AMP hydrolysis in soluble and microsomal rat cardiac cell fractions: kinetic characterization and molecular identification of 5'-nucleotidase.

Biosci Rep

Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rua Ramiro Barcelos, 2600 - ANEXO, 90035-003, Porto Alegre, RS, Brazil.

Published: October 2008

The present study describes the enzymatic properties and molecular identification of 5'-nucleotidase in soluble and microsomal fractions from rat cardiac ventricles. Using AMP as a substrate, the results showed that the cation and the concentration required for maximal activity in the two fractions was magnesium at a final concentration of 1 mM. The pH optimum for both fractions was 9.5. The apparent K(m) (Michaelis constant) values calculated from the Eadie-Hofstee plot were 59.7+/-10.4 microM and 134.8+/-32.1 microM, with V(max) values of 6.7+/-0.4 and 143.8+/-23.8 nmol P(i)/min/mg of protein (means+/-S.D., n=4) from soluble and microsomal fractions respectively. Western blotting analysis of ecto-5'-nucleotidase revealed a 70 kDa protein in both fractions, with the major proportion present in the microsomal fraction. The presence of these enzymes in the heart probably has a physiological function in adenosine signalling. Furthermore, the presence of ecto-5'-nucleotidase in the microsomal fraction could have a role in the modulation of the excitation-contraction-coupling process through involvement of the Ca(2+) influx into the sarcoplasmic reticulum. The measurement of maximal enzyme activities in the two fractions highlights the potential capacity of the different pathways of purine metabolism in the heart.

Download full-text PDF

Source
http://dx.doi.org/10.1042/BSR20070039DOI Listing

Publication Analysis

Top Keywords

soluble microsomal
12
rat cardiac
8
molecular identification
8
identification 5'-nucleotidase
8
microsomal fractions
8
microsomal fraction
8
fractions
7
microsomal
5
amp hydrolysis
4
hydrolysis soluble
4

Similar Publications

Advancing mitochondrial therapeutics: Synthesis and pharmacological evaluation of pyrazole-based inhibitors targeting the mitochondrial pyruvate carrier.

Eur J Med Chem

February 2025

Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO, 63110, USA; Center for Clinical Pharmacology, Washington University School of Medicine and University of Health Sciences and Pharmacy, St. Louis, Missouri, 63110, USA; Department of Pharmaceutical and Administrative Sciences, University of Health Sciences and Pharmacy, St. Louis, Missouri, 63110, USA. Electronic address:

Inhibition of mitochondrial pyruvate transport via the mitochondrial pyruvate carrier (MPC) has shown beneficial effects in treating metabolic diseases, certain cancers, various forms of neurodegeneration, and hair loss. These benefits arise either from the direct inhibition of mitochondrial pyruvate metabolism or from the metabolic rewiring when pyruvate entry is inhibited. However, current MPC inhibitors are either nonspecific or possess poor pharmacokinetic properties.

View Article and Find Full Text PDF

Inhibiting microsomal prostaglandin E synthase-1 (mPGES-1), an inducible enzyme involved in prostaglandin E (PGE) biosynthesis and tumor microenvironment (TME) homeostasis, is a valuable strategy for treating inflammation and cancer. In this work, 5-methylcarboxamidepyrrole-based molecules were designed and synthesized as new compounds targeting mPGES-1. Remarkably, compounds 1f, 2b, 2c, and 2d were able to significantly reduce the activity of the isolated enzyme, showing IC values in the low micromolar range.

View Article and Find Full Text PDF

The SARS-CoV-2 pandemic has significantly challenged global public health, highlighting the need for effective therapeutic options. This study focuses on the papain-like protease (PLpro) of SARS-CoV-2, which is a critical enzyme for viral polyprotein processing, maturation, and immune evasion. We employed a combined approach that began with computational models in a virtual screening campaign, prioritizing compounds from our in-house chemical library against PLpro.

View Article and Find Full Text PDF

Design, synthesis and biological evaluation of novel diaryl-substituted fused nitrogen heterocycles as tubulin polymerization inhibitors to overcome multidrug resistance in vitro and in vivo.

Eur J Med Chem

February 2025

School of Pharmacy, Fudan University, Shanghai, 201203, China; School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, 453007, China. Electronic address:

Article Synopsis
  • * A new compound, benzoimidazole derivative 37, shows strong cytotoxic effects and can overcome MDR in resistant A549 cells by disrupting microtubule assembly and reducing P-glycoprotein levels.
  • * In vivo tests indicate that compound 37 inhibits tumor growth effectively with low toxicity, making it a promising candidate for treating multidrug-resistant LUAD in future clinical applications.
View Article and Find Full Text PDF

Unveiling the Antimycobacterial Potential of Novel 4-Alkoxyquinolines: Insights into Selectivity, Mechanism of Action, and Exposure.

J Med Chem

December 2024

Instituto Nacional de Ciência e Tecnologia em Tuberculose, Centro de Pesquisas em Biologia Molecular e Funcional, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul 90616-900, Brazil.

Article Synopsis
  • The research focuses on developing a new set of 4-alkoxyquinolines aimed at treating tuberculosis, particularly against both regular and drug-resistant strains.
  • The key compound shows good solubility and stability, even in harsh acidic environments, making it a strong candidate for further testing.
  • Despite some challenges with absorption and metabolism, it demonstrated effectiveness in laboratory models, indicating potential for use as an antituberculosis drug.
View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!