3-methylcrotonyl-CoA carboxylase (MCC) is a biotin-dependent mitochondrial enzyme necessary for leucine catabolism in most organisms. While the crystal structure of recombinant bacterial MCC has been characterized, the structure and potential polymerization of native MCC remain elusive. Here, we discovered that native MCC from Leishmania tarentolae (LtMCC) forms filaments, and determined the structures of different filament regions at 3.4, 3.9, and 7.3 Å resolution using cryoEM. αβ LtMCCs assemble in a twisted-stacks architecture, manifesting as supramolecular rods up to 400 nm. Filamentous LtMCCs bind biotin non-covalently and lack coenzyme A. Filaments elongate by stacking αβ LtMCCs onto the exterior α-trimer of the terminal LtMCC. This stacking immobilizes the biotin carboxylase domains, sequestering the enzyme in an inactive state. Our results support a new model for LtMCC catalysis, termed the dual-swinging-domains model, and cast new light on the function of polymerization in the carboxylase superfamily and beyond.
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http://dx.doi.org/10.1016/j.str.2022.11.015 | DOI Listing |
Eur J Med Chem
February 2025
College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu, 215123, China. Electronic address:
Corosolic acid (CA), a natural triterpenoid, exhibits various biological activities and is often called as plant-derived insulin due to its significant hypoglycemic effects, making it especially beneficial for individuals with diabetes or high blood glucose levels. However, CA has notable in vitro toxicity, low water solubility, and poor pharmacokinetic properties. To address these limitations, a series of CA derivatives were synthesized, resulting in the identification of derivative H26, which demonstrates a significantly enhanced hypoglycemic effect, reduced toxicity, and improved pharmacokinetic characteristics compared to CA.
View Article and Find Full Text PDFJ Ayub Med Coll Abbottabad
November 2024
Jinnah Sindh Medical University, Karachi-Pakistan.
Methods Enzymol
November 2024
Department of Biological Sciences, Marquette University, Milwaukee, WI, United States.
Biotin-dependent carboxylases catalyze the MgATP- and bicarbonate-dependent carboxylation of various acceptor substrates through a two-step carboxylation reaction. Biotin-dependent carboxylases play an essential role in the metabolism of key biomolecules and, therefore, they are the subject of ongoing drug discovery efforts, as well as of studies seeking to better characterize their structure and function. It has been an ongoing challenge to obtain high yields of mammalian biotin-dependent carboxylases for in vitro experimentation; these enzymes have not been successfully purified when recombinantly expressed from a bacterial expression host and only low yields of these recombinant, vertebrate enzymes have been obtained through expression in cell culture systems.
View Article and Find Full Text PDFMol Genet Metab Rep
December 2024
Genetic and Precision Medicine Department, King Abdullah Specialized Children Hospital, King Abdulaziz Medical City, Ministry of National Guard Health Affairs (MNGHA), Riyadh, Saudi Arabia.
Mol Genet Metab Rep
December 2024
Genetics Division, Pediatrics, Los Angeles General Hospital, University of Southern California, Los Angeles, CA, USA.
3-methylcrotonyl-CoA carboxylase (3-MCC) deficiency is an autosomal recessive disorder of leucine metabolism. Since 3-MCC deficiency is thought to be a benign condition, a few newborn screening programs discontinued to screen this condition. We report a case of a 24-year-old previously healthy male patient who developed generalized rhabdomyolysis, weakness, respiratory and renal failure, acute pancreatitis, hyperammonemia, and altered consciousness after strenuous exercise.
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