title: Myxobacter AL-1 protease II: specific peptide bond cleavage on the amino side of lysine.
abstract: A second extracellular protease from myxobacter strain AL-1 has been purified to homogeneity and named protease II; the enzyme crystallizes as fine needles. The extracellular, cell wall lytic protease reported previously from the same organism is now designated protease I. Protease II exhibits a pH optimum of 8.5 to 9.0 and is stable from pH 3.0 to 9.0. The enzyme is heat stable at 50 C for 18 hr. Results of sedimentation equilibrium studies yielded a molecular weight of 17,000, and amino acid analysis revealed 157 residues with a minimal molecular weight of 16,660. Cleavage of peptide bonds in the oxidized B-chain of insulin, cytochrome c (horse heart). lysozyme, and vasopressin is restricted to the amino side of lysine. Dilysine and trilysine were not hydrolyzed. Products from digestions of polylysine were lysine and dilysine.
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000645:Ammonium Sulfate; D002499:Centrifugation, Density Gradient; D011232:Chemical Precipitation; D002845:Chromatography; D002855:Chromatography, Thin Layer; D003460:Crystallization; D003574:Cytochrome c Group / Q000378:metabolism; D004586:Electrophoresis; D006863:Hydrogen-Ion Concentration; D007328:Insulin / Q000378:metabolism; D008239:Lysine; D008858:Microscopy, Phase-Contrast; D008970:Molecular Weight; D009113:Muramidase / Q000378:metabolism; D009231:Myxococcales / Q000201:enzymology*; D010447:Peptide Hydrolases / Q000032:analysis / Q000302:isolation & purification / Q000378:metabolism; D010455:Peptides / Q000378:metabolism*; D013696:Temperature; D014667:Vasopressins / Q000378:metabolism
chemical_list: D000596:Amino Acids; D003574:Cytochrome c Group; D007328:Insulin; D010455:Peptides; D014667:Vasopressins; D009113:Muramidase; D010447:Peptide Hydrolases; D008239:Lysine; D000645:Ammonium Sulfate