single-molecule-analysis-sf9-purified-superprocessive-kinesin-3

Single-Molecule Analysis of Sf9 Purified Superprocessive Kinesin-3 Family Motors

A complex cellular environment poses challenges for single-molecule motility analysis. However, advancement in imaging techniques have improved ...

Indian Institute of Technology Gandhinagar

Sambalpur University

We use two-state ratchet models containing single and coupled Brownian motors to understand the role of motor-microtubule binding, ATPase reaction rate and dimerisation on the translational velocities of Kinesin motors. We use model parameters derived from the experimental measurements on KIF1A, KIF13A, KIF13B, and KIF16B motors to compute velocities in μm/s. We observe that both the models show the same trend in velocities (KIF1A > KIF13A > KIF13B > KIF16B) as the experimental results. However, the models significantly underpredict the velocities when compared with the experiments. The predictions of the coupled-motor model are closer to the experiments than those of the single-motor model. Our results indicate that the variation of ATPase reaction rate governs the trend in velocities for the above four motors. The variation of motor-microtubule binding affinity and the coupling strength between the motor domains may only have a secondary effect. More rigorous models that incorporate the power-stroke mechanism are necessary for better quantitative compliance with the experiments.

Effect of Binding-Affinity and ATPase Activity on the Velocities of Kinesins Using Ratchet Models.

Metal Organic Frameworks (MOFs) are extensively used for a wide range of applications due to their exceptionally high surface area. MOF particles are conventionally in micron size, but the nanosized MOFs show good transportation/mobility due to their small size, and when combined with the high surface area of MOFs, it makes MOF nanoparticles an ideal candidate to study for environmental remediation. Therefore, it is important to study the ecotoxicological impact of these MOFs. In this study, we developed rhodamine labelled nanoparticles of zinc imidazolate metal organic framework (ZIF-8 MOFs) as a means of  tracing the MOF translocation in . Rhodamine B isothiocyanate functionalized ZIF-8 MOFs nanoparticles (RBITC@ZIF-8 MOF nanoparticles; size 44 ± 7 nm) were fed to the worms naturally within a concentration range of 0.16-16.4 μg mg. Fluorescence was detected in the pharyngeal and gut lumen regions of the worms after 4 h of treatment, for exposure concentrations >0.163 μg mg. A higher intensity of fluorescence was observed at the end of 24 h for all exposure concentrations. Worms treated with RBITC@ZIF-8 MOF concentrations of ≥1.63 μg mg for 24 h showed a bright stable fluorescence signal at the tail region. The uptake of RBITC@ZIF-8 MOF for an exposure concentration of 0.163, 1.63, and 8.2 μg mg was found to be 52.1, 11.4 and 28.6%, respectively. Through this study, we showed that RBITC@ZIF-8 MOFs can be exposed to  and imaged at low concentrations of ∼0.16 μg mg.

Article	Year
Effect of Binding-Affinity and ATPase Activity on the Velocities of Kinesins Using Ratchet Models. Cell biochemistry and biophysics\| PubMed ID: 35088234	2022
Toxicological Impact and Tracing of Rhodamine Functionalised ZIF-8 Nanoparticles. Frontiers in toxicology\| PubMed ID: 35846435	2022

Pushpanjali Soppina

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