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Full-Text Articles in Engineering
Modeling The Construction Of Polymeric Adsorbent Media: Effects Of Counter-Ions On Ligand Immobilization And Pore Structure, Enrico Riccardi, Jee-Ching Wang, Athanasios I. Liapis
Modeling The Construction Of Polymeric Adsorbent Media: Effects Of Counter-Ions On Ligand Immobilization And Pore Structure, Enrico Riccardi, Jee-Ching Wang, Athanasios I. Liapis
Chemical and Biochemical Engineering Faculty Research & Creative Works
Molecular dynamics modeling and simulations are employed to study the effects of counter-ions on the dynamic spatial density distribution and total loading of immobilized ligands as well as on the pore structure of the resultant ion exchange chromatography adsorbent media. The results show that the porous adsorbent media formed by polymeric chain molecules involve transport mechanisms and steric resistances which cause the charged ligands and counter-ions not to follow stoichiometric distributions so that (i) a gradient in the local nonelectroneutrality occurs, (ii) non-uniform spatial density distributions of immobilized ligands and counter-ions are formed, and (iii) clouds of counter-ions outside the …
A Mechanistic Model Of Early Fcεri Signaling: Lipid Rafts And The Question Of Protection From Dephosphorylation, Dipak Barua, Byron Goldstein
A Mechanistic Model Of Early Fcεri Signaling: Lipid Rafts And The Question Of Protection From Dephosphorylation, Dipak Barua, Byron Goldstein
Chemical and Biochemical Engineering Faculty Research & Creative Works
We present a model of the early events in mast cell signaling mediated by FcεRI where the plasma membrane is composed of many small ordered lipid domains (rafts), surrounded by a non-order region of lipids consisting of the remaining plasma membrane. The model treats the rafts as transient structures that constantly form and breakup, but that maintain a fixed average number per cell. The rafts have a high propensity for harboring Lyn kinase, aggregated, but not unaggregated receptors, and the linker for the activation of T cells (LAT). Phosphatase activity in the rafts is substantially reduced compared to the nonraft …
A Molecular Dynamics Study On The Transport Of A Charged Biomolecule In A Polymeric Adsorbent Medium And Its Adsorption Onto A Charged Ligand, Enrico Riccardi, Jee-Ching Wang, Athanasios I. Liapis
A Molecular Dynamics Study On The Transport Of A Charged Biomolecule In A Polymeric Adsorbent Medium And Its Adsorption Onto A Charged Ligand, Enrico Riccardi, Jee-Ching Wang, Athanasios I. Liapis
Chemical and Biochemical Engineering Faculty Research & Creative Works
The transport of a charged adsorbate biomolecule in a porous polymeric adsorbent medium and its adsorption onto the covalently immobilized ligands have been modeled and investigated using molecular dynamics modeling and simulations as the third part of a novel fundamental methodology developed for studying ion-exchange chromatography based bioseparations. To overcome computational challenges, a novel simulation approach is devised where appropriate atomistic and coarse grain models are employed simultaneously and the transport of the adsorbate is characterized through a number of locations representative of the progress of the transport process. The adsorbate biomolecule for the system studied in this work changes …
A Bipolar Clamp Mechanism For Activation Of Jak-Family Protein Tyrosine Kinases, Dipak Barua, James R. Faeder, Jason M. Haugh
A Bipolar Clamp Mechanism For Activation Of Jak-Family Protein Tyrosine Kinases, Dipak Barua, James R. Faeder, Jason M. Haugh
Chemical and Biochemical Engineering Faculty Research & Creative Works
Most cell surface receptors for growth factors and cytokines dimerize in order to mediate signal transduction. For many such receptors, the Janus kinase (Jak) family of non-receptor protein tyrosine kinases are recruited in pairs and juxtaposed by dimerized receptor complexes in order to activate one another by trans-phosphorylation. An alternative mechanism for Jak trans-phosphorylation has been proposed in which the phosphorylated kinase interacts with the Src homology 2 (SH2) domain of SH2-B, a unique adaptor protein with the capacity to homo-dimerize. Building on a rule-based kinetic modeling approach that considers the concerted nature and combinatorial complexity of modular protein domain …