Stolz A, Knackmuss H J
Institut für Mikrobiologie, Universität Stuttgart, Germany.
J Gen Microbiol. 1993 May;139(5):1019-25. doi: 10.1099/00221287-139-5-1019.
5-Aminosalicylate (5AS) was converted to L-malate, pyruvate and ammonia by cell-free extracts from Pseudomonas sp. BN9 in the presence of glutathione. In the absence of glutathione, 5AS was oxidized to the ring-fission product cis-4-amino-6-carboxy-2-oxo-hexa-3,5-dienoate (cis-ACOHDA). Glutathione catalysed the spontaneous isomerization of cis-ACOHDA to its trans-isomer. The same reaction was catalysed by light and by acidic conditions. trans-ACOHDA was enzymically deaminated to fumarylpyruvate (trans-2,4-dioxo-5-hexenoate). The trans-ACOHDA hydrolase was induced after growth of Pseudomonas sp. BN9 with 5AS, but not after growth with acetate or nutrient broth. At the fumarylpyruvate stage, the metabolism of 5AS converged with a pathway described for the degradation of gentisate. Fumarylpyruvate was cleaved by Pseudomonas sp. BN9 to fumarate and pyruvate.
在谷胱甘肽存在的情况下，5-氨基水杨酸（5AS）被假单胞菌属BN9的无细胞提取物转化为L-苹果酸、丙酮酸和氨。在没有谷胱甘肽的情况下，5AS被氧化为开环产物顺式-4-氨基-6-羧基-2-氧代-己-3,5-二烯酸酯（顺式-ACOHDA）。谷胱甘肽催化顺式-ACOHDA自发异构化为其反式异构体。光和酸性条件也能催化相同的反应。反式-ACOHDA被酶促脱氨生成富马酰丙酮酸（反式-2,4-二氧代-5-己烯酸）。在用5AS培养假单胞菌属BN9后，反式-ACOHDA水解酶被诱导产生，但在用乙酸盐或营养肉汤培养后则不会。在富马酰丙酮酸阶段，5AS的代谢与描述的龙胆酸盐降解途径汇合。富马酰丙酮酸被假单胞菌属BN9裂解为富马酸和丙酮酸。
