MBIO 2360 Lecture Notes - Lecture 8: Sodium Dodecyl Sulfate, Coomassie Brilliant Blue, Molecular Sieve
Document Summary
Except for water, proteins are the most abundant substance in most cells: 10-20% by weight. Humans manufacture at least 25,000 different proteins, for a variety of purposes. Some proteins are simple polypeptides, or are conjugated with sugars (glycoproteins) and lipids (lipoproteins) Others require non-amino acid cofactors or prosthetic groups for full activity. Cofactors may be inorganic (metal ions) or organic (sugar, lipid, heme, flavin) They may be covalently or non-covalently attached to the protein. Some proteins are very flexible: they are dynamic and constantly moving. Proteins may be purified on the basis of differences in: charge, size, solubility. Not commonly used: affinity for materials. Something unique amount this protein that no other protein is bound to. Ion exchange chromatography can be used to separate proteins with different pis. Polystyrene or silica-based beads have anionic or cationic functional groups attached: the anion functional group is the cation exchanger and vice versa.