A study of Pb2+ induced unfolding and aggregation of arginine kinase from Euphausia superba: kinetics and computational simulation integrating study. Issue 18 (19th October 2022)

• Record Type: Journal Article
• Authors: Yin, Shang-Jun; Lee, Jinhyuk; Lim, Gyutae; Chen, Zhongfa; Qian, Guo-Ying; Si, Yue-Xiu; Park, Yong-Doo
• Is Part Of: Journal of biomolecular structure & dynamics. Volume 40:Issue 18(2022)
• Page Start: 8206
• Page End: 8215
• Publication Date: 2022-10-19
• Subjects: Euphausia superba -- arginine kinase -- Pb2+ -- inhibition -- molecular dynamics simulation; Biomolecules -- Periodicals; Molecular structure -- Periodicals; Molecular Biology -- Periodicals; Biomechanics -- Periodicals; 572
• DOI: 10.1080/07391102.2021.1908168
• Languages: English
• ISSNs: 0739-1102

Abstract

Abstract: Arginine kinase is a crucial phosphagen kinase in invertebrates, which is associated to the environmental stress response, plays a key role in cellular energy metabolism. In this study, we investigated the Pb 2+ -induced inhibition and aggregation of Euphausia superba arginine kinase (ESAK) and found that significantly inactivated ESAK in a dose-dependent manner ( IC 50 = 0.058 ± 0.002 mM). Spectrofluorimetry results showed that Pb 2+ induced tertiary structural changes via the internal polarity increased and the non-polarity decreased in ESAK and directly induced ESAK aggregation. The ESAK aggregation process induced by Pb 2+ occurred with multi-phase kinetics. The addition of osmolytes did not show protective effect on Pb 2+ -induced inactivation of ESAK. The computational molecular dynamics (MD) simulation showed that three Pb 2+ interrupt the entrance of the active site of ESAK and it could be the reason on the loss of activity of ESAK. Several important residues of ESAK were detected that were importantly contributed the conformation and catalytic function of ESAK. Our study showed that Pb 2+ -induced misfolding of ESAK and the complete loss of activity irreversibly, which cannot be recovered by osmolytes. Communicated by Ramaswamy H. Sarma