Peter Leube on
“The Effect of Parathyroid Hormone on
Poly(Methoxydi(Ethylene Glycol)Acrylates)
Investigated by Spin Probing Electron Spin Resonance Spectroscopy”
Location: Martin-Luther-Universität Halle-Wittenberg Von-Danckelmann-Platz 3, SR 1.06 06120 Halle (Saale) Time: 3.30pm - 5.00pm Link to Google-Maps
Abstracts
The Effect of Parathyroid Hormone on Poly(Methoxydi(Ethylene Glycol)Acrylates) Investigated by Spin Probing Electron Spin Resonance Spectroscopy
Peter Leube
Thermoresponsive polymers are promising materials for a variety of applications like in drug delivery or smart interfaces. But they can also be used to investigate complex mechanisms like the fibrillation of amyloids. Through a cooperation between the projects A03 and A06 of the SFB TRR 102 it is known, that thermoresponsive poly(methoxydi (ethylene glycol)acrylates) (PMDEGAs) are able to accelerate the fibrillation process of the amyloid parathyroid hormone (PTH).
Since these studies were focused on the altered behaviour of the peptide, they leave a lack of knowledge about effects on the polymer’s phase separation. The aims of the presented study were to investigate the thermoresponsive behaviour of PMDEGAs in fibrillation environment and how PTH1−84 affect the demeanour of PMDEGAs in a physical mixture and in a conjugate, respectively.
As main method electron spin resonance spectroscopy of spin probes was used. Those radicals were added to the systems and enable a indirect investigation of nanoscopic hydrophobic inhomogeneities, which can be formed by lower critical solution temperature polymers like PMDEGAs.
It can be shown that in comparison to water the effect of the collapsed polymer on the spin probes is weakened in fibrillation buffer. If the molecular mass of the polymer is increased the mobility and the direct environmental polarity/hydrophilicity of the probes seem to increase. In a physical mixture of a PMDEGA and PTH1−84 the probes face similar interactions like in a pure polymer solutions, while in a conjugate solution they are more mobile and a smaller extent is affected by the polymer.
The gained data show a hindered ability of PMDEGAs to form nanoscopic hydrophobic inhomogeneities in the fibrillation buffer and that a covalent binding to PTH1−84 may causes a further loss of its thermoresponsivity.
Since these studies were focused on the altered behaviour of the peptide, they leave a lack of knowledge about effects on the polymer’s phase separation. The aims of the presented study were to investigate the thermoresponsive behaviour of PMDEGAs in fibrillation environment and how PTH1−84 affect the demeanour of PMDEGAs in a physical mixture and in a conjugate, respectively.
As main method electron spin resonance spectroscopy of spin probes was used. Those radicals were added to the systems and enable a indirect investigation of nanoscopic hydrophobic inhomogeneities, which can be formed by lower critical solution temperature polymers like PMDEGAs.
It can be shown that in comparison to water the effect of the collapsed polymer on the spin probes is weakened in fibrillation buffer. If the molecular mass of the polymer is increased the mobility and the direct environmental polarity/hydrophilicity of the probes seem to increase. In a physical mixture of a PMDEGA and PTH1−84 the probes face similar interactions like in a pure polymer solutions, while in a conjugate solution they are more mobile and a smaller extent is affected by the polymer.
The gained data show a hindered ability of PMDEGAs to form nanoscopic hydrophobic inhomogeneities in the fibrillation buffer and that a covalent binding to PTH1−84 may causes a further loss of its thermoresponsivity.
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