Search results
Results from the WOW.Com Content Network
Protein crystallization is the process of formation of a regular array of individual protein molecules stabilized by crystal contacts. If the crystal is sufficiently ordered, it will diffract . Some proteins naturally form crystalline arrays, like aquaporin in the lens of the eye.
Crystallization separates a product from a liquid feed stream, often in extremely pure form, by cooling the feed stream or adding precipitants that lower the solubility of the desired product so that it forms crystals. The pure solid crystals are then separated from the remaining liquor by filtration or centrifugation.
Streak seeding [1] is a method first described during ICCBM-3 by Enrico Stura to induce crystallization in a straight line into a sitting or hanging drop for protein crystallization by introducing microseeds. The purpose is to control nucleation and understand the parameters that make crystals grow. It is also used to test any particular set of ...
Unwanted proteins can be removed from a protein solution mixture by salting out as long as the solubility of the protein in various concentrations of salt solution is known. After removing the precipitate by filtration or centrifugation , the desired protein can be precipitated by altering the salt concentration to the level at which the ...
Proteins differ markedly in their solubilities at high ionic strength, therefore, "salting out" is a very useful procedure to assist in the purification of the desired protein. Ammonium sulfate is commonly used for precipitation because of its high solubility, additionally, it forms two ions high in the Hofmeister series .
Protein methods are the techniques used to study proteins. There are experimental methods for studying proteins (e.g., for detecting proteins, for isolating and purifying proteins, and for characterizing the structure and function of proteins, [1] often requiring that the protein first be purified). Computational methods typically use computer ...
For protein crystals this method is conducted by soaking the crystal of a sample to be analyzed with a heavy atom solution or co-crystallization with the heavy atom. The addition of the heavy atom (or ion) to the structure should not affect the crystal formation or unit cell dimensions in comparison to its native form, hence, they should be ...
The source of the protein can be either natural or produced in a production system using recombinant DNA techniques through genetic engineering. Recombinantly expressed proteins are usually easier to produce in sufficient quantity, and this method makes isotopic labeling possible. [citation needed]