UREA, ULTRA PURE

 

57-13-6

 

 

Carbamide; Isourea; Carbonyldiamide; Carbonyldiamine; Ureophil; Carbamimidic acid; Pseudourea; Ureaphil; Urevert

Urea is the principal end product of nitrogen metabolism in most mammals, formed by the enzymatic reactions of the Kreb's cycle which is a mild agent usually used in the solubilization and denaturation of proteins. It is DNAse RNAse free and useful for renaturing proteins from samples already denatured with 6 M guanidine hydrochloride such as inclusion bodies; and in the extraction of the mitochondrial complex. Urea in solution is in equilibrium with ammonium cyanate ,form that reacts with protein amino groups is isocyanic acid. Urea in the presence of heat and protein leads to carbamylation of the proteins. It has an OD260(7M sq solution) and OD280 as 0.0215 and 0.0049 respectively.

Urea is commonly used to solubilize and denature proteins for denaturing isoelectric focusing and two-dimensional electrophoresis and in acetic acid-urea PAGE gels. When performing enzymatic protein digests it is important to remove urea first. Even though some enzymes will tolerate small amounts of urea, the elevated temperature used for most reactions will lead to carbamylation during the course of the digest. It can be removed prior to digest by fast reversed phase chromatography, spin columns, or dialysis. It is used in cell or tissue culture media to increase the osmolality and also used as fertilizer because of the easy availability of nitrogen; in animal feeds; it is reacted with aldehydes to make resins and plastics; condensed with malonic ester to form barbituric acid; used in the paper industry to soften cellulose; used as a diuretic; enhances the action of sulfonamides; an antiseptic. Urea is typically used at a concentration of 8 M for protein denaturation or solubilization. A final concentration of 5 M urea is commonly used in molecular biology for sequencing gels. To prevent carbamylation, do not heat urea containing buffers above 37°C.Ultra pure Urea is used in an experiment to study the role of Vimentin protein as a marker of liver tumorigenicity (Yasushi Nakamura,2009 ,Actin and Vimentin proteins with N-terminal deletion detected in tumor bearing rat livers induced by intraportal-vein injection of Ha-ras transfected rat liver cells ,National Institute Of Health Public Access Author Manuscript,124(11),2512–2519).