Enteropeptidase: A Gene Associated With a Starvation Human Phenotype and a Novel Target for Obesity Treatment.

Enteropeptidase: a gene associated with a starvation human phenotype and a novel target for obesity treatment.

Filed under: Drug and Alcohol Rehabilitation

PLoS One. 2012; 7(11): e49612
Braud S, Ciufolini MA, Harosh I

Obesity research focuses essentially on gene targets associated with the obese phenotype. None of these targets have yet provided a viable drug therapy. Focusing instead on genes that are involved in energy absorption and that are associated with a “human starvation phenotype”, we have identified enteropeptidase (EP), a gene associated with congenital enteropeptidase deficiency, as a novel target for obesity treatment. The advantages of this target are that the gene is expressed exclusively in the brush border of the intestine; it is peripheral and not redundant.Potent and selective EP inhibitors were designed around a boroarginine or borolysine motif. Oral administration of these compounds to mice restricted the bioavailability of dietary energy, and in a long-term treatment it significantly diminished the rate of increase in body weight, despite ad libitum food intake. No adverse reactions of the type seen with lipase inhibitors, such as diarrhea or steatorrhea, were observed. This validates EP as a novel, druggable target for obesity treatment.In vivo testing of novel boroarginine or borolysine-based EP inhibitors validates a novel approach to the treatment of obesity.
HubMed – drug

Botulinum neurotoxin serotype a specific cell-based potency assay to replace the mouse bioassay.

Filed under: Drug and Alcohol Rehabilitation

PLoS One. 2012; 7(11): e49516
Fernández-Salas E, Wang J, Molina Y, Nelson JB, Jacky BP, Aoki KR

Botulinum neurotoxin serotype A (BoNT/A), a potent therapeutic used to treat various disorders, inhibits vesicular neurotransmitter exocytosis by cleaving SNAP25. Development of cell-based potency assays (CBPAs) to assess the biological function of BoNT/A have been challenging because of its potency. CBPAs can evaluate the key steps of BoNT action: receptor binding, internalization-translocation, and catalytic activity; and therefore could replace the current mouse bioassay. Primary neurons possess appropriate sensitivity to develop potential replacement assays but those potency assays are difficult to perform and validate. This report describes a CBPA utilizing differentiated human neuroblastoma SiMa cells and a sandwich ELISA that measures BoNT/A-dependent intracellular increase of cleaved SNAP25. Assay sensitivity is similar to the mouse bioassay and measures neurotoxin biological activity in bulk drug substance and BOTOX® product (onabotulinumtoxinA). Validation of a version of this CBPA in a Quality Control laboratory has led to FDA, Health Canada, and European Union approval for potency testing of BOTOX®, BOTOX® Cosmetic, and Vistabel®. Moreover, we also developed and optimized a BoNT/A CBPA screening assay that can be used for the discovery of novel BoNT/A inhibitors to treat human disease.
HubMed – drug

Plasmodium falciparum UvrD Helicase Translocates in 3′ to 5′ Direction, Colocalizes with MLH and Modulates Its Activity through Physical Interaction.

Filed under: Drug and Alcohol Rehabilitation

PLoS One. 2012; 7(11): e49385
Ahmad M, Ansari A, Tarique M, Satsangi AT, Tuteja R

Malaria is a global disease and a major health problem. The control of malaria is a daunting task due to the increasing drug resistance. Therefore, there is an urgent need to identify and characterize novel parasite specific drug targets. In the present study we report the biochemical characterization of parasite specific UvrD helicase from Plasmodium falciparum. The N-terminal fragment (PfUDN) containing UvrD helicase domain, which consists of helicase motifs Q, Ia-Id, II, III and most of motif IV, and the C-terminal fragment (PfUDC1) containing UvrD helicase C terminal domain, consisting of remaining part of motif IV and motifs IVa-IVc and 161 amino acids of intervening sequence between motif IV and V, possess ssDNA-dependent ATPase and DNA helicase activities in vitro. Using immunodepletion assays we show that the ATPase and helicase activities are attributable to PfUDN and PfUDC1 proteins. The helicase activity can utilize the hydrolysis of all the nucleotide and deoxynucleotide triphosphates and the direction of unwinding is 3′ to 5′. The endogenous P. falciparum UvrD contains the characteristic DNA helicase activity. PfUDN interacts with PfMLH (P. falciparum MutL homologue) and modulates the endonuclease activity of PfMLH and PfMLH positively regulates the unwinding activity of PfUDN. We show that PfUvrD is expressed in the nucleus distinctly in the schizont stages of the intraerythrocytic development of the parasite and it colocalizes with PfMLH. These studies will make an important contribution in understanding the nucleic acid transaction in the malaria parasite.
HubMed – drug

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