The importance of Asn52 in the structure-function relationship of human cytochrome c

Dan Lou; Xi-Chun Liu; Xiao-Juan Wang; Shu-Qin Gao; Ge-Bo Wen; Ying-Wu Lin

doi:10.1039/d0ra09961a

The importance of Asn52 in the structure-function relationship of human cytochrome c

RSC Adv. 2020 Dec 18;10(73):44768-44772. doi: 10.1039/d0ra09961a. eCollection 2020 Dec 17.

Authors

Dan Lou¹, Xi-Chun Liu¹, Xiao-Juan Wang¹, Shu-Qin Gao², Ge-Bo Wen², Ying-Wu Lin^{1

2}

Affiliations

¹ School of Chemistry and Chemical Engineering, University of South China Hengyang 421001 China ywlin@usc.edu.cn.
² Laboratory of Protein Structure and Function, University of South China Medical School Hengyang 421001 China.

Abstract

The function of the highly conserved residue Asn52 in human cytochrome c (H-Cyt c) is not fully understood. Herein, we show that the naturally occurring variant N52S H-Cyt c has a perturbed secondary structure, with a small fraction of high-spin species. Remarkably, it exhibits an enhanced peroxidase activity by 3-8-fold at neutral pH, as well as self-oxidation in reaction with H₂O₂. This study suggests that the H-bond network mediated by Asn52 is essential to suppress the apoptotic activity of H-Cyt c under physiological conditions.