Researchers from the Department of Chemistry, Aleksandra Maršavelski and Tomica Hrenar, in collaboration with scientists from the Technion – Israel Institute of Technology in Haifa, Israel (H. Cai, S. Shulami, and A. Fishman) and the Ruđer Bošković Institute (Z. Štefanić), have published a scientific article titled "Allosteric regulation of L-lactate dehydrogenase: Beyond effector-mediated tetramerization" in the prestigious journal Protein Science (IF = 5.2).
In this research, we investigated the allosteric regulation of the enzyme L-lactate dehydrogenase from Geobacillus stearothermophilus (GsLDH), a homotetrameric enzyme important for industrial biocatalysis due to its role in the conversion of lactate and pyruvate, as well as the regeneration of the NAD⁺/NADH cofactor. We combined experimental and computational approaches to elucidate the mechanisms of allosteric activation by fructose 1,6-bisphosphate (FBP), which stabilizes the tetrameric structure of the enzyme and increases its affinity for the substrate pyruvate. By comparing the wild-type (wt) enzyme with a triple and a single mutant, we demonstrated that the triple mutant retains its tetrameric structure and exhibits high affinity for pyruvate regardless of the presence of FBP. In contrast, the single mutant also remains tetrameric but does not display increased substrate affinity, indicating that oligomerization alone is not sufficient to transmit the allosteric signal. Our results show that both oligomerization and effector binding are essential for establishing effective communication pathways that modulate substrate affinity.
Pristupačnost
