The nucleotide sequence of a cDNA encoding the proenzyme of hamster S-adenosylmethionine decarboxylase including 169 nucleotides of the 5' untranslated region has been determined. The deduced amino ...acid sequence shows a remarkable similarity to the human proenzyme with only seven differences out of 334 amino acids. The nucleotide sequence of the 5' untranslated region showed 93% homology with the corresponding rat and human sequences suggesting that this region may play an important role in the regulation of S-adenosylmethionine decarboxylase expression.
Chlorpromazine (CPZ) caused suppression in release of microfilariae in vitro from Setaria cervi at 10-5 M concentration. The inhibitory effect of CPZ was further stimulated by Ca2+ (2 mM), whereas ...addition of EGTA (2 mM) resulted in partial reversal. Addition of dopamine (1 mM) along with CPZ (10-5 M) caused similar inhibition as was observed in the presence of CPZ (10-5 M) alone. CPZ did not effect in vitro oxygen uptake by worm homogenates up to 0.5 mM concentration. The results indicate the Ca2+/calmodulin-dependent anthelmintic action of CPZ on S. cervi.
Availability of complete genome sequence for Plasmodium falciparum has been useful in drawing a comprehensive metabolic map of the parasite. Distinct and unique metabolic characteristics of the ...parasite may be exploited as potential targets for new antimalarial drug discovery research. Reversible phosphorylation of proteins is a ubiquitous process and an indispensable part of cell signaling cascades, which regulate different cellular functions. Not so long ago the role of protein phosphatases in the cell life was underestimated but now these enzymes strongly focus attention of many researches. Based on primary structure and functional characteristics protein phosphatases have been divided into number of families and subfamilies. The amino acid sequences of catalytic subunits of protein phosphatases of particular families stay highly conserved in eukaryotic organisms during evolutionary changes. Serine/threonine protein phosphatases (PPPs) constitute an important family, which are involved in mitotic and meiotic cell divisions, cell development, apoptosis and many other crucial cellular processes. Complex life cycle of the malaria parasite, which encompasses through distinct developmental stages, offers highly sophistical roles for the protein phosphatases. We have researched and analyzed characteristics of 17 putative or/and confirmed catalytic subunits of PPPs on P. falciparum genome. Evidences have been gathered that indicate functional expression of some PPP isoforms in P. falciparum. A few of them have been found to be essential or play important cellular functions in the parasite. Identification of distinct molecular and functional characteristics of these enzymes shall be useful in designing selective inhibitors of plasmodial PPPs as potential new antimalarials.
The air-dried aerial parts of Croton campestris, C. chaetocalyx, C. eriocladus, and C. glandulosus, with occurrence in the Eastern Brazilian Amazon, yielded essential oils, and their volatile ...constituents were analyzed by GC and GC-MS. Sesquiterpenes, both hydrocarbons and oxygenated, were the most highly represented classes in the oils: the former ranging from 55.3% to 85.1%, and the latter varying from 7.2% to 33.2%. The oils were separated into two groups using hierarchical cluster analysis whose main constituents were β-caryophyllene, germacrene D, γ-elemene, β-elemene, α-humulene and δ-elemene (Group A, C. campestris and C. eriocladus); and spathulenol, bicyclogermacrene, δ-elemene, germacrene D, β-caryophyllene and δ-cadinene (Group B, C. chaetocalyx and C. glandulosus). Percentage of sesquiterpene hydrocarbons was higher in Group A (83-85%) than in Group B (55-63%). However, regarding the oxygenated sesquiterpenes, it was reversed, being bigger in Group B (28-33%) than in Group A (7-8%). Percentage of similarity in Group A was 92% and in Group B it was 86%. These chemotaxonomic results showed a significant contribution for the better botanical knowledge of these four Croton species occurring in North Brazil.
