Muthukrishnan S, Malathi K, Padmanaban G
Biochem J. 1972 Aug;129(1):31-7. doi: 10.1042/bj1290031.
The activity of delta-aminolaevulinate dehydratase is very low in the mould Neurospora crassa compared with the activities detected in bacterial and animal systems. The enzyme is inducible in iron-deficient cultures by addition of iron and is repressed by protoporphyrin. The properties of the purified enzyme indicate its allosteric nature and susceptibility to feedback inhibition by coproporphyrinogen III. Neurospora extracts also contain a protein inhibitor of the enzyme and a small-molecule activator, which appears to be associated with the enzyme. The regulatory function of this enzyme in vivo is correlated with the accumulation of delta-aminolaevulinic acid in normal cultures of N. crassa. The decay curve of the iron-induced enzyme in vivo shows a biphasic pattern, with one of the components showing a half-life of 4-5 min.
与在细菌和动物系统中检测到的活性相比，在霉菌粗糙脉孢菌中，δ-氨基乙酰丙酸脱水酶的活性非常低。通过添加铁，该酶在缺铁培养物中可被诱导，并且被原卟啉抑制。纯化酶的特性表明其别构性质以及对粪卟啉原III反馈抑制的敏感性。粗糙脉孢菌提取物还含有该酶的一种蛋白质抑制剂和一种小分子激活剂，后者似乎与该酶相关。该酶在体内的调节功能与粗糙脉孢菌正常培养物中δ-氨基乙酰丙酸的积累相关。体内铁诱导酶的衰变曲线呈现双相模式，其中一个组分的半衰期为4 - 5分钟。
