In biological systems, polymeric materials block the movement of some macromolecules while allowing the selective passage of others. We developed a model motivated by features of the nuclear pore complex (NPC) which are highly conserved and could potentially be applied to other biological systems. We show that a single feature of the NPC is sufficient for selective transport: the bound-state motion resulting from transient binding to flexible filaments. We generalized this observation to model nanoparticle transport through mucus as well. Our model provides a framework to control binding- induced selective transport in biopolymeric materials.
Biological filters control the passage of proteins and other macromolecules between compartments of living systems. Determination of molecular mechanisms giving selective transport would enable the design of both selective filters and particles designed to penetrate biological barriers for drug delivery. One such mechanism arises from transient binding to dynamic polymer tethers. We designed a biomaterial which supports this type of tethered diffusion, demonstrating the potential to engineer bio-inspired filters.
Adam Lamson's paper was highlighted on the Biophysical Journal webpage on 5/7/19 when it was published. This paper examines how the mitotic spindle assembles due to crosslinkers in the absence of motor proteins.
In-cell NMR in S. cerevisiae is a novel way of looking at disordered proteins in a crowded cellular environment. The methodology has been developed here, which could be broadly applicable to other protein systems. In an example, the non-specific interactions of the FG Nup construct, FSFG-K, with the cytoplasm is similar to previously found bacterial interactions using NMR relaxation techniques. This work was recently published in Biophysical Journal.
Betterton group 2018
Members of the Biophysics group went to the mountains for hiking and the group research retreat.
Bipolar mitotic spindles form from a monopolar initial condition in a fundamental construction problem. Microtubules, motors, and cross-linkers are important for bipolarity, but the mechanisms necessary and sufficient for spindle assembly remain unknown. We developed a physical model that exhibits de novo bipolar spindle formation that agrees quantitatively with our experiments in fission yeast, thereby establishing a minimal system with which to interrogate collective self-assembly. This work was published in Science Advances.