Structural and functional analysis and application of decarboxylases catalyzing reverse carboxylation

厌氧微生物中存在2，4-二羟基苯甲酸脱羧酶。然而，微生物尚未被分离出来。因此，脱羧酶还没有被表征。在本研究中，通过半厌氧条件下的富集化培养，分离到了具有2，4-二羟基苯甲酸脱羧酶活性的微生物。对脱羧酶进行了纯化，并对其进行了性质鉴定。在底物专一性和亚基结构方面，该酶不同于以往报道的各种羟基苯甲酸脱羧酶。逆羧化反应区域选择性地进行，生成2，4-二羟基苯甲酸酯，无任何副产物。

The existence of 2,4-dihydroxybenzoate decarboxylase had been suggested in anaerobic microorganisms. However, microorganisms had not yet be isolated. Therefore, the decarboxylase had not be characterized. In the present study, microorganisms showing 2,4-dihydroxybenzoate decarboxylase activity have been isolated through enrichment culture under semi-anaerobic conditions. The decarboxylase was purified to homogeneity and characterized. In the point of substrate specificity and subunit structure, the present enzyme was different from various hydroxybenzoate decarboxylases reported previously. The reverse carboxylation reaction proceeded regioselectively to form 2,4-dihydroxybenzoate without any by-product.