title: Protein kinase A of Leishmania amazonensis as a potential target for methoxy-amidine.
abstract: Cyclic 3',5'-adenosine monophosphate (cAMP) is one of the most important signaling molecules for cell growth and differentiation in several systems including protozoal parasites such as Trypanosoma cruzi and Leishmania species. The most important event during Leishmania developmental cycle is the differentiation of procyclic into metacyclic promastigotes, which is associated with the appearance of pathogenicity. As previously demonstrated Leishmania amazonensis metacyclogenesis is associated with an increase of a protein kinase A activity, and therefore further studies on the activity of this phosphorylating enzyme as a target for chemotherapy were performed. Among several amidine derivatives tested by the authors against trypanosomatids (T. cruzi, T. evansi and L. amazonensis) the most effective compounds was defined as that with a methoxy group as substituent. In this work the inhibitory effect of this derivative on the phosphorylating activity of cAMP-dependent protein kinase (PKA) of promastigotes (containing high amounts of metacyclic forms) and axenic amastigotes of L. amazonensis is demonstrated. Soluble fractions (SF) and enriched membrane fractions (MF) were submitted to anion exchange chromatography in a DEAE-cellulose column and the collected fractions used to evaluate the phosphorylating activity associated with cAMP, in the presence/absence of methoxy-amidine and pentamidine (CAS 100-33-4), the latter being used as reference drug.
authors.affiliation: Department of Immunology, Oswaldo Cruz Institute, Oswaldo Cruz Foundation (FIOCRUZ), Brazil.
authors.forename: M
authors.initials: M
authors.lastname: Genestra
authors.forename: A
authors.initials: A
authors.lastname: Echevarria
authors.forename: L
authors.initials: L
authors.lastname: Cysne-Finkelstein
authors.forename: L L
authors.initials: LL
authors.lastname: Leon
mesh_terms: D000262:Adenylyl Cyclases / Q000378:metabolism; D000578:Amidines / Q000494:pharmacology*; D000818:Animals; D000981:Antiprotozoal Agents / Q000494:pharmacology*; D001550:Benzamidines / Q000494:pharmacology*; D002852:Chromatography, Ion Exchange; D000242:Cyclic AMP / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors*; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D066298:In Vitro Techniques; D007202:Indicators and Reagents; D007894:Leishmania mexicana / Q000187:drug effects* / Q000201:enzymology* / Q000648:ultrastructure; D010766:Phosphorylation / Q000187:drug effects; D013347:Subcellular Fractions / Q000187:drug effects / Q000201:enzymology
chemical_list: D000578:Amidines; D000981:Antiprotozoal Agents; D001550:Benzamidines; D004791:Enzyme Inhibitors; D007202:Indicators and Reagents; C443260:N,N'-diphenyl-4-methoxybenzamidine; D000242:Cyclic AMP; D017868:Cyclic AMP-Dependent Protein Kinases; D000262:Adenylyl Cyclases