Simple proteins

SIMPLE PROTEINS

  • These are proteins, which on complete hydrolysis yield only amino acids as an end product.
  • They are further subdivided, into
    • Albumins: These proteins are soluble in water coagulated by heat and precipitated by saturated salt solution like ammonium sulphate. Eg: serum albumin and lactalbumin
    • Globulins: These proteins are insoluble in pure water, but soluble in dilute salt solutions. They may be coagulated by heat. Eg: Serum globulin, ovoglobulin.
    • Glutelins: These are soluble in dilute acids and alkalis and insoluble in water and neutral solvents. Eg: glutenin from wheat.
    • Prolamine: Soluble in 70 – 80 % alcohol, insoluble in water, absolute alcohol and other neutral solvents. Eg: zein of corn and glyadin of wheat.
    • Histones: These proteins are soluble in water and very dilute acids, insoluble in dilute ammoniun hydroxide. These proteins are not coagulated by heat. They are strongly basic in nature due to the presence of excess amounts of arginine and lysine. Eg: Histones associated with nucleic acids.
    • Protamines: Basic polypeptide, soluble in water or ammonium hydroxide, not coagulated by heat. Basic amino acids will predominate in their structure.Eg: protamines of sperm cells.
    • Albuminoids (Sclero roteins): Insoluble in all neutral solvents and in dilute acids and alkalis. These are the proteins of supportive tissue. Eg: Keratins and collagen.
Last modified: Tuesday, 22 March 2011, 12:20 PM