Purification and characterization of two leaf polypeptide inhibitors of leaf protease from alfalfa (Medicago sativa).
Two polypeptides with antiproteolytic activities have been isolated from alfalfa leaves. Polypeptide I resembles the previously described plant protease inhibitors in both structural and functional features; it has a molecular weight of 15,000, a random coil secondary structure, and inhibits exogenous protease as well as alfalfa leaf protease. Polypeptide II is a novel type of plant inhibitor with a molecular weight of 6300 and a highly organized structure with a high (40-50%) alpha-helix content. It only inhibits endogenous protease with a molar stoichiometry polypeptide/enzyme protein of 1.
D000596:Amino Acids / Q000032:analysis; D055598:Chemical Phenomena; D002621:Chemistry; D002845:Chromatography / Q000379:methods; D002942:Circular Dichroism; D006863:Hydrogen-Ion Concentration; D000455:Medicago sativa / Q000032:analysis* / Q000201:enzymology; D008970:Molecular Weight; D010940:Plant Proteins / Q000302:isolation & purification* / Q000494:pharmacology; D011480:Protease Inhibitors / Q000302:isolation & purification*; D011487:Protein Conformation
D000596:Amino Acids; D010940:Plant Proteins; D011480:Protease Inhibitors