Crystallization of a substance satisfies one of the classical criteria for homogeneity. Crystallization provides a useful purification step. Furthermore, when large, ordered single crystals can be obtained, the molecule's tertiary structure may be determined by X-ray crystallography. Numerous techniques are developed for the crystallization of protein. However, no generalized procedure has been discovered, and many proteins remain uncrystallized. The most widely used approach involves the addition to the protein solution of a crystallizing agent, which is commonly a salt, such as ammonium sulfate or ammonium citrate, or an organic solvent, such as ethanol or 2-methyl-2,4-pentanediol. One of the most versatile crystallizing agents is polyethylene glycol (PEG), which combines some of the characteristics of the salts and the organic solvents. Recombinant human leukocyte interferon A (IFLrA) crystallizes readily from PEG, occasionally in large single crystals. With the preparation of appropriate crystals of IFLrA and other interferons, it will be possible to initiate X-ray crystallography to elucidate its tertiary structure. Series: Methods in Enzymology (Book 79) Hardcover: 720 pages Publisher: Academic Press; Language: English ISBN-10: 0121819795 ISBN-13: 978-0121819798 Product Dimensions: 6 x 1.5 x 9 inches Link Download http://nitroflare.com/view/28CB4D27D86D4CDhttps://drive.google.com/drive/folders/1yLBzZ1rSQoNjmWeJTZ3WGQHg04L1
