title: Pantothenases from pseudomonads produce either pantoyl lactone or pantoic acid.
abstract: A pseudomonad was separated having a pantothenase that produced beta-alanine and pantoic acid. The pantothenase from an old strain, Pseudomonas fluorescens UK-1, was shown to produce beta-alanine and pantoyl lactone. The pantoic acid-producing pantothenase was characterized and compared with the pantothenase from the strain UK-1. The Mr was 240,000; it apparently consists of four subunits. The Km value for pantothenate is 3 mM. The enzymic activity is affected by an ionizable group of pK 8.4, the enzyme is active at higher pH, and V but not Km is affected by pH. This pantothenase is not inhibited by di-isopropyl phosphorofluoridate or phenylmethanesulphonyl fluoride, unlike the enzyme from the strain UK-1. Both pantothenases are inhibited by m-aminophenylboronic acid, oxalate, oxaloacetate and Cl- ions. The pantoic acid-producing pantothenase is inhibited also by SO4(2-) ions. The strong inhibitions by many compounds make this pantothenase unsuitable for the assay of pantothenic acid.
mesh_terms: D015107:4-Butyrolactone / Q000031:analogs & derivatives / Q000378:metabolism*; D000581:Amidohydrolases / Q000037:antagonists & inhibitors / Q000302:isolation & purification / Q000378:metabolism*; D005663:Furans / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D006885:Hydroxybutyrates / Q000378:metabolism*; D007700:Kinetics; D008970:Molecular Weight; D010205:Pantothenic Acid / Q000378:metabolism; D011551:Pseudomonas fluorescens / Q000201:enzymology*
chemical_list: D005663:Furans; D006885:Hydroxybutyrates; C016031:pantoic acid; D010205:Pantothenic Acid; C005412:pantolactone; D000581:Amidohydrolases; C022317:pantothenase; D015107:4-Butyrolactone