Dynamic regulation of Zn(II) sequestration by calgranulin C
Date
2022-08-13
Journal Title
Journal ISSN
Volume Title
Publisher
Protein Science
Abstract
Calgranulin C performs antimicrobial activity in the human immune response by sequestering Zn(II). This biological function is afforded with the aid of two structurally distinct Ca(II)-binding EF hand motifs, wherein one of which bears an unusual amino acid sequence. Here, we utilize solution state NMR relaxation measurements to investigate the mechanism of Ca(II)-modulated enhancement of Zn(II) sequestration by calgranulin C. Using C13/N15 CPMG dispersion experiments we have measured pH-dependent major and minor state populations exchanging on micro-to-millisecond timescale. This conformational exchange takes place exclusively in the Ca(II)-bound state and can be mapped to residues located in the EF-I loop and the linker between the tandem EF hands. Molecular dynamics (MD) simulations spanning nano-to-microsecond timescale offer insights into the role of pH-dependent electrostatic interactions in EF-hand dynamics. Our results suggest a pH-regulated dynamic equilibrium of conformations that explore a range of “closed” and partially “open” sidechain configurations within the Zn(II) binding site. We propose a novel mechanism by which Ca(II) binding to a non-canonical EF loop regulates its flexibility and tunes the antimicrobial activity of calgranulin C.
Description
This is the peer reviewed version of the following article: Wang, Q, Kuci, D, Bhattacharya, S, Hadden-Perilla, JA, Gupta, R. Dynamic regulation of Zn(II) sequestration by calgranulin C. Protein Science. 2022; 31( 9):e4403. https://doi.org/10.1002/pro.4403, which has been published in final form at https://doi.org/10.1002/pro.4403. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. This article may not be enhanced, enriched or otherwise transformed into a derivative work, without express permission from Wiley or by statutory rights under applicable legislation. Copyright notices must not be removed, obscured or modified. The article must be linked to Wiley’s version of record on Wiley Online Library and any embedding, framing or otherwise making available the article or pages thereof by third parties from platforms, services and websites other than Wiley Online Library must be prohibited. This article will be embargoed until 08/13/2023.
Keywords
Ca(II) binding proteins, molecular dynamics simulations, NMR spectroscopy, zinc sequestration
Citation
Wang, Q, Kuci, D, Bhattacharya, S, Hadden-Perilla, JA, Gupta, R. Dynamic regulation of Zn(II) sequestration by calgranulin C. Protein Science. 2022; 31( 9):e4403. https://doi.org/10.1002/pro.4403