced by several factors, including the amount of starting material. If the crystal number increases, meaning more crystals are present in the well, it can lead to a decrease in the average size of the individual crystals. This is because when the available protein molecules are distributed among more crystals, there will be less protein available for each crystal to grow larger. As a result, the individual crystals tend to be smaller when there are more of them.
To monitor the size and quality of the crystals, it is common to examine them under a microscope or using X-ray diffraction techniques. By observing the crystals and measuring their dimensions, you can assess any changes in size that may occur with varying amounts of starting material.
2) Thoroughly mixing the lysosome and precipitate solutions can have a negative consequence by potentially hindering or preventing crystal formation. In protein crystallography, the crystallization process typically requires the controlled growth of well-defined protein crystals. Mixing the solutions too thoroughly can disrupt the delicate balance of protein molecules, ions, and other components needed for crystal growth.
Crystal nucleation and growth depend on a gradual and controlled assembly of protein molecules in a supersaturated solution. When the solutions are mixed too vigorously or quickly, it can disrupt this delicate process, causing the proteins to aggregate or precipitate instead of forming well-ordered crystals. As a result, no crystals, or only very few poorly-formed crystals, may appear.
In order to optimize crystal growth, it is usually recommended to gently mix the solutions to allow proteins to interact and form crystals over time. This can be achieved by techniques such as vapour diffusion, sitting drop, or hanging drop methods, which provide controlled conditions for crystal growth while minimizing disturbance to the system.
Overall, careful handling and control of the crystallization process are crucial to obtaining high-quality protein crystals for further structural analysis.