Studies in which (14)C-labeled precursors were fed to etiolated barley leaves (Hordeum vulgare L. var. Proctor) yielded chlorophyll and protoheme having similar specific radioactivities. These findings indicate: (a) there appears to be a rapid turnover of protoheme in the absence of net synthesis; (b) both pigments probably originate from a single 5-aminolevulinic acid pool; (c) the efficient u...

A hemA mutant of Escherichia coli containing a multicopy plasmid which complemented the mutation excreted 5-aminolevulinic acid (ALA) into the medium. [1-14C]glutamate was substantially incorporated into ALA by this strain, whereas [2-14C]glycine was not. Periodate degradation of labeled ALA showed that C-5 of ALA was derived from C-1 of glutamate. The synthesis of ALA by two sonicate fractions...

OBJECTIVE It is important to identify and save the normal parathyroid glands during head and neck surgery because of their role in regulating the blood calcium level, yet it is often difficult to localize normal parathyroid glands during surgery. Fluorescence-guided parathyroidectomy in patients with hyperparathyroidism has already proved useful. However, there are few reports of fluorescence-g...

5-Aminolevulinic acid dehydratase (ALAD) activity in two patients with compound heterozygous 5-aminolevulinic acid dehydratase deficiency porphyria was studied over the last 20 years. The patients' enzyme activity was <10% from 1977 to 1997. An acute crisis in each patient was successfully treated by infusion of glucose and heme arginate. After this therapy both urinary 5-aminolevulinic acid (A...

6-Aminolevulinic acid synthesis has been demonstrated in both porphyric and normal liver homogenates. A study of the factors which affect &aminolevulinic acid production indicates that the enzyme b-aminolevulinic acid synthetase can be measured in liver homogenates, with use of added glycine and endogenously generated succinyl coenzyme A. 6Aminolevulinic acid production in this system is greate...

The 14C labelled inactive protein obtained by sodium borohydride reduction of the enzyme, porphobilinogen synthase of Rhodopseudomonas spheroides, in the presence of [4-14C]5-aminolevulinic acid, gave on acid hydrolysis and subsequent electrophoresis or two-dimensional chromatography a major radioactive spot which was confirmed to be N-epsilon-[4-(-5aminovaleric acid)]lysine (ALA-lysine) by com...

In extension of two previous series of experiments, the results of which have been partially reported (1), further long-term tests were performed with daily oral doses of 5 mg Pb++ in 2 subjects. Lead in whole blood, free protoporphyrin 9 (III) and 5-aminolevulinate dehydratase activity in erythrocytes, hemoglobin, and urinary 5-aminolevulinic acid and coproporphyrin III excretion values were m...

The present study describes some characteristics of soluble hepatic d-aminolevulinic acid synthetase, including end product inhibition by hemin. The enzyme is shown to contain a -SH group at its active center which is associated with the initial binding of the cofactor pyridoxal-S/-PO4 to the enzyme. In addition, the -SH group may influence the activation of d-aminolevulinic acid synthetase by ...