ABSTRACT
trans
-2′-Carboxybenzalpyruvate hydratase-aldolase was purified from a phenanthrene-degrading bacterium,
Nocardioides
sp. strain KP7, and characterized. The purified enzyme was found to have molecular masses of 38 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and 113 kDa by gel filtration chromatography. Thus, the homotrimer of the 38-kDa subunit constituted an active enzyme. The
K
m
and
k
cat values of this enzyme for
trans
-2′-carboxybenzalpyruvate were 50 μM and 13 s
−1
, respectively.
trans
-2′-Carboxybenzalpyruvate was transformed to 2-carboxybenzaldehyde and pyruvate by the action of this enzyme. The structural gene for this enzyme was cloned and sequenced; the length of this gene was 996 bp. The deduced amino acid sequence of this enzyme exhibited homology to those of
trans
-2′-hydroxybenzalpyruvate hydratase-aldolases from
Pseudomonas putida
PpG7 and
Pseudomonas
sp. strain C18.
摘要
反式
-从一种
菲类降解细菌中纯化出了-2′-羧基
苯丙酮酸水解酶-醛酸酶、
Nocardioides
sp.菌株 KP7 中纯化了
菲降解菌 Nocardioides sp.通过
十二烷基硫酸钠-聚
丙烯酰胺凝胶电泳发现,纯化后的酶的分子质量为 38 kDa,通过凝胶过滤层析发现,纯化后的酶的分子质量为 113 kDa。因此,38 kDa 亚基的同源三聚体构成了一种活性酶。其
K
m
和
k
cat 值。
反式
-2′-羧基
苯丙酮酸的 k cat 值分别为 50 μM 和 13 s
-1
的 k cat 值分别为 50 μM 和 13 s -1。
反式
-2′-羧基
苯丙酮酸在这种酶的作用下转化为 2-羧基
苯甲醛和
丙酮酸。该酶的结构
基因已被克隆并测序,其长度为 996 bp。该酶的
氨基酸序列推断与
反式
-2′-hydroxybenzalpyruvate hydratase-aldolases from
假单胞菌
PpG7 和
假单胞菌
菌株 C18.