1. Using protein-separative chromatographic procedures and assays specific for putrescine oxidase and spermidine oxidase, adult bovine serum was found to contain a single polyamine-degrading enzyme with substrate preferences for spermidine and spermine. Apparent Km values for these substrates were approx. 40 microM. The apparent Km for putrescine was 2 mM. With spermidine as substrate, the Ki v...

E&acts of pineapple stem tissue constitute the most potent known source of indoleacetic acid oxidase, despite the presence of an inhibitor which is difficult to remove without simultaneously removing some other factor necessary for maximal activity (I). Dialysis invariably lowers the enzyme activity as compared with photolysis, and even prolonged photolysis is never completely effective in remo...

Alcaligenes species CF8 isolated from surface water of a lake produced a novel serine type metallo-caffeine oxidase. The optimal medium for caffeine oxidase production by this strain was (w/v) NaNO(3), 0.4%; KH(2)PO(4), 0.15%; Na(2)HPO(4), 0.05%; FeCl(3).6H(2)O, 0.0005%; CaCl(2).2H(2)O, 0.001%; MgSO(4).7H(2)O, 0.02%; glucose, 0.2%; caffeine, 0.05%, pH 7.5. The enzyme was purified to 63-fold by ...

Although many investigations have been carried out on the n-amino acid oxidase since its discovery in 1935 (2)) the metabolic role of this enzyme remains somewhat obscure. It is generally believed, on the basis of indirect evidence, that in animals the enzyme functions in the inversion of exogenous n-amino acids over the pathway n-amino acid --+ Lu-keto acid -+ L-amino acid (3). The first step ...

The determination of creatinine levels in biological fluids is an increasingly important clinical requirement. Amperometric biosensors have been developed based on a three-enzyme system which converts creatinine to amperometrically measurable hydrogen peroxide. The development of the amperometric creatinine biosensor has been slow due the complexity of the three-enzyme system. This paper, the f...

in this study, the effect of salicylic acid (sa) on root knot nematode (meloidogyne javanica) pathogenicity and induction of some defense mechanisms such as polyphenol oxidase enzyme activity and total phenol accumulation were investigated in greenhouse conditions. we demonstrated that application of 5mm salicylic acid through foliar spray could induce resistance against m. javanica in tomato. ...

objective: polyphenol oxidase or ppo (ec 1.14.18.1) is considered the enzyme responsible for quality deterioration and browning in different fruits during postharvest period. the objective of this study was to evaluate the antibrowning (inhibition of polyphenol oxidase activity) effect of cysteine, ascorbic acid, citric acid, kojic acid and glycine at two different ph (6 and 7) in  hawthorn. me...

Antersera prepared against both enantiozymes, D- and L-6-hydroxynicotine oxidase, formed precipitins in double diffusion tests with their respective antigens only. A mixture of the two antisera caused spur formation of the two precipitin lines obtained with the pure enzymes. Antiserum to L-apoprotein reacted with native L-enzyme and L-apoprotein but not with the D-sspecific enzyme. D-6-hydroxyn...