title: Native Electrophoresis-Coupled Activity Assays Reveal Catalytically-Active Protein Aggregates of Escherichia coli β-Glucuronidase.
abstract: β-glucuronidase is found as a functional homotetramer in a variety of organisms, including humans and other animals, as well as a number of bacteria. This enzyme is important in these organisms, catalyzing the hydrolytic removal of a glucuronide moiety from substrate molecules. This process serves to break down sugar conjugates in animals and provide sugars for metabolism in bacteria. While β-glucuronidase is primarily found as a homotetramer, previous studies have indicated that the human form of the protein is also catalytically active as a dimer. Here we present evidence for not only an active dimer of the E. coli form of the protein, but also for several larger active complexes, including an octomer and a 16-mer. Additionally, we propose a model for the structures of these large complexes, based on computationally-derived molecular modeling studies. These structures may have application in the study of human disease, as several diseases have been associated with the aggregation of proteins.
authors.affiliation: Department of Chemistry, Radford University, Radford, VA, United States of America.
authors.forename: Gina G
authors.initials: GG
authors.lastname: Burchett
authors.affiliation: Department of Chemistry, Radford University, Radford, VA, United States of America.
authors.forename: Charles G
authors.initials: CG
authors.lastname: Folsom
authors.affiliation: Department of Chemistry, Radford University, Radford, VA, United States of America.
authors.forename: Kimberly T
authors.initials: KT
authors.lastname: Lane
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry*; D002241:Carbohydrates / Q000737:chemistry; D002384:Catalysis; D020134:Catalytic Domain; D003198:Computer Simulation; D019281:Dimerization; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods*; D004926:Escherichia coli / Q000201:enzymology*; D005966:Glucuronidase / Q000737:chemistry*; D020719:Glucuronides / Q000737:chemistry; D006801:Humans; D006868:Hydrolysis; D007700:Kinetics; D008958:Models, Molecular; D066329:Protein Aggregates; D011485:Protein Binding; D011487:Protein Conformation; D017510:Protein Folding
chemical_list: D001426:Bacterial Proteins; D002241:Carbohydrates; D020719:Glucuronides; D066329:Protein Aggregates; D005966:Glucuronidase