Naphthylamidase Activity of Leptospira1

Abstract

Extracts of 18 serotypes of the genus Leptospira were found to possess naphthylamidase activity, and differences in the pathogenic and saprophytic strains were noted. The former exhibited a preference for the leucyl naphthylamide substrate, whereas the latter demonstrated greater hydrolysis of alanyl naphthylamide. With the leucyl naphthylamide as substrate, pathogenic strains showed 10 to 20 times higher naphthylamidase activity than saprophytic strains. Optimal temperature and pH for enzymatic hydrolysis also differed between pathogenic and saprophytic strains. Maximal enzymatic activities for pathogenic and saprophytic naphthylamidases were 41 and 37 C, respectively, at pH 8.0 to 8.5. The pH and temperature optima suggested that the leptospiral enzyme activity was not leucine aminopeptidase.

Purification and Properties of an Aryl Acylamidase of Bacillus sphaericus, Catalyzing the Hydrolysis of Various Phenylamide Herbicides and Fungicides

“…Similar properties were also described by other authors for the arylamide hydrolyzing enzymes of Pseudomonas aeruginosa (25), chick kidney (23), rice (17), and rat liver and kidney (22). Most bacterial enzymes do not require metal ions for activity (7,11), whereas the arylamidase of P. aeruginosa (25) requires Mn2+ or Mg2+ ions, the naphthylamidase from Baker's yeast (28) requires Ba2+, and the mammalian arylamidases (4, 22) require Co'+, Mn2+, Ni '+, or Zn2+ ions for optimal activity.…”

“…The utilization of aminoacylor acyl-arylamides by bacteria (5,6,11), fungi. (13,28), human, and animal tissues (9, 22, 23) has been a subject of investigations in many laboratories.…”

Physiology and evolution of spirochetes.

“…Other reports on the dissimilatory metabolism of leptospires describe studies on lipase activity (16,17,41,53,94,104,108,133,134), transamination reactions (122), and various enzymatic activities (35,63,65,66).…”

Arylamidase Activity of Salmonella Species

“…Studies by Tappel (15) and Marks et al (8) suggested that arylamidases function at some stage in protein catabolism; however, the in vivo function of the enzyme has not been defined. Burton et al (4) demonstrated that pathogenic strains of Leptospira possessed 10 to 20 times higher arylamidase activity than saprophytic strains, suggesting a possible role for the enzyme in pathogenicity.…”