Albumins

Albumins, a group of proteins possessing characteristic properties that distinguish them from other proteins in terms of solubility and precipitability by various salts. For dissolution in water at neutral reaction, albumins do not require the presence of salts; they dissolve in weak acids and alkalis. From solutions, they are precipitated by strong mineral acids and are precipitated upon heating in the presence of salts. They are completely precipitated from a neutral solution when the latter is saturated with ammonium sulfate (distinction from globulins). From a neutral solution saturated with NaCl or MgSO₄, they are not precipitated at 30°, but are precipitated upon acidification of such a solution. They contain a significant amount of sulfur (1.6-2.2%). They do not contain glycocoll. Most albumins can be obtained in crystalline form. The principal representatives of albumins: serum albumin - in blood serum, in urine in nephritis, and in exudates; egg albumin (ovalbumin) - in eggs; lactalbumin - in milk.