Capturing protein dynamics in biological crowded environments is essential for under- standing cellular function. In this project, we have explored the dynamic properties of apoferritin in aqueous solutions under varying conditions, including different temper- ature, solvent viscosity and protein concentrations. Dynamic light scattering (DLS) was applied here at various scattering angles from 90 to 150 degrees and at temperatures 295 K and 263 K on three different samples, including one with 19.5 mg/ml apo- ferritin, 6 mg/ml NaCl and 50% glycerol in volume fraction, one with 20 mg/ml apoferritin and 6 mg/ml NaCl, and one with 196.7 mg/ml apoferritin, 6 mg/ml NaCl and 50% glycerol in volume fraction. With the intensity autocorrelation func- tions from DLS measurements, the corresponding diffusion coefficients, hydrodynamic radii and relaxation time constants for each sample under varying conditions were ex- tracted. By comparing with the previous studies, unexpectedly large hydrodynamic radii were noticed and were attributed to undissolved protein crystallites. Still, it can be indicated from our experiment that applying smaller momentum transfer, decreas- ing temperature, increasing solvent viscosity and increasing protein concentration in the solutions can slow down the diffusion dynamics of protein molecules and clusters. Especially by increasing protein concentration, the slowing down of dynamics may be due to crowding effects, as well as increased size of the crystallites. In addition, the data indicate that in all cases, larger solution viscosity can lead to slower diffusivity of proteins.
| Identifer | oai:union.ndltd.org:UPSALLA1/oai:DiVA.org:su-208550 |
| Date | January 2022 |
| Creators | Huiting, Huang |
| Publisher | Stockholms universitet, Fysikum |
| Source Sets | DiVA Archive at Upsalla University |
| Language | English |
| Detected Language | English |
| Type | Student thesis, info:eu-repo/semantics/bachelorThesis, text |
| Format | application/pdf |
| Rights | info:eu-repo/semantics/openAccess |
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