Prikladnaia Biokhimiia i Mikrobiologiia 2013-01-01

[Catalytic properties of enzymes from Erwinia carotovora involved in transamination of phenylpyruvate].

A M Paloian, L A Stepanian, S A Dadaian, A A Ambartsumian, G P Alebian, A S Sagian

Index: Prikl. Biokhim. Mikrobiol. 49(2) , 129-35, (2013)

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Abstract

Km for L-phenylalanine, L-glutamic acid, L-aspartic acid, and the corresponding keto acids were calculated, as well as Vmax, was measured for the following pairs of substrates: L-phenylalanine-2-ketoglutarate, L-phenylalanine-oxaloacetate, L-glutamic acid-phenylpyruvate, and L-aspartic acid-phenylpyruvate for aminotransferases PATI, PAT2, and PAT3 from Erwinia carotovora catalyzing transamination of phenylpyruvate. The ping-pong bi-bi mechanism was shown for the studied aminotransferases. The substrate inhibition (Ks) of PAT3 with 2-ketoglutarate and oxaloacetate was 10.23 +/- 3.20 and 3.73 +/- 1.99 mM, respectively.