Kinetic characterisation of arylamine N-acetyltransferase from Pseudomonas aeruginosa

BMC Biochemistry

Table 4 Comparison of PANAT-catalysed N-acetylation with p-nitrophenyl acetate or AcCoA as acetyl donor^a

Substrate	Specific Activity – PNPA (nmol·min^-1·mg^-1)^b	Specific Activity – AcCoA (nmol·min^-1·mg^-1)^c	Fold Difference
5-Aminosalicylic acid	1040 ± 30	73300 ± 3300	70.5
2-Aminofluorene	1470 ± 40	44710 ± 2720	30.4
Hydralazine	2990 ± 10	29550 ± 3110	9.9
p-Aminobenzoic acid	841 ± 17	8200 ± 78	9.8
p-Anisidine	2220 ± 40	13500 ± 0	6.1
Isoniazid	602 ± 3	2324 ± 0	3.9
Aniline	567 ± 7	629 ± 40	1.1

^aThe rate of production of p-nitrophenol was followed as described in Materials and Methods. Assay mixtures (100 μL) contained PANAT (50 ng), p-nitrophenyl acetate (400 μM) and acceptor substrate (500 μM) in PBS buffer with 5% (v/v) DMSO. Reactions were performed at 25°C, and specific activities are expressed as the mean ± standard deviation from triplicate measurements.
^bPNPA, p-nitrophenyl acetate.
^cSpecific activities with AcCoA as acetyl donor are the literature values determined under similar experimental conditions [7].

ISSN: 1471-2091