The design, syntheses, and enzymatic activity of two submicromolar competitive inhibitors of aspartate transcarbamoylase (ATCase) are described. The phosphinate inhibitors are analogs of N-phosphonacetyl-l-aspartate (PALA) but have a reduced charge at the phosphorus moiety. The mechanistic implications are discussed in terms of a possible cyclic transition-state during enzymatic catalysis.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2743340 | PMC |
http://dx.doi.org/10.1016/j.bmcl.2008.11.115 | DOI Listing |
describes the ability of biological macromolecules to transmit signals spatially through the molecule from an site – a site that is distinct from binding sites of primary, endogenous ligands – to the functional or active site. This review starts with a historical overview and a description of the classical example of allostery – hemoglobin – and other well-known examples (aspartate transcarbamoylase, Lac repressor, kinases, G-protein-coupled receptors, adenosine triphosphate synthase, and chaperonin). We then discuss fringe examples of allostery, including intrinsically disordered proteins and inter-enzyme allostery, and the influence of dynamics, entropy, and conformational ensembles and landscapes on allosteric mechanisms, to capture the essence of the field.
View Article and Find Full Text PDFbioRxiv
November 2024
Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853, USA.
Discovered nearly 70 years ago, the allosteric regulation of aspartate transcarbamoylase (ATCase) is discussed in every biochemistry textbook. ATCase catalyzes the first step in pyrimidine biosynthesis. Despite extensive research, the mechanism by which this enzyme is regulated by pyrimidine and purine nucleotides has remained elusive.
View Article and Find Full Text PDFCurr Microbiol
November 2024
Department of Chemistry, Texas A&M University, Commerce, TX, 75429, USA.
J Mol Biol
December 2024
Structure of Macromolecular Targets Unit, Instituto de Biomedicina de Valencia (IBV), CSIC, Eduardo Primo Yúfera, 3, 46012 Valencia, Spain; Group CB06/07/0077 Centro de Investigación Biomédica en Red de Enfermedades Raras, CIBERER-ISCIII, Monforte de Lemos 3-5, 28029 Madrid, Spain; Valencia Biomedical Research Foundation, Centro de Investigación Príncipe Felipe (CIPF) - Associated Unit to the Instituto de Biomedicina de Valencia (IBV), Eduardo Primo Yúfera, 3, 46012 Valencia, Spain. Electronic address:
CAD, the multi-enzymatic protein essential for initiating the de novo biosynthesis of pyrimidine nucleotides, forms large hexamers whose structure and function are not fully understood. Defects in CAD cause a severe neurometabolic disorder that is challenging to diagnose. We developed a cellular functional assay to identify defective CAD variants, and in this study, we characterized five pathogenic missense mutations in CAD's dihydroorotase (DHO) and aspartate transcarbamoylase (ATC) domains.
View Article and Find Full Text PDFNucleosides Nucleotides Nucleic Acids
November 2024
Section of Infection and Immunity, Herman Ostrow School of Dentistry, Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, California, USA.
Glutamine amidotransferases (GATs) catalyze the synthesis of nucleotides, amino acids, glycoproteins and an enzyme cofactor, thus serving as key metabolic enzymes for cell proliferation. arbamoyl-phosphate synthetase, spartate transcarbamoylase, and ihydroorotase (CAD) is a multifunctional enzyme of the GAT family and catalyzes the first three steps of the pyrimidine synthesis. Following our findings that cellular GATs are involved in immune evasion during herpesvirus infection, we discovered that CAD reprograms cellular metabolism to fuel aerobic glycolysis and nucleotide synthesis deamidating RelA.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!