Approximations of stationary calcium nanodomains in the presence of buffers with two binding sites

Tuesday, June 15 at 03:15pm (PDT)
Tuesday, June 15 at 11:15pm (BST)
Wednesday, June 16 07:15am (KST)

SMB2021 SMB2021 Follow Tuesday (Wednesday) during the "PS02" time block.
Share this

Victor Matveev

New Jersey Institute of Technology, Dept of Math Sciences
"Approximations of stationary calcium nanodomains in the presence of buffers with two binding sites"
Calcium ion (Ca2+) elevations near open Ca2+ channels, termed Ca2+ nanodomains, trigger secretory vesicle fusion, myocyte contraction, and other fundamental physiological processes. Ca2+ nanodomains are shaped by the interplay between Ca2+ influx, diffusion, and binding to Ca2+ buffers and sensors, which absorb most of the Ca2+ entering the cell. The dependence of Ca2+ concentration on the distance from the Ca2+ channel can be modeled with reasonable accuracy using closed-form approximations of quasi-stationary solutions of the corresponding reaction-diffusion equations. Such stationary approximations help to reveal the qualitative characteristics of Ca2+ nanodomains without resorting to computationally expensive numerical simulations. Although a variety of nanodomain approximations are known when Ca2+ is diffusing in the presence of Ca2+ buffers with a single Ca2+ binding site, most biological buffers have more complex Ca2+-binding stoichiometry. We present several closed-form approximations of Ca2+ nanodomains in the presence of buffers with two binding sites, extending prior work on stationary Ca2+ nanodomains. Our approximants interpolate between the short-range and long-range distance-dependence of Ca2+ concentration using a combination of rational and exponential functions. We shows that this method achieves significant accuracy for a very wide range of Ca2+ buffering parameter values. Supported by NSF DMS-1517085 (V.M)

Hosted by SMB2021 Follow
Virtual conference of the Society for Mathematical Biology, 2021.