title: A rapid chromogenic microtitre assay of arginine aminopeptidase activity in Mycoplasma strains.
abstract: Arginine-utilizing strains of Mycoplasma can be screened by assay of their arginine aminopeptidase activity. A standardized chromogenic method is described that enables enzyme detection in small volumes of cell suspension in less than 3 h. Cell suspensions (10 microl) in 96-well microtitre plates are incubated at 37 degrees C, pH 8.0, with 0.1 mM arginyl-beta-naphthylamide (100 microl). This is hydrolysed to release beta-naphthylamine, which gives a coloured product on diazotization with fast garnet. M. alkalescens can be detected in this way with as few as 1.1 x 10(5) viable cells and M. fermentans with 2.3 x 10(6) cells. The method has been shown to enable division of 28 strains into three groups of fermentative and arginine-hydrolysing mycoplasmas. This procedure has potential for routine laboratory use.
authors.affiliation: Department of Life Sciences, King's College London, Franklin Wilkins Building, 150 Stamford Street, London SE1 9NH, UK.
authors.forename: Yi-Ching
authors.initials: YC
authors.lastname: Lin
authors.forename: Roger J
authors.initials: RJ
authors.lastname: Miles
authors.forename: Robin A J
authors.initials: RA
authors.lastname: Nicholas
authors.forename: Ann P
authors.initials: AP
authors.lastname: Wood
mesh_terms: D000626:Aminopeptidases / Q000032:analysis / Q000378:metabolism*; D000818:Animals; D003124:Colorimetry; D006801:Humans; D009174:Mycoplasma / Q000201:enzymology* / Q000378:metabolism
chemical_list: D000626:Aminopeptidases; C019721:aminopeptidase B