Nomenclature of Proteins  -   

Historically based upon SOLUBILITY OF PROTEINS in solvents.... esp. water
Two classes - Simple & Complex 
   SIMPLE - release only amino acids on acid hydrolysis
  1. Albumins  soluble in pure water; globular; includes many enzymes
  2. Globulins  soluble in dilute aqueous solutions (some ions - NaCl - added)
  3. Prolamins  insoluble in water;  soluble in 50% to 90% simple alcohols
  4. Glutenins  insoluble in most solvents;  but, soluble in dilute acids/bases
  5. Protamines  not based on solubility;  low MW proteins w 80% Arg & no Cys
  6. Histones  unique; complexed w DNA; high basic aa's  > 90% Arg, Lys, His
  7. Scleroproteins
 the fibrous proteins: insoluble in most solvents...
    fibrous structure - found in cartilage & connective tissue
      Collagen - high Gly, Pro & no Cys; when boiled makes gelatin
      Keratins - proteins of skin & hair; high amt basic aa's w Cys







  COMPLEX  protein made of amino acids & some other macromolecule
 ...acid hydrolysis of protein yields more than alpha amino acid


 + lipids:   blood, membrane, & transport proteins 


 + carbohydrates:   antibodies, cell surface proteins (receptors)


 + nucleic acids:   ribosomes & other organelles
     Protein Data Bank -  Protein of the Month
      at the Research Collaboratory for Structural Bioinformatics
back The Protein Data Bank (PDB) is a repository for 3-D structural data of proteins and nucleic acids. These data, typically obtained by X-ray crystallography or NMR spectroscopy and submitted by biologists and biochemists from around the world, are released into the public domain, and can be accessed for free.