title: A secreted metallo protease from Aeromonas hydrophila exhibits prothrombin activator activity.
abstract: Detection, purification, and partial characterization of a protease from Aeromonas hydrophila capable of cleaving prothrombin into active thrombin is described. The protease has been characterized with respect to enzymatic characteristics such as optimum reaction conditions for prothrombin activation, usage of additional substrates, as well as sensitivity against inhibitors. The protease activity can reversibly be inhibited by Me2+ chelating agents like ethylenediamine tetraacetic acid. The enzyme exhibits a pI value of 4.4 and can withstand temperatures up to 55 degrees C without loss of activity. With respect to prothrombin the enzyme exhibits a K(M) value of 1.47 micromol/l and a vmax value of 1.66 mol/min per mol enzyme. Amino terminal sequence analysis as well as mass spectrometry of fragments obtained by trypsin digest showed identity to a recently described elastase type protease from the same organism and homology to known proteases from other procaryotes (e.g. Aeromonas caviae, Vibrio proteolytica, Pseudomonas aeruginosa).
authors.affiliation: Paul Ehrlich Institut, Langen, Germany.
authors.forename: Thorsten
authors.initials: T
authors.lastname: Keller
authors.forename: Rainer
authors.initials: R
authors.lastname: Seitz
authors.forename: Johannes
authors.initials: J
authors.lastname: Dodt
authors.forename: Herbert
authors.initials: H
authors.lastname: König
mesh_terms: D016980:Aeromonas hydrophila / Q000201:enzymology*; D000590:Amino Acid Chloromethyl Ketones / Q000494:pharmacology; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology*; D002614:Chelating Agents / Q000494:pharmacology; D004492:Edetic Acid / Q000494:pharmacology; D010450:Endopeptidases / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D007526:Isoelectric Point; D045726:Metalloproteases / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology*; D008969:Molecular Sequence Data; D011516:Prothrombin / Q000037:antagonists & inhibitors*; D017386:Sequence Homology, Amino Acid; D013696:Temperature; D013917:Thrombin / Q000096:biosynthesis
chemical_list: D000590:Amino Acid Chloromethyl Ketones; D001426:Bacterial Proteins; D002614:Chelating Agents; D011516:Prothrombin; D004492:Edetic Acid; D010450:Endopeptidases; D045726:Metalloproteases; D013917:Thrombin; C020097:ecarin; C040308:phenylalanyl-prolyl-arginine-chloromethyl ketone