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The nucleotide sequences for Brugia malayi and Wuchereria bancrofti GST have been submitted to EMBL, GenBank, and DDBJ Nucleotide Sequence Databases under Accession Nos. Y12788 and AY195867.

The genes encoding three forms of superoxide dismutase, the cytosolic and extracellular CuZn superoxide dismutases and the mitochondrial Mn superoxide dismutase, were isolated from an Onchocerca volvulus lambda fix II genomic library. Genomic Southern blot analyses indicate single-copy genes in the O. volvulus genome. The O. volvulus cytosolic and extracellular CuZnSOD genes (Ov-sod-1 and Ov-sod-2) are separated by 0.8 kb of sequence and are convergently transcribed. Since the transcripts from all three sod genes are trans-spliced, the transcription start point of each gene was determined in a heterologous system that lacks trans-splicing machinery by in vitro transcription using Drosophila embryo nuclear extracts, followed by primer extension experiments. The ability of the 5' flanking region of the genes encoding the three Ov-SODs to promote transcription was further examined in transient transfections of Chinese hamster ovary cells. In firefly luciferase reporter assays, the Ov-sod-1 and -2 and the MnSOD (Ov-sod-3) gene promoters showed minimal, strong, and moderate levels of activity in these cells, respectively. Both Ov-sod-2 and -3 gene promoter regions showed an initial increase in activity in response to 5' deletions. The results from the in vitro transcription experiments and the luciferase reporter assays were consistent and suggest the presence of Inr-like elements in the promoter regions of the Ov-sod genes., (Copyright 2000 Academic Press.)

Putrescine-dependent S-adenosyl-L-methionine decarboxylase has been detected in the malaria parasite Plasmodium falciparum. Mg2+ did not affect the enzyme activity. The apparent Km value of the plasmodial enzyme for adenosyl-methionine was found to be 33 microM. Methylglyoxal bis(guanylhydrazone) competitively inhibited the enzyme activity with respect to adenosylmethionine. The inhibition constant for methylglyoxal bis(guanylhydrazone) was determined to be 0.46 microM. Spermidine was the main polyamine detected in the parasite. There was significant decrease in the S-adenosyl-L-methionine decarboxylase activity when the infected erythrocytes were incubated with chloroquine and mefloquine for 2 hr at 1 and 10 microM, respectively. Since at similar concentrations these drugs did not directly affect the plasmodial enzyme activity, the interaction of these drugs with the polyamine biosynthesis remains unclear.

Putrescine-dependent S-adenosylmethionine decarboxylase (EC 4.1.1.50) was demonstrated in Ascaris suum and Onchocerca volvulus; activation was found to be about fourfold by putrescine. Mg2+ did not affect the enzyme activity. A. suum was taken as a model nematode and its S-adenosylmethionine decarboxylase was partially purified and characterized. The molecular weight was estimated to be 220,000. The apparent Km-value for adenosylmethionine was determined to be 17 microM. Methylglyoxal bis(guanylhydrazone) and berenil competitively inhibited the enzyme activity; the apparent Ki-values were found to be 0.24 microM and 0.11 microM, respectively. The dependence of filarial worms on uptake and interconversion of putrescine and polyamines as well as properties of the S-adenosylmethionine decarboxylase, different from the host enzyme, points to the polyamine metabolisms as a useful target for chemotherapy.

Dolichol kinase, a rate limiting enzyme for the supply with dolichyl monophosphate as glycosyl carrier lipid, was demonstrated in Plasmodium falciparum. The enzyme was found to be associated with the pellet fraction and to depend on cytidine triphosphate as phosphoryl donor. The apparent Km values of the plasmodial enzyme were determined to be 0.8 mM for cytidine triphosphate and 17 micrograms ml-1 for dolichol. In the presence of 0.5 mM mefloquine, the inhibition of enzyme activity was found to be about 50%.