In early stages of Alzheimer's disease (AD), amyloid beta (Aβ) accumulates in the mitochondrial matrix and interacts with mitochondrial proteins, such as cyclophilin D (cypD) and 17β-hydroxysteroid dehydrogenase 10 (17β-HSD10). Multiple processes associated with AD such as increased production or oligomerization of Aβ affect these interactions and disbalance the equilibrium between the biomolecules, which contributes to mitochondrial dysfunction. Here, we investigate the effect of the ionic environment on the interactions of Aβ (Aβ1-40, Aβ1-42) with cypD and 17β-HSD10 using a surface plasmon resonance (SPR) biosensor. We show that changes in concentrations of K+ and Mg2+ significantly affect the interactions and may increase the binding efficiency between the biomolecules by up to 35% and 65% for the interactions with Aβ1-40 and Aβ1-42, respectively, in comparison with the physiological state. We also demonstrate that while the binding of Aβ1-40 to cypD and 17β-HSD10 takes place preferentially around the physiological concentrations of ions, decreased concentrations of K+ and increased concentrations of Mg2+ promote the interaction of both mitochondrial proteins with Aβ1-42. These results suggest that the ionic environment represents an important factor that should be considered in the investigation of biomolecular interactions taking place in the mitochondrial matrix under physiological as well as AD-associated conditions.

• Klíčová slova
• 17β-hydroxysteroid dehydrogenase 10 (17β-HSD10), amyloid beta (Aβ), biomolecular interactions, cyclophilin D (cypD), ionic environment, mitochondrial matrix, surface plasmon resonance (SPR),
• MeSH
• 17-hydroxysteroidní dehydrogenasy chemie   genetika   MeSH
• Alzheimerova nemoc diagnóza   genetika   patologie   MeSH
• amyloidní beta-protein chemie   MeSH
• biosenzitivní techniky metody   MeSH
• ionty chemie   MeSH
• lidé MeSH
• mitochondriální proteiny chemie   MeSH
• mitochondrie chemie   MeSH
• peptidové fragmenty chemie   genetika   MeSH
• peptidylprolylisomerasa F chemie   genetika   MeSH
• povrchová plasmonová rezonance metody   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• 17-hydroxysteroidní dehydrogenasy MeSH
• 3 (or 17)-beta-hydroxysteroid dehydrogenase MeSH Prohlížeč
• amyloidní beta-protein MeSH
• ionty MeSH
• mitochondriální proteiny MeSH
• peptidové fragmenty MeSH
• peptidylprolylisomerasa F MeSH

Progressive mitochondrial dysfunction due to the accumulation of amyloid beta (Aβ) peptide within the mitochondrial matrix represents one of the key characteristics of Alzheimer's disease (AD) and appears already in its early stages. Inside the mitochondria, Aβ interacts with a number of biomolecules, including cyclophilin D (cypD) and 17β-hydroxysteroid dehydrogenase type 10 (17β-HSD10), and affects their physiological functions. However, despite intensive ongoing research, the exact mechanisms through which Aβ impairs mitochondrial functions remain to be explained. In this work, we studied the interactions of Aβ with cypD and 17β-HSD10 in vitro using the surface plasmon resonance (SPR) method and determined the kinetic parameters (association and dissociation rates) of these interactions. This is the first work which determines all these parameters under the same conditions, thus, enabling direct comparison of relative affinities of Aβ to its mitochondrial binding partners. Moreover, we used the determined characteristics of the individual interactions to simulate the concurrent interactions of Aβ with cypD and 17β-HSD10 in different model situations associated with the progression of AD. This study not only advances the understanding of Aβ-induced processes in mitochondria during AD, but it also provides a new perspective on research into complex multi-interaction biomolecular processes in general.

• Klíčová slova
• 17β-hydroxysteroid dehydrogenase 10 (17β-HSD10), amyloid beta (Aβ), biomolecular interaction analysis, cyclophilin D (cypD), kinetic parameters, surface plasmon resonance (SPR),
• MeSH
• 17-hydroxysteroidní dehydrogenasy chemie   metabolismus   MeSH
• Alzheimerova nemoc metabolismus   MeSH
• amyloidní beta-protein chemie   metabolismus   MeSH
• biosenzitivní techniky MeSH
• lidé MeSH
• mitochondriální proteiny chemie   metabolismus   MeSH
• peptidylprolylisomerasa F chemie   metabolismus   MeSH
• povrchová plasmonová rezonance MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• 17-hydroxysteroidní dehydrogenasy MeSH
• amyloidní beta-protein MeSH
• mitochondriální proteiny MeSH
• peptidylprolylisomerasa F MeSH

In early stages of Alzheimer's disease (AD), amyloid-β (Aβ) accumulates in neuronal mitochondria where it interacts with a number of biomolecules including 17beta-hydroxysteroide dehydrogenase 10 (17β-HSD10) and cyclophilin D (cypD). It has been hypothesized that 17β-HSD10 interacts with cypD preventing it from opening mitochondrial permeability transition pores and that its regulation during AD may be affected by the accumulation of Aβ. In this work, we demonstrate for the first time that 17β-HSD10 and cypD form a stable complex in vitro. Furthermore, we show that factors, such as pH, ionic environment and the presence of Aβ, affect the ability of 17β-HSD10 to bind cypD. We demonstrate that K+ and Mg2+ ions present at low levels may facilitate this binding. We also show that different fragments of Aβ (Aβ1-40 and Aβ1-42) affect the interaction between 17β-HSD10 and cypD differently and that Aβ1-42 (in contrast to Aβ1-40) is capable of simultaneously binding both 17β-HSD10 and cypD in a tri-complex.

• MeSH
• 17-hydroxysteroidní dehydrogenasy metabolismus   MeSH
• Alzheimerova nemoc metabolismus   patologie   MeSH
• amyloidní beta-protein metabolismus   MeSH
• lidé MeSH
• mitochondrie metabolismus   MeSH
• peptidylprolylisomerasa F metabolismus   MeSH
• přechodový pór mitochondriální permeability MeSH
• techniky in vitro MeSH
• transportní proteiny mitochondriální membrány metabolismus   MeSH
• vápník metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• 17-hydroxysteroidní dehydrogenasy MeSH
• 3 (or 17)-beta-hydroxysteroid dehydrogenase MeSH Prohlížeč
• amyloidní beta-protein MeSH
• peptidylprolylisomerasa F MeSH
• přechodový pór mitochondriální permeability MeSH
• transportní proteiny mitochondriální membrány MeSH
• vápník MeSH