Open Access. Powered by Scholars. Published by Universities.®

Molecular Biology Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 5 of 5

Full-Text Articles in Molecular Biology

Activation Of The Phospholipid Scramblase Tmem16f By Nanosecond Pulsed Electric Field (Nspef) Facilitates Its Diverse Cytophysiological Effects, Claudia Muratori, Andrei G. Pakhomov, Elena Gianulis, Jade Meads, Maura Casciola, Peter A. Mollica, Olga N. Pakhomova Oct 2017

Activation Of The Phospholipid Scramblase Tmem16f By Nanosecond Pulsed Electric Field (Nspef) Facilitates Its Diverse Cytophysiological Effects, Claudia Muratori, Andrei G. Pakhomov, Elena Gianulis, Jade Meads, Maura Casciola, Peter A. Mollica, Olga N. Pakhomova

Bioelectrics Publications

Nanosecond pulsed electric fields (nsPEF) are emerging as a novel modality for cell stimulation and tissue ablation. However, the downstream protein effectors responsible for nsPEF bioeffects remain to be established. Here we demonstrate that nsPEF activate TMEM16F (or Anoctamin 6), a protein functioning as a Ca2+-dependent phospholipid scramblase and Ca2+-activated chloride channel. Using confocal microscopy and patch clamp recordings, we investigated the relevance of TMEM16F activation for several bioeffects triggered by nsPEF, including phosphatidylserine (PS) externalization, nanopore-conducted currents, membrane blebbing, and cell death. In HEK 293 cells treated with a single 300-ns pulse of 25.5 kV/cm, …


Computing Spatiotemporal Heat Maps Of Lipid Electropore Formation: A Statistical Approach, Willy Wriggers, Frederica Castellani, Julio A. Kovacs, P. Thomas Vernier Apr 2017

Computing Spatiotemporal Heat Maps Of Lipid Electropore Formation: A Statistical Approach, Willy Wriggers, Frederica Castellani, Julio A. Kovacs, P. Thomas Vernier

Mechanical & Aerospace Engineering Faculty Publications

We extend the multiscale spatiotemporal heat map strategies originally developed for interpreting molecular dynamics simulations of well-structured proteins to liquids such as lipid bilayers and solvents. Our analysis informs the experimental and theoretical investigation of electroporation, that is, the externally imposed breaching of the cell membrane under the influence of an electric field of sufficient magnitude. To understand the nanoscale architecture of electroporation, we transform time domain data of the coarse-grained interaction networks of lipids and solvents into spatial heat maps of the most relevant constituent molecules. The application takes advantage of our earlier graph-based activity functions by accounting for …


A Balanced Approach To Adaptive Probability Density Estimation, Julio Kovacs, Cailee Helmick, Willy Wriggers Apr 2017

A Balanced Approach To Adaptive Probability Density Estimation, Julio Kovacs, Cailee Helmick, Willy Wriggers

Mechanical & Aerospace Engineering Faculty Publications

Our development of a Fast (Mutual) Information Matching (FIM) of molecular dynamics time series data led us to the general problem of how to accurately estimate the probability density function of a random variable, especially in cases of very uneven samples. Here, we propose a novel Balanced Adaptive Density Estimation (BADE) method that effectively optimizes the amount of smoothing at each point. To do this, BADE relies on an efficient nearest-neighbor search which results in good scaling for large data sizes. Our tests on simulated data show that BADE exhibits equal or better accuracy than existing methods, and visual tests …


Characterization And Analysis Of Real-Time Capillary Convective Pcr Toward Commercialization, Xianbo Qiu, Shiyin Zhang, Lanju Mei, Di Wu, Ke Li, Shengxiang Ge, Xiangzhong Ye, Ningshao Xia, Michael G. Mauk Mar 2017

Characterization And Analysis Of Real-Time Capillary Convective Pcr Toward Commercialization, Xianbo Qiu, Shiyin Zhang, Lanju Mei, Di Wu, Ke Li, Shengxiang Ge, Xiangzhong Ye, Ningshao Xia, Michael G. Mauk

Mechanical & Aerospace Engineering Faculty Publications

Almost all the reported capillary convective polymerase chain reaction (CCPCR) systems to date are still limited to research use stemming from unresolved issues related to repeatability, reliability, convenience, and sensitivity. To move CCPCR technology forward toward commercialization, a couple of critical strategies and innovations are discussed here. First, single- and dual-end heating strategies are analyzed and compared between each other. Especially, different solutions for dual-end heating are proposed and discussed, and the heat transfer and fluid flow inside the capillary tube with an optimized dual-end heating strategy are analyzed and modeled. Second, real-time CCPCR is implemented with light-emitting diode and …


Quantitative Limits On Small Molecule Transport Via The Electropermeome - Measuring And Modeling Single Nanosecond Perturbations, Esin B. Sözer, Zachary A. Levine, P. Thomas Vernier Mar 2017

Quantitative Limits On Small Molecule Transport Via The Electropermeome - Measuring And Modeling Single Nanosecond Perturbations, Esin B. Sözer, Zachary A. Levine, P. Thomas Vernier

Bioelectrics Publications

The detailed molecular mechanisms underlying the permeabilization of cell membranes by pulsed electric fields (electroporation) remain obscure despite decades of investigative effort. To advance beyond descriptive schematics to the development of robust, predictive models, empirical parameters in existing models must be replaced with physics- and biology-based terms anchored in experimental observations. We report here absolute values for the uptake of YO-PRO-1, a small-molecule fluorescent indicator of membrane integrity, into cells after a single electric pulse lasting only 6 ns. We correlate these measured values, based on fluorescence microphotometry of hundreds of individual cells, with a diffusion-based geometric analysis of pore-mediated …