Ambivalence on the multiplicity of mammalian aromatic L-amino acid decarboxylase.
Ambivalence on the multiplicity of mammalian aromatic L-amino acid decarboxylase.
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对哺乳动物芳香族 L-氨基酸脱羧酶多样性的矛盾心理。
DOI：
10.1007/978-1-4684-5952-4_10
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发表时间：
1991
影响因子：
--
通讯作者：
Simonneaux,V
中科院分区：
文献类型：
--
作者：
Ebadi,M;Simonneaux,V
羟色氨酸通过芳香族L-氨基酸脱羧酶脱羧为5-羟色胺（5-羟色胺），该酶需要磷酸吡哆醛，并广泛分布于整个哺乳动物组织中，在松果体、肝脏、肾脏、肾上腺髓质和纹状体中最丰富。早期的研究得出结论，3，4-二羟基苯丙氨酸脱羧酶（催化多巴脱羧，产生多巴胺）和5-羟色氨酸脱羧酶（催化5-羟色氨酸脱羧，产生血清素）是相同的酶，IUPAC生物医学名词委员会在1972年将其命名为芳香族L-氨基酸脱羧酶（EC 4.1.1.28）。然而，最近的研究质疑的有效性，一个单一的酶能够脱羧两个基板。例如，由于松果体积累了大量的5-羟色胺、褪黑激素和其他吲哚胺，因此推测该酶的功能是5-羟色氨酸脱羧酶。另一方面，由于纹状体和肾上腺髓质主要积聚多巴胺、去甲肾上腺素和肾上腺素，因此认为酶主要使多巴脱羧。处理催化过程的复杂性的其他因素是报告的结果，其揭示多巴脱羧酶和组氨酸脱羧酶都表现出完全的免疫化学交叉反应性，表明存在相似的抗原识别位点。
Hydroxytryptophan is decarboxylated to 5-hydroxytryptamine (serotonin) by aromatic L-amino acid decarboxylase which requires pyridoxal phosphate and is widely distributed throughout mammalian tissues, occurring most abundantly in the pineal gland, liver, kidney, adrenal medulla, and striatum. Earlier studies concluded that 3,4-dihydroxyphenylalanine decarboxylase (which catalyzes the decarboxylation of dopa, producing dopamine) and 5-hydroxytryptophan decarboxylase (which catalyzes the decarboxylation of 5-hydroxytryptophan, yielding serotonin) are the same enzyme, which the IUPAC Commission on Biomedical Nomenclature in 1972 named aromatic L-amino acid decarboxylase (EC 4.1.1.28). However, recent studies have questioned the validity of a single enzyme capable of decarboxylating both substrates. For example, since the pineal gland accumulates a large concentration of serotonin, melatonin and other indoleamines, it is assumed that the enzyme functions as a 5-hydroxytryptophan decarboxylase. On the other hand, since the striatum and the adrenal medulla accumulate mainly dopamine, norepinephrine and epinephrine, it is felt that the enzyme primarily decarboxylates dopa. Other factors dealing with the complexity of catalytic process are the results of reports revealing that both dopa decarboxylase and histidine decarboxylase exhibit complete immunochemical cross reactivity, suggesting the presence of similar antigenic recognition sites.